Apparatus for tissue cauterization

The present invention relates to tissue cauterization. More specifically, the present invention relates to improved electrodes for tissue cauterization.

Tissue and organ resection is required for a variety of purposes in many surgeries. One of the major challenges in any tissue resection surgery is to stop bleeding, or bleeding. All blood vessels that supply blood to the organ or part of the tissue to be excised must be blocked by either sutures or cauterization to reduce bleeding when the tissue is excised. For example, when the uterus is removed in a hysterectomy, bleeding must be controlled in the neck to be removed and along the blood vessels along the sides of the uterus that supply the uterus. Similarly, when a portion of the liver is removed in connection with or for other purposes, the blood vessels in the liver must be individually blocked. The liver is an organ with highly developed blood vessels, and the blockade of blood vessels takes an extremely long time. Achieving hemostasis is necessary in both open and minimally invasive surgery. However, in the latter case, vascular blockade can be more time consuming and problematic due to limited access through the cannula and other narrow passages.

Achieving hemostasis is especially important in laparoscopic surgery and other limited access surgery where organs or other tissues must be shredded prior to removal. Most organs are too large to be removed as-is through a cannula or other limited access passage, so the tissue is shredded (eg, cut into smaller pieces, ground, or other) before removal. It is necessary to break it into small pieces by a method). It will be understood that vascularized tissue shredding can be very problematic.

<patcit num="1"><text>U.S. Pat. No. 4,979,948</text></patcit><patcit num="2"><text>U.S. Pat. No. 3,845,771</text></patcit><patcit num="3"><text>U.S. Pat. No. 4,972,846</text></patcit><patcit num="4"><text>U.S. Pat. No. 5,178,618</text></patcit><patcit num="5"><text>U.S. Pat. No. 5,078,736</text></patcit><patcit num="6"><text>U.S. Pat. No. 6,203,541</text></patcit><patcit num="7"><text>U.S. Pat. No. 6,398,779</text></patcit><patcit num="8"><text>U.S. Pat. No. 5,443,463</text></patcit><patcit num="9"><text>U.S. Patent Application No. 11 / 371,988</text></patcit><patcit num="10"><text>U.S. Pat. No. 5,431,676</text></patcit><patcit num="11"><text>U.S. Pat. No. 5,234,425</text></patcit><patcit num="12"><text>U.S. Pat. No. 4,018,230</text></patcit><nplcit num="1"><text>"Min. Ivas. Ther. Allied Technol. 5: 511-516" (1996)</text></nplcit>

<p> For these reasons, it would be desirable to provide improved methods, systems, and devices for achieving hemostasis in connection with organ and tissue resection surgery. Specifically, surgeons can achieve time-efficient hemostasis using readily available surgical equipment (eg, high frequency power supplies as described below), while on the other hand. It would be desirable to provide methods and systems that reduce patient risk and trauma. It would be even more desirable if this method and system could be applied to a wide range of tissue resection surgery, including at least hysterectomy, liver tissue resection, cholecystectomy, prostatectomy, lung resection, etc. .. It would be even more desirable if this method could provide complete or substantially complete coagulation and hemostasis of the entire tissue to be excised to facilitate procedures such as subsequent shredding. For example, the ability to shred tissue while minimizing bleeding would be a significant benefit to performing laparoscopic surgery and other minimally invasive surgery, as well as other surgical procedures.</p><p> It is known to use radio frequency (RF) energy to necrotize organs or parts of the body. Patent Document 1 describes a balloon electrode that inflates inside the uterus and is used to apply high frequency energy to necrotize the endometrium of the uterus. Patent Document 2 describes gloves having flexible electrodes on the thumb and middle finger. The purpose of these gloves is to pass a high-frequency current through conventional forceps, a surgical scalpel, and the like. Patent Document 3 describes a pair of electrode patches that directly engage the epicardium, which is useful as a lead for a cardiac fibrillation remover. Patent Documents 4 and 5 describe stents that can be energized to apply high frequency energy inside the lumen of the body. Non-Patent Document 1 of Lorentzen et al. Describes a loop electrode that can be rotated within a tissue to excuse the tissue portion.</p><p> Patent Document 6 discloses an automatic circuit having a pair of bipolar electrodes for controlling a surgical instrument. This circuit includes a means for measuring the current between a pair of electrodes, an impedance detection circuit electrically connected to the current measurement means, a comparator electrically connected to the impedance detection circuit, and the like. It is equipped with a controller that is electrically connected to the comparator. The impedance detection circuit calculates the impedance between the electrodes based on the measured current and generates a first signal indicating the calculated impedance. The comparator processes the first signal, generates an working signal if the calculated impedance is within a predetermined impedance value range, and is non-working if the calculated impedance exceeds the non-working threshold. Generate an operation signal. The controller receives the activation / non-operation signal, sends the first control signal for operating the electrode to the high frequency energy output stage in response to the activation signal, and deactivates the electrode in response to the non-operation signal. The second control signal for this is sent to the high frequency output stage.</p><p> Patent Document 7 is a method of electrosurgically sealing a tissue, which is a step of applying an initial pulse of high frequency energy to the tissue so that the pulse is not heated to the extent that the tissue can be recognized. Used in the first high frequency energy pulse applied to the tissue according to the step and the step measuring the tissue impedance value and the response to the applied pulse with the properties selected and according to the measured impedance value. It teaches steps to determine the initial set of pulse parameters for, and how to concludes. The present invention teaches that the pulse parameters of individual pulses of a subsequent high frequency energy pulse are varied according to at least one characteristic of the electrical transient that occurs during the subsequent high frequency energy pulse. This method ends the subsequent generation of high frequency energy pulses when it is determined that there is no electrical transient or the minimum output voltage has been reached.</p><p> Patent Document 8 teaches coagulation forceps for selectively coagulating blood vessels or tissues containing blood vessels. The method taught involves placing a blood vessel or tissue containing the blood vessel between the tips of the forceps, and the jaws of the forceps include multiple electrodes that are energized by high frequency power. Multiple sensors are associated with the electrodes, which contact the blood vessel or tissue, measure the temperature rise of the blood vessel or tissue, and provide feedback to control the heating to coagulate the blood vessel or tissue. , Provides high frequency power. The invention also teaches that the upper tip of the device is divided into two parts and the cutting edge between these two upper parts provides excision of the coagulated blood vessel after coagulation.</p>

