Fluid-assisted medical devices and systems

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DESCRIPTION

Fluid-assisted medical devices and systems.

Ambit

This invention relates generally to the field of medical devices, systems, and methods for use on a body during surgery. More particularly, the invention relates to electrosurgical devices, systems and methods for use on human body tissues during surgery, particularly open surgery and minimally invasive surgery, such as laparoscopic surgery.

Background

Electrosurgical devices configured for use with a dry point use electrical energy, most commonly radio frequency (RF) energy, to cut tissue or to cauterize blood vessels. During use, a voltage gradient is created at the tip of the device, inducing current flow and related heat generation in the tissue. With sufficiently high levels of electrical energy, the heat generated is sufficient to cut tissue and, advantageously, to stop bleeding from severed blood vessels.

Current dry-point electrosurgical devices can cause the temperature of the treated tissue to rise significantly well over 100 ° C, resulting in desiccation of tissue, sticking of tissue to electrodes, perforation of tissue, formation of charring and the generation of smoke. Maximum tissue temperatures as a result of RF treatment of the target tissue can be as high as 320 ° C, and these very high temperatures can be transmitted to adjacent tissues by thermal diffusion. The unwanted results of such transmission to adjacent tissues include unintended thermal damage to the tissue.

The use of a saline solution in accordance with the present invention to apply RF electrical energy to tissues inhibits such unwanted effects as sticking, desiccation, smoke production, and char formation. A key factor is the inhibition of tissue desiccation, which occurs when the tissue temperature exceeds 100 ° C and all intracellular water boils, leaving the tissue extremely dry and much less electrically conductive. However, an uncontrolled or heavy flow of saline can provide too much cooling at the electrode / tissue contact point. This cooling reduces the temperature of the target tissue being treated, and the rate at which thermal coagulation of the tissue occurs is determined by the temperature of the tissue. This, in turn, can result in a longer treatment time to achieve the desired tissue temperature for tissue treatment. Long treatment times are undesirable for surgeons, as it is in the best interest of the patient, physician, and hospital to perform surgical procedures as quickly as possible.

RF energy delivered to tissue can be unpredictable and is often not optimal when using general purpose generators. Most general-purpose RF generators have modes for different waveforms (for example, cut, coag, or a mixture of these two) and device types (for example, monopole, bipolar), as well as power levels that can be set in watts. However, once these settings have been chosen, the actual power delivered to the tissue and the associated heat generated can vary dramatically over time as the impedance of the tissue changes over the course of RF treatment. This is because the power delivered by most generators is a function of tissue impedance, with the power dropping as the impedance either decreases toward zero or increases significantly to several thousand ohms. Current dry-point electrosurgical devices are not configured to cope with a change in the power provided by a generator when the impedance of the tissues and the associated effect on the tissues changes and are based on the surgeon's experience to overcome this limitation. .

WO 00/78240 discloses a bipolar electrosurgical device with fluid delivery and the electrodes with blunt spherical capsule tips.

Summary of the invention

In a certain arrangement a system for treating tissues is provided. The system comprises radio frequency power provided by a power source with a power level; an electrically conductive fluid supplied from a fluid source with a flow rate of fluid; and an electrosurgical device configured to provide radio frequency power and electrically conductive fluid to tissue.

In certain arrangements the conductive fluid is an indicator of the tissue temperature. The conductive fluid can relate the temperature of the tissue to boiling, a boiling amount, or a boiling start of the conductive fluid.

Conductive fluid can cool tissue or dissipate heat from tissue. Alternatively or additionally, the conductive fluid dissipates heat from at least one of the tissue and the conductive fluid by boiling at least a portion of the fluid.

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For other arrangements, at least one of the radio frequency power level and the flow rate of conductive fluid is used to effect a boiling of the electrically conductive fluid. Furthermore, in some arrangements, the effect of boiling may comprise at least one of initiating, increasing, decreasing, and eliminating the boiling of the electrically conductive fluid.

For other arrangements, the electrically conductive fluid functions to limit the temperature of the fabric at the surface of the fabric to about a boiling temperature of the electrically conductive fluid.

In general, electrically conductive fluid protects tissue from desiccation. In some arrangements, the conductive fluid protects the tissue from boiling out of at least a portion of the electrically conductive fluid. In other embodiments, the electrically conductive fluid protects the tissue from drying out by boiling at least a portion of the conductive fluid at a temperature below the drying temperature of the tissue.

For some arrangements, the electrically conductive fluid is delivered to the tissues on the surface of the tissue and the radio frequency power is also delivered to the tissues on the surface of the tissue. Radio frequency power reaches the tissue below the surface of the tissue via (through) the electrically conductive fluid on the tissue surface.

At least one of the radio frequency power level and the flow rate of the conductive fluid can be adjusted based on a boiling of the conductive fluid. Furthermore, for other arrangements, adjusting at least one of the radio frequency power level and the flow rate of conductive fluid based on a boiling of the conductive fluid comprises one of electrically initiating, increasing, decreasing, and eliminating the boiling of the fluid. conductive.

In certain arrangements, a method of treating tissue is provided, which comprises providing radio frequency power with a power level; providing an electrically conductive fluid with a flow rate of fluid; and providing an electrosurgical device configured to provide radio frequency power and electrically conductive fluid to tissue.

Still further, a system is provided for treating tissues, the system comprises radio frequency power provided by a power source with a power level; an electrically conductive fluid supplied from a fluid source with a flow rate of fluid; an electrosurgical device configured to provide radio frequency power and electrically conductive fluid to tissue; and a fluid coupling that is coupled to tissue and the electrosurgical device, the coupling comprises the conductive fluid.

In certain arrangements the fluid coupling is an indicator of the temperature of the fabric. Fluid coupling can function as an indicator of tissue temperature through the use of boiling; a boiling amount; or a boiling start of the fluid coupling.

For other arrangements, the fluid coupling cools the fabric or dissipates heat from the fabric. The fluid coupling can dissipate heat from at least one of the tissue and the fluid coupling by boiling at least a portion of the fluid coupling. For other arrangements, the fluid coupling may limit the temperature of the fabric at the surface of the fabric to near a boiling temperature of the fluid coupling.

Fluid coupling can protect tissue from desiccation. In some arrangements, the fluid coupling protects the tissue from boiling out of at least a portion of the fluid coupling. In other embodiments, the fluid coupling protects the tissue from desiccation by boiling at least a portion of the fluid coupling at a temperature that protects the tissue from desiccation.

For other arrangements, at least one of the radio frequency power level and the flow rate of conductive fluid is used to boil the fluid coupling. In addition, in some arrangements, the effect of boiling may be at least one of initiating, increasing, decreasing, and eliminating boiling of the fluid coupling.

The conductive fluid can be provided to the tissue on the surface of the tissue, and the radio frequency power can also be provided to the tissue on the surface of the tissue. Radio frequency power can be delivered to an area below the tissue surface by (through) fluid coupling at the tissue surface.

In certain arrangements, a method for treating tissues is provided, the method comprising supplying radio frequency power with a power level; providing an electrically conductive fluid with a flow rate of fluid; providing an electrosurgical device configured to provide radio frequency power and electrically conductive fluid to tissue; and forming a fluid coupling that couples the tissue and the electrosurgical device. The fluid coupling comprises conductive fluid.

The fluid coupling can be used as an indicator of tissue temperature. This can be done by boiling; a boiling amount of the fluid coupling; or a boiling start of the fluid coupling.

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For some arrangements, the fluid coupling is used to cool the fabric or dissipate heat from the fabric by transferring heat to the fluid coupling. The fluid coupling can dissipate heat from at least one of the tissue and the fluid coupling by boiling at least a portion of the fluid coupling.

For other arrangements, at least one of the radio frequency power level and the flow rate of conductive fluid is adjusted based on a boiling of the fluid coupling. In addition, for other arrangements, adjusting at least one of the radio frequency power level and the flow rate of conductive fluid based on a boiling of the fluid coupling comprises one of starting, increasing, decreasing, and eliminating boiling of the fluid coupling. .

For other arrangements, the temperature of the fabric at the surface of the fabric is limited to about a boiling point of the fluid coupling.

For other arrangements, the fabric is protected from drying out with fluid coupling. In addition, for other arrangements, the fabric is protected from drying out with fluid coupling by boiling at least a part of the fluid coupling. In addition, for other arrangements, the fabric is protected from desiccation with fluid coupling by boiling at least a part of the fluid coupling at a temperature that protects the fabric from desiccation.

The method for treating fabrics may further comprise supplying the conductive fluid to the fabric at the surface of the fabric; and providing radio frequency power to tissue on the surface of the tissue and below the surface of the tissue in the tissue through fluid coupling.

With regard to specific devices, in certain arrangements there is provided a surgical tissue treatment device comprising a handle having a proximal end and a distal end; a stem extending distally beyond the distal end of the handle, the stem having a proximal end and a distal end; an electrode tip, at least a portion of the electrode tip extends distally beyond the distal end of the stem, the electrode tip extends distally beyond the distal end of the stem comprising an end surface portion spherical and a cylindrical lateral surface part, the spherical end surface portion is distal of the cylindrical lateral surface portion and comprises at least a portion of the distal end surface of the surgical device; and a fluid passage directed to provide fluid toward the cylindrical side of the electrode tip.

In other arrangements, a surgical tissue treatment device is provided comprising a handle having a proximal end and a distal end; a stem extending distally beyond the distal end of the handle, the stem having a proximal end and a distal end; an electrode tip, at least a portion of the electrode tip extends distally beyond the distal end of the stem, the electrode tip extends distally beyond the distal end of the stem comprising a neck portion and an enlarged head portion, the enlarged head portion is distal of the neck portion and comprises at least a portion of the distal end surface of the surgical device; and a fluid passage directed to provide fluid to the enlarged head portion of the electrode tip.

In still other arrangements, a tissue treatment device is provided comprising a handle having a proximal end and a distal end; a stem extending distally beyond the distal end of the handle, the stem having a proximal end and a distal end; an electrode tip, the electrode tip comprises a spherical end surface portion and a cylindrical lateral surface portion, the spherical end surface portion lies distal to the cylindrical lateral surface portion and comprises at least a part of the distal end surface of the device ; a fluid passage can be connected to a source of fluid; and a plurality of fluid outlet ports in fluid communication with the fluid passage, the fluid outlet ports are positioned to provide a fluid from the fluid source around the cylindrical side surface portion of the electrode tip.

In still other arrangements, a tissue treatment device is provided comprising a handle having a proximal end and a distal end; a stem extending distally beyond the distal end of the handle, the stem having a proximal end and a distal end; an electrode tip comprising a distal rounded end surface portion configured for blunt tissue dissection and a lateral surface portion configured to seal tissue from at least one of the flow of body fluids and air, the lateral surface portion has a surface area greater than the surface area of ​​the distal end surface portion; a fluid passage can be connected to a source of fluid; and at least one fluid outlet opening in fluid communication with the fluid passage, the fluid outlet opening is positioned to provide fluid from the fluid source to the lateral surface portion of the electrode tip and proximal to the distal extreme surface part.

According to the invention, a tissue treatment device is provided comprising a first electrode tip spaced from a second electrode tip, the first and second electrode tips can be connected to different terminals of a radio frequency generator to generate the flow of electric current between them; at least one fluid passage that can be connected to a fluid source; at least one

ES 2 355 872 T3 fluid outlet opening In fluid communication with the fluid passage, the fluid outlet opening is configured to provide a fluid from the fluid source to at least one of a tissue surface and through at least one of the first and second electrode tips; and the first and second electrode tips are configured to slide and rotate over the tissue and seal it in the presence of a fluid supplied from the fluid outlet port and an electrical current supplied from the electrode tips.

Other methods for treating fabrics may also comprise providing a fabric having a fabric surface; supplying radio frequency power with a power level; providing an electrically conductive fluid with a flow rate of fluid; providing a surgical device configured to simultaneously provide radio frequency power and electrically conductive fluid to tissue; providing the electrically conductive fluid to the tissue on the surface of the tissue; forming a fluid coupling comprising the electrically conductive fluid that couples the tissue and the surgical device; providing radio frequency power to tissue on the surface of the tissue and below the surface of the tissue to the tissue through fluid coupling; sealing the tissue against at least one of the flow of body fluids and air by at least one of the contraction of collagen and the coagulation of blood in the tissue; and make a blunt dissection of the tissue.

In other arrangements, the methods for treating fabrics may also comprise providing a fabric having a fabric surface; supplying radio frequency power with a power level; providing an electrically conductive fluid with a flow rate of fluid; providing a surgical device configured to simultaneously provide radio frequency power and electrically conductive fluid to tissue, the surgical device comprises a first electrode tip and a second electrode tip; providing the electrically conductive fluid to the tissue at the surface of the tissue; forming a fluid coupling comprising the electrically conductive fluid that couples the tissue and the surgical device; providing radio frequency power to tissue on the surface of the tissue and below the surface of the tissue to the tissue through fluid coupling; sliding the first electrode tip and the second electrode tip over the surface of the tissue; and sealing the tissue against at least one of the flow of body fluids and air by at least one of the contraction of collagen and the coagulation of blood in the tissue.

Brief description of the drawings

For a better understanding and appreciation of the invention, reference is made to the following detailed description in connection with the accompanying hand and computer generated drawings:

Figure 1 is a block diagram showing an arrangement of a control system that is not part of the invention, and an electrosurgical device;

Figure 2 is a schematic graph describing the relationship between RF power in tissue (P), saline flow rate (Q), and tissue temperature (T), when heat conduction to tissues is considered. adjacent;

Figure 3 is a schematic graph that describes the relationship between RF power in tissue (P), saline flow rate (Q) and tissue temperature (T), when heat conduction to the tissues is not considered. adjacent tissues;

Figure 4 is a schematic graph describing the relationship between RF power in tissue (P), saline flow rate (Q), and tissue temperature (T), when considering the heat required to heat tissue at maximum temperature (T) 68;

Figure 5 is a graph showing the relationship between percent saline boiling and saline flow rate (cc / min) for an example 75 watt RF generator output;

Figure 6 is a schematic graph describing the relationship between load impedance (Z, in ohms) and generator output power (P, in watts), for an example generator output of 75 watts in a mode bipolar;

Figure 7 is a schematic graph depicting the relationship between time (t, in seconds) and tissue impedance (Z, in ohms) after RF activation;

Figure 8 is a schematic perspective view of a cannula that can be used with an electrosurgical device in accordance with the present invention;

Figure 9 is an exploded schematic view of an electrosurgical device assembly in accordance with the present invention;

Figure 10 is a lateral cross-sectional longitudinal schematic view of the tip and stem of the device of Figure 9 taken along line 10-10 of Figure 12;

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Figure 11 is a schematic longitudinal close-up view in lateral cross-section of the portion of the device tip delimited by circle 45 shown in Figure 10, taken along line 10-10 of Figure 12;

Figure 12 is a schematic view from a distal end of the tip portion of the device delimited by circle 45 shown in Figure 10;

Figure 13 is a schematic side view of the tip and shaft of the device of Figure 9 with fluid engagement on a tissue surface of the tissues;

Figure 14 is a cross-sectional close-up schematic side view of an alternate tip portion;

Figure 15 is a close-up sectional schematic side view of the tip portion of Figure 14 taken along line 15-15 of Figure 14;

Figure 16 is a cross-sectional close-up schematic side view of the tip portion of Figure 14 disposed in a tissue crack;

Figure 17 is a schematic graph of impedance Z versus time t showing changes in impedance represented by impedance peaks;

Figure 18 is a schematic graph of impedance Z versus% boiling of the fluid;

Figure 19 is a cross-sectional close-up schematic view of the tube taken along line 19-19 of Figure 15;

Figure 20 is a close-up schematic perspective view of an alternate tip portion;

Figure 21 is a close-up sectional schematic side view of the tip portion of Figure 20 taken along line 21-21 of Figure 20;

Figure 22 is a cross-sectional close-up schematic side view of the tip portion of Figure 20 disposed in a tissue crack;

Figure 23 is a close-up perspective front schematic view of the electrode for the tip portion of Figure 20;

Figure 24 is a close-up perspective rear schematic view of the electrode for the tip portion of Figure 20;

Figure 25 is a close-up cross-sectional schematic view of a porous slotted electrode;

Figure 26 is a close-up cross-sectional schematic view of an electrode with semicircular grooves;

Figure 27 is a close-up cross-sectional schematic view of an electrode with V-shaped grooves;

Figure 28 is a close-up cross-sectional schematic view of an electrode with U-shaped grooves;

Figure 29 is a close-up schematic perspective view of an alternate tip portion;

Figure 30 is a sectional close-up schematic side view of the tip portion of Figure 29 taken along line 30-30 of Figure 29;

Figure 31 is a close-up perspective front schematic view of the electrode for the tip portion of Figure 29;

Figure 32 is a close-up perspective rear schematic view of the electrode for the tip portion of Figure 29;

Figure 33 is a close-up, schematic perspective view of an alternate tip portion;

Figure 34 is a sectional close-up schematic side view of the tip portion of Figure 33 taken along line 34-34 of Figure 33;

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Figure 35 is a close-up perspective front schematic view of the electrode for the tip portion of Figure 33;

Figure 36 is a close-up perspective rear schematic view of the electrode for the tip portion of Figure 33;

Fig. 37 is a close-up, schematic perspective view of an alternate tip portion;

Figure 38 is a sectional close-up schematic side view of the tip portion of Figure 37 taken along line 38-38 of Figure 37;

Figure 39 is a close-up schematic perspective view of an alternate tip portion;

Figure 40 is a sectional close-up schematic side view of the tip portion of Figure 39 taken along line 40-40 of Figure 39;

Figure 41 is a close-up front rear perspective schematic view of the electrode for the tip portion of Figure 39;

Figure 42 is a close-up front perspective schematic view of the electrode for the tip portion of Figure 39;

Figure 43 is a schematic side view of the tip portion of Figure 39 with fluid engagement on a tissue surface of the tissue;

Figure 44 is a schematic front view of the tip portion of Figure 39 with fluid engagement on a tissue surface of the tissue;

Figure 45 is a schematic side view of the tip portion of Figure 39 with fluid engagement on a tissue surface of the tissue;

Figure 46 is a schematic exploded perspective view of an alternative electrosurgical device assembly in accordance with the present invention;

Figure 47 is a close-up cross-sectional schematic side view of the tip portions of Figure 46 assembled with fluid engagement on a tissue surface of the tissue;

Figure 48 is a close-up cross-sectional schematic side view of the tip portions of Figure 46 assembled with an alternative fluid coupling on a tissue surface of the tissue;

Figure 49 is a schematic exploded perspective view of an alternative electrosurgical device assembly not in accordance with the present invention;

Figure 50 is a close-up cross-sectional schematic side view of the tip portions of Figure 49 assembled with fluid engagement on a tissue surface of the tissue;

Figure 51 is a schematic exploded perspective view of an alternative electrosurgical device assembly not in accordance with the present invention;

Figure 52 is a close-up perspective side schematic view of a distal end portion of the device of Figure 51;

Figure 53 is a close-up cross-sectional schematic side view of a distal end portion of the device of Figure 51 assembled with fluid engagement on a tissue surface of the tissue;

Figure 54 is a schematic perspective view of an alternative electrosurgical device not in accordance with the present invention;

Figure 55 is a schematic perspective view of an alternative electrosurgical device not in accordance with the present invention;

Figure 56 is a close-up schematic perspective view of the arms of the device of Figure 55;

Figure 57 is a close-up schematic perspective view of a distal end portion of the device of Figure 55;

Figure 58 is a close-up schematic perspective view of a distal end portion of the device of Figure 55;

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Figure 59 is a schematic perspective view of an alternative electrosurgical device not in accordance with the present invention;

Figure 60 is a close-up schematic perspective view of the arms of the device of Figure 59;

Figure 61 is a close-up schematic perspective view of a distal end portion of the device of Figure 59;

Figure 62 is a close-up schematic perspective view of a distal end portion of the device of Figure 59;

Figure 63 is a schematic close-up perspective view of a distal end portion of an alternative electrosurgical device not in accordance with the present invention;

Figure 64 is a close-up schematic perspective view of a distal end portion of the device of Figure 63 with tissue;

Figure 65 is a close-up perspective schematic view of the arms of an alternative electrosurgical device not in accordance with the present invention;

Figure 66 is a close-up, schematic perspective view of a distal end portion of the arms of the device of Figure 65 with the collar removed;

Figure 67 is a close-up schematic perspective view of a distal end portion of the device of Figure 65;

Figure 68 is a close-up schematic perspective view of a distal end portion of the device of Figure 65 with one arm removed;

Figure 69 is a close-up schematic perspective view of the collar of the device of Figure 65;

Figure 70 is a schematic close-up perspective view of a distal end portion of an alternative electrosurgical device not in accordance with the present invention;

Figure 71 is a close-up schematic perspective view of a distal end portion of the device of Figure 70;

Figure 72 is a close-up perspective schematic view of a distal end portion of an alternative electrosurgical device not in accordance with the present invention;

Figure 73 is a close-up side schematic view of a distal end portion of the device of Figure 72;

Figure 74 is a schematic perspective view of an alternative electrosurgical device not in accordance with the present invention;

Figure 75 is a schematic perspective view of a handle portion of the device of Figure 74 assembled with various components;

Figure 76 is a close-up side schematic view of a portion of the assembly of Figure 75;

Figure 77 is a close-up side schematic view of a portion of the assembly of Figure 75;

Figure 78 is a front partial cross-sectional schematic view of the electrical connections for the device of Figure 74;

Figure 79 is a rear partial schematic cross-sectional view of the electrical connections for the device of Figure 74;

Figure 80 is a schematic perspective view of an alternative electrosurgical device not in accordance with the present invention;

Figure 81 is a schematic side view of a handle portion of the device of Figure 80 assembled with various components;

Figure 82 is a schematic perspective view of an alternative electrosurgical device in accordance with the present invention;

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Figure 83 is a schematic perspective view of a handle portion of the device of Figure 82 assembled with various components;

Figure 84 is a side schematic view of a handle portion of the device of Figure 82 assembled with various components;

Figure 85 is a side schematic view of a handle portion of the device of Figure 82 assembled with various components;

Figure 86 is a side schematic view of a handle portion of the device of Figure 82 assembled with various components;

Figure 87 is a schematic perspective view of an alternative electrosurgical device in accordance with the present invention;

Figure 88 is a schematic perspective view of a handle portion of the device of Figure 87;

Figure 89 is a side schematic view of a handle portion of the device of Figure 87;

Figure 90 is a schematic perspective view of a handle portion of an alternative electrosurgical device not in accordance with the present invention; Y

Figure 91 is a side schematic view of the handle portion of Figure 90.

Figure 92 is a schematic perspective view of a handle portion of an alternative electrosurgical device not in accordance with the present invention; Y

Figure 93 is a side schematic view of the handle portion of Figure 92.

Detailed description

Throughout the present description, reference numerals and like letters indicate a corresponding structure throughout the various views, and such a corresponding structure does not have to be explained separately. Furthermore, any particular feature (s) of a particular embodiment may equally apply to any other embodiment (s) of this specification as appropriate. In other words, the characteristics between the different embodiments described in this specification are interchangeable as appropriate and are not mutually exclusive.

The invention is provided in accordance with the device of claim 1. The invention is particularly useful during surgical interventions on body tissues, in which it is desirable to coagulate and contract the tissue, to occlude the internal passages of the blood vessels ( eg arteries, veins), airways (eg, bronchi, bronchioles), bile ducts, and lymphatic ducts.

The disclosure includes electrosurgical procedures, preferably using RF power and electrically conductive fluid, for the treatment of tissues. Preferably, a desired tissue temperature range is achieved by adjusting parameters, such as the flow rate of conductive fluid, that affect the temperature at the tissue / electrode interface. Preferably, the device achieves a desired tissue temperature by utilizing a desired percent boiling of the conductive solution at the tissue / electrode contact point.

In one arrangement, the invention provides a control device, the device comprises a flow controller that receives a signal indicating the power applied to the system and adjusts the flow rate of conductive fluid from a fluid source to an electrosurgical device. The disclosure also contemplates a control system comprising a flow controller, a metering device that measures the power applied to the system and a pump that supplies the fluid with a selected flow rate.

The disclosure will be explained generally with reference to Figure 1. Figure 1 shows a block diagram of an exemplary arrangement of a system of the invention. Preferably, as shown in Figure 1, an electrically conductive fluid 24 is supplied from a fluid source 1 through a fluid line 2 to a pump 3, which has a fluid outlet line 4a which is connected as a pipe. 4b fluid inlet to an electrosurgical device 5. In a preferred arrangement, the fluid outlet pipe 4a and the fluid inlet pipe 4b are flexible and made of a polymeric material, such as polyvinyl chloride (PVC) or polyolefins (eg, polypropylene, polyethylene ) and the conductive fluid comprises a saline solution. More preferably, the saline solution comprises a sterile solution and even more preferably a normal saline solution. Although the description in this specification specifically describes the use of saline as the fluid 24, other electrically conductive fluids, as well as non-conductive fluids, may be used in accordance with the invention.

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For example, in addition to conductive fluid comprising physiological saline (also known as "normal" saline, isotonic saline, or 0.9% sodium chloride (NaCl) solution), the conductive fluid may comprise hypertonic saline. , a hypotonic saline solution, Ringer's solution (a physiological solution of distilled water containing certain amounts of sodium chloride, calcium chloride and potassium chloride), Ringer's lactate solution (a sterile crystalloid electrolyte solution of distilled water containing specified amounts of calcium chloride, potassium chloride, sodium chloride, and sodium lactate), Ringer-Locke's solution (isotonic buffer solution of distilled water that contains contains specified amounts of sodium chloride, potassium chloride, calcium chloride, sodium bicarbonate, magnesium chloride, and dextrose), or any other electrolyte solution. In other words, a solution that conducts electricity through an electrolyte, a substance (salt, acid, or base) that dissociates into electrically charged ions when dissolved in a solvent solution, such as water, resulting in a solution comprising an ionic conductor.

While a conductive fluid is preferred, as will become more apparent on reading this specification, fluid 24 may also comprise an electrically non-conductive fluid. The use of a non-conductive fluid is less preferred than a conductive fluid since the non-conductive fluid does not conduct electricity. However, the use of a non-conductive fluid still offers certain advantages over the use of a dry electrode including, for example, less appearance of tissue sticking to the electrode of device 5 and cooling of the electrode and / or tissue. Therefore, it is also in the disclosure to include the use of a non-conductive fluid, such as deionized water.

Returning to Figure 1, the energy to heat the tissues is provided from a power source, such as an electrical generator 6, which preferably provides alternating current RF energy through a cable 7 to the output measurement device of the power supply, such as a power measurement device 8, which measures the electrical power of alternating current RF. In an exemplary arrangement, preferably the power measurement device 8 does not disconnect, connect or alter the power in any way. The generator manufacturer preferably provides a power switch 15 connected to generator 6 and is used to turn generator 6 on and off. The power switch 15 may comprise any switch for turning the power on and off, and is often provided in the form of a foot switch or other user-friendly switch, such as a switch 15a mounted on the electrosurgical device 5. The power switch 15 or 15a can also function as a manual actuation device to increase or decrease the rate of energy delivered from the surgical device 5. Alternatively, the internal circuitry and other components of the generator 6 can be used to automatically increase or decrease the rate of energy provided by the surgical device 5. A cable 9 preferably carries the RF energy from the power measurement device 8 to the device. electrosurgical 5. The power, or any output from the power source, is preferably measured before the electrosurgical device 5 arrives.

For the situation where the effects of capacitance and induction are negligible, from Ohm's law, the power P, or the rate of energy supply (for example joules / s), can be expressed by the product of voltage and current (that is, I x V), resistance times current squared (that is, I² x R), or the voltage squared divided by the resistance (that is, V²/ R); where current I can be measured in amperes, voltage V can be measured in volts, electrical resistance R can be measured in ohms, and power P can be measured in watts (joules / s). Since the power P is a function of the current I, the voltage V and the resistance R as indicated above, it should be understood that a change in the power P is the reflection of a change in at least one of the input variables . Therefore, alternatively, changes in such input variables can be measured, rather than the power P directly, with such changes in the input variables corresponding mathematically to changes in the power P, as indicated above.

Regarding the frequency of RF electrical energy, it is preferably provided within a frequency band (i.e. a continuous range of frequencies extending between two boundary frequencies) the range between and including about 9 kHz (kilohertz) at 300 GHz (gigahertz). More preferably, the RF energy is provided within a frequency band ranging from and including about 50 kHz (kilohertz) to 50 MHz (megahertz). Even more preferably, the RF energy is provided within a frequency band ranging from and including about 200 kHz (kilohertz) to 2 MHz (megahertz). More preferably, the RF energy is provided within a frequency band ranging from and including about 400 kHz (kilohertz) to 600 kHz (kilohertz). Furthermore, it should also be understood that, for any frequency band identified above, the frequency range can be further reduced in 1 (one) hertz increments anywhere between the lower and upper cutoff frequencies.

While RF electrical energy is preferred, it should be understood that electrical energy (i.e., the energy available from the flow of electrical charge, typically through a conductor or by self-propagating waves) can comprise any frequency of the electromagnetic spectrum (that is, the entire range of radiation that ranges in frequency from 1,023 hertz to 0 hertz) and includes, but is not limited to, gamma rays, X-rays, ultraviolet radiation, visible light, infrared radiation, microwaves, and any combination thereof.

With regard to the utilization of electrical energy, heating of the tissue is preferably carried out by means of resistance heating. In other words, the increase in tissue temperature as a result of the flow of electrical current through the tissue, the electrical energy being absorbed from the voltage and transformed into energy

ES 2 355 872 T3 thermal (heat for example) through the accelerated movement of ions as a function of the electrical resistance of the tissue.

Heating with electrical energy can also be done by diathermy (capacitance). In other words, the increase in tissue temperature by dissipation of electrical energy as a result of internal dielectric losses when the tissue is placed in a variable electric field, such as a high frequency alternating electromagnetic field (eg microwave). Dielectric loss is the loss of electrical energy as heat in the polarization process in the presence of the applied electric field. In the case of an alternating current field, energy is absorbed from the alternating current voltage and converted into heat during polarization of the molecules.

However, it should be understood that the energy provided to heat the tissue may comprise a surgical device other than electrosurgical devices, power sources other than generators, forms of energy other than electrical energy, and mechanisms other than resistance heating. For example, supplying thermal energy to tissue from the energy source with a (eg, greater) temperature difference. This can be provided, for example, to the tissue from a heated device that heats the tissue through direct contact with the energy source (conduction), heats it through contact with a flowing fluid (convection), or from a heat source at a distance (radiation).

Also, for example, the supply of energy to the tissues can be provided by mechanical energy which is transformed into thermal energy by the accelerated movement of the molecules, such as by mechanical vibrations provided, for example, by the energy source, such as a transducer that contains a piezoelectric substance (for example, a quartz crystal oscillator) that converts high-frequency electrical current into vibrating ultrasonic waves that can be used, for example, by an ultrasonic surgical device.

Also, for example, the supply of energy to the tissues can be provided by radiant energy (ie energy that is transmitted by radiation / waves) which is transformed into thermal energy by absorption of the radiant energy by the tissue. Preferably, the radiation / waves comprise electromagnetic radiation / waves including, but not limited to, radio waves, microwaves, infrared radiation, visible light radiation, ultraviolet radiation, X-rays, and gamma rays. More preferably, said radiant energy comprises energy with a frequency of 3 x 10¹¹ hertz at 3 x 10¹⁶ Hertz (that is, the infrared, visible, and ultraviolet frequency bands of the electromagnetic spectrum). Also preferably the electromagnetic waves are coherent and the electromagnetic radiation is emitted from the power source, such as a laser device.

A flow controller 11 preferably includes a selection switch 12 that can be adjusted to achieve desired levels of percent fluid boiling (eg, 100%, 98%, 80% boiling). Preferably, the flow controller 11 receives an input signal 10 from the power measurement device 8 and calculates a mathematically predetermined appropriate fluid flow rate based on the percent boiling indicated by the selection switch 12. In a preferred arrangement, a fluid switch 13 is provided so that the fluid system can be primed (eg, remove air) prior to turning on the generator 6. The output signal 16 of the flow controller 11 is preferably sent to the pump motor 3 to regulate the flow rate of conductive fluid and thereby provide a suitable fluid flow rate corresponding to the amount of power being supplied.

In an exemplary arrangement, the disclosure comprises a flow controller 11 that is configured and arranged to be connected to an RF power source (eg generator 6), and a fluid source (eg source 1). fluid), for example, a source of conductive fluid. The device of the disclosure receives information about the level of RF power applied to an electrosurgical device 5, and adjusts the flow rate of fluid 24 to the electrosurgical device 5, thereby controlling the temperature at the tissue treatment site.

In another layout example, the elements of the system are physically included together in a single electronic enclosure. Such an arrangement is shown by the enclosure in the outline box 14 of Figure 1. In the illustrated arrangement, the pump 3, the flow controller 11 and the power measurement device 8 are enclosed within an enclosure, and these elements are connected by electrical connections to allow the signal 10 to pass from the power measurement device 8. power to flow controller 11 and signal 16 passes from flow controller 11 to pump 3. Other elements of a system may also be included within an enclosure, depending on factors such as the desired application of the system and user requirements.

Pump 3 can be any suitable pump used in surgical procedures to deliver saline or other liquid at a desired flow rate. Preferably, pump 3 comprises a peristaltic pump. With a rotary peristaltic pump, a fluid 24 is normally transmitted within the confines of a flexible tube (e.g. 4a) by contraction waves located externally in the tube that are produced mechanically, usually by rotating rollers that squeeze the flexible tube. against a support intermittently. Alternatively, with a linear peristaltic pump, a fluid 24 is typically transmitted within the confines of a flexible tube by contraction waves placed externally in the tube that are produced mechanically, typically by a series of compression fingers or plates that squeeze the tube. flexible tube against a support intermittently. Peristaltic pumps are generally preferred as the electromechanical force mechanism (eg, rollers driven by an electric motor) does not make contact with the fluid 24, thus reducing the likelihood of accidental contamination.

ES 2 355 872 T3

Alternatively, pump 3 can be a "syringe pump", with a built-in fluid supply. With such a pump, typically a filled syringe is in an electromechanical force mechanism (eg, a cylinder driven by an electric motor) that acts on the syringe plunger to force delivery of the fluid 24 contained therein. Alternatively, the syringe pump may comprise a double-acting syringe pump with two syringes so that they can draw saline from a reservoir (eg from a fluid source 1), either simultaneously or intermittently. With a double-acting syringe pump, the pumping mechanism is generally capable of both infusion and extraction. Typically, while fluid 24 is being expelled from one syringe, the other syringe is receiving fluid 24 into it from a separate reservoir. In this way, the delivery of fluid 24 remains continuous and uninterrupted, as the syringes operate in series. Alternatively, it should be understood that a multi-syringe pump with two syringes or any number of syringes can be used, in accordance with the disclosure.

In addition, fluid 24, such as a conductive fluid, can also be delivered from an intravenous (IV) bag filled with saline (eg, from a fluid source 1) flowing under the influence (ie, force) of gravity. In such a way, fluid 24 can flow directly to electrosurgical device 5, or first to pump 3 in between. Alternatively, fluid 24 from a fluid source 1, such as an IV bag can be delivered through an IV flow controller that can provide a desired flow rate by adjusting the cross-sectional area of ​​a flow orifice (e.g. , the internal passage of the connective tube with the electrosurgical device 5), while detecting the flow rate with a sensor such as an optical drip meter. In addition, fluid 24 from a fluid source 1, such as an intravenous bag, can be delivered by a manually or automatically activated device such as a flow controller, such as a roller clamp, which also adjusts the cross-sectional area of ​​a flow orifice and can be adjusted manually, for example, by the user of the device in response to their visual observation (for example, fluid boiling) at the tissue treatment site or a pump.

Similar pumps can be used in connection with the disclosure, and the illustrated embodiments are only examples. The exact configuration of pump 3 is not critical for disclosure. For example, pump 3 can include other types of infusion and extraction pumps. Furthermore, the pump 3 can comprise the pumps that can be classified as piston pumps, rotary vane pumps (eg axial rotor, centrifugal rotor), cartridge pumps and diaphragm pumps. In some arrangement, the pump 3 can be replaced by any type of flow controller, such as a manual roller clamp that is used in conjunction with an IV bag, or in combination with the flow controller to allow the user to control the flow rate of conductive fluid to the device. Alternatively, a valve configuration can replace pump 3.

In addition, similar system configurations can be used in connection with the disclosure, and the illustrated embodiments are only examples. For example, the fluid source 1, the pump 3, the generator 3, the power measurement device 8 or the flow controller 11, or any other component of the system that is not expressly mentioned above, may comprise a part of the device. electrosurgical 5. For example, in an exemplary embodiment, the fluid source 1 may comprise a compartment of the electrosurgical device 5, which contains fluid 24, as indicated by the reference character 1a. In another example arrangement, the compartment can be removably connected to electrosurgical device 5, such as a canister that can be threadedly attached to device 5. In yet another example arrangement, the compartment may be configured to hold a cartridge filled with fluid 24, rather than the fluid directly.

Also, for example, with respect to alternatives for the generator 6, a power source such as a direct current (DC) battery used in conjunction with an inverter circuit and a transformer to produce alternating current at a given frequency, may comprise a part of the electrosurgical device 5, as indicated by the reference character 6a. In one arrangement the battery element of the power source may comprise a rechargeable battery. In yet another example arrangement, the battery cell can be removably connected to electrosurgical device 5, such as for recharging. The components of the system will be described in more detail below. In the specification, it should be clear that any use of the terms "distal" and "proximal" is made by reference to the user of the device, and not the patient.

The flow controller 11 controls the flow rate from the fluid source 1. Preferably, the flow rate of fluid from the fluid source 1 is based on the amount of RF power from the generator 6 to the electrosurgical device 5. In other words, as shown in Figure 2, there is preferably a flow rate relationship Q of fluid and RF power P indicated by the Y and X axes of the schematic graph, respectively. More precisely, as shown in Figure 2, the relationship between the fluid flow rate Q and the RF power P can be expressed as a direct and linear relationship. The flow rate Q of conductive fluid 24, such as a saline solution, interacts with the RF power P and various modes of heat transfer out of the target tissue, as described herein.

Throughout this disclosure, when the terms "boiling point of saline solution", "evaporation point of saline solution" and their variants are used, what is actually referred to, for purposes of explanation, is the boiling point of water (i.e., 100 ° C) in saline solution since the difference between the boiling point of a normal saline solution (approximately 100.16 ° C) and the boiling point of water is negligible.

ES 2 355 872 T3

Figure 2 shows a schematic graph describing the relationship between saline flow rate, RF power to tissue, and boiling rates as detailed below. Based on a simple one-dimensional model of grouped parameters of heat transfer, the maximum temperature of the tissue can be estimated, and once the temperature of the tissue has been estimated, it is directly continued whether it is hot enough to boil the solution. saline. The total electrical power of RF, P, that is converted to heat can be defined as:

<img file="ES2355872T3_D0001.tif" />

where P = the total RF electrical power that is converted to heat.

Driving. The term [AT / R] in equation (1) is the heat conducted to the adjacent tissue, represented as 70 in figure 2, where:

AT = (T - T_ra) the temperature difference between the maximum tissue temperature (T) and the normal temperature (T_ra) of body tissue (° C). Normal body tissue temperature is generally 37 ° C;

^Y

R = Thermal resistance of surrounding tissues, the ratio of temperature difference to heat flux (° C / watts).

This thermal resistance can be estimated from published data collected in human tissue experiments (see, for example, Phipps, JH, "Thermometry studies with bipolar diathermy during hysterectomy," Gynecological Endoscopy, 3: 5-7 (1994)). As described by Phipps, Kleppinger used bipolar forceps with an RF power of 50 watts, and the maximum tissue temperature reached 320 ° C. For example, using the energy balance from equation (1), and assuming that all RF heat put into the tissue is conducted away, then R can be estimated:

R = AT / R = (320-37) / 50 = 5.7 = 6^or C / watt

However, it is undesirable to allow the temperature of the fabric to reach 320 ° C, as the fabric can dry out. At a temperature of 320 ° C, the fluid contained in the tissue tends to evaporate, giving rise to the undesirable tissue effects described herein. Instead, it is preferred to keep the maximum tissue temperature at no more than about 100 ° C to inhibit desiccation of the tissue. Assuming that the saline solution boils at approximately 100 ° C, the first term in equation (1) (AT / R) equals (100-37) / 6 = 10.5 watts. Thus, based on this example, the maximum amount of heat conducted to adjacent tissues without any significant risk of tissue drying out is 10.5 watts.

Referring to Figure 2, the RF power in the tissue is plotted on the X axis as P (watts) and the saline flow rate (cc / min) is plotted on the Y axis as Q. When the solution flow rate salt is equal to zero (Q = 0), there is an RF power "offset" that shifts the origin of sloping lines 76, 78 and 80 to the right. This phase shift is the heat conducted to the adjacent tissues. For example, using the above calculation for bipolar forceps, this RF power offset is 10.5 watts. If the power is increased above this level without saline flow, the maximum tissue temperature can rise well above 100 ° C, resulting in tissue desiccation from the boiling of water in the tissue cells.

Convection. The second term [pc_pQiAT] in equation (1) is the heat used to heat the flow of saline without boiling the saline, represented as 72 in figure 2, where:

ρ = density of saline fluid that heats up but does not boil (approximately 1.0 g / cm³);

_cp = specific heat of saline solution (approximately 4.1 watt-s / g ° C);

^Qi = Flow rate of the saline solution that is heated (cm³/ s); Y

AT = Temperature rise of the saline solution. Assuming that the saline solution is heated to body temperature before it reaches the electrode and that the maximum temperature of the saline solution is similar to the maximum temperature of the tissue, this is the same AT as for the conduction calculation above.

ES 2 355 872 T3

The onset of boiling can be predicted by equation (1) with the last term on the right being zero (not boiling) (pQ_bh_v = 0), and solving equation (1) for Qi leads to:

Qi = [P - ΔΤ / RJ / pCpAT (2)

This equation defines the line shown in Figure 2 as the boiling start line 76.

Boiling. The third term [pQ_bh_v] in equation (1) refers to the heat that goes into converting water in a liquid saline solution into water vapor, and is represented as 74 in figure 2, where:

Qb = flow rate of boiling saline solution (cm³/ s); yh_v = heat of vaporization of saline solution (approximately 2,000 watt-s / gm).

A flow rate as low as 1 cc / min will absorb a significant amount of heat if fully boiled, or about pQ_bh_v = (1) (1/60) (2,000) = 33.3 watts. The heat required to heat the flow from body temperature to 100 ° C is much less, or pc_pQ₁ ΔΤ = (1) (4.1) (1/60) (100-37) = 4.3 watts. In other words, the most significant factor contributing to heat transfer from a wet electrode device may be fractional boiling. This disclosure acknowledges and exploits this fact.

Fractional boiling can be described by the following equation (3):

₌ {P-AT / R} '{pc_pAT + ph_vQ_b/ Q,} ''

If the relation of Q_b/ Q₁ is 0.50 this is the 50% boiling line 78 shown in figure 2. If the ratio is 1.0 this is the 100% boiling line 80 shown in figure 2.

As stated earlier in the specification, the use of a fluid to couple energy with tissue inhibits such unwanted effects as sticking, drying, smoke production, and char formation, and that one of the factors key is the inhibition of tissue desiccation, which occurs when the tissue temperature exceeds 100 ° C and all intracellular water evaporates, leaving the fabric extremely dry and much less electrically conductive.