<p> The present invention provides methods, systems, and devices that facilitate surgical ablation of tissue, such as excision and removal of tissue from patients undergoing a wide range of surgery. Surgery can include excision of the entire organ (eg, hysterectomy, cholecystectomy, prostatectomy, lung resection, etc.). Instead, the method is intended for the removal of parts of an organ or other tissue, such as a tumor from a highly vascularized organ (eg, liver, lung, etc.). be able to. The method generally involves two steps, first in which the tissue is necrotic or cauterized in whole or in part using high frequency energy. Specifically, cauterization is performed along at least the desired cut surface within the tissue. Tissue is then excised along this (one or more) plane. Resection within necrotic or cauterized tissue has been found to result in substantially minimal and, in some cases, no bleeding due to tissue resection, which is advantageous. Tissue cauterization is preferably performed on the target volume of tissue, generally the entire organ or part thereof (eg, uterus, liver lobe, part of lung, prostate, etc.). By performing a substantially complete cauterization of the target volume of the tissue, the bleeding capacity of the tissue is reduced or reduced, which facilitates subsequent shredding and tissue resection. Therefore, by significantly reducing bleeding and the time required for surgery, resection of organs and tissues is greatly facilitated.</p><p> In a first particular aspect, the method according to the invention engages at least the first electrode structure and the second electrode structure with the isolated surfaces of the tissue portion, generally the opposing surfaces of the tissue portion. It has steps. The first and second electrode structures can have similar geometries to each other so that they make symmetrical contact with the tissue. Alternatively, the electrode structure can have different geometric shapes, eg, one electrode structure is configured as a probe for insertion into a natural body opening and the other electrode structure is the opening. It can be configured to engage the outer surface of the tissue away from the portion. In some cases, three or more electrode structures can be used, but at least two electrode structures (or separate regions of one structure) are provided to provide the application of high frequency energy to the tissue. , It is energized with the opposite polarity. In some other cases, the electrode structure can be different regions formed as part of one support structure, eg, can be placed in an organ or other tissue part, and two. One elastic tube or shell on which the above electrode surfaces are formed. Of course, the different electrode surfaces are isolated from each other when high frequency energies of opposite polarities are intended to be applied. Equally important, the electrodes are not in contact even if they have the same polarity. In yet another case, one electrode structure can have multiple conductive or active regions, which can be energized with the same or opposite polarities. In other cases, the electrode structure to increase the contact between the electrode and the tissue and increase the total available area of the electrically active (one or more) regions in the electrode structure that supplies the tissue with high frequency energy. Tissue-penetrating elements) can be provided. Such tissue penetration elements can be used in addition to or in place of the use of electrodes with conformable or rigid surfaces. In each case, the electrode structure, or its electrically active region, is configured to engage a substantially contiguous portion or portion of the tissue surface with the smallest region, as described below. Has been done. When tissue-penetrating elements are used, they are generally dispersed almost uniformly over the electrically active regions of the electrode structure.</p><p> High frequency (usually radio frequency) power is applied to the tissue portion by electrically active (one or more) regions of the electrode structure, and this power is sufficient to cauterize or necrotize the tissue between the electrodes. Only the time and amount, preferably at least along the desired cut surface. The target volume of tissue is often excised by chopping (eg, chopping into small pieces, chopping, chopping, etc.). Such shredding is greatly facilitated by necrosis of the target volume of tissue. By necrosis, the cells of the tissue are killed during subsequent excision and the bleeding of the tissue is substantially suppressed. Usually, the tissue is excised along a plane within the necrotic tissue portion with minimal bleeding as described above.