As shown in Figure 2, one strategy or control mechanism that can be employed for the electrosurgical device 5 is to adjust the power P and the flow rate Q such that the power P used with a corresponding flow rate Q is equal to or less than the P power required to boil 100% of the fluid and do not exceed the P power required to boil 100% of the fluid. In other words, this control strategy focuses on using the electrosurgical device 5 in the areas of Figure 2 identified as T &lt;100 ° C and T = 100 ° C, and includes the line 80 of 100% boiling. In other words, this control strategy focuses on not using the electrosurgical device 5 only in the area of ​​figure 2 identified as T &gt;&gt; 100 ° C.

Another control strategy that can be used for electrosurgical device 5 is to operate device 5 in the zone of T &lt;100 ° C, but at a temperature high enough to contract tissue containing type I collagen (for example, the walls of blood vessels, bronchi, bile ducts, etc.), which contracts when exposed to approximately 85 ° C for an exposure time of 0.01 seconds, or when exposed to approximately 65 ° C for an exposure time of 15 minutes. An example of a target temperature / time for tissue shrinkage is approximately 75 ° C with an exposure time of approximately 1 second. As explained herein, determining the top of the scale (that is, when the fluid reaches 100 ° C) can be done by changing the fluid's phase from liquid to vapor. However, the determination at the lower end of the scale (for example, when the fluid reaches, for example, 75 ° C for 1 second) requires a different mechanism since the temperature of the fluid is below the boiling temperature. and there is no apparent phase shift. In order to determine when the fluid reaches a temperature that facilitates tissue shrinkage, eg 75 ° C, a thermochromic material, such as a thermochromic dye (eg, leuco dye), can be added to the fluid. The colorant can be formulated to provide a predetermined first color for the fluid at temperatures below a temperature threshold, such as 75 ° C, then, upon heating above 75 ° C, the colorant provides a second color, such as as transparent, thereby rendering the fluid transparent (ie, no color or color reduction). This color change can be gradual, progressive or instantaneous. Therefore, a change in the color of the fluid, from a first color to a second color (or its absence) provides a visual indication to the user of the electrosurgical device 5 as to when a fluid temperature threshold has been achieved by below the boil. Thermochromic colorants are available, for example, from Color Change Corporation, 1740 Cortland Court, Unit A, Addison, IL 60101.

ES 2 355 872 T3

It is also observed that the above mechanism (that is, a change in the color of the fluid due to a dye) can also be used to detect when the fluid reaches a temperature that will facilitate tissue necrosis; As a general rule, this ranges from about 60 ° C for a 0.01 second exposure time and decreases to about 45 ° C for a 15 minute exposure time. An example of a target temperature / time for tissue necrosis is about 55 ° C for an exposure time of about 1 second.

In order to reduce the clotting time, it is preferable to use the electrosurgical device 5 in the zone of T = 100 ° C of Figure 2 to the use of the electrosurgical device 5 in the zone of T &lt;100 ° C. Consequently, as shown in Figure 2, another strategy or control mechanism that can be employed for the electrosurgical device 5 is to adjust the power P and the flow rate Q such that the power P used with a corresponding flow rate Q is equal to or less than the power P needed to start the fluid boiling but still less than the power P needed to boil 100% of the fluid. In other words, this control strategy focuses on the use of the electrosurgical device 5 in the area of ​​figure 2 identified as T = 100 ° C, and includes the lines of the beginning of boiling 76 and the line 80 of 100% of boiling. In other words, this control strategy focuses on the use of the electrosurgical device 5 at or between the lines of the beginning of boiling 76 and the line 80 of 100% boiling and does not use the electrosurgical device 5 in the areas of the Figure 2 identified as T &lt;100 ° C and T &gt;&gt; 100 ° C.

For a consistent tissue effect, it is desirable to control the saline flow rate so that it is always on a “constant% boiling line” such as the beginning of boiling line 76 or the 100% line 80. boiling point or any constant% boiling line in the middle (for example, the 50% boiling line 78) as shown in Figure 2. Consequently, another control strategy that can be used for the electrosurgical device 5 is to adjust the power P and the flow rate Q such that the power P used with a corresponding flow rate Q targets a constant% boiling line.

It should be noted from the above equations that the slope of any constant% boiling line is known. For example, for the boiling start line 76, the slope of the line is given by (pc_pAT), while the slope of the line 80 of 100% boiling is given by 1 / (pc., AT + ph_v). Looking at the 50% boiling line 78, for example, the slope is given by 1 / (pc_pAT + ph_v0,5).

If, with the application of the electrosurgical device 5 to the tissue, the boiling of the fluid is not detected, this indicates that the temperature is below 100 ° C, as indicated in the area of ​​figure 2, and the flow rate Q should be reduced to start boiling. The flow rate Q can then be decreased until boiling of the fluid is detected for the first time, at which point the boiling start line 76 is passed and the pass point is determined on line 76. From the determination of a point on the line of onset of boiling 76 for a particular power P and flow rate Q, and the known slope of line 76 as indicated above (i.e., 1 / pc_pAT), it is also possible to determine the heat conducted to the adjacent tissues 70.

On the contrary, if after the application of the electrosurgical device 5 to the tissue, the boiling of the fluid is detected, this indicates that the temperature is approximately equal to 100 ° C as indicated in the areas of figure 2, and the flow rate Q should increased to reduce boiling until boiling stops, at which point the start-of-boiling line 76 is exceeded and the overshoot point is determined on line 76. As before, from the determination of a point on the line of the beginning of boiling 76 for a particular power P and flow rate Q, and the known slope of the line 76, it is also possible to determine the heat conducted to the tissues adjacent 70.

Regarding the detection of the boiling of the fluid, it can be physically detected by the user (for example, visually with the naked eye) of the electrosurgical device 5 in the form of bubbles or vapor that develop from the fluid coupling at the electrode contact point. /tissue. Alternatively, such a phase change (i.e. from liquid to vapor or vice versa) can be measured with a sensor that preferably detects either an absolute change (for example, the existence or non-existence of boiling with binary response, such as yes or not) or a change of a physical quantity or intensity and turns the change into a useful input signal for an information gathering system. For example, the phase change associated with the onset of boiling can be detected with a pressure sensor, such as a pressure transducer, located in the electrosurgical device 5. Alternatively, the phase change associated with the onset of boiling it can be detected with a temperature sensor, such as for example a thermistor or thermocouple, located in the electrosurgical device 5, such as next to the electrode. Also alternatively, the phase change associated with the onset of boiling can be detected by a change in the electrical properties of the fluid itself. For example, a change in the electrical resistance of the fluid can be detected by an ohm meter; a change in amperage can be measured by an ammeter; how the change in voltage can be detected by a voltmeter; and a change in power can be determined by a power meter.

Another control strategy that can be employed for electrosurgical device 5 is to remove the heat conduction term from equation (1) (ie AT / R). Since the amount of heat dissipated to adjacent tissues can be difficult to predict accurately, as it may vary, for example, by the type of tissue, it may be preferable, from a control point of view, to assume the worst situation of zero conduction heat, and provide enough saline solution so that, if necessary, full RF power can be used to heat and boil the solution

ES 2 355 872 T3 saline, thus providing that the maximum tissue temperature does not exceed 100 ° C by a significant amount. This situation is shown in the schematic graph in Figure 3.

In other words, if the heat conducted to the adjacent tissues 70 is overestimated, the power P required to cross the line 80 of 100% boiling will in turn be overestimated and the line 80 of 100% boiling will be exceeded in the T &gt;&gt; 100 ° C zone of Figure 2, which is undesirable as explained above. Thus, assuming the worst case scenario of zero heat conduction provides a "factor of safety" to avoid exceeding the line 80 of 100% boiling. Assuming that the heat conduction to adjacent tissues 70 is zero also provides the advantage of eliminating the only term in equation (1), which is tissue dependent, ie tissue type dependent. Therefore, as long as p, c are known_p, ΔΤ and h_v As stated above, the equation of the line is known for any constant% boiling line. Thus, for example, the 98% boiling line, the 80% boiling line, etc. they can be determined in response to a corresponding input on the selection switch 12. In order to promote flexibility, it should be understood that the input of the selection switch may preferably comprise any percent boiling. Preferably, the percent boil can be selected in individual percent increments (i.e., 100%, 99%, 98%, etc.)

With the determination of the onset boiling line 76, the 100% boiling line 80, or any constant% boiling line in between, it is generally desirable to control the flow rate Q so that it is always a certain% boiling line. constant for a consistent fabric effect. In such a situation, the flow controller 11 will adjust the flow rate Q of the fluid 24 to reflect changes in the power P supplied by the generator 6, as explained in more detail below. For this use the flow controller 11 can be set to a constant boiling mode line, in which the% boiling is then selected accordingly.

As noted above, it is desirable to control the saline flow rate Q so that it is always on a constant% boiling line for a consistent effect on the tissue. However, the preferred constant% boiling line may vary depending on the type of electrosurgical device 5. For example, if with the use of device 5, drift through the saline solution is not a problem, then it may be preferable to operate near or directly at, but not above, the boiling start line, such as at 76a in Figure 3. This preferably keeps the fabric as hot as possible without causing desiccation. Alternatively, if with the use of the device 5 the diversion of electrical energy (for example, from a jaw with an opposite jaw of certain compatible bipolar devices) by excess saline solution is a problem, then it may be preferable to operate at the same time. along a constant boiling line, such as line 78a in Figure 3, the 50% line. This simple proportional control will have the flow rate determined by equation (4), where K is the constant of proportionality:

Qi = K x P (4)

In essence, when the power P increases, the flow rate Q will increase proportionally. On the contrary, when the power P drops, the flow rate Q will decrease proportionally.

The constant of proportionality K depends mainly on the fraction of saline that boils, as shown in equation (5), which is equation (3) solved for K after removal of P using equation (4), and neglecting the conduction term (ΔΤ / R):

{pc_pAT + ph_vQ_b/ Q₁J (5)

Therefore, the present disclosure provides a method of controlling the boiling of the fluid, such as a conductive fluid, at the tissue / electrode contact point. In a preferred arrangement, this provides a method of treating tissues without the use of tissue sensors, such as temperature or impedance sensors. Preferably, the disclosure can control the boiling of the conductive fluid at the tissue / electrode contact point and thereby control the temperature of the tissue without the use of feedback loops.

In describing the control strategy of the present disclosure described thus far, the approach has been taken to a steady state situation. However, the heat required to heat the tissue to maximum temperature (T) can be incorporated into equation (1) as follows:

P = ΔΤ / R + pCpQiAT + pQbh_v + pc_pVAT / At (6)

ES 2 355 872 T3 where pc_pVAT / At represents the heat required to heat the tissue to the maximum temperature (T) 68 and where:

p = Density of saline fluid that is heated but does not boil (approximately 1.0 g / cm³);

_cp = specific heat of saline solution (approximately 4.1 watt-s / g ° C);

V = Volume of tissue treated

ΔΤ = (TT_m) the temperature difference between the maximum tissue temperature (T) and the normal temperature (T_ra) of body tissue (° C). Normal body tissue temperature is generally 37 ° C; Y

At = (tU) the time difference to achieve the maximum tissue temperature (T) and the normal temperature (L) of the body tissue (° C).

The inclusion of the heat necessary to heat the tissue to the maximum temperature (T) in the control strategy is plotted at 68 in Figure 4. With respect to the control strategy, the effects of the heat required to heat the tissue to the Maximum temperature (T) 68 must be taken into account before approaching the flow rate setting Q to detect the location of the boiling start line 76. In other words, the flow rate Q should not be reduced in response to the lack of boiling before an at least quasi-steady state has been achieved since the location of the boiling start line 76 will continue to move during the transient period. Otherwise, if the flow rate Q is decreased during the transitional period, it may be possible to decrease the flow rate Q to a point beyond the start boiling line 76 and continue beyond the line 80 of 100% boiling, which is undesirable. In other words, as the temperature (T) approaches the heat 68 decreases to zero so that the constant boiling lines shift to the left towards the Y axis.

Figure 5 is an example graph of flow rate Q versus% boiling for a situation where the RF power P is 75 watts. The percent boiling% is plotted on the X-axis, and the flow rate Q (cc / min) of saline is plotted on the Y-axis. According to this example, at 100% boiling, the most desirable predetermined flow rate Q of saline is 2 cc / min. Also according to this example, the flow rate Q vs.% boiling at the remaining points of the graft illustrates a non-linear relationship as follows:

TABLE 1% Boiling and Flow Rate Q (cc / min) with 75 Watt RF Power

<td> 0%</td><td> 17,4</td>

<td> 10%</td><td> 9,8</td>

<td> 20%</td><td> 6,8</td>

<td> 30%</td><td> 5,2</td>

<td> 40%</td><td> 4,3</td>

<td> 50%</td><td> 3,6</td>

<td> 60%</td><td> 3,1</td>

<td> 70%</td><td> 2,7</td>

<td> 80%</td><td> 2,4</td>

<td> 90%</td><td> 2,2</td>

<td> 100%</td><td> 2,0</td>

Typical RF generators used in the field have a power selector switch at 300 watts of power, and it has sometimes been found that some can be selected at up to 400 watts of power. According to the above methodology, at 0% boiling with a corresponding power of 300 watts, the calculated flow Q is 69.7 cc / min and with a corresponding power of 400 watts the calculated flow Q is 92.9 cc / min. Therefore, when used with typical RF generators in the field, a fluid flow rate Q of about 100 cc / min or less is expected with the present disclosure to be sufficient for the vast majority of applications.

ES 2 355 872 T3

As explained herein, the delivery of RF energy to tissue can be unpredictable and varies over time, even though the generator has been "set" to a fixed power. The schematic graph in Figure 6 shows the general trends of the output curve of a typical general-purpose generator, with the output power changing as the impedance Z of the load (tissue plus leads) changes. The impedance Z (in ohms) of the load is plotted on the X axis, and the output power P (in watts) of the generator is plotted on the Y axis. In the illustrated arrangement the electrosurgical (RF) power is set to 75 watts in bipolar mode. As shown in the figure, the power will remain constant as set as long as the impedance Z is between two cutoff points, low and high, of the impedance, that is, for example, between 50 ohms and 300 ohms in the illustrated arrangement. Below the impedance Z of the 50 ohm load, the power P decreases, as shown by the low impedance ramp 28a. Above the impedance Z of the 300 ohm load, the power P decreases, as shown by the high impedance ramp 28b. Of particular interest to saline-enhanced electrosurgery is the low impedance cutoff point (low impedance ramp 28a) at which the power begins to drop as the impedance Z falls further. This change in output is invisible to the user of the generator and is not apparent when the generator is in use, such as in an operating room.

Figure 7 shows the general trend of how tissue impedance generally changes with time in saline-enhanced electrosurgery. As the tissue heats up, the temperature coefficient of the tissue and the saline in the cells is such that the impedance of the tissue decreases to a steady state temperature, during which time the impedance remains constant. In this way, the tissue heats up, the load's Z impedance decreases, which could approach the cutoff Z impedance of 50 ohms. If the tissue has been heated sufficiently so that the low impedance cutoff point is passed, the power P decreases along the lines of the low impedance ramp 28a of FIG. 6.

Combining the effects shown in figure 6 and figure 7 it is clear that when using a general purpose generator set to a “fixed” power, the actual power delivered can change dramatically over time as the tissue heats up and the impedance decreases. Looking at figure 6, if the impedance Z drops from 100 to 75 ohms over time, the power output does not change because the curve is "flat" in that impedance zone. However, if the impedance Z falls from 75 to 30 ohms the low impedance cutoff point is exceeded and the corner is “turned” over part of the low impedance ramp 28a of the curve and the power output would be dramatically reduced.

According to an example of an arrangement of the invention, the control device, such as the flow regulator 11, receives a signal indicating the drop in the actual power delivered to the tissue and adjusts the flow rate Q of saline solution to maintain the point tissue / electrode contact at a desired temperature. In a preferred arrangement, the drop in the actual delivered power P is detected by the power measurement device 8 (shown in Figure 1), and the flow rate Q of saline solution is reduced by the flow regulator 11 (also shown in figure 1). Preferably, this reduction in the flow rate Q of the saline solution allows the temperature of the tissue to be kept as warm as possible without desiccation. If the control device were not in operation and the flow rate Q could remain higher, the tissue would get too cold with a lower power input. This would lead to a decrease in tissue temperature at the treatment site.

The flow controller 11 of FIG. 1 may be a simple "wired" analog or digital device that does not require programming by the user or manufacturer. The flow controller 11 may alternatively include a processor, with or without a storage medium, in which the determination procedure is performed by software, hardware, or a combination of both. In another arrangement the flow controller 11 may include semi-programmable hardware configured, for example, using a hardware description language, such as Verilog. In another arrangement the flow controller 11 of Figure 1 is a microprocessor computer based controller with embedded software. In another arrangement, the flow controller 11 may include additional features, such as a delay mechanism, such as a timer, to automatically maintain the flow of saline for several seconds after the RF is turned off to provide post-cooling. tissue coagulation or "tempering", which can increase the strength of tissue closure Also, in another arrangement, the flow controller 11 may include a delay mechanism, such as a timer, to automatically activate the saline flow for several seconds before activating the RF to inhibit the possibility of undesirable effects such as sticking, desiccation, smoke production and char formation. Also in another arrangement the flow controller 11 may include a low flow hold-down mechanism, such as a valve, that follows the flow of saline at a hold flow level (which prevents the flow from going to zero when RF power is disabled) below the level of surgical flow commonly encountered during use of the electrosurgical device 5.

An example of an electrosurgical device of the present disclosure that can be used in conjunction with the system of the present disclosure is shown by reference character 5a in Figure 9, and more particularly in Figures 9-13. Although various electrosurgical devices of the present disclosure are described with reference to their use with the remainder of the disclosure system, it should be understood that the description of the combination is for purposes of illustrating the remainder of the disclosure system only. Accordingly, it should be understood that the electrosurgical devices of the present invention can be used alone or in combination with the remainder of the system of the invention, or that a wide variety of electrosurgical devices can be used in conjunction with the remainder of the system of the disclosure. The electrosurgical devices disclosed herein are preferably further configured for both open and laparoscopic surgery. For laparoscopic surgery, the devices are preferably configured to fit through a 5mm or 12mm trocar cannula.

ES 2 355 872 T3

As shown in Figure 8, the electrosurgical device 5a can be used in conjunction with a cannula such as that illustrated by reference character 19, during laparoscopic surgery such as, for example, a laparoscopic cholecystectomy. The cannula 19 comprises a proximal part 19a separated from a distal part 19b by an elongated rigid stem part 19c. The proximal part 19a of the cannula 19 preferably comprises a head part 19d connected to the rigid stem part 19c, preferably by a threaded coupling. Most importantly, the cannula 19 has a working channel 19e that extends through the head part 19d and the stem part 19c from the proximal part 19a to the distal part 19b of the cannula 19. In a particular arrangement, during insertion into cannula 19, electrosurgical device 5a is configured to enter the proximal end of working channel 19e, move along channel 19e distally, and then extend from the distal end of the working channel 19e. In the same arrangement, during retraction from cannula 19, electrosurgical device 5a is configured to enter the distal end of working channel 19e, move along channel 19e proximally, and then withdraw from the proximal end of the working channel 19e.

Returning to Figure 9, as shown the electrosurgical device 5a comprises a monopolar electrosurgical device. As shown in Figure 9, the electrosurgical device 5a preferably includes a self-supporting rigid hollow shaft 17, a proximal handle comprising handle portions 20a, 20b, and a tip portion, as shown by circle 45. The handle 20a, 20b is preferably made of a rigid, non-conductive material that can be sterilized such as a polymer (eg, polycarbonate). As shown in Figures 10 and 11, the tip portion 45 includes a contact element preferably comprising an electrode 25 which, as shown, comprises a solid ball having a smooth and seamless surface. Also as shown in Figures 10 and 11, the tip portion 45 also comprises a sheath 82 having a uniform diameter along its longitudinal extension, a spring 88, and a distal portion of the stem 17. As shown in FIG. Figure 10, the longitudinal axis 31 of the tip portion 45 may be configured at an angle A relative to the longitudinal axis 29 of the proximal remainder of the stem 17. Preferably, the longitudinal axis 31 of the tip portion 45 is configured at an angle A, of approximately 5 degrees to 90 degrees relative to the longitudinal axis 29 of the proximal remainder of the stem 17. More preferably, the longitudinal axis 31 of the tip portion 45 is configured with an angle A, of approximately 8 degrees to 45 degrees relative to the longitudinal axis 29 of the proximal remainder of the stem 17.

As shown in Figures 10 and 11, for electrosurgical device 5a, electrode 25 generally has a spherical shape with a corresponding spherical surface, a portion 42 of which is exposed to tissue 32 (less than 180 degrees and more specifically approximately 100-120 degrees) at the distal end of device 5a. When the electrode 25 is in the shape of a sphere, the sphere can have any suitable diameter. However, the sphere preferably has a diameter in the range between and including about 1mm to about 7mm. Although, it has been found that when a sphere is larger than about 4mm and smaller than about 2mm the tissue treatment can be adversely affected (in particular the tissue treatment time) due to the electrode surface being, respectively, very large or very small. Thus, more preferably the sphere has a diameter in the range of between and including about 2.5mm to about 3.5mm. Even more preferably, the sphere has a diameter of about 3mm.

It is understood that shapes other than a sphere can be used for the contact element. Examples of such shapes include oblong or elongated shapes. However, as shown in Figures 10 and 11, preferably a distal end surface of electrosurgical device 5a always offers a rounded blunt surface that is not pointed and is not sharp, as shown by electrode 25.

As shown in Figures 10 and 11, the electrode 25 is preferably located in a cavity 81 of a sheath 82 that provides a receptacle for the electrode 25. Among other things, the tube 82 guides the movement of the electrode 25. Among others things, tube 82 also functions as a housing to retain electrode 25.

Also as shown in Figure 11, a portion 44 of the electrode is retained within the cavity 81, while another portion 43 extends distally through the fluid outlet opening provided by the circular hole 26 of fluid outlet. Also as shown, sheath 82 is connected, preferably by silver soldering, to distal end 53 of stem 17. For device 5a, electrode 25, sheath 82 and stem 17 preferably comprise, and more preferably at least in essence consist of, an electrically conductive metal, which is also preferably non-corrosive, and more particularly stainless steel. Other metals include copper, titanium, gold, silver, and platinum. Furthermore, stem 17 preferably comprises thick-walled hypodermic tubing of stainless steel.

As for the cavity 81, the internal diameter of the cavity 81 surrounding the electrode 25 is preferably slightly larger than the diameter of the sphere, usually about 0.25 mm. This allows the ball to rotate freely within the cavity 81. Accordingly, the cavity 81 of the sleeve 82 also preferably has a diameter in the range of about 1mm to about 7mm.

As best shown in Figures 11 and 12, in order to maintain electrode 25 within cavity 81 of sheath 82, preferably fluid outlet port 26, which ultimately provides a fluid outlet opening, of cavity 81 at its distal end 83 comprises a pinched distal area 86 that is reduced to a size smaller than the diameter of electrode 25, to prevent leakage of electrode 25 from sheath 82. More preferably, the fluid outlet port 26 comprises a diameter smaller than the diameter of the electrode 25.

ES 2 355 872 T3

As best shown in Figure 12, the fluid outlet port 26 preferably has a diameter smaller than the diameter of the electrode 25, which can be achieved with at least one fold 84 located at the distal end 83 of the sheath 82. which is directed into the sheath 82 and distal to the portion 44 of the electrode 25 confined in the cavity 81. When a pleat 84 is employed, the pleat 84 may comprise a single continuous circular edge pattern. In this manner, the contact element portion extending distally through the fluid outlet port (i.e., the electrode portion 43) provided by the fluid outlet port 26 has a shape complementary to that of fluid outlet opening provided by fluid outlet port 26, here both circular.

However, as shown in Figure 12, the fold 84 may also comprise a discontinuous circular edge pattern in which the fold 84 is interrupted by at least one rectangular hole slot 85 formed in the distal end 83 of the sheath. 82. Therefore, the fluid outlet opening located at the distal end of the device 5a may comprise a first part (for example, the circular fluid outlet port part 26) and a second part (for example, the slot part 85 fluid outlet hole). As shown in Figure 12, preferably, the fold 84 comprises at least four fold sections that form a circular edge pattern separated by four distinct grooves 85 positioned radially in between at 90 degrees to each other and equally positioned around the first part. fluid outlet opening. Grooves 85 are preferably used to provide a fluid outlet opening adjacent to electrode 25, when electrode 25 is fully seated (as will be explained later) and / or when electrode 25 is not in use (i.e. , without electrical charge) to keep the surface portion 42 of the electrode surface of the electrode 25 wet. Preferably, the grooves 85 have a width in the range of between and including about 0.1mm to 1mm, and more preferably have a width in the range of between and including about 0.2mm to 0.3mm. In terms of length, the grooves 85 preferably have a length in the range between and including about 0.1 mm to 1 mm, and more preferably have a length in the range between and including about 0.4 mm to 0, 6 mm.

As shown in Figure 12, the contact element portion that extends distally through the fluid outlet opening (i.e., the electrode portion 43) extends distally through the first portion. fluid outlet opening portion (for example, the circular fluid outlet port portion 26) and does not extend distally through the second fluid outlet opening portion (for example, the fluid outlet port groove portion 85). In this way an edge 91 of slot 85 is exposed to tissues 32 to provide a tissue separating edge as explained below.

It should be understood that the particular geometry of the fluid outlet opening provided by the fluid outlet port located at the distal end of the device 5a for the electrode is not decisive for the disclosure, and all that is needed is the presence of a fluid outlet port that supplies fluid 24 as needed. For example, fluid outlet port 26 may comprise an oval shape, while electrode 25 may comprise a different shape, such as a round shape.

As shown in Figure 12, in addition to the groove 85 providing a fluid outlet, at least one edge 91 of the groove 85 may provide a tissue separating edge alongside a blunt surface (e.g., the surface portion 42 of electrode 25) that can be used for blunt dissection when manipulating electrosurgical device 5a, particularly by twisting (eg twisting), abrasion or impact. When the edge 91 is used in this sense, it is preferred that the edge comprises a sharp edge with an acute angle that has not been rounded by, for example, a chamfer.

Changing to the proximal end of the tip (comprising electrode 25, spring 88, and sheath 82) of device 5a and electrode 25, as shown in Figure 11, preferably the portion of sheath 82 proximal to electrode 25, it also has a pinched proximal area 87, which retains the electrode 25 in the cavity 81 of the sheath 82 and prevents the escape of the electrode 25 from the cavity 81 of the sheath 82, such as a diameter smaller than the diameter of the electrode 25.

Although only the pinched distal area 86 and the pinched proximal area 87 can be used to support the electrode 25, in its position of use, the electrode can be further supported by a compression spring 88 as shown in Figure 11. The use of spring 88 to provide variable length support within the working length of spring 88 is preferred to overcome manufacturing tolerances (eg, length) between fixed supports (i.e., pinched areas 86 and 87) cover 82. Regarding the maintenance of the correct position of the spring 88, the sleeve 82 also comprises an inner passage 89 as shown in Figure 11 (i.e., the cavity of an elongated hollow structure, such as a tube or a similar structure to a tube; typically cylindrical) which, in addition to providing a direct passage for fluid, provides a guide tube for spring 88. In addition, the surface portion 60 of the electrode 25, which contacts the spring 88, may comprise a flat surface rather than a curvilinear surface to better seat the spring against the electrode 25.

In addition to the above, spring 88 provides a multitude of functions and advantages. For example, the configuration of the pinched distal area 86, the pinched proximal area 87, and the spring 88 provide the ability to move the electrode 25, distally and proximally within the sheath 82. As shown in Figure 11, spring 88 is proximal to electrode 25 between a load bearing surface that comprises electrode surface 60 and a second load bearing surface that comprises distal end 53 of stem 17. From this way,

The spring 88 may be configured to provide a decompression force to seat the electrode 25 against the pinched distal area 86, in this case the perimeter edge 92 of the fold 84, prior to using the electrosurgical device 5a.

In contrast, upon application of electrode 25 of device 5a against surface 22 of tissue 32 with sufficient force to overcome the compressive force of spring 88, spring 88 is compressed and electrode 25 retracts proximally away from the pinched distal area 86, in this case the perimeter edge 92 of the fold 84, changing the position thereof. In the above manner, the contact element comprising the electrode 25 is retractable in the cavity 81 of the housing provided by the sheath 82 with the application of a proximally directed force against the surface 42 of the portion 43 of the electrode 25 which is it extends distally beyond distal opening 26 located in distal end 83 of the housing and spring 88 functions as a retraction biasing member.

By making the electrode 25 positionable in the above manner by the spring 88, in various arrangements the electrosurgical device 5a may be provided with a damping mechanism that dampens the force of the electrode 25 on the tissue 32 to be treated.

In addition, in various arrangements of the electrosurgical device 5a, an electrode 25 that can be positioned as described above may comprise a fluid flow adjustment mechanism that gradually increases the area of ​​the fluid outlet port 26 and the corresponding fluid flow rate in response. to the progressive proximal retraction of the electrode 25. In such a case the electrode 25 functions as a valve to regulate the flow of fluid 24 through the fluid outlet port 26.

In various arrangements, spring 88 can be used in conjunction with pinched distal area 86 (for example, pleat 84 comprising a single continuous circular pattern) to provide a fluid seal between electrode 25 and pinched distal area 86 that stops the fluid flow from electrosurgical device 5a. In this way, the electrosurgical device 5 can be used to provide both a wet electrode and a dry electrode (that is, when the fluid flow is on and off, respectively) with the energy and fluid provided sequentially as well as simultaneous. Incorporation of a dry electrode feature in the device of the current disclosure may be desirable to provide a mechanism for electrosurgical cutting.

In addition, in various arrangements of the electrosurgical device 5a, an electrode 25, which can be positioned as described above, may comprise a plunger mechanism that retracts to provide access to unclog fluid outlet ports, such as ports 26 and 85 of fluid leakage, which can restrict flow as a result of loose debris (eg tissue, blood) getting stuck in it. For example, when a biasing force, such as from a handheld cleaning device (eg, a brush) or from pushing the distal tip against a hard surface such as a spacer, is applied to surface 42 of electrode 25, which overcomes the compression force of spring 88 causing spring 88 to compress and electrode 25 to retract, the tip of the handheld cleaning device may extend into fluid outlet port 26 to clean fluid outlet port 26, perimeter edge 92, groove 85, and edge 91. In other words, an electrode 25, which can be positioned as indicated, provides a method of unclogging a fluid outlet port by increasing the cross-sectional area of ​​the fluid outlet port to provide access thereto.

Furthermore, in various arrangements of electrosurgical device 5a, spring 88 comprises an electrical conductor, particularly when electrode 25 is retracted to a non-contact (ie, non-contact) position with sheath 82.

In other arrangements, the proximal pinched area 87 may comprise one or more folds similar to the distal pinched area 86, such that the electrode 25 is retained in the sheath 82 both distally and proximally by folds. Furthermore, in other arrangements the sheath 82 may be disposed within the stem 17, rather than being connected to the distal end 53 of the stem 17. Furthermore, in still other arrangements, the sleeve 82 may be formed unitary (ie, as a single piece or unit) with the stem 17 as a unitary piece.

As best shown in Figures 10 and 11, electrode 25 is retained in sheath 82 such that a portion 43 of electrode 25 extends distally beyond distal end 83 of sheath 82. As shown, preferably the surface 42 of this exposed portion 43 of the electrode 25 is blunt and does not comprise any sharp corners. Furthermore, the portion 43 of the electrode 25 that extends distally beyond the distal end 83 of the sheath 82 is controlled by the shape of the fluid outlet port 26 in the sheath 82 relative to the shape of the electrode 25. In In other words, the portion 43 of electrode 25 that extends distally beyond distal end 83 of sheath 82 is controlled by contact of the electrode surface with edge 92.

As shown in Figures 10 and 11, where stem 17 and sheath 82 are electrically conductive (for device 5a, preferably stem 17 and sheath 82 are fully electrically conductive and do not comprise non-conductive parts). conductive), preferably an electrical insulator 90 (i.e., comprising non-conductive or insulating material), preferably surrounds stem 17 and sheath 82 along substantially their entire exposed length (e.g., the part outside the limits of the handle 20), ending a short distance (for

For example, at the proximal beginning of the fold 84 or less than about 3mm) of the distal end 83 of the sheath 82. The insulation 90 preferably comprises a shrinkable polymer wrap tubing.

As with the other electrosurgical devices described, a fluid inlet line 4b and a power source, preferably comprising a generator 6 that preferably provides radio frequency power through cable 9, are preferably fluidly and electrically coupled, respectively, to the tip portion 45 of the electrosurgical device 5a.

As indicated above, device 5a comprises a monopolar device. In other words, a first electrode, often known as the active electrode, comprises an electrode of the electrosurgical device 5a (for example, electrode 25), while a second electrode, often known as the indifferent or return electrode, comprises a ground plate scattering electrode located on the patient, usually on the back or other suitable anatomical location. Preferably, the two electrodes are electrically coupled to generator 6 to form an electrical circuit. Preferably, the active electrode is coupled to generator 6 via insulated wire rope lead wire 9 to outer surface 18 of stem 17 within the limits of handle 20a, 20b, typically through a switch 15a.

In other arrangements, the stem 17 may be made of an electrically non-conductive material except for a part at its distal end 53 that comes into contact with the sheath 82. This portion of the stem 17 that makes contact with the sheath 82 must be electrically conductive. In this arrangement, the wire conductor of the insulated wire cable 9 extends to this electrically conductive portion of the stem 17. In still other arrangements the stem 17 may fully comprise a non-conductive material such as where the wire conductor of the insulated wire rope 9 extends directly into the sheath 82.

With respect to fluid coupling, fluid 24 from fluid source 1 for use with electrosurgical device 5a preferably communicates from fluid source 1 through flexible polyvinyl chloride (PVC) tubing 4b of fluid outlet to a flexible polyvinyl chloride (PVC) fluid inlet tubing 4b connected to electrosurgical device 5a. The outlet fluid line 4a and the inlet fluid line 4b are preferably connected through a male and female mechanical clamping configuration, preferably comprising a Luer-Lok® connection from Becton, Dickinson and Company. The inner passage of the inlet line, then, preferably fits snugly over the outer diameter of stem 17 to provide an intermediate press fit seal. In addition, an adhesive may be provided in between to reinforce the seal. Fluid 24 is then communicated down internal passage 23 of stem 17 through internal passage 89 and cavity 81 of sheath 82 where it is expelled everywhere and over exposed surface 42 of electrode 25. This provides a wet electrode to perform electrosurgery.

As shown in Figure 13, during use of the electrosurgical device 5a, a fluid coupling 30 is typically provided which preferably comprises a localized discrete band and preferably comprises a triangular shaped band or a cord portion providing a fluid film 24 between surface 22 of tissue 32 and electrode 25. When the user of electrosurgical device 5a places electrode 25 at a tissue treatment site and moves electrode 25 across surface 22 of tissue 32, fluid 24 is expelled around and onto surface 42 of electrode 25 at the distal end 83 cover 82 and onto surface 22 of fabric 32 through coupling 30. Fluid 24, in addition to providing an electrical coupling between electrosurgical device 5a and tissue 32, lubricates surface 22 of tissue 32 and facilitates movement of electrode 25 across surface 22 of tissue 32. During movement of electrode 25, the Electrode 25 normally slides across surface 22 of tissue 32, but can also rotate as electrode 25 moves across surface 22 of tissue 32. Typically, the user of the electrosurgical device 5a slides the electrode across the surface 22 of the tissue 32 back and forth in a painting-like motion while using the liquid 24 as, among other things, a lubricating coating. Preferably, the thickness of the fluid 24 between the distal end surface of the electrode 25 and the surface 22 of the tissue 32 at the outer edge of the coupling 30 is in the range of between and including about 0.05mm to 1.5mm. More preferably, the fluid 24 between the distal end surface of the electrode 25 and the surface 22 of the tissue 32 at the outer edge of the coupling 30 is in the range of between and including about 0.1 mm to 0.3 mm. Also preferably, in certain arrangements, the distal end tip of electrode 25 contacts surface 22 of tissue 32 without any fluid 24 in between.

Another example of an electrosurgical device of the present disclosure that can be used in conjunction with the system of the present disclosure is shown referenced character 5b in Figures 14-16. In these arrangements, electrical insulator 90 preferably terminates proximally at sheath 82, where sheath 82 connects to distal end 53 of stem 17. In certain arrangements where sheath 82 is unitary with stem 17, electrical insulator 90 preferably terminates proximally with pinched proximal area 87. In this way, in addition to the spherical surface portion 42 of the electrode 25 and the tapered surface portion 41, here conical, of the sheath 82 that is used for treating tissue 32 when exposed to it, a cylindrical surface 40 of a cylindrical portion 39 of the sheath 82 and an enlarging surface portion 47 of the enlarging portion 54, here the two cones, of the sheath 82 also function as electrode surfaces for treating tissue. Thus, the tissue-exposed electrode 32 now comprises a cylindrical surface portion 40 and an enlarging surface portion 47, in addition to the spherical surface portion 42 and the narrowing surface portion 41, with the cylindrical surface portion 40 increasing substantially. the surface area of ​​the electrode. As a result, the

ES 2 355 872 T3 electrode 25 now also comprises surfaces that are parallel and perpendicular to the longitudinal axis 31 of the tip portion 45, and more particularly the sheath 82, of the electrosurgical device 5b. In the above manner, the use of the front end (for example, surfaces 41 and 42), the use of the sides (for example, surface 40 and 47) or the use in oblique (for example, surfaces 40, 41 and 42) of the electrosurgical device 5b.

In the above manner, the tip portion 45 now comprises a first tissue treatment surface (eg, spherical surface 42 at the distal end) and a second tissue treatment surface (eg, side surface 40). As explained above, preferably the first tissue treatment surface is configured for blunt dissection, while the second tissue treatment surface is configured for coagulation. In addition, the tip portion 45 also comprises a third tissue treatment surface (eg, surface 41) located between the first tissue treatment surface (eg, surface 42) and a second tissue treatment surface (eg. , surface 40). In addition, tip portion 45 also comprises a fourth tissue treatment surface (eg, surface 47) located proximal and adjacent to surface 40.

With device 5a, when electrode 25 is placed directly in contact with surface 22 of tissue 32, it may be possible for tissue 32 to occlude fluid flow from fluid outlet ports 26, 85 located at the end distal of device 5a. Consequently, for device 5b the fluid outlet ports 93, 94 can be located in the cylindrical side 39 of the sheath 82, either proximal or next to the electrode 25, and either as a complement or as an alternative to the fluid outlet ports 26, 85.

As shown in Figures 14 and 15, at least one fluid outlet port 93 is preferably formed in the longitudinal cylindrical side surface 40 and by the side wall 39 of the sheath 82 adjacent to the electrode 25 when the electrode 25 is fully seated. Furthermore, preferably at least one fluid outlet port 94 is formed in the cylindrical side portion 39 of the sheath 82 proximal to the electrode 25 when the electrode 25 is fully seated.

Preferably, holes 93, 94 comprise more than one hole which are equally spaced radially in a circular pattern around longitudinal axis 31 of tip portion 45, and more particularly sheath 82. More preferably, holes 93, 94 comprise four discrete holes equidistant at 90 degrees around the cylindrical side portion 39 of the sleeve 82. Preferably, the holes 93, 94 have a diameter in the range of between and including about 0.1mm to 1mm, and more preferably have a length in the range of between and including about 0.2mm to 0.6mm. Electrode 25, which can be positioned as indicated above, may comprise not only a valve for regulating fluid flow from fluid outlet ports, such as fluid outlet port 26, but also comprise a valve that while opening one fluid flow outlet it closes another fluid flow outlet. For example, when electrode 25 is retracted proximally, fluid outlet port 26 opens while fluid outlet port 93 closes. In other words, an electrode 25, which can be positioned as described above can provide a mechanism to alter the size and / or location of the fluid outlet ports during use of the electrosurgical device 5b which may be necessary, for for example, to direct fluid to a particular location in tissue or balance fluid flow between fluid exit points.

Thus, as shown in Figures 14 and 15, surfaces 40, 41, and 47 of sheath 82, and surface 42 of electrode 25 are all active electrode surfaces and can provide electrical energy to tissue 32. Parts of this combined electrode surface can be wetted by fluid flow from ports 26, 94, or 93, as well as from port slots 85 in fold 84 adjacent to electrode 25.

The holes 94, 93 in the cylindrical sleeve 82 of the electrode surface are generally intended to ensure that fluid 24 is provided to the smooth, less harsh, non-traumatic sides of the electrodes that are used to produce coagulation and hemostasis of the tissue (eg, surfaces 40 and 47) rather than blunt dissection (eg, surfaces 41 and 42). The most distal part of the device may have a rougher, but also wet, electrode surface, which can perform blunt dissection as well as tissue coagulation.

The electrode configuration shown in Figures 14 and 15 is particularly useful for a surgeon performing liver resection. Once the external capsule of the liver is marked with a dry Bovie sheet along the planned line of resection the distal tip of the tip portion 45 is painted back and forth along the line, which has as resulted in coagulation of the liver parenchyma. As tissue coagulates under and around electrode surfaces 40, 41, and 42, the electrode is used for blunt dissection into the coagulated parenchyma, with the edge 91 of the grooves 85 around the fold 84 providing elements of roughness that help disrupt tissue 32 and allow separation of tissue 32.

As shown in FIG. 16, device 5b can be used deep into a crack 97 of tissue 32 for blunt dissection of tissue 32 and coagulation thereof at the same time. Blunt dissection is preferred over acute dissection, such as with a blade or scissors, since blunt dissection is less prone to tearing or damaging the major blood vessels or other vessels. Once identified by blunt dissection, larger vessels can be safely trimmed, tied with suture thread, or sealed with some other device. If the larger vessels are not “skeletonized” (separated from the tissue) in the first place without being damaged by blunt dissection, they can bleed profusely and it takes much longer to stop the bleeding. The device also

ES 2 355 872 T3 can be used to coagulate first without simultaneous blunt dissection and then perform blunt dissection at a different stage.

This technique can also be used in other parenchymal organs, such as the pancreas, kidney, and lung. In addition, it can also be useful in muscle tissue and subcutaneous fat. Its use can also be extended to benign tumors, cysts or other tissue masses found in the urological or gynecological areas. It would also allow the removal of tumors with many vessels such as hemangiomas.

In Figure 16, zone 99 identifies the part of the electrode that has the ability to perform coagulation and blunt dissection, and zone 98 identifies the part that is primarily intended for coagulation and hemostasis. Line 100 indicates the depth of the area of ​​tissue being coagulated, typically 3mm to 5mm deep.

For the devices described herein, the presence of various boiling fractions can be estimated visually with the naked eye, or by detecting changes in electrical impedance. Figure 17 shows a diagram of electrical impedance Z versus time t. The impedance peaks 101 shown in FIG. 17 occur with a frequency of about one cycle per second and with an amplitude that is of the same order as the baseline impedance. This frequency is shown in FIG. 17 as the interval 102 between successive peaks in impedance. Impedance is directly measurable by dividing voltage by current as described above. The use of electrical impedance to detect the onset of tissue desiccation when the impedance rises dramatically as a result of being heated to the smoking and charring point, but not to detect the presence of boiling, has been described above. As shown in Figure 17, the impedance Z can change from a level of about 100 ohms without boiling, to a level of about 400 ohms or more with a large portion of the conductive fluid boiling. The boiling percentages shown are examples as are impedance levels.