</p><p> The electrically active region of the electrode structure has an area of at least 1 cm2, usually at least 2 cm2, often 5 cm2 or more, often 10 cm2 or more, and more. In the case of, it has an area of 50 cm2 or more. Electrodes can have a wide range of properties and can generally be rigid, flexible, elastic, malleable, conformable and the like. It is preferred that the electrodes are flexible to facilitate engagement between the electrodes and the tissue surface and fit snugly against the tissue surface. In at least some cases, it is desirable to provide an electrode that is flexible and elastic and that can fit snugly around the tissue or on the surface of the organ, in which case the elastic properties of the electrode are tightly engaged. And ensure electrode contact. However, in other cases, the electrodes can be specifically configured to have the desired geometry for engaging with a particular tissue surface.</p><p> The high frequency energy applied to an organ or tissue is generally provided at radio frequencies, but is not limited to the range of 100kHz to 10MHz, usually 200kHz to 750kHz. The power level depends on the surface area and volume of the tissue to be treated, but is generally within the range of 10W to 500W, usually 25W to 250W, and more usually 50W to 200W. Power is usually 1 W / cm2 ~ 500 W / cm2, more usually 10 W / cm2 ~ 100 Applies at the level of W / cm2. Electricity raises the tissue temperature of the part of the tissue to be treated above the threshold level required for cauterization or necrosis, usually at least 60 ° C or higher, often 70 ° C or higher, and often 80 ° C or higher. Applies only for enough time. However, the application of energy should be limited so that adjacent tissues are not significantly heated or damaged in any way. In this regard, the use of opposing bipolar electrodes is particularly advantageous because it concentrates the energy flux between the electrodes and limits the effect on adjacent tissues that are not enclosed within the opposing electrodes. This is because it is done. The resulting necrotic tissue can contain substantially the entire organ to be treated, or in other cases, a narrower area (eg, a planar area).</p><p> In another aspect, the invention comprises a system comprising at least a plurality of electrodes, eg, a power supply that can be connected to the electrodes and applies bipolar high frequency power between the electrodes. There is. Electrodes can generally be configured as described above and are usually supported by an electrosurgical probe for ease of placement. The probe can have a wide range of shape configurations, but usually includes at least a shaft and a handle for manipulating the shaft. The electrodes are attached to the ends of the shaft and are usually the front end of the shaft so that they can open and close each other to engage and capture intervening organs or other tissue parts. It can be operated from. The electrode can have any of the properties described above, and in particular can be provided with a metal or metallized mesh that can elastically engage and fit snugly against the tissue surface. it can. The electrosurgical probe can be used in a conventional bipolar scheme, i.e., each of the electrodes is energized with opposite polarities. Alternatively, the electrode surface can be energized with the same polarity and another electrode (one or more) can be used to complete the high frequency circuit. These separate electrodes (one or more) are generally one or more probes that can be inserted into a natural body opening or lumen or introduced into an organ or other tissue part. Is in the form of. This (one or more) probes can fit snugly into the natural lumen and, in some cases, introduce saline or other conductive fluid into the lumen to help establish a conductive pathway. You can also do it.</p><p> In certain embodiments, the electrosurgical device can comprise one compatible structure, eg, an elastically or inelastically inflatable tubular member (eg, an inflatable tubular blade mesh). Electrodes are formed at multiple locations on the compatible support structure and are usually formed, for example, by applying an insulator or by relying on the inherently non-conductive nature of the compatible support structure. Insulated from each other.</p>