The qualitative nature of boiling is shown in Figure 18 as% boiling increases, indicated by the small values ​​of each of five examples of boiling "rates". At each small value a tip portion 45 of device 5a is shown in the vicinity of tissue 32. When boiling begins in regime 104, there are a few small bubbles 37 of vapor in conductive fluid 24, here saline, from the coupling 30. As the percent boiling in regime 106 increases there are a greater number of small bubbles 37. As the percent boil increases further at regime 107, the bubbles 37 become much larger. At an even higher percent boil in regime 108, intermittent threads of saline form and evaporate rapidly. Finally, at the highest rate level 109, a few drops 36 of saline solution boil instantly upon contact with the hot surface 22 of tissue 32 and arc from metal to tissue 32.

Returning to Figures 14 and 15, fluid outlet openings are provided by substantially linear through holes, which supply conductive fluid 24 to the treatment site. However, in an alternative arrangement, as shown in Figure 19, the fluid outlet openings in the sheath 82 may be provided by the interconnected, tortuous path-shaped holes 59, which are formed in a material permeable to the passage of the fluid. fluid 24, through it, such as a porous material. The discrete and linear through holes 93, 94 can be supplemented or replaced by a plurality of interconnected and tortuous paths 59 formed in the porous material which, among other things, provides porous surfaces 40, 41 and 47 to more evenly distribute the flow of fluid and supplying conductive fluid 24 to tissue 32 at the treatment site. According to the disclosure all or part of the sheath 82 may comprise a material permeable to the passage of fluid 24 through it as described herein.

In certain arrangements, the contact element, here the electrode 25 may also comprise a material permeable to the passage of fluid 24 through it, such as a porous material (eg, metals, polymers, or ceramics) to provide the tortuous paths 59. In these arrangements, the porous structure of electrode 25 allows fluid 24 to not only pass around electrode 25 on porous outer surface 42 as it is expelled, but also allows fluid 24 to pass through electrode 25, to be expelled. . According to the disclosure all or part of the electrodes or any particular tissue treatment electrode 32 may comprise a material permeable to the passage of fluid 24 therethrough as described herein.

When the contact element and sheath provide electrodes for tissue treatment and comprise a porous material, preferably the porous material further comprises a porous metal. Porous sintered metal is available in many materials (such as 316L stainless steel, titanium, Ni-chrome) and shapes (such as cylinders, discs, plugs) from companies such as Porvair, located in Henderson, North Carolina. .

Porous metal components can be formed by a sintered metal powder process or by injection molding a combination of two pieces of metal and a material that can burn to form pores that connect (open cell) to each other. With sintering, for example, normally the solid particles of material are placed in a mold with heat and pressure in such a way that the outer surface of the particles softens and they bond together with the pores that comprise the interstices between the particles. Alternatively, when porosity is formed by burning of material, it is not the gap between the particles that provides the porosity as with sintering, but rather a partial gutting of the material generally provided by the removal of a component with a lower temperature. melting than burning temperature.

ES 2 355 872 T3

Although the electrode provided by the contact element and / or the sheath preferably comprises an electrically conductive material, such as metal, a non-electrically conductive porous contact element and sheath, such as polymers and porous ceramics, can be used to replace an electrically conductive sleeve and contact element. Although porous polymers and ceramics are not generally conductive, they can also be used to conduct radio frequency energy through the porous surface and thickness of porous ceramic and polymer to the tissue to be treated, by virtue of the conductive fluid 24 contained within the plurality of interconnected tortuous paths 59.

Preferably, the tortuous paths in porous materials have a pore size (cross-sectional dimension) in the range between and including about 2.5 microns (0.0025mm) to 500 microns (0.5mm) and more preferably has a pore size in the range of between and including about 10 microns (0.01mm) to 120 microns (0.12mm). Even more preferably, the porous material has a pore size in the range of between and including about 20 microns (0.02mm) to 80 microns (0.08mm).

In addition to the ability to provide a more uniform distribution of fluid 24, porous materials can also provide other benefits. For example, when electrode surfaces, such as surfaces 40, 41, 42, and 47, in contact with surface 22 of tissue 32 are porous and dissipate fluid 24, tissue 32 is less apt to stick to the surfaces. 40, 41, 42 and 47 of the electrode compared to the situation where the surfaces 40, 41, 42 and 47 are not porous. In addition, by supplying fluid 24 to surfaces 40, 41, 42, and 47 through tortuous paths 59, heated or electrified fluid 24 can now be provided more uniformly to surfaces 40, 41, 42, and 47, which can result in a larger tissue treatment zone compared to when the surfaces are non-porous.

Preferably, the porous material provides the wicking (ie, sinking into the fluid by capillary action or capillary action) of the fluid 24 in the pores of the porous material. In order to promote the wicking effect of the fluid 24 in the pores of the porous material, preferably the porous material and in particular the surface of the tortuous paths is hydrophilic. The porous material can be hydrophilic with or without subsequent treatment (for example, plasma surface treatment such as super-cleaning (hypercleaning), chemical etching or micro roughness, plasma surface modification of the molecular structure, surface chemical activation or crosslinking), or made hydrophilic by a coating disposed thereon, such as a surfactant.

Although not preferable, the fluid coupling 30 of the fluid 24 need not be present between the metal electrode surfaces (eg, 40, 41, 42) and the tissue 32 at all tissue treatment sites and there may be direct contact points with the tissue by the electrode surfaces without any fluid coupling between them. In such a case, the convection cooling of the metal electrode by the saline flow is usually sufficient to keep the metal electrode and tissue in contact with the metal electrode at or below a temperature of 100 ° C. In other words, heat can also first be dissipated from the tissue 32 to the electrodes by conduction, then be dissipated from the electrodes to the fluid 24 by convection.

Preferably, the relationship between the material of the electrodes, in particular their surface, (for example, 40, 41, 42, 47), and the fluid 24 throughout the various arrangements should be such that the fluid 24 wets the surface of the electrodes to form a continuous thin film coating (for example, see Figure 19A) and not to form streams or isolated circular beads (for example, with a contact angle 8 of more than 90 degrees), that freely come off the surface of the electrode. The contact angle, θ, is a quantitative measure of the wetting of a solid by a liquid. It is geometrically defined as the angle formed by a liquid at the three-phase boundary at which liquid, gas, and solid intersect. In terms of the thermodynamics of the materials involved, the contact angle 8 implies the interfacial free energies between the three phases given by the equation Y_LV cos θ = y_SV - Ysl where and_LV, Y_SV yy_SL refer to the interfacial energies of the liquid / vapor, solid / vapor, and solid / liquid contact points, respectively. If the contact angle θ is less than 90 degrees the liquid is said to wet the solid. If the contact angle is more than 90 degrees the liquid does not wet. A contact angle θ of zero represents complete wetting. Therefore, preferably the contact angle is less than 90 degrees.

For clarity, while it is known that the contact angle θ can be defined by the above equation, actually the contact angle θ is determined by various models for an approximation. According to the publication entitled "Surface Energy Calculations" (September 13, 2001) by First Ten Angstroms (465 Dinwiddie Street, Portsmouth, Virginia, 23704), there are five models that are widely used to approximate a contact angle θ and a host of others that have small followers. The five predominant models and their synonyms: (1) Zisman's critical wetting stress; (2) Girifalco, Good, Fowkes and Young combination rule; (3) geometric mean of Owens, Wendt; (4) Wu harmonic mean; and (5) Lewis acid / base theory. Also according to the First Ten Angstroms publication, for well-known and well-characterized surfaces, there may be a 25% difference in the answers given for the contact angle θ by the models. Also for clarity, any of the five predominant models above, which computes a contact angle θ within a particular range of contact angles θ or the necessary contact angle θ of a particular provision of the disclosure should be considered as meeting the layout requirements, even if the remaining four models calculate a contact angle θ that does not meet the layout requirements.

ES 2 355 872 T3

The effects of gravity and surface tension tend to wick fluid 24, here saline, around the circumference of cylindrical sheath 82 to preferably cover the entire surface of the active electrode. More specifically, the effects of gravity and surface tension in fluid 24 found on the electrode surfaces can be modeled by the number N_BO of Bond.

The number N_BO Bond measures the relationship between gravitational forces and surface tension forces and can be expressed as:

NBO = gravitational force / surface tension force

Nbo = pL²g / ^ where:

p = Density of saline fluid (approximately 1.0 g / cm³);

L = drop diameter (cm) g = gravitational acceleration (980 cm / s²) _σ = Surface tension (approximately 72.8 dynes) cm @ 20 ° C)

For a Bond number NBO = 1, the droplet diameter equals about 0.273 cm or about 2.7 mm, which is of the same order of magnitude as the preferred electrode size. For the purpose of the present invention, preferably the Bond number NBO for a drop of fluid 24 on a surface of the electrode 25 is preferably less than 1.

Another tip portion of an exemplary electrosurgical device 5c of the present disclosure that can be used in conjunction with the system of the present disclosure is shown by reference character 45 in Figures 20-24. As best shown in Figures 20 and 21 the separate sleeve 82 of the arrangements 5a and 5b has been removed from the tip portion 45 of the device 5c. Accordingly, the contact element, which still preferably comprises an electrode 25, is directly assembled with the stem 17. The electrode 25 is preferably assembled (for example mechanically connected by press fit, a mechanical connector, threaded, welded, glued with adhesive) adjacent to the distal end 53 of stem 17. In certain arrangements the electrode 25 is preferably removably assembled to the stem 17 such that it can be removed from the stem 17, preferably manually by human hand, so that the stem 17 can be used with multiple contact elements. different electrodes / electrodes, or the stem 17 may be reusable and used with disposable electrodes / contact elements.

As shown in Figures 20-24, the electrode 25 preferably comprises an enlarged head portion comprising a spherical portion 43 and a corresponding spherical surface portion 42 located at the distal end of the device 5c that provides a smooth, contoured outer surface. blunt. More specifically, as shown, spherical portion 43 and spherical surface portion 42 further provide a domed hemisphere, (ie, less than a full sphere), and a hemispherical surface portion preferably comprises approximately 180 degrees.

Also as shown in Figures 20-24, the enlarged head portion of the electrode 25 preferably also comprises a cylindrical portion 39 and a corresponding cylindrical surface portion 40 located proximally and adjacent to the spherical portion 43 and the spherical surface portion 42, respectively. .

Continuing further with Figures 20-24, the electrode 25 preferably comprises a connector portion, preferably comprises a pin 46, connecting the remainder of the electrode 25 and the stem 17. Among other things, the connector portion of the electrode 25 is connected. preferably configured to form a connection with a mating connector portion of stem 17. As shown, preferably the spike portion 46 is configured to extend into the cavity 50 of the stem 17, which comprises a cylindrical receptacle and provides the mating connector portion for the spike 46. More preferably, the surface 48 of the spike portion 46 is configured to mate against and form a tight fit with surface 52 of cavity 50 to provide the connection.

Continuing with Figures 20-24, the spike portion 46 is preferably cylindrical and lies proximal and adjacent to a neck portion 56. As shown, here the neck portion 56 also comprises a cylindrical portion 57 (having a corresponding cylindrical surface 58) located proximal and adjacent to an enlarging portion 54 (having a corresponding enlarging surface portion 47). Here the enlarging portion 54 and the corresponding enlarging surface portion 47 are spherical, and more specifically comprise a domed hemisphere, and the hemispherical surface portion preferably comprises approximately 180 degrees, located proximal and adjacent to the cylindrical portion 39 and the portion cylindrical surface 40.

As shown in Figures 20-24, the cylindrical portion 57 of the neck portion 56 preferably has a cross-sectional dimension, here diameter, greater than the cross-sectional dimension, here also diameter,

ES 2 355 872 T3 of the spike 46. In this way, in certain arrangements the proximal end of the neck portion 56 may lie alongside and in contact with the distal end 53 of the stem 17.

Also as shown in Figures 20-24, electrode 25 comprises at least one slit 64 that provides an elongated channel for fluid flow for distribution of fluid 24. The use of device 5c, and in particular grooves 64, for fluid distribution 24 is generally preferred over fluid outlet ports 93, 94 of device 5b in particularly deep tissue cracks 97 where tissue 32 may occluding fluid flow from fluid outlet ports located in cylindrical portion 39 of electrode 25.

As shown, electrode 25 preferably comprises a plurality of longitudinally directed grooves 64 and, more specifically, four grooves 64 equidistant at 90 degrees around spike 46 and / or neck portion 56, both proximal to cylindrical portion 39. As best shown in FIG. 24, in certain arrangements, groove 64 may comprise a first side wall 64a, an opposite second side wall 64b, and a bottom wall 64c.

In use, when tissue 32 covers and occludes fluid outlet opening 55 from slit 64 for a portion of its longitudinal extension, thereby inhibiting fluid 24 from exiting therefrom, fluid 24 from slit 64 still it may be expelled from electrosurgical device 5c after flowing longitudinally in channel 64 to a remote location where channel 64 is unoccluded and uninhibited for fluid flow to exit therefrom.

However, in certain cases, it may be possible for the slit 64 to be occluded by tissue 32 entirely along its longitudinal extent, completely inhibiting fluid flow from exiting the opening 55. In order to To overcome this problem, at least a part of the electrode 25 may comprise a material permeable to the passage of fluid 24, therethrough, such as a porous material described above.

As shown in Figure 25, in another arrangement of the electrosurgical device of the present disclosure as shown by reference character 5d of Figure 25, the walls 64a, 64b of the groove 64, the surface 48 of the spike portion 46, and / or the surfaces of neck portion 56 of electrode 25 may be porous and connected by a plurality of tortuous paths 59 in the porous material. Consequently, instead of flowing out of slit 64 from a direct fluid outlet opening 55, which can be occluded by tissue 32, fluid 24 can indirectly exit slit 64 by first flowing through tortuous pathways 59 of electrode 25 from side walls 64a, 64b of slit 64 and then exiting electrode 25 from surface 58, which may be without tissue occlusion 32. Alternatively, if adjacent surface 58 of electrode 25 is also occluded by tissue 32, fluid 24 may continue to flow through tortuous paths 59 of electrode 25 and exit electrode 25 from surface 64a, 64b of a slit. 64 or a surface such as 40, 42, 47 or 58 that may be without tissue occlusion 32.

When the electrode 25 comprises a porous material, the groove 64 can be supplemented or replaced by the plurality of interconnected tortuous passageways 59 formed in the porous material, as shown in Figure 25, with porous surfaces, such as 40, 42, 47 or 58 to more evenly distribute fluid flow and supply conductive fluid 24 to the tissue treatment site. All or part of the electrodes may be porous according to the disclosure.

In other arrangements of the disclosure, slot 64 may comprise cross-sectional shapes other than rectangular shapes. For example, as shown in Figures 26-28 the slit 64 comprises a semicircular shape, a V shape, or a U shape, respectively, or any combination thereof.

Returning to Figure 21, in order to facilitate direct fluid communication of the groove 64 with the internal passage 23 of the stem 17, the grooves preferably 64 of the device 5c start within the limits of the stem 17. In other words, within cavity 50 of stem 17 proximal to distal end 53. Preferably, the configuration of the grooves 64 in terms of geometry (eg, width, depth) and / or the material and / or surface treatment of the electrode 25 can be arranged such that the surface tension will act to retain fluid. collected in slit 64 where the force of gravity acts to remove fluid from slit 64. However, while it is desirable for a certain predetermined amount of surface tension to act to retain fluid collected in slit 64 in the presence of gravity, the surface tension must be balanced against inhibition of fluid flow from slit 64.

As indicated above, the use of device 5c, and in particular grooves 64, for fluid distribution 24 is generally preferred over fluid outlet ports 93, 94 of device 5b in particularly deep tissue cracks 97 in the that tissue 32 can occlude fluid flow from fluid outlet ports 93, 94 located in cylindrical portion 39 of electrode 25. Furthermore, since ports 93, 94 are not present with a plunger mechanism, such as that provided for fluid outlet ports 26 and 85, ports such as 93, 94 that can be occluded simply by normal contact with the tissue / electrode will sooner or later become irreversibly stuck.

As shown in Figure 21, with device 5c the fluid outlet openings 73 are provided by the electrode structure 25 (i.e., grooves 64) at the distal end 53 of stem 17 which is protected

ES 2 355 872 T3 protected from contact and occlusion of the surface 22 of the tissue 32. The fluid outlet openings 73 of the device 5c are protected from the occlusion of the surface 22 of the tissue 32 since the structure of the device 5c defining openings 73 is at least partially configured not to contact surface 22 of tissue 32. More specifically, here the structure of the device defining the openings 73 is fully configured so as not to contact the surface 22 of the tissue 32. In other words, the openings 73 are arranged in the device 5c at a location removed from the surface 22 tissue. Furthermore, as shown, the openings 73 are particularly sheltered from occlusion of the surface 22 of the tissue 32 by a portion of the stem 17. Also as shown, when apertures 73 are formed substantially perpendicular to surface 22 of tissue 32 and thereby move away from direct contact with surface 22 of tissue 32.

Another tip portion of an exemplary electrosurgical device 5e of the present disclosure that can be used in conjunction with the system of the present disclosure is shown by reference character 45 in Figures 2932. As best shown in Figures 31 and 32, the enlarging portion 54 has been removed and the cylindrical portion 39 has an equal cross-sectional dimension, here diameter, as the neck portion 56. In contrast, for the device 5c, the cylindrical part 39 has a cross-sectional dimension, also diameter, greater than the cross-sectional dimension, also diameter, of the neck part 56.

Also as shown in Figures 31 and 32, the cylindrical part 39 further comprises a rectilinear (straight) cylindrical part 39a having a rectilinear cylindrical surface part 40a and a curvilinear cylindrical part 39b having a curvilinear cylindrical surface part 40b. As shown, the device is in the shape of a hockey stick. The cylindrical part 39 for the device 5c can be arranged similarly.

Another tip portion of an exemplary electrosurgical device 5f of the present disclosure that can be used in conjunction with the system of the present disclosure is shown by reference character 45 in Figures 33-36. As best shown in Figures 35 and 36, the cylindrical portion 39 has a cross-sectional dimension, here diameter, less than the cross-sectional dimension, here also diameter, of the neck portion 56. As shown, neck portion 56 is proximal and adjacent a tapering portion 49 with a corresponding tapering surface portion 51, here both tapered.

Also as shown in Fig. 34, the cylindrical part 39 further comprises a rectilinear cylindrical part 39a having a rectilinear cylindrical surface part 40a and a curvilinear cylindrical part 39b having a curvilinear cylindrical surface part 40b. Furthermore, as shown, the cylindrical part 39, and more specifically at least one of the rectilinear cylindrical part 39a and the curvilinear cylindrical part 39b, comprises a part of a hook. Preferably, as shown both the rectilinear cylindrical part 39a and the curvilinear cylindrical part comprise hook parts. As shown in Figures 35 and 36, the hook further comprises an L-shaped hook.

Another tip portion of an exemplary electrosurgical device 5g of the present disclosure that can be used in conjunction with the system of the present disclosure is shown by reference character 45 in Figures 37-38. As shown, for the device 5g the cylindrical part 39, and more specifically both the rectilinear cylindrical part 39a and the curvilinear cylindrical part comprise hook parts. Also as shown in Figures 37 and 38, the hook further comprises a J-shaped hook.

Another tip portion of an exemplary 5h electrosurgical device of the present disclosure that can be used in conjunction with the system of the present disclosure is shown at 45 in Figures 3942. As shown in Figures 39 and 40, the electrode 25 preferably comprises a finger portion 65 (preferably comprising a cylindrical portion 39 and a cylindrical surface portion 40) having a distal end (preferably comprising a spherical portion 43 and a spherical surface part 42) which, among other things, is configured for blunt dissection or electrosurgical tissue dissection 32. Electrosurgical dissection occurs when stress or force is applied to tissues while RF energy is also applied. Radio frequency energy heats the tissues, thereby weakening them, and the tissue yields or breaks when desired. Surgeons may refer to this type of dissection with a hook-type electrode as "hook and cook." Furthermore, the finger portion 65 is preferably also configured to function as a hook, in particular the anterior (i.e. front) surface portion 66 of the finger portion 65, which is configured, among other things, to engage and limit the tissues 32.

As shown, the finger portion 65 is rectilinear and forms an L-hook at an angle of approximately 90 degrees relative to the longitudinal axis 31 of the tip portion 45, particularly the shank 45. However, the finger portion may be formed at angles other than 90 degrees. For example, finger portion 65 may be formed at any angle in the range of between and including about 60 degrees from tip portion 45 to about 180 degrees from tip portion 45, or any other range of angles. or particular angles included therein (eg, 75 °, 105 °, 120 °, 135 °, 180 °, 90 ° -135 °, 90 ° -180 °).

Among other things, the electrode 25 preferably comprises a knuckle portion 61 which comprises a rounded protrusion having a raised protrusion on the rear (rear) surface portion 62 of the electrode 25. Also as shown, the knuckle portion 61 also comprises a rounded protrusion having a raised protrusion on the lateral surface portion 75 of the electrode 25. Among other things, the posterior knuckle surface 62 and

The knuckle lateral surface portion 75 formed by the knuckle portion 61 is configured for coagulation and stasis (eg, hemostasis, aerostasis) of tissue 32.

The key to the 5g device is the cross-sectional dimension of the knuckle Z with the cross-sectional dimension of the finger F. When comparing the functions of blunt or electrosurgical dissection and coagulation / hemostasis, the coagulation / hemostasis portion of the electrode 25 preferably it comprises a larger surface area than the blunt or electrosurgical dissecting portion of the electrode 25.

As shown in Fig. 36, preferably the cross-sectional dimension Z of the knuckle portion 61 is greater than the cross-sectional dimension F of the finger portion 65. Here, as shown, the Z and F dimensions in cross section comprise the diameters. However, in other arrangements where the Z and / or F dimension in cross section cannot be correctly considered as comprising a diameter, the dimension Z and / or F in cross section could comprise a width or thickness.