The methods, systems, and devices of the present invention are useful for treating various organs, parts of organs, or other solid tissue areas of a patient. Organs or other tissue parts have isolated tissue surfaces, usually opposite tissue surfaces, which are accessible by electrode structures and high frequency power between these surfaces. Can be applied. The tissue surface is easily accessible or requires pretreatment to make it accessible (eg, blunt incision, excision of small tissue or blood vessels using conventional surgical techniques). Sometimes. Organs that can be treated by the present invention include the uterus, liver, prostate, kidney, intestine, pancreas, lungs, chest, muscles and the like.

Organs and other tissues are treated with bipolar high frequency power guided to the tissue area of interest as defined by the spacing of the electrode structures. The high frequency power can be supplied by a conventional general purpose electrosurgical power supply operating at any acceptable frequency, generally within the frequencies listed above. The power supply can use conventional sinusoidal or non-sinusoidal waveforms and can operate at constant power levels and / or controlled power levels (voltage, current, or both can be selected). it can. Suitable power supplies are available from private sector manufacturers (eg Valleylab, Aspen, Bovie). In some cases, it may be desirable to use an impedance matching transformer between the power supply and the electrodes to increase the efficiency of the energy supply.

The electrodes can be constructed by any method suitable for engaging with the tissue surface. Therefore, the electrodes can be rigid, flexible, elastic, inelastic (non-expandable), planar, non-planar, etc., optionally to enhance electrical contact between the electrode structure and the tissue. , Tissue-penetrating elements can be used to increase the electrode area. Is the preferred electrode shape configuration compatible so that it can engage and adapt to a wide variety of different tissue surfaces (eg,).<patcit num="9"><text>(See reference number ARGA0003)) (this entire document is incorporated as a reference in this document), or to have geometry intended to engage the geometry of a particular organ or tissue. , Especially configured. In either case, the electrode structure may be further provided with a tissue penetrating element. Each example is described below.</text></patcit>

One shape configuration of the electrodes uses a flexible and elastic metallized mesh. Such meshes are suitable for use in retractable electrodes (eg, retractable electrodes useful for minimally invasive surgery). The mesh can be suspended to or between the more rigid frame members, which can itself expand or contract to place the mesh electrodes. Such meshes are also useful in creating elastic tubes or shells that can be placed over organs or tissue parts like socks. In the case of such tubular electrodes, it is often desirable to form two or more separate electrode surfaces on a mesh, in which case the electrode surfaces are usually the material properties of the mesh itself (ie, ie). , The mesh is polymer and non-conductive). The elastic mesh can take the form of a braid or other woven structure as described in, for example, Patent Document 10, Patent Document 11, and Patent Document 12, and the entire disclosure of these documents is in this document. Is incorporated as a reference in. The use of a braided structure that is inflatable in the radial direction is desirable because the diameter of the lumen that receives the tissue can be controlled by axial extension. That is, the blade can be expanded by shortening its length and contracted by extending its length. All such mesh and blade structures can be metallized by conventional electroless plating techniques. Suitable metals to be plated include gold, silver, copper, stainless steel, and combinations thereof, and alloys thereof. Suitable elastomer mesh materials include a wide range of elastomers. Suitable blade mesh materials include nylon and other generally non-expandable polymers.

All types of electrode structures can be configured to have a conductive surface and a non-conductive surface. This configuration is usually achieved by leaving one surface as an exposed metal surface, while covering or insulating the other surface of the electrode. In the case of rigid electrodes, the insulator can be laminated, coated, or otherwise applied directly to the opposite surface. In the case of flexible and elastic electrodes, the insulating layer also needs to be flexible so that it can expand and contract with the electrode without loss or detachment of the insulating layer. In some cases, it is desirable to use a separate sheet-like material that covers the surface that is desired to be insulated and expands with the electrodes.

Next, referring to FIG. 1, the system 10 according to the present invention includes a first composite electrode 12, a second electrode 14, and a high-frequency power supply device 16. The first electrode comprises a plurality of rigid plates independently connected to one pole of the power supply 16, and the second electrode is a rigid plate connected to the opposite pole. In another embodiment, the second electrode can be non-rigid and can also represent multiple electrodes. In fact, in certain cases, a plurality of return electrodes are preferred. Electrodes 12 and 14 can be engaged with the tissue portion T so as to engage the opposing surfaces of the tissue portion T. Any of the multiple rigid plates forming the electrode 12 (as described in more detail later) are then used to completely cauterize the tissue portion captured between the electrodes 12 and 14. Depending on the combination, high frequency power is selectively applied to the tissue. After the tissue has been cauterized, the tissue can be excised along the lines within the ablated area of the tissue. Resection within the ablated tissue minimizes bleeding and simplifies hemostasis, which is advantageous.

For example, when used in ablation of uterine tissue, compatible electrodes can be placed on the opposite outer surface of the uterus. As outlined above, rather than applying high frequency energies of opposite polarities, the power supply can energize the electrodes with a common polarity. The probe can be inserted into the uterine cavity and energized with the opposite polarity. In this case, the opposing tissue surface is composed of the interior lining of the uterine cavity and the outer surface of the uterus. In the case of the uterus, it is generally desirable to cauterize substantially the entire tissue (excluding the neck in some cases). However, in the case of other organs and tissue parts of the body, it may be desirable to cauterize only part of the tissue. By selecting the electrode configuration, high frequency energy can be directed to a limited part of the tissue.

The electrodes preferably have a plurality of different conductive regions, in which case the regions can be electrically isolated from each other or electrically coupled to each other. One electrode structure can include three, four, five, or ten or more different conductive regions. Such conductive regions are usually defined by electrically insulating regions or structures between them. When it is desirable to electrically couple two or more conductive regions, a small electrical connection can be provided to bridge the insulator between the regions. Normally, at least some of the insulated conductive regions in the electrode structure are energized with opposite polarities, and in some cases, the method of the invention is a single electrode having multiple conductive regions. It can be carried out using only the structure. Alternatively, the insulated conductive regions of one electrode structure can be energized with the same polarity, in which case the main purpose of the different regions is to control the high energy flux supplied to the tissue portion. Or to set. For example, it may be desirable to supply high frequency electrical energy to the isolated regions of the tissue portion without cauterizing another region between or adjacent to the region to be cauterized. In such a case, the electrode structure can be constructed by appropriately arranging the conductive region.