Preferably, the cross-sectional dimension Z of the knuckle portion 61 is in the range of between and including about 1.6 to 3.3 times greater than the cross-sectional dimension F of the finger portion 65, with typical dimensions being they comprise the ratios of 2.5 mm to 1.5 mm (1.6 times) and 2.5 mm to 0.75 mm (3.3 times). Even more preferably, the cross-sectional dimension Z of the knuckle portion 61 is in the range of between and including about 2 to 2.5 times greater than the cross-sectional dimension F of the finger portion 65, with typical dimensions being they comprise the ratios of 2.5 mm to 1.25 mm (2 times) and 2.5 mm to 1 mm (2.5 times).

From the above dimensions, the ratio of the surface of the knuckle portion 61 to the surface of the distal end (e.g., surface 42) of the finger portion 65 can be approximated using a formula for half the surface of a sphere. By the above dimensions, preferably the surface of the knuckle portion 61 is in the range of between and including about 2.8 times to 11 times larger than the surface of the distal end of the finger portion 65. More preferably the surface of the knuckle portion 61 is in the range between and including about 4 times to 6.2 times larger than the surface of the distal end of finger portion 65.

Also as shown in Figures 39 and 40, the neck portion 56 preferably comprises a cylindrical portion 57 positioned proximal and adjacent to a spatula portion 67. As shown, the spatula portion 67 comprises a substantially flat anterior surface portion 69 of electrode 25. In certain arrangements, electrode 25 may comprise one, any combination, or all of the features of finger portion 65, knuckle portion 61, and spatula portion 67.

Regarding the use of the devices, similar to device 5b, device 5c is particularly useful for a surgeon performing liver resection. After the outer capsule of the liver is marked with a dry Bovie sheet along the planned line of resection, the distal tip of the tip portion 45 is painted back and forth along the line, with a power radio frequency signals and fluid flow 24 activated, resulting in coagulation of the liver parenchyma. Once tissue coagulates under and around electrode surface 42 and, as device 5c enters a crack 97, surface 40, surface 42 of electrode 25 is used for blunt dissection of the clotted parenchyma. Blunt dissection of the coagulated parenchyma is performed by continuous abrasion or division of the parenchyma with substantially the same forward and backward movement as in coagulation and with the device 5c clamped in substantially the same orientation as for coagulation of the liver parenchyma. However, with blunt dissection, the surgeon typically applies more force to the tissue. In various arrangements, once the liver parenchyma coagulates, blunt dissection can be performed with or without radio frequency power (ie, on or off) and / or with or without the presence of fluid 24.

In addition to liver resections, the 5h device is particularly useful for a surgeon performing a laparoscopic cholecystectomy (abbreviated "col. Lap.") For, for example, either acute cholecystitis or an intrahepatic gallbladder in which The device provides multi-functional applications. More particularly, the device is useful to the surgeon for coagulation and dissection of a layer of inflamed serous tissue 32 between the liver and the gallbladder, which may include tough, highly vascular, connecting fibrous tissue between the organs.

For coagulation, the 5h device can be positioned in at least three different orientations. For the first orientation, as shown in Fig. 43, coagulation can be performed with the posterior surface of knuckle 62 formed by knuckle portion 61. Like device 5c, coagulation with device 5h is performed with radio frequency power and fluid flow 24 activated. Preferably, the power is applied in the coagulation mode of the generator and with a power level in the range between and including about 10 watts to 60 watts. More preferably, the power level is in the range between and including about 20 watts to 50 watts. Even more preferably, the power level is in the range between and including about 30 watts to 40 watts. With respect to movement of surface portion 62 during coagulation, coagulation can be performed with surface portion 62 stationary, or with a paint movement by moving surface portion 62 back and forth substantially along the longitudinal axis. 29 or laterally from one side to the other.

ES 2 355 872 T3

For the second orientation, as shown in Figure 44, coagulation can be performed with a combination of the knuckle surface side portion 75 formed by the knuckle portion 61 and the cylindrical surface portion 40, and more specifically a surface side portion. cylindrical of the cylindrical surface part, of the finger part 65. For the third orientation, as shown in Figure 45, coagulation can also be performed with another combination of knuckle portion 61 and finger portion 65. As shown in Figure 45, coagulation can be performed with a a rear cylindrical surface portion of the cylindrical surface portion 40 and a rear surface of the knuckle portion 61. In the various orientations, coagulation can be used to stop active bleeding (for example, such as a spleen injury involving a splenic capsule tear) or pre-clotting of tissue prior to dissection with bloodless surgery. .

When the surgeon has previously coagulated tissue 32, the surgeon can dissect tissue 32 with simultaneous mechanical traction (i.e., the process of pulling or stretching tissue 32 with a mechanical device) with the anterior surface (i.e., frontal) 66 of finger portion 65 which is configured, among other things, to engage and retain tissue 32. More specifically, the surgeon can engage tissue 32 for dissection against surface portion 66 of finger portion 65 and apply traction to tissue 32, then dissect tissue 32.

Since tissue 32 has coagulated, blunt dissection can be performed with or without radio frequency power (ie, on or off) and / or with or without the presence of fluid 24. When tissue 32 is dissected without fluid 24 , but with the RF power turned on and with the generator set for coagulation mode, the dissection process may be referred to in the art as "hook and cook." While dissection in this manner is rapid, it suffers from the problems of significant arcing, the production of smoke and charring, and the possibility of inadvertent perforation of the gallbladder wall. Alternatively, dissection without activated RF power can eliminate arcing problems, smoke and charring, and the possibility of inadvertent perforation, but can lead to hemorrhage if tissue 32 is insufficiently clotted. . In order to overcome the aforementioned problems, dissection of tissue 32 with traction can be performed similarly to coagulation (ie, in the presence of radio frequency power and fluid 24). However, this alternative usually takes more time than "hook and cook".

Regarding the sequence of events to dissect tissue 32 with traction and with the use of the "hook and cook" technique (ie, no fluid 24), the surgeon first engages tissue 32 at the surface portion 66 of the finger portion 65. The surgeon then applies traction to the attached tissue 32. Once complete, the surgeon checks for correct position and then applies radio frequency energy. With the application of radio frequency power, tissue 32 yields, separates and ruptures. Then the surgeon turns off the radio frequency power. This process can then be repeated several times as the surgeon progressively dissects the tissue 32 along a length in a gradual manner.

Certain embodiments of the invention can be specially configured for bipolar devices. For example, an exemplary electrosurgical device of the present disclosure that can be used in conjunction with the system of the present disclosure is shown referenced character 5i in Figures 46-48. With a bipolar device, the ground plate electrode located on the patient is removed and replaced with a second electrical pole as part of the device. An alternating current electrical circuit is then created between the first and second electrical poles of the device. Consequently, the alternating current no longer flows through the patient's body to the ground plate electrode, but through a localized part of the tissue preferably between the poles of the bipolar device.

In certain embodiments, an exemplary bipolar surgical device of the present invention may comprise, among other things, multiple, substantially parallel arms. As shown in Figure 46, the electrosurgical device 5i preferably includes two rigid arms comprising rigid hollow stems 17a, 17b, a proximal handle comprising paired handle portions 20a, 20b, and arm tip portions as shown. in circles 45a, 45b. In this embodiment, the stems 17a, 17b preferably comprise thick-walled hypodermic tube. In this way, the trunks 17a, 17b have sufficient rigidity to maintain their shape during use of the device without bending or significant curvature.

Preferably, the arms of the device 5i (comprising the trunks 17a, 17b) are retained in the relative position to each other by a mechanical coupling device comprising a collar 95 and relative separation and / or rotation with respect to each other is prevented. Collar 95 preferably comprises a polymer (eg, acrylonitrilobutadiene-styrene or polycarbonate) and is preferably located at the distal portion of the arms. More preferably, collar 95 is proximal to distal ends 53a, 53b of stems 17a, 17b. Preferably, the collar 95 comprises two openings 96a, 96b, which preferably comprise opposing C-shapes, configured to receive a portion of the trunks 17a, 17b, which preferably snap fit therein. Once the collar 95 is connected to the trunks 17a, 17b, preferably via a snap fit connection, the collar 95 can be configured to slide along the trunks 17a, 17b to adjust or vary the location of the collar 95 on logs 17a, 17b. Alternatively, the location of collar 95 can be fixed relative to logs 17a, 17b by welding, for example.

Device 5i comprises a first arm tip part 45a and a second arm tip part 45b. As shown, preferably both the first arm tip portion 45a and the second arm tip portion 45b are individually configured identical to the tip portion 45 of the device 5a. As a result, the device

ES 2 355 872 T3

5i has two independent contact elements, spatially separated (by void space) that preferably comprise electrodes 25a, 25b.

As shown in Figure 47, when device 5i is in use electrodes 25a, 25b are laterally spaced adjacent to tissue surface 22 32. Electrodes 25a, 25b are connected to a source of alternating electrical current and a alternating current electric field between electrodes 25a and 25b. In the presence of alternating current, the alternating polarity of the electrodes between positive and negative charges changes with the flow of current from positive to negative charge.

Like the device 5a, for the device 5i the fluid 24 communicates from a source 1 of fluid inside the internal passage 23a, 23b of the trunks 17a, 17b, through the internal passages 89a, 89b and the cavities 81a, 81b of the sheaths 81a, 82b, where it is ejected from around and onto the surface 42a, 42b of the electrodes 25a, 25b.

As with the use of the device 5a, with the use of the device 5i between the surface 22 of the tissue 32 and the electrodes 25a, 25b fluid couplings 30a, 30b are provided that preferably comprise discrete, localized bands and more preferably that comprise a triangular shaped band or cord portion providing a fluid film 24. When the user of the electrosurgical device 5i places the electrodes 25a, 25b at a tissue treatment site and moves the electrodes 25a, 25b across the surface 22 of the tissue 32, fluid 24 is expelled around and on the surfaces 42a, 42b of the electrodes 25a, 25b at distal ends 83a, 83b of sheaths 82a, 82b and on surface 22 of tissue 32 through couplings 30a, 30b. At the same time, RF electrical energy, displayed by electric field lines 130, is provided to tissues 32 on tissue surface 22 and below tissue surface 22 on tissue 32 through fluid couplings. 25a, 25b.

As with device 5z, fluid 24, in addition to providing an electrical coupling between electrosurgical device 5i and tissue 32, lubricates surface 22 of tissue 32 and facilitates movement of electrodes 25a, 25b across surface 22 of tissue 32 . During the movement of the electrodes 25a, 25b, the electrodes 25a, 25b normally slide across the surface 22 of the tissue 32, but can also rotate when the electrodes 25a, 25b move across the surface 22 of the tissue 32. Typically, the user of the electrosurgical device 5i slides the electrodes 25a, 25b across the surface 22 of the tissue 32 back and forth in a painting-like motion while using the fluid 24 as, among other things, a lubricating coating. Preferably, the thickness of the fluid 24 between the distal end surface of the electrodes 25a, 25b and the surface 22 of the tissue 32 at the outer edge of the couplings 30a, 30b is in the range of between and including about 0.05mm to 1mm. , 5 mm. More preferably, fluid 24 between the distal end surface of electrodes 25a, 25b and surface 22 of tissue 32 at the outer edge of couplings 30a, 30b is in the range of between and including about 0.1 mm to 0, 3 mm. Also preferably, in certain embodiments, the distal end tip of electrode 25 contacts surface 22 of tissue 32 without any fluid 24 in between.

As shown in Figure 48, the fluid coupling for device 5i may comprise a bridge 27 of conductive fluid between electrodes 25a, 25b, which rests on surface 22 of tissue 32 and forms a shunt between electrodes 25a, 25b. In this scenario, a certain amount of RF energy can be deflected and not enter the tissue 32 and actually pass between the electrodes 25a, 25b through the conductive fluid bridge 27. This loss of RF energy can slow down the process of tissue coagulation and production of the desired tissue hemostasis or aerostasis.

In order to counteract the energy loss through the bridge 27, once enough energy has entered the bridge 27 to boil the liquid 24 from the bridge 27, the RF energy loss decreases accordingly with the loss of the bridge. 27. Preferably, fluid 24 in bridge 27 is provided with energy by dissipating heat from tissue 32.

In this way, where a% boiling of the conductive fluid 24 of the bridge 27 is created, the loss of radio frequency energy through the bridge 27 can be reduced or eliminated, because all of the fluid 24 of the bridge 27 evaporates or a large part Boiling creates enough interruption in the continuity of bridge 27 to interrupt the electrical circuit through bridge 27. Therefore, a control strategy of the present invention is to reduce the presence of a conductive fluid bypass by increasing the% boiling of the conductive fluid.

Another arrangement of a bipolar device is shown at 5j in Figures 49 and 50. Similar to device 5i, electrosurgical device 5j preferably includes two rigid arms comprising rigid self-supporting stems 17a, 17b, a proximal handle comprising portions paired handle 20a, 20b and first and second arm tip portions as shown in circles 45a, 45b. However, as shown in figure 50, unlike device 5j, for device 5j the trunks 17a, 17b can comprise solid rods (that is, they do not have internal passages) that allow electrical connection to a power source. , but they do not have internal passages to supply the conductive fluid through the sheaths 82a, 82b. Instead conductive fluid 24 is preferably provided by way of an internal passage 122 of a separate fluid line 120, which preferably comprises either a metallic material (eg, stainless steel hypodermic tubes) or polymer (eg, stainless steel tubes). PVC), which extends distally and substantially parallel to the arms along the lateral trunks 17a, 17b. In order to minimize the risk of jamming the lumen 122 in the distal end exit opening 124 of the fluid line 120, as shown, preferably the distal end

ES 2 355 872 T3

126 of fluid line 120 is proximal and adjacent to the distal end of device 5j and more preferably proximal to spherical surface portions 42a, 42b of electrodes 25a, 25b, or other surfaces of tissue treatment electrodes as electrode configurations vary.

Also as shown for device 5j, outlet opening 124 for fluid line 120 is preferably evenly spaced between electrodes 25a, 25b such that conductive fluid 24 expelled from outlet opening 124 can form a fluid coupling comprising bridge 27 between tissue surface 22 and surface 42a, 42b of each of electrodes 25a, 25b. If a collar 95 is used with device 5j preferably the collar contains a third C-shaped opening to accommodate fluid line 120 therethrough.

In certain arrangements, at least a portion of the length of the two arms (comprising trunks 17a, 17b and sheaths 82a, 82b) or the two arms and fluid line 120 of device 5j can be positioned and housed within the cavity 132, typically an interior passageway, of an elongated hollow tubular enclosure 128 as shown in Figure 49. The elongated tubular enclosure 128 may or may not be connected to the handle portions 20a, 20b. When the tubular enclosure is not connected to the handle portions 20a, 20b, similar to the collar 95, the tubular enclosure 128 can be configured to slide along the logs 17a, 17b to adjust or vary the location of enclosure 128 on the logs. 17a, 17b, or alternatively, it may be fixed in relation to the logs 17a, 17b by welding, for example.

The elongated tubular enclosure 128 may comprise, for example, a wrap, such as a shrink wrap polymer film or shrink wrap polymer tubing, that can be formed and positioned on the surface of the cavity 132 against the insulations 90a, 90b with the application of heat to them. In this way, the elongated member trunks 17a, 17b or the trunks 17a, 17b and the fluid pipe 120 are kept in the position relative to each other and are prevented from being separated from each other.

Another arrangement of a bipolar device is shown at 5k in Figures 51-53. As shown in Figures 51 and 53, the electrosurgical device 5k preferably includes a housing comprising paired handle portions 20a, 20b and paired elongated handle portions 134a, 134b forming a hollow shaft. As best shown in Figure 51, stem portions 134a, 134b preferably comprise two elongated semi-circular portions which respectively connect to handle portions 20a, 20b, preferably as part of a unitary polymer molding (i.e. only one piece).

As best shown in FIG. 53, electrodes 25a, 25b are preferably directly assembled with stem portions 134a, 134b, adjacent to the distal end of stem portions 134a, 134b. As shown, preferably the electrodes 25a, 25b are mechanically assembled adjacent the distal end of the stem portions 134a, 134b via a spool configuration. More specifically, electrodes 25a, 25b preferably comprise interlocking portions comprising proximal circular rim portions 136a, 136b and distal circular rim portions 138a, 138b spaced apart and connected by circular stems 140a, 140b therebetween forming the respective configurations. reel.

The circular grooves 142a, 142b formed between the circular proximal flange portions 136a, 136b and the circular distal flange portions 138a, 138b provide a receptacle for receiving the interlocking semi-circular tab portions 144a, 144b of the distal end portions 146a, 146b of the trunk parts 134a, 134b.

During assembly, the interlocking tongue portions of one of the stem portions are first located in a portion of the grooves 142a, 142b of the electrodes 25a, 25b. In other words, for example, the electrodes 25a, 25b may first be assembled with the interlocking semicircular tab portions 144a of the distal end portion 146a of the stem portion 134a which then occupies a first semicircular portion of the circular grooves 142a, 142b . Then, once the electrodes 25a, 25b have been correctly seated with respect to the first part, here 134a, of the trunk, the interlocking tongue parts of the second part, here 144b, of the trunk of the trunk 134b, are located in the remaining semicircular portion of circular grooves 142a, 142b. After the electrodes 25a, 25b have been properly seated with respect to both stem parts 134a, 134b and all remaining components are positioned correctly, the stem parts 134a, 134b and the handle parts 20a, 20b can be assembled between yes using, for example, an adhesive (eg cyanoacrylate) or solder.

As best shown in Figure 53, the electrodes 25a, 25b of device 5k preferably comprise spherical portions 43a, 43b and corresponding spherical surface portions 42a, 42b located at the distal end of the device that provide a smooth, contoured outer surface. blunt. More specifically, as shown, spherical portions 43a, 43b and spherical surface portion 42a, 42b further provide a domed hemisphere, (ie, less than a full sphere) and the hemispherical surface portion preferably comprises about 180 degrees. Also as shown in figure 53, the electrodes 25a, 25b preferably also comprise cylindrical parts 39a, 39b and corresponding cylindrical surface parts 40a, 40b located proximal and adjacent to the spherical parts 43a, 43b and the spherical parts 42a, 42b , respectively.

Electrodes 25a, 25b of device 5k are preferably coupled to generator 6 by cable conductors 38a, 38b of insulated cables 21a, 21b. At their distal ends, leads 38a, 38b can be coupled

ES 2 355 872 T3 to the electrodes 25a, 25b being first inserted into the internal passages 148a, 148b of the hollow metal tubes 150a, 150b, such as hypodermic tubes, then pressing the tubes 150a, 150b. Tubes 150a, 150b are then preferably inserted and retained in proximal end sockets 152a, 152b of electrodes 25a, 25b by a tight fit. Alternatively, tubes 150a, 150b can be removed and wire leads 38a, 38b attached to electrodes 25a, 25b by welding, brazing, mechanical fasteners, or other suitable methods.

For device 5k the conductive fluid 24 is preferably provided via an interior passageway 122 of a separate fluid line 120, which preferably comprises either a metallic material (eg, stainless steel hypodermic tube) or polymer (eg, tubing). PVC), extending distally and in parallel substantially within the interior passageway of the stem comprising the stem portions 134a, 134b.

Similarly to device 5j, in order to minimize the risk of jamming of the lumen 122 in the outlet end distal opening 124 of the fluid line 120, as shown, preferably the distal end 126 of the fluid line 120 is proximal to the distal end of the device 5k and more preferably proximal to the spherical surface portions 42a, 42b and the cylindrical surface portions 40a, 40b of the electrodes 25a, 25b, or other surfaces of tissue treatment electrodes as electrode configurations vary.

Also similar to device 5j, for device 5k the outlet opening 124 for fluid line 120 is preferably evenly spaced between electrodes 25a, 25b such that conductive fluid 24 is expelled from outlet opening 124 can form a fluid coupling comprising bridge 27 between tissue surface 22 and surface 42a, 42b of each of electrodes 25a, 25b.

The effect of the bipolar devices of the present invention on tissue can be varied by changing the separation distance between the contact elements. Consequently, as shown in Figure 54, in contrast to certain arrangements where the separation distance cannot be adjusted, the bipolar device 51 provides an adjustment mechanism to change the separation distance (either increasing or decreasing). between electrodes 25a, 25b. As shown in figure 54, the change of the separation distance between the electrodes 25a, 25b is provided by a scissor-type adjustment mechanism with two arms 117a, 117b hinged relative to each other in the middle of a pivot 110 preferably comprising a pin. The device 51 may also comprise a latching mechanism 111 that progressively fixes the position of the electrodes 25a, 25b relative to each other during tissue treatment, by increasing or decreasing the separation distance.

Furthermore, as shown, the arms 117a, 117b are themselves preferably articulated at the pivots 110a and 110b, which preferably also comprise pins, which divide the arms 117a, 117b into proximal arm parts 118a, 118b and distal parts 112a, Arm 112b. The distal arm portions 112a, 112b are preferably connected by a link 113, which maintains the distal arm portions 112a, 112b and the electrodes 25a, 25b substantially parallel to each other during use of the device 51. As shown, the link 113 it comprises a rod 114 attached to the distal arm portion 112b and having an elongated opening 116 therein. The link also comprises a pin 115 attached to the distal arm portion 112a that moves along and within the aperture 116 during use of the device 51 with the change of the gap distance between the electrodes 25a, 25b. For device 51, tip portions 45a, 45b, particularly may comprise the configuration disclosed with device 5i.

Another arrangement of a bipolar device is shown at 5m in Figures 55-58. As best shown in Figures 55 and 56 and similarly to device 5i, electrosurgical device 5m preferably includes two stationary immobile arms comprising self-supporting rigid hollow trunks 17a, 17b. The trunks 17a, 17b of the device 5m preferably comprise thick-walled hypodermic tubes that provide sufficient rigidity to maintain their shape during use of the device without significant kinks or bends. In certain arrangements, the logs 17a, 17b can be malleable by hand.

As shown in Figures 55-58 and similarly to device 5i, preferably the arms of device 5m (comprising trunks 17a, 17b) are held in position relative to each other by a mechanical coupling device comprising a collar 95 and are prevented from separating from each other. Also as shown in Figures 55-58, collar 95 is preferably located at a distal portion of the arms. More preferably, collar 95 is located adjacent to distal ends 53a, 53b of stems 17a, 17b. As best shown in Figures 57 and 58, preferably the collar 95 comprises two openings 96a, 96b, shown to comprise a C-shape, configured to receive a distal end portion of the arms of the logs. Once collar 95 is mechanically connected to logs 17a, 17b, preferably with a snap-fit ​​or slip-through connection, the location of collar 95 can be further set relative to logs 17a, 17b, for example, gluing collar 95 to trunk insulators 90a, 90b. This adhesive bonding can be achieved, for example, either with the use of a separate adhesive or by autogenously bonding the collar 95 to the insulators 90a, 90b, for example, by welding such as ultrasonic welding.

Collar 95 comprises an electrically insulating (dielectric) material. In some arrangements the electrically insulating material for collar 95 may comprise polymer, either thermoplastic or thermoset, reinforced or unreinforced, with or without filling. Examples of polymer materials include, but are not limited to, polyacetal.

ES 2 355 872 T3 (POM), polyamide (PA), polyamideimide (PAI), polyetheretherketone (PEEK), polyetherimide (PEI), polyethersulfone (PES), polyimide (PI), polyphenylenesulfide (PPS), polyphthalamide (PPA), polysulfone (PSO), polytetrafluoroethylene (PTFE) and syndiotactic polystyrene (SPS). Preferably, the electrically insulating polymer comprises any liquid crystal polymer and, more particularly, an aromatic liquid crystal polyester that is reinforced with fiberglass, such as Vectra® A130 from Ticona, or 10% Ultem® glass filled polyetherimide from General Electric Company. Examples of reinforcing materials for polymers include, but are not limited to, glass fibers and boron fibers. Examples of fillers for polymers are mica, calcium carbonate, and boron nitride. Reinforcing materials for the polymer material may be preferred for greater strength while filler materials may be preferred for greater heat resistance and / or thermal conductivity. Even other electrically insulating materials for collar 95 can be a ceramic such as boron nitride.

As explained above with reference to device 5i and FIG. 48, the tissue fluid coupling for device 5i may comprise a bridge 27 of conductive fluid between electrodes 25a, 25b, which rests on surface 22 of tissue 32 and forms a shunt between the electrodes 25a, 25b. As explained above, a certain amount of RF energy can be deflected so as not to enter tissue 32 and actually pass between electrodes 25a, 25b through conductive fluid bridge 27 . This loss of RF energy can slow down the process of tissue coagulation and production of the desired tissue hemostasis or aerostasis. Also as previously explained, the loss of RF energy through bridge 27 may be reduced or eliminated because all of the fluid 24 from bridge 27 evaporates or a large portion of the boil creates enough interruption in the continuity of bridge 27 to interrupt the electrical circuit through bridge 27. Thus, as indicated above a control strategy of the present disclosure is to reduce the presence of a conductive fluid bypass, by increasing the% boiling of the conductive fluid.

Rather than increasing the% boiling of the conductive fluid bridge 27 to reduce the presence of a fluid shunt between the electrodes 25a, 25b, in certain applications it may be advantageous to provide the electrosurgical device with a dam between the electrodes 25a, 25b, which reduce and preferably prevent the formation of the conductive fluid bridge 27 between the electrodes 25a, 25b.

As best shown in Figures 57 and 58, the collar 95 of the device 5m preferably further includes a substantially flat sheet-shaped electrically insulating spacer portion 154, located laterally between the electrodes 25a, 25b. In addition to keeping the electrodes 25a, 25b separated by a predetermined minimum separation distance (as dictated by the thickness of the separating part 154), the separating part 154 also provides a dam between the electrodes 25a, 25b, which reduces and preferably prevents the formation of the bridge 27 of conductive fluid between the electrodes 25a, 25b.

Furthermore, as best shown in Figures 57 and 58, the distal end surface 156 of the spacer portion 154 preferably follows the contour of the adjacent distal end surfaces 158a, 158b of the electrodes 25a, 25b such that the distal end surface 156 of spacer portion 154 is substantially flush, and preferably completely flush, with adjacent distal end surfaces 158a, 158b of electrodes 25a, 25b. In this manner, spacer portion 156 and electrodes 25a, 25b are better configured to slide across the tissue surface since there are no raised or recessed ridges created between distal end surface 156 of spacer portion 154 and adjacent distal end surfaces. 158a, 158b of the electrodes 25a, 25b, which could hinder the sliding movement.

Similarly to the device 5c, the electrodes 25a, 25b of the device 5m are preferably assembled together with the distal ends 53a, 53b of the stems 17a, 17b by means of connecting parts, which preferably comprise spike parts 46a, 46b, which connect the rest of the electrodes 25a, 25b to the stems 17a, 17b. Among other things, the connecting part of the electrodes 25a, 25b is preferably configured to form a connection with a paired connecting part of the stems 17a, 17b. Also similar to device 5c, preferably spike portions 46a, 46b of device 5m are configured to extend into cavities 50a, 50b, of trunks 17a, 17b, which comprise cylindrical receptacles and provide the paired connector portions for the portions. spike 46a, 46b. Also similar to device 5c, preferably surfaces 48a, 48b of spike portions 46a, 46b of device 5m are configured to mate against and form a tight fit with surfaces 52a, 52b of cavities 50a, 50b to provide the connection.

Similar to device 5c, spike portions 46a, 46b of device 5m are preferably cylindrical and lie proximal and adjacent to neck portions 56a, 56b. As best shown in Figures 57 and 58, neck portions 56a, 56b comprise cylindrical portions 57a, 57b which preferably have a cross-sectional dimension, here the diameter, greater than the cross-sectional dimension, here also the diameter. , of the spike parts 46a, 46b. In this manner, similar to device 5c, in certain arrangements, the proximal end of neck portions 56a, 56b of device 5m can be positioned alongside and in contact with distal ends 53a, 53b, of stems 17a, 17b.

As best shown in Figures 57 and 58, similar to slit 64 of device 5c, electrodes 25a, 25b of device 5m preferably comprise at least one slits 63a, 63b, which provide an elongated fluid flow channel. and an outlet for fluid distribution 24.

ES 2 355 872 T3

Electrodes 25a, 25b of device 5m preferably comprise an enlarged head portion. Each enlarged head portion preferably comprises a hemispherical side portion 160a, 160b with a hemispherical surface that preferably comprises approximately 180 degrees. As best shown in Figures 57 and 58, preferably the hemispherical portions 160a, 160b, are disposed back to each other in opposite relationship facing outward on opposite sides of the device. The hemispherical portions 160a, 160b are preferably located on the sides of the transverse oriented cylindrical mid-transition portions 162a, 162b which preferably provide a smooth transition between the hemispherical portions 160a, 160b and the spacer portion 154 of collar 95. As shown , the electrodes 25a, 25b and the spacer portion 154 may comprise flat bearing surfaces 164a, 164b which are arranged opposite each other. In alternative arrangements, mid-transition portions 162a, 162b of the electrodes 25a, 25b may be eliminated resulting in the head portion of the electrodes 25a, 25b comprising only the hemispherical portions 160a, 160b, with a hemispherical surface comprising preferably about 180 degrees.

In certain arrangements the spacer portion 154 may comprise a thickness in the range of between and including about 0.5mm to 10mm, or in any 0.1mm increment or range in between, or provide a spacing distance between the electrodes 25a. , 25b thereof. For example, the spacer portion 154 comprises a thickness in the range of between and including about 1.5mm and 4mm.

As an alternative to adjusting the spacing distance between the electrodes 25a, 25b by changing the thickness of the spacer part 154, the electrode parts 25a, 25b can be coated with a thin (eg 0.010.5mm) electrically insulating coating comprising , for example, a polymer or ceramic material. As shown in Figures 59-62, a portion of electrodes 25a, 25b for device 5n, here neck portions 56a, 56b, mid-transition portions 162a, 162b, and about half of each hemisphere portion 160a , 160b of the enlarged head portion are shown with an electrically insulating coating 166 thereon. As a result, the active tissue treatment electrode surface is now limited to approximately quarter sphere surfaces 168a, 168b and the spacing distance between the tissue treatment electrode surfaces has increased the thickness of the transition parts. middle 162a, 162b of the electrodes 25a, 25b.

Another arrangement of a bipolar device is shown at 5o in Figures 63-64. Similar to device 5n, the active tissue treatment electrode surface of electrodes 25a, 25b can be limited to approximately quarter-sphere surfaces 168a, 168b (approximately 90 degrees) with the other electrode surfaces extending from the distal end of stem insulators 90a, 90b having electrically insulating coating 166 thereon. However, unlike device 5n, the enlarged head portion of the electrodes, 25a, 25b of device 5o comprises two substantially circular spheres (ie, except where they meet neck portions 56a, 56b). The spheres can be of any suitable diameter. However, the spheres preferably have a diameter in the range between and including about 0.5mm to about 7mm. More preferably the spheres have a diameter in the range between and including about 1.0mm to about 4mm. Even more preferably the spheres have a diameter in the range between and including about 1.5mm to about 3mm. When the coating 166 is not on it, the active electrical surface of the spheres is approximately 260 degrees.

Also different from device 5n, collar 95 of device 5o does not include a spacing portion 154. With device 5o, electrodes 25a, 25b are separated by an air gap in between. As a result, as shown in Figure 64, when the electrodes 25a, 25b of the device 5o are pressed against the surface 22 of the tissue 22 and the tissue 32 against the electrodes 25a, 25b they compress and form the grooves 170a, 170b, the device 5o is configured to allow tissue 32 located next to gap 172 between electrodes 25a, 25b to form a downward sloping tissue bulge 174 at slits 170a, 170b. Since fluid 24 that may exist between electrodes 25a, 25b will tend to flow with gravity down the slopes of tissue bulge 174 and into adjacent grooves 170a, 170b, the possibility of formation of a bridge 27 of conductive fluid between electrodes 25a, 25b. Furthermore, even if a bridge 27 of conductive fluid is formed between the electrodes 25a, 25b (for example, where the electrodes 25a, 25b of the device 5o are not pressed against the tissue 32 significantly enough to form the grooves 170a , 170b) coating 166 on the internal facing surfaces of electrodes 25a, 25b reduces the possibility of such a bridge being directly electrified by electrodes 25a, 25b.

Another arrangement of a bipolar device is shown at 5p in Figures 65-69. As best shown in Figure 66, the electrodes 25a, 25b now comprise hollow metal tubes. More specifically, the distal end portion of the tubes comprises approximately a 90 degree bend (within approximately ± 5 degrees) forming two right-angle elbows and curving the distal end portions toward each other as they extend in the direction. distal. Furthermore, the distal ends of the tubes are arranged facing each other. Consequently, the electrodes 25a, 25b are substantially mirror images of each other.

As shown in Figure 66, collar 95 has been removed to better show that electrodes 25a, 25b preferably comprise circular stainless steel hypodermic tube. When the electrodes 25a, 25b comprise separate pieces of the trunks 17a, 17b, the electrodes 25a, 25b of the device 5p are preferably connected to the trunks 17a, 17b with a tight fit of the internal diameter of the trunks 17a, 17b with the internal diameter. of the electrodes 25a, 25b. However, in order to minimize the number of components and their assembly, preferably a single piece of continuous tube provides both the stem and the electrode. In other words, like

ES 2 355 872 T3 is shown, preferably the electrodes 25a, 25b, are provided by the same piece of pipe used for the logs 17a, 17b.

As best shown in Figures 67-69, preferably the device 5p includes a collar 95, which includes an insulating electrical spacer portion 154 located laterally between the electrodes 25a, 25b. In addition, the spacer portion 154 preferably includes at least one slit 176a, 176b, which provides an elongated fluid flow channel and a fluid passage portion for the distribution of fluid 24 from the openings 178a, 178b. As shown, both the distal end openings 180a, 180b of the tubes and the openings 178a, 178b of the slits, 176b are located in a position substantially inaccessible to direct contact with tissue or are otherwise configured remote from direct contact with the tissue to avoid being occluded by the tissue with the use of the 5p device.

Preferably spacer portion 154 includes projections 182a, 182b, and more specifically projections configured to engage distal end openings 180a, 180br and at least partially occlude openings 180a, 180b. In this way electrodes 25a, 25b are held against movement relative to spacer 154, as well as the remainder of collar 95.

In certain arrangements, in order that heat can be transferred out of the electrodes 25a, 25b by the spacer portion 154, preferably the material for the collar 95 has a thermal conductivity k_tc at 300 ° K (degrees Kelvin) equal to or greater than about 0.01 watts / cm ° K. More preferably, the material for the collar 95 has a thermal conductivity k_tc at 300 ° K (degrees Kelvin) equal to or greater than approximately 0.16 W / cm ° K. Even more preferably, the material for the collar 95 has a thermal conductivity k_tc at 300 ° K (degrees Kelvin) equal to or greater than approximately 0.35 W / cm ° K.

The use of the openings 178a, 178b of the slits 176a, 176b for the distribution of fluid 24 may be preferable to at least one fluid outlet opening 184a, 184b that can be provided on the distal end side of the electrodes 25a, 25b proximal to the distal end (see FIG. 66), particularly in deep tissue cracks where tissue can occlude fluid flow from openings 184a, 184b. However, as shown in Figures 70-71 for device 5q, in which fluid outlet openings 184a, 184b are positioned substantially inaccessible to direct tissue contact or are otherwise configured away from the direct contact with the tissue so as not to be occluded by the tissue (such as the grooves shown in the inner side wall of the electrodes 25a, 25b along the inner radius of the bend of the elbow and the distal end of the electrode), openings 184a, 184b may be equally effective as openings 178a, 178b.

More particularly, as shown, openings 184a, 184b in Figures 70-71, for example, are closer to the inner radius of the bend of the elbow than the other radius of the bend of the elbow, which helps in reducing the occlusion by tissue. However, in other arrangements the fluid outlet openings 184a, 186a may be closer to the outer radius of the elbow bend than the internal radius of the elbow bend, as shown in FIG. 66. In even other arrangements the fluid outlet openings 184a, 186a may be equidistant from the outer radius of the elbow bend and the inner radius of the elbow bend, as shown in FIG. 73.

Another arrangement of a bipolar device is shown at 5r in Figures 72-73. As shown, the distal end of spacer portion 154 includes a slit 186 configured to allow tissue 32 to form a tissue bulge 174 therein to reduce the possibility of bridge 27 of conductive fluid between electrodes 25a, 25b. as explained above.

The device of the present invention may include assemblies that control the power and / or flow of fluid in the tissue treatment portion of the device. The ability to control the flow of fluid from the device can provide certain advantages over a device that does not have it. These advantages include reducing the amount of fluid at the tissue treatment site and the likelihood of having to apply suction at the treatment site to remove the fluid.

For the device 5s of Figures 74-79, a single multi-function, multi-position switch and valve assembly 190 comprises a toggle button 192. The button 192 protrudes through an opening 194 formed in the handle portions 20a, 20b. . Button 192 is preferably integrally connected by molding a single piece of polymer into a proximally extending switch arm 196 that provides a portion of a fluid flow control mechanism, preferably formed by interaction with the handle part 20a to connect (full flow, ie unregulated flow at full flow through the tubes) and disconnecting (no flow) fluid flow 24 to the tissue treatment portion of the device.

More specifically, the fluid flow control mechanism of the valve / switch assembly 190 is provided by changing the gap distance between the proximal end portion of the switch arm 196 and the wall section 200 of the handle portion 20a. , when switch arm 196 moves proximally and distally along track 206 formed and defined by openings 208 of ribs 210 of handle portion 20a, in response to button 192 moving proximally and distally in switch button opening 194.

As shown in FIG. 76, the fluid line 4b is located between the proximal end portion 198 of the switch arm 196 and the wall section 200 of the handle portion 20a. As button 192 and switch arm 196 are moved proximally by hand force, thereby decreasing the distance of the switch.

ES 2 355 872 T3 separation between the proximal end portion 198 of the switch arm 196 and the wall section 200 of the handle portion 20a, the fluid tubing 4b is squeezed and compressed externally therebetween and its internal passage is correspondingly occluded to decrease and preferably completely stopping the flow of fluid. As exhibited by the above fluid flow control mechanism, preferably the mechanism does not contact fluid 24, thus reducing the likelihood of accidental contamination.

Continuing with Figure 76, preferably the fluid flow control mechanism of the valve / switch assembly 190 comprises a mechanism that holds the arm 196 in a fixed locked position while the fluid line 4b is compressed and occluded. As shown, preferably the locking mechanism comprises a locking tab 202 of the handle portion 20a that holds the arm 196 in its rearwardly locked position by engagement of a distal end portion 204 of the switch arm 196.

Locking flange 202 is disengaged from distal end portion 204 of switch arm 196 by depressing button 192. As button 192 is depressed, distal end portion 204 of switch arm is also disengaged from flange 202 and flange 202 disengages from distal end portion 204. As best shown in FIG. 77, at the same time switch arm 196 is forced distally by decompression of elastic fluid tubing 4b such that flange 202 enters notch 212. Preferably the switch arm 196 is also forced distally by the decompression of a linear spring 228 that predisposes the proximal movement of the arm 196 to the switch off position against the fluid line 4b with the compression thereof, and , upon decompression thereof, helps to return switch 192 to its on position with the arm being disengaged from flange 202. As shown, spring 228 is supported on arm 196 by a circular post 234 and is compressed between a flange 238 located at the base of post 234 and one of the ribs 210. With disengagement of the distal end portion 204l of the arm 196 relative to flange 202, button and switch arm 196 can be moved distally until flange 202 engages proximal end 214 of notch 212.

Once the flow of fluid 24 has been resumed, the switch button 192 of the valve / switch assembly can now be depressed to activate the flow of electrical current to the electrodes 25a, 25b. As explained above, the electrodes 25a, 25b are preferably coupled to the generator 6 by conductors 38a, 38b of insulated cables 21a, 21b. Here, for example, the active and return electrodes comprise electrodes 25a, 25b.

As shown in Figures 78-79, electrode 25a is directly coupled to generator 6, without any further inclusion of an on / off switch with an associated control circuit in between. However, in addition to being directly coupled to generator 6, the electrical coupling of electrode 25b to generator 6 now includes the presence of two separate electrical contacts 216 and 218 which, in the open position, create an open control circuit between electrode 25b. and the generator 6. The wiring of this electrical control circuit to the generator 6 is known in the art and will be briefly explained below.

As best shown in Figures 77-79, contacts 216 and 218 are arranged on a platform 222 partially underlying button 192 of switch 192 and arm 196. As best shown in Figure 78, contact 216 comprises a contact domed covering 218 contact. In the open, or depressed position, contact 216 remains separate from underlying contact 218 by virtue of the domed configuration of contact 216, resulting in an open control circuit between electrode 25b and generator 6. However, when the switch button 192 of the valve / switch assembly 190 is in its depressed position, the post 220 in turn presses the domed contact 216 toward contact with the contact 218, thus closing the control circuit between the electrode. 25b and generator 6. The presence of the closed control circuit formed by the cable 21 is then detected by the generator 6 through a low voltage sensor which then provides the set power to the electrodes 25a, 25b.

When a depressing force is removed from switch button 192, contact 216 returns to its pre-depressed domed position as a result of its resilience or elastic memory, thereby returning switch button 192 to its non-depressed position, and by reopening the control circuit between electrode 25b and generator 6. The presence of the open control circuit is then detected by the generator which then stops supplying power to the electrodes 25a, 25b. Alternatively, when the switch button 192 is not used and the physician decides to activate the electrodes 25a, 25b, with a foot switch, the electrical power set at the electrodes 25a, 25b only flows directly through the contact 218 to complete the procedure. electrical circuit.

It should be understood that valve / switch assembly 190 is configured such that electrical current cannot be provided to electrodes 25a, 25b while fluid flow is off. As shown in FIG. 77, when switch button 192 and switch arm 196 are in their proximal position, post 220 does not overlap domed contact 216. Consequently, if the switch button 192 is depressed, the post 220 only makes contact with the platform 222 and the electrical circuit between the electrodes 25a, 25b and the generator 6 remains open.

It should also be understood that in the case of a single primary fluid passageway that may branch into multiple secondary passages, preferably the switch / valve assembly 190 acts on the primary fluid passage to reduce

ES 2 355 872 T3 complexity. As shown in Figures 76-77, preferably valve / switch assembly 190 is proximal of divider 240.

In other arrangements one or more of the devices of the present disclosure may include separate power switch and fluid flow valve assemblies rather than a part of a single multi-position switch / valve assembly. As shown in Figures 80-81, device 5t comprises a switch assembly 224 for turning power on and off for the tissue treatment portion of the device and a valve assembly 226 for turning on fluid flow (full flow). and turn it off (no flow) to the tissue treatment portion of the device.

As best shown in FIG. 81, switch button 230 of switch assembly 224 turns fluid flow on and off in substantially the same way as switch button 192 of valve / switch assembly 190 (i.e., with a distal and proximal movement). However, unlike device 5s, the proximal end portion 198 of switch arm 196 of device 5t includes a roller wheel 236 to assist with compression and decompression of fluid line 4b.

In terms of power, the switch button 232 of the valve assembly 226 turns on and off in substantially the same manner as the switch button 192 of the valve / switch assembly 190 (ie, in depressed and depressed positions). However, unlike valve / switch assembly 190, with valve assembly 226 power can be turned on and off independently of fluid flow. In other words, the valve assembly 226 switch button 232 may be in the "on" power position, while the switch assembly 224 switch button 230 is in the "off" fluid flow position. Thus, device 5t can be configured to function as a dry, fluidless electrosurgical device 24 that is simultaneously delivered from the tissue treatment portion of the device.