FIG. 2 shows a system 300 with a pair of electrode structures 302 and 304. At least one electrode structure 304 comprises a plurality of individual conductive pieces 310 that are spaced apart so as to be electrically isolated from each other. In another embodiment, the conductive pieces can be separated by an electrically insulating material. The conductive piece 310 can be selectively energized in substantially any pattern with opposite polarities. Often, it may be desirable to energize the pieces so that the adjacent pieces have opposite polarities. Those skilled in the art will appreciate that the electrodes can be individual electrodes or can be formed by techniques such as screening, electrodeposition and the like.

In the description so far, the conductive surface of the electrode structure is generally a continuous surface shape, i.e., a surface shape selected such that an uninterrupted interface with the engaging tissue surface is formed. Consists of rigid or compatible components with. In some cases, it may be desirable to provide additional structures or components on the electrode structure to improve or increase the quality of the effective electrical contact area between the electrode structure and the tissue surface. Specifically, to increase electrical contact, that is, to reduce the electrical impedance between the electrode and the tissue, and more importantly, to increase the total contact surface area between the electrode and the tissue. It is often desirable to provide tissue penetration elements on the electrode structure for both purposes. The tissue penetrating element can be a needle, pin, protrusion, groove, etc., but is usually a pin with a pointed end so that it can penetrate the tissue surface and reach the underlying tissue portion. This pin can have a depth in the range of 1 mm to 5 cm, typically 3 mm to 1 cm. Pin diameters can range from 0.1 mm to 5 mm, typically 0.5 mm to 3 mm. Usually, the pins are uniformly dispersed on the region of the electrode structure that comes into contact with the tissue, and the density of the pins is 0.1 pin / cm2 to 10 pin / cm2, usually 0.5 pin / cm2 to 5 pin / cm2. Pins or other tissue penetration elements are typically provided in addition to a compatible or rigid and conductive electrode surface, but in some cases the pins are the total conductive region or total of the electrode structure. An active region can be provided.

A system having a plurality of electrode structures can include, for example, conductive pieces separated by insulating rods. However, in addition to this, tissue-penetrating pins can be placed along each of the conductive pieces. It will be appreciated that the plurality of pins are arranged along the longitudinal direction of each piece. The electrode structure is generally a curved structure so that it can be placed in a tubular structure or tissue portion of the body. However, it will be appreciated that pieces can be formed from compatible meshes that allow the electrode structure to be flattened or take a wide range of other shapes. In addition, the insulating structure can also be formed from a flexible or compatible material, in which case further shape changes of the electrode structure are possible.

The conductive pieces can be energized in a configuration in which the polarities alternate. In the simplest case, adjacent pieces are connected in opposite polarities in one power supply. However, it is easy to reorganize the electrical connections so that the pieces are energized in virtually any pattern. Furthermore, it is also possible to electrically insulate these regions so that different regions of each piece (eg No. 1 and No. 2) can be energized with opposite polarities.

With System 300, a variety of different tissue ablation patterns can be achieved by selectively energizing different surfaces or regions of the electrode surface or region. A limited tissue area is cauterized by selectively energizing two adjacent electrode surfaces in a bipolar manner, while leaving all other surfaces unenergized. On the other hand, by energizing another electrode surface (eg No.4,5,6,7), a larger area is cauterized. Slightly different patterns are achieved depending on the exact pattern of polarity on the electrode surface. The electrode surface can be energized in alternating polarity patterns (+,-, +,-) to form a cauterized pattern of tissue. Patterns such as (+, +,-,-), (+,-,-, +), (-, +, +,-) can also be used to form slightly different cauterization patterns.

FIG. 2 shows an electrosurgical probe 50 containing a pair of jaws 56 with an end 58 and a front end 60. Alternatively, the probe can be equipped with a generally cylindrical shaft that is sized for introduction through a conventional cannula of the type used in minimally invasive surgery. Therefore, shafts generally have diameters in the range of 5 mm to 15 mm and are usually nominal values of 5 mm, 10 mm, or 12 mm to match conventional cannulas. The length of the shaft is generally in the range of 10 cm to 30 cm and is within a specific range depending on the desired surgery.

The electrosurgical probe 50 includes a handle assembly 62 attached to the front end 60 of the jaw 56. This handle includes a lever assembly 64 that is connected to actuate the electrode 304 after the electrodes have been placed. The handle also includes a coaxial connector for connecting the electrodes to an electrosurgical power supply as described in this document, but the electrodes can also be energized by a conventional power supply.