In yet another arrangement, as shown in Figures 82-86, the second valve assembly for activating and deactivating fluid flow to the tissue treatment portion of the device may comprise a roller pinch clamp assembly. As best shown in Figures 83-86, device 5u includes a roller pinch gripper assembly 242 and, more specifically, a ramping roller pinch gripper assembly (rather than a parallel drive gripper).

As best shown in Figures 84-85, the caliper includes a housing provided by handles 20a, 20b, a roller wheel 244 having a wheel center axle 246, and a guide pin hub. As shown, the guide pin hub is provided by a pair of opposing, integrally formed cylindrical trunnions 248a, 248b, but may also be provided by a separately formed pin. Trunnions 248a, 248b are within and move along a track 250 preferably provided and defined by channels 252a, 252b of the opposing trunnion formed between upper guide surfaces 254a, 254b of the wheel and lower guide surfaces. 256a, 256b of the wheel extending longitudinally and parallel inwardly from the side wall portions of the handles 20a, 20b. As shown, the upper guide surfaces 254a, 254b of the wheel are provided by a lip portion of the handles 20a, 20b, which in part define the opening 258 through which the roller wheel partially extends, while the surfaces lower guide 256a. 256b of the wheel are provided by ribs 260a, 260b.

Handles 20a, 20b preferably also provide tube guide surfaces 272a, 272b, at least a portion of which provides a clamping surface against which plastic tube 4b is held by roller 244. As shown Best in Figures 84-85, tube guide surfaces 272a, 272b are provided by ribs 270a, 270b. During use, the fluid line 4b is squeezed and compressed externally between the outer perimeter surface 262 of the roller wheel 244 and at least a portion of the tube guide surfaces 272a, 272b. In this arrangement, surface 262 is preferably serrated.

Trunnions 248a, 248b support movement of roller wheel 244 in two opposite directions, here proximally and distally, along track 250. As best shown in Figures 85-86, the distance of The spacing between the outer perimeter surface 262 of the roller wheel 244 and the tube guide surfaces 272a, 272b changes along the proximal and distal travel of the roller wheel 244 along the track 250. More specifically, the separation distance between the outer perimeter surface 262 of the roller wheel 244 and the tube guide surfaces 272a, 272b is greater between the outer perimeter surface 262 of the roller wheel 244 and the distal end portions 274a, 274b of tube guide surfaces 272a, 272b provided by distal end portions 264a, 264b of ribs 270a, 270b, that between the outer perimeter surface 262 of the roller wheel 244 and the proximal end portions 276a, 276b of the tube guide surfaces 272a, 272b provided by the proximal end portions 266a, 266b of the ribs 270a, 270b.

As shown in Figures 84-85, when the axis 246 of the roller wheel 244 opposes the distal end portions 274a, 274b of the tube guide surfaces 272a, 272b, preferably the separation distance is configured such so that tube 4b can be decompressed and the inner passage of tube 4b fully open for full flow through it. On the contrary, as shown in Fig. 86, when the axis 246 of the roller wheel 244 opposes the proximal end portions 276a, 276b of the tube guide surfaces 272a, 272b preferably the separation distance is set to such that the tube 4b is compressed and the interior passage of the tube 4b is completely blocked so that the flow of fluid through the tube 4b is prevented.

ES 2 355 872 T3

The distal end portions 274a, 274b of the tube guide surfaces 272a, 272b are separated from the proximal end portions 276a, 276b of the tube guide surfaces 272a, 272b by the transition surfaces 278a, 278b, which are provided by transition rib portions 268a, 268b of ribs 270a, 270b. Preferably, tubing compression initially begins between transition surfaces 278a, 278b and outer perimeter surface 262 of roller wheel 244 and increases as wheel 244 moves proximally along the proximal end portions. 276a, 276b of the tube guide surfaces 272a, 272b. With this configuration, consideration can be given to eliminating at least the portion of the distal end portions 274a, 274b of the tube guide surfaces 272a, 272b that do not contribute to compression of the tube 4b. However, since distal end portions 274a, 274b of tube guide surfaces 272a, 272b guide tube 4b to divider 240, this may not be desirable.

As shown in Figures 84-86, both the transition surfaces 278a, 278b and the proximal end portions 276a, 276b of the tube guide surfaces 272a, 272b offer proximally sloping sloping surfaces along their lengths. respective that the gap distance between the outer perimeter surface 262 of the roller wheel 244 and the tube guide surfaces 272a, 272b decreases as the wheel 244 moves proximally. As shown, preferably the transition surfaces 278a, 278b and the proximal end portions 276a, 276b of the tube guide surfaces 272a, 272b have different inclinations such that the separation distance decreases at a faster rate along of transition surfaces 278a, 278b, compared to proximal end portions 276a, 276b of tube guide surfaces 272a, 272b. Thus, the compression of the tube 4b is not linear along the extent of the travel of the wheel 244 with a majority of the compression occurring between the roller wheel 244 and the transition surfaces 278a, 278b. Preferably, the inner passage of tube 4b is fully blocked when roller wheel 244 is compressing tube 4b against the proximal portion of transition surfaces 278a, 278b, and the added compression of tube 4b along the proximal end portions 276a, 276b of the tube guide surfaces 272a, 272b provides additional security to ensure complete blockage of the interior passage, even when there are variations in the tubes, such as the size of the inside step.

It should be appreciated that, due to the slope of the rib transition portion 268a, 268b, when the roller wheel 244 is moved proximally relative to the transition surfaces 278a, 278b the interior passage of the tube 4b is blocked accordingly. Progressive form. Thus, in addition to providing an on / off mechanism, the roller pinch clamp assembly 242 can also be used to regulate fluid flow between two non-zero flow values. It should also be noted that the device's roller pinch clamp assembly 242 can be used in series in combination with another roller pinch clamp assembly that is normally provided as part of an IV set (i.e. bag of IV, IV bag tip, drip chamber, connecting tube, roller clamp, slide clamp, luer connector). When used in this manner, the IV set's roller pinch clamp assembly can be used to achieve a primary (important) adjustment for fluid flow, while the device's roller pinch clamp assembly 242 can be used to achieve a primary (important) adjustment for fluid flow. you can use to get a secondary (more precisely minor) setting for the fluid flow rate.

In another arrangement, as shown in Figures 87-89 for device 5v, the roller pinch clamp assembly 242 may include a cover 280 that at least partially closes the opening 258 and / or conceals the roller wheel. 244. Among other things, cover 280 reduces the possibility of unwanted foreign fluid (eg, blood and other body fluids) entering the limits of handle 20a, 20b through opening 258. In addition, the cover 280 reduces the exposure of the internal mechanics of the roller nip clamp assembly 242. In this way, the cover 280 reduces the possibility of foreign bodies (eg rubber practitioner gloves) entering the limits of the handle 20a, 20b through the aperture 258 and catching, for example, between the trunnions 248a. , 248b and runway 250.

As shown in Figures 88-89, preferably cover 280 overlaps and moves distally and proximally to roller wheel 244, and is configured to provide a button portion 282 of the switch when the wheel is covered within the wheel. semicircular receptacle 284 and is inaccessible to direct manipulation. Preferably cover 280 is configured to substantially close aperture 258 regardless of the position of wheel 244, preferably by means of a distal shield portion 286 and a proximal shield portion 288. Preferably, the distal shield portion 286 and a shield portion proximal shield 288 have a length equal to or greater than the length of the opening 258 minus the length of the switch button portion 282.

Also as shown, cover 280 preferably comprises a distal guide portion 290 and a proximal guide portion 292 located below the distal shield portion 286 and a proximal shield portion 288 on opposite sides of the wheel 244. As shown , guide portion 292 and distal guard portion 286 comprise rectangular guide pins and preferably move along track 250 similar to wheel 244. Wheel 244 partially extends into socket 284 which has a slightly larger diameter than wheel 244.

Upon movement of the switch button portion 282 proximally by a proximally directed force applied by, for example, a finger, the inner surface 294 of the distal guide portion 290 contacts the wheel surface 262. 244 and pushes the wheel proximally. In contrast, upon movement of the switch button portion 282 distally by a distally directed force applied by, for example, a finger, the inner surface 296 of the distal guide portion 292 makes contact with the surface 262. wheel 244 and pushes

ES 2 355 872 T3 the wheel distally. In this arrangement, surface 262 of wheel 244 is preferably smooth and wheel 244 preferably comprises a self-lubricating polymeric material, such as polyacetal.

In another arrangement, as shown in Figures 90-91 for device 5w, the button portion 282 of the cover switch 280 may include side portions 298 that cover opposite sides of the wheel 244. However, unlike From the 5v arrangement, a part of the cover 280 for the device 5w is not contained or guided directly by the track 250 since the distal guide part 290 and the proximal guide part 292 have been removed. While tire 280 for the 5w arrangement still applies a directional force to wheel 244 to move wheel 244, tire 280 is now attached to wheel 244 and carried along track 250 by trunnions 248a, 248b 244. As shown, cover 280 includes two opposing C-shaped openings 300, which provide wheel hub receptacles for trunnions 248a, 248b. As shown, trunnions 248a, 248b are in openings 300.

Thus, upon movement of the switch button portion 282 proximally by a proximally directed force, the inner surface 302 of the cover 280 defining the openings 300 contacts the cylindrical side surface 304 of the trunnions 248a, 248b and pushes the wheel proximally. Conversely, with movement of the switch button portion 282 distally by a distal directed force, the inner surface 302 of the cover 280 defining the openings 300 also contacts the cylindrical side surface 304 of the trunnions 248a. , 248b and pushes the wheel distally.

In another arrangement, as shown in Figures 92-93 for the device, the button portion 282 of the cover switch 280 has been removed. In this way, the roller wheel 244 will be exposed and can be operated directly and not by the button portion 282 of the switch.

While the various switch assembly arrangements described above have been described primarily with reference to bipolar devices, it should be understood that the various switch assemblies may be equally adaptable to other fluid-assisted medical devices, such as the monopolar devices herein. divulgation.

The 5i-5x bipolar devices are particularly useful as non-binding tissue sealants since they do not grasp tissue. The 5i-5x devices are particularly useful for surgeons to achieve hemostasis after dissection through soft tissues, as part of a hip or knee replacement. The tissue treatment portions can be painted on top of the raw surface 22 oozing out of the tissue 32 to close the tissue 32 against bleeding, or focused on larger individual bleeding vessels to stop bleeding from the vessels.

The 5i-5x devices are also useful for stopping bleeding from the surface of cut bone tissue as part of any orthopedic procedure that requires the bone to be cut. The 5i-5x bipolar devices are particularly useful for these applications over a 5a monopolar device since a much larger surface area 22 of tissue 32 can be treated in an equivalent period of time and with a better controlled depth of treatment.

As is well known, bone or bone tissue is a particular form of dense connective tissue consisting of bone cells (osteocytes) embedded in a matrix of calcified intercellular substance. The bone matrix contains mainly collagen fibers and minerals calcium carbonate, calcium phosphate and hydroxyapatite. Among the many types of bones in the human body are compact bones and spongy bones. Compact bone is a hard, dense bone that forms the superficial layers of bones and also the trunks of long bones. They are made primarily of Haversian systems that are covered by the periosteum. Compact bone contains discrete nutrient channels through which blood vessels gain access to the Haversian systems and the medullary canal of the long bones. For example, Volkmann canals which are small canals found in compact bone through which the blood vessels of the periosteum pass and connect with the blood vessels of the Haversian canals or the medullary cavity. Bipolar devices as described herein may be particularly useful for treating compact bones and for providing hemostasis and closing of bleeding vessels (eg, by reduction to complete closure) and other structures associated with Volkmann's canals and Havers systems. Unlike compact bone, lattice bone is cancellous bone and makes up most of the short, flat, and irregular bones and the ends of the long bones. The network of bone tissue that constitutes the reticular bone structure comprises many small trabeculae, partially enclosing many intercommunicating spaces filled with bone marrow. Consequently, due to their trabecular structure, reticular bones are more amorphous than compact bones, and they have many more channels with various precursors of blood cells mixed with capillaries, venules, and arterioles. Bipolar devices such as those described herein may be particularly useful for treating reticular bone and for providing hemostasis and closure of bleeding structures such as anterior micro-vessels (i.e., capillaries, venules, and arterioles), in addition to veins and arteries. These devices may be particularly useful for use during orthopedic knee, shoulder, hip, and spinal procedures (eg, arthroplasty).

During a knee replacement procedure, the condyle of the distal epiphysis of the femur and the tibial plateau at the proximal epiphysis of the tibia are often cut and made flat with saw devices to provide in

ES 2 355 872 T3 is ultimately a more suitable support structure for the femoral condyle prosthesis and the tibial prosthesis attached thereto, respectively. The cutting of these long bones results in the bleeding of the reticular bone at each location. In order to close and stop the bleeding of the reticular bone, which has been exposed by cutting the epiphysis of each long bone, the bipolar devices described herein can be used. Subsequently, the respective prosthesis can be connected.

Switching to a hip replacement procedure, the head and neck of the femur is removed at the proximal epiphysis of the femur, usually cutting with a saw device, and the inter-trochanteric region of the femur is made flatter to provide a structure of most suitable support for the femoral stem prosthesis subsequently attached to it. With respect to the hip, a ball reamer is often used to ream and widen the innominate bone (hip) acetabulum to accommodate the insertion of an acetabular cup prosthesis therein, which will provide the socket into which it fits the head of the femoral stem prosthesis. Cutting of the femur and reaming of the hip bone results in bleeding of the reticular bone at each location. In order to close and stop the bleeding of the reticular bone, which has been cut and exposed, the bipolar devices described herein can be used. Thereafter, as with knee replacement, the respective prostheses can be attached.

The bipolar devices described herein can be used for the treatment of connective tissues, such as by reduction of the intervertebral discs during spinal surgery. Intervertebral discs are flexible pads of fibrocartilaginous tissue firmly fixed between the vertebrae of the spinal column. Discs comprise a flat, circular capsule about 1 inch (2.54 cm) in diameter and about 0.25 inch (0.635 cm) thick, composed of a strong, fibrous outer membrane called the annulus fibrosus, which surrounds a nucleus. elastic called nucleus pulposus.

Under stress, the nucleus pulposus may swell and herniate, pushing through a weak spot in the membrane of the annulus fibrosus and into the spinal canal. Consequently, all or part of the material of the nucleus pulposus can exit through the weak point, pressing against the surrounding nerves, causing pain and immobility.

The bipolar devices described herein can be used to reduce herniated and protruding intervertebral discs which, upon reduction to normal size, reduce pressure on surrounding nerves and relieve pain and immobility. The devices described herein can be applied through a posterior spinal access under medical supervision, for any targeted reduction of the annulus fibrosus membrane.

When an intervertebral disc cannot be repaired and must be removed as part of a discectomy, the devices described herein may be particularly useful in closing and stopping bleeding from the reticular bone of the opposing surfaces of the upper and lower vertebrae (e.g. , the surface towards the head of the vertebral body of the upper vertebra and the surface of a lower vertebra). When the disc is removed from the front of the patient, for example, as part of an earlier procedure, thoracic spine procedure, the devices described herein may be especially useful in closing and stopping bleeding from the segmental vessels in the vertebral body.

The bipolar devices described herein can be used to close and stop bleeding from epidural veins that bleed as a result of removal of tissue around the dura membrane during, for example, a laminectomy or other neurosurgery. Epidural veins can begin to bleed when the dura is retracted out of them as part of decompression. Also, during a laminectomy, the devices described herein can be used to close and stop bleeding from the vertebral arch and, in particular, the lamina of the vertebral arch.

One or more of the features of the above-described system can be built into a custom RF generator. This arrangement can provide one or more advantages. For example, this type of system can save space and reduce overall complexity for the user. This system can also allow manufacturers to increase the power delivered into low impedance loads, further reducing the time to achieve the desired effects on the tissue. This changes the curve of FIG. 5, by removing or decreasing the slope of the low impedance ramp 28a of power versus impedance.

Alternatively, for situations where the high impedance ramp 28a can be overcome with the use of the devices of the present disclosure, it may be desirable to provide an impedance transformer 224 in a series circuit configuration between the electrode (s). of device 5 and the power output of the generator

6. Consequently, the impedance transformer 224 can be supplied with the device 5, the generator 6 or any of the wire connectors (for example, the wire 21) that connect the device 5 and the generator.

6. The impedance transformer 224 is configured to match the load impedance supplied to the generator 6 such that it is within the duty range of the generator 6 and, more preferably, the duty range between the low and high cut-off points. .

To effectively treat thick tissues, having the ability to send pulsed RF power can be advantageous. In some circumstances, the deep tissue temperature can rise rapidly beyond the 100 ° C drying point even though the electrode / tissue contact point is boiling at 100 ° C. This is

ES 2 355 872 T3 manifests in the form of a "rattle", since the steam generated deep in the tissue boils too quickly and erupts towards the surface. In one arrangement of the invention, a switch is provided on the control device or custom generator to allow the user to select a "pulse" mode of the RF power. Preferably, the RF power system in this arrangement is further controlled by software.

In some arrangements, it may be desirable to control the temperature of the conductive fluid before it is released from the electrosurgical device. In one arrangement, a heat exchanger is provided for the outgoing saline flow to heat or cool the saline solution. The heat exchanger can be provided as part of the electrosurgical device or as part of another part of the system, such as within enclosure 14. Preheating the saline solution to a predetermined level below boiling reduces the transient time to warm up the device since the RF is initially on, thereby reducing the time required to cause tissue coagulation. Alternatively, pre-cooling of the saline solution is useful when the surgeon wishes to protect certain tissues at the electrode / tissue interface and treat only the deeper tissue. An example of the application of this arrangement is the treatment of varicose veins, where it is desirable to avoid thermal damage to the skin surface. At the same time, treatment is provided by contracting the underlying blood vessels using thermal coagulation. Thus the temperature of the conductive fluid can be controlled prior to release from the surgical device, to provide the desired effect of treatment.

In another arrangement the flow controller has been modified to provide a flow rate of saline that results in greater than 100% boiling at the tissue treatment site. For example, the selection switch 12 of the flow controller 11 (shown in Figure 1) may include settings corresponding to 110%, 120% and higher boiling percentages. These higher settings may be of value to a surgeon in situations such as when thick tissue is encountered, where the thickness of the tissue can increase conduction away from the electrode grip. Since the basic control strategy neglects heat conduction, the setting for 100% boiling can result in 80% or 90% boiling, depending on the amount of conduction. With the teachings herein in mind, the flow controller switch can be adapted to any desirable flow setting to achieve the desired saline boiling at the tissue treatment site.

Certain provisions of the disclosure may provide one or more advantages over current electrosurgical techniques and devices. For example, the disclosure preferably achieves the desired effect on tissue (eg, coagulation, cutting, and the like) quickly. In a preferred arrangement, actively controlling the flow rate of the saline solution, both in quantity (Q vs. P) and in location (for example, using channels to direct fluid distal to tissues, using holes to direct the fluid flow or other similar methods) the electrosurgical device can create a hot electrode / tissue contact point without desiccation and thus a rapid thermally induced tissue coagulation effect.

Use of the disclosed devices can result in significantly less blood loss during surgical procedures such as liver resection. Typical blood loss from a right hepatectomy can be in the range of 500-1000 cubic centimeters. The use of the devices described herein to perform coagulation prior to liver transection can result in less blood loss in the range of 50-300 cubic centimeters. This reduction in blood loss can reduce or eliminate the need for blood transfusions, and therefore the cost and negative clinical consequences associated with blood transfusions, such as prolonged hospitalization and an increased likelihood of cancer recurrence. The use of the device can also provide better closure of the bile ducts and reduce the incidence of postoperative bile leaks, which is considered a major surgical complication.

The disclosure may, in some arrangements, offer rapid tissue treatment without the use of a temperature sensor built into the device or a custom generator for special purposes. In a preferred arrangement, there is no built-in temperature sensor or other type of tissue sensor, nor is there a custom generator. Preferably, the disclosure provides a means to control flow rate to the device such that the device and flow controller can be used with a wide variety of general purpose generators. Any general purpose generator is useful in conjunction with the fluid delivery system and flow controller to provide the desired power; the flow controller will accept the power and constantly adjust the saline flow rate according to the control strategy. Preferably, the generator is not actively controlled by the disclosure, so that standard generators are usable according to the disclosure. Preferably, there is no active return feed from the device and the saline flow control is "open loop". Thus, in this arrangement, the control of the saline flow rate is not dependent on the return feed, but rather on the measurement of the RF power output to the device.

For the purposes of the appended claims, the term "tissue" includes, but is not limited to, organs (eg liver, lung, spleen, gallbladder), highly vascular tissues (eg liver, spleen), soft and hard tissues (e.g. adipose, areolar bone, bronchial-associated lymphoid, reticular, chondroid, chord, chromaffin, scar, connective, elastic, embryonic, endothelial, epithelial, erectile, fatty, fibrous, gelatinous, granular, glandular, homologous, indifferent, interstitial, lymphoid, lymphadenoid, mesenchymal, mucosa-associated lymphoid, mucous, muscular, myeloid, nervous, bony, reticular, scar, scleros, skeletal, subcutaneous, splenic), and the tissue masses (e.g., tumors).

ES 2 355 872 T3

While a preferred embodiment of the present invention has been described, it should be understood that various modifications, adaptations, and modifications may be made to it and the scope of the appended claims. The scope of the invention must, therefore, be determined not with reference to the foregoing description, but must be determined with reference to the appended claims together with their full scope of equivalents. Furthermore, it should be understood that the appended claims do not necessarily encompass the broadest scope of the invention that the applicant is entitled to claim, or the only manner (s) in which the invention can be claimed, nor that all of the indicated features are necessary.