The electrosurgical probe 50 can be used to cauterize and excise a portion of the liver. For example, the probe can be introduced through the cannula and the electrodes are advanced and opened so that a portion of the liver L to be resected can be captured. After the electrodes are closed on the opposite surface of the liver, high frequency energy can be applied as described above. After the tissue has been completely cauterized, the tissue can be excised along any line within the necrotic tissue portion. As an option, this electrosurgical probe is used to cauterize a series of adjacent tissue parts to cauterize and excise larger tissue parts than possible when using only one application of high frequency energy. can do.

In one embodiment, the electrodes can be used, for example, to cauterize and excise the uterus. The uterus has a main body with oviducts extending from both sides. In addition to the fallopian tubes, some large blood vessels extend from approximately the centerline of the uterus. The electrodes can be placed on the anterior or posterior surface of the uterus, with the fallopian tubes remaining attached and extending outward from between the electrode structures. Depending on the surgery, in some cases the fallopian tubes may be included in the area to be blocked, cauterized, and incised, in other cases the fallopian tubes may be selected not to be blocked and cauterized. This decision is based on whether or not the ovaries are removed along with the uterus. Then, for a time in the range of 10 seconds to 20 minutes, generally 10 W / cm 2-100, until the body of the uterus is virtually completely necrotic. High frequency power can be applied to the uterus at power levels within the range of W / cm2. Due to the geometry of the electrodes, the borderline of the necrotic body of the uterus is approximately along the line of the cervical end of the uterus and along the line adjacent to the fallopian tubes. The uterus can then be resected along the lines adjacent to the neck and fallopian tubes within the ablated tissue area. Resection within the ablated uterine tissue substantially minimizes bleeding and facilitates hemostasis. Then, in the case of open surgery, the uterus can be removed as it is. For minimally invasive surgery, the uterus can optionally be shredded (shredded into small pieces) before removal.

In one embodiment of the invention, parallel electrodes are provided along the device to prevent positive and negative contact when the opposing jaws and electrodes come into contact. In this embodiment, electrodes that are attached to the same jaw and are energized with opposite polarities must be attached to a non-conductive material to prevent short circuits.

The jaws can be offset by a soft compressible material (eg foam rubber) to ensure contact with all tissue in between while preventing contact between the electrodes. This embodiment of the present invention can accommodate a variety of tissue thicknesses (often expected to be 5-10 cm tissue).

To prevent the local high impedance region from impacting the system's overall impedance along the entire electrode, which in some cases reduces the system's overall power output, when the voltage reaches its maximum capacitance. , A plurality of electrodes can be arranged physically continuously. These electrodes can be energized simultaneously, repeatedly, continuously, or in any other order. The electrodes can also be energized completely independently of each other. In this scheme, if one region is already well sealed and thus reaches a high impedance value, this tissue can affect another region where the tissue is also unblocked and therefore low impedance. None, that is, the impedance rises as the blockade takes place, which can limit the propagation of power. Each electrode or electrode pair can have a unique power / energy supply profile based on the characteristics of the tissue at a particular electrode position / position.

As is clear from the disclosure in this document, it is beneficial to use longer electrosurgical electrodes, or other high energy blockade impedance mechanisms, to reduce surgical time in multiple surgical procedures. For example, an electrosurgical jaw and power supply, depending on the structure of the tissue involved and the thickness along the longitudinal direction of the tissue to be cauterized, to facilitate surgical resection of part or all of a particular organ. Variations in the geometry of both vessels can be optimized.

For example, the connective tissue or ligaments of the uterus are often relatively thin, based on animal models, and have a relatively low impedance (ie, less than 3 ohms) before energy is delivered to the tissue. However, this impedance is not constant both along the longitudinal direction of the ablated tissue and during the ablation process. So, for example, a power supply with a capacity of less than 100 volts is not enough to completely block and coagulate all the tissues and blood vessels that support the organs, because first to cauterize the tissues. After applying the power, it is often necessary to gradually increase the voltage in order to maintain the power level, taking into account the impedance that increases as the sealing and cauterization process progresses. In addition, thicker tissues or organs (eg) For the liver, lungs, intestines), or for longer parts of the tissue, significantly higher voltages are likely to be required. For more delicate tissues or sites, high voltage power energy levels may not be safe. In addition, due to the high impedance of some more delicate organs and tissues, the power supply must have sufficient shutoff function to stop power to the organs at the end of the blockade cycle. Therefore, the power supply should automatically terminate the flow of current to the tissue when it determines that the blockade cycle is complete. Manually stopping the power supply is an option, but it is less desirable because it is subjective and less likely to accurately analyze the condition of the tissue or organ. The automated feedback system disclosed in this document prevents excessive heating or cauterization of surrounding healthy tissues and organs, minimizing tissue adhesion to electrodes while ensuring adequate blockage of blood vessels. To do. Therefore, the power supply in this document has a plurality of adjustable settings that can be selected by the user based on the organ to be treated. The preset voltage upper bounds and curves for each particular organ and the final cutoff (end point) parameters are time, impedance, voltage, current, temperature, or energy data, by preliminarily characterizing each organ. Alternatively, it is determined based on some combination of these. Therefore, a process that optimizes safety and efficacy for a particular surgery is used. Different tissues and organs require different settings based on the degree of vascular development and the size of the blood vessels present.

In another embodiment of the invention, a test burst of current is performed on the tissue for a short period of time (ie, less than 5 seconds) at a low and safe power level. The profile data generated during this test is quickly (ie, less than 5 seconds) and automatically programmed into the algorithm, which meets the conditions required during the test to safely and effectively seal the tissue or organ. Based on, optimize voltage, energy, time, and / or power supply.

Similarly, the jaw / electrode geometry is optimized for each indication. The length of the jaw and handle portions is optimized for the length of the tissue and position to be sealed and incised. The forces generated by the jaws and / or the minimum compression gap are also optimized for the selected tissue. Minimal force is required to ensure a sufficient and uniform seal over the entire length of the tissue. However, excessive force results in unwanted tissue damage and causes heavy bleeding prior to the sealing process. The optimum compressive force is predetermined for each organ, or the compression handle is designed so that a predetermined force level is applied in the case of a particular organ. In one embodiment of the invention, the compressive force is controlled by a slip clutch type mechanism similar to a torque wrench, or by a jaw travel distance limiter. Thus, there are individual devices designed for each application, or one device that can have multiple individual settings that are adjusted to a given setting for the organ to be operated on or excised or the thickness of the organ. In some embodiments, the force can be adjusted automatically and dynamically by detecting pressure along the longitudinal direction of one or both jaws with one or more strain gauges associated with the jaws. it can.

In another embodiment, the force applied by the jaws can be limited by the material used for the jaws themselves. For organs or tissues that require less force to safely compress and seal the tissue, a material with a lower flexural modulus is more appropriate, while higher levels to ensure effective sealing. Materials with higher modulus can be used in tissues that can be safely tightened with.

In another embodiment, the thickness of the jaws is adjusted by inflating the hollow chamber within the jaws with a pressurized fluid.

The angle between the handle of the device and the jaws can also be optimized for the application. This angle is primarily determined by the angle of attack of the surgery in the surgical environment. The device can have a gentle or gentle curve rather than a sharp angle for certain applications.

The cutting / incision part (blade) of the process can also be optimized for specific organs. If the cutting is done with a sharp blade, the width of the blade can be varied based on the thickness of the tissue or organ to be excised. The thickness of the cutting blade material can also be optimized based on the specific thickness / ease of cutting the tissue. Hard-to-cut tissues may require more sawing motion, or thicker or serrated blades, or scissors mechanisms, which are also predetermined for the particular application. If a high energy system is used to make an incision in the tissue, this too can be optimized for the application, as mentioned above in the power supply paragraph.

In the multi-electrode algorithm taught in this document, each of the electrodes is treated independently with respect to energy propagation and high frequency cycle monitoring, tuning, and termination. In the currently preferred embodiments of the present invention, the monitored parameters are current, voltage, impedance, energy, power, time, and temperature. Any combination of these parameters and the values of the other parameters can be monitored. These values can be monitored in a mathematical model that combines them into one algorithm, which determines the quality of the high frequency blockade process based on prior empirical analysis. Blockade of arteries and veins for as short a time as possible (preferably less than 1 minute, preferably without generating excessive heat transfer that can damage surrounding healthy tissue or cause tissue to adhere to the electrode surface. Optimizes in less than 30 seconds), so energy and / or power output can be adjusted. Cycle optimization can be based on an algorithm program programmed into the power generator software / firmware, which is empirical so that the conditions of the surgical procedure being performed are safely and iteratively met. When the conditions required for are met, the cycle is adjusted and finally terminated. For example, when a certain impedance and / or temperature value is reached, the power level is continued for a predetermined time from that point, or when a certain impedance and pressure or temperature threshold is reached, the power level is set. Lower (or vice versa).

When the tissue is dried, the impedance tends to reach the horizontal range and no longer serves as a measure of the quality of the sealing process that occurs after the time the drying begins. Therefore, impedance measurements alone cannot be an accurate determinant of successful vascular / tissue closure. Therefore, multiple adjustments, step functions, or continuous changes of power, voltage, and / or energy are made to optimize the blockade process. As a result of cycle changes or adjustments, variables can be changed in a complex upward or downward manner to optimize vascular / tissue blockade conditions. As a result, each electrode or electrode pair has different cycle times and different profiles of power, current, voltage, and energy as a result of feedback data about a particular part of the tissue in contact with a particular electrode. Can have. The adjustment / determination program can be a complex algorithm based on a step of monitoring a plurality of variables and a step of adjusting and ending the cycle in response to a combination of predetermined conditions.

Below are the general values for these variables.

Power: 10-1000 watts / channel or electrode pair, generally 100-500 watts / channel or electrode pair Impedance: 2 to 500 ohms, generally 2 to 200 ohms Voltage: 5 to 500 volts, generally 50 to 250 volts Time: 1 to 1200 seconds, generally 5 to 30 seconds Energy: 1 to 30,000 joules, generally 1,000 to 10,000 joules In the currently preferred embodiment, the power generator consists of a constant output power design rather than a constant voltage or constant current design. In the design of the present invention, the power output is set based on the load on the system. Therefore, if the system is loaded with very high impedance, the voltage will be maintained at a reasonable level to avoid arc discharge. In applications where power generators are used (ie, electrocauterization), the impedance range can vary during tissue ablation, eg, between 2 ohms and 150 ohms. The power source of the present invention provides a large current at low impedance to achieve initial drying when the tissue is first ablated by applying a constant amount of power, and as the ablation progresses, the tissue is sealed. Apply a higher voltage to complete the process. Thus, the present invention provides a higher current and a lower voltage at the beginning of the ablation process and a higher voltage and a lower voltage at the blockade stage of the process. All that is required to control such a power generator is for the system to monitor power.

In a currently preferred embodiment, the power source is provided with a mechanism for setting the desired power. This mechanism can be by profile or otherwise, as will be explained later. Pulse width adjustment is used in connection with flyback transformers. The system energizes the primary side of the flyback transformer and produces a tuned output. The secondary side can be adjusted to, for example, 15 volts at the desired amperage to produce the desired power output. The power curve is determined based on the time length determined by the width of the pulse energizing the primary side. Thus, in the present invention, a particular power level is established on the primary side of the flyback transformer, and the same power level is provided by the secondary side regardless of the impedance of the load (ie, tissue).

In a preferred embodiment of the invention, the power generator is a power source for multiple electrodes in an electrosurgical device. Therefore, the power generator is provided with a plurality of output channels, each of which can be adjusted independently. FIG. 3 provides a block diagram showing an electrosurgical device 300 containing a plurality of electrodes 310, described above in connection with FIGS. 1 and 2. This electrosurgical device typically includes multiple conductors (one for each output channel of the power generator), with a conductive path 355 for receiving power from the power generator 16 and a ground path and / or power. It includes a return path 360 to provide feedback to the generator (which can have any information about current, voltage, impedance, energy, power, and temperature). The electrosurgical device is equipped with suitable sensors. For example, a thermistor can be used to detect the temperature, while the impedance between any two or more electrodes can be measured. Alternatively, one jaw of the electrosurgical device can be provided with a ground plane and individual electrodes can be placed on the other jaw of the electrosurgical device, thus providing a path from electrode to return electrode. Will be done. In this way, one jaw can establish a ground plane for the electrodes located on the other jaw. In addition, the power generator can be connected to the electrodes at the positive and / or negative terminals. Thus, the electronics in the power generator can reassign the polarities and / or uses of the various terminals 310 in the device in real time. For example, one of the electrodes or terminals can be left as an impedance detection element. In another embodiment of the invention, this element can be dedicated to detecting impedance throughout the process.

The power generator 16 consists of a power source 335 with multiple outputs, these outputs being controlled by a control electronic circuit 350 and routed to individual electrodes in an electrosurgical device as described above. There is. These multiple outputs are independently manipulated by a microprocessor or other control mechanism 330 and are easily tuned and assignable. Thus, at a particular point in time in the operation of the ablation cycle, the output can be assigned to any one or more electrode elements and at another point in time it can be dynamically reassigned. For example, if the power source is a four-channel power source and the electrosurgical device has 16 electrodes, each of the channels can support the four electrodes in the electrosurgical device. However, this arrangement can be modified so that some channels support more electrodes than others.

The microprocessor 330 can be configured by a set of profiles 340 to operate the device by a power curve according to the surgery performed and power distribution between various electrodes. Thus, a particular profile for hysterectomy can be established for the electrosurgical device, while another profile can be established for liver surgery. In addition, a smart card reader 365 can be provided that configures the system for a particular operation and provides memory for recording information about the operation of the power generator during the operation. For example, the application of power to each channel, the detected impedance, the detected temperature, etc. are acquired and the surgery is documented.

FIG. 4 is a flow chart showing an algorithm for power adjustment according to the present invention. At the beginning of the process, the user determines the profile applied to a particular surgery (400). For example, some tissue or surgery requires a higher initial power level and then reduces the power level during the cauterization process.

A probe (electrosurgical device) is placed (405) and the power source is powered on (410). The system initializes itself (415) and produces a profile for the tissue to be cauterized, for example, by taking measurements of initial impedance along various electrodes in an electrosurgical device. Initialization can also include taking initial temperature measurements, strain pressure measurements (indicating tissue thickness along the surface of the surgical device), and other measurements. To obtain these values, a pilot signal can be transmitted to the electrosurgical device. For example, a low initial voltage can be provided to measure impedance. In this way, a real-time profile can be created for the actual tissue to be cauterized, and this profile can be used as an adaptation of a pre-established profile for a particular surgical procedure. In this way, the established profile for surgery can be modified according to measurements for the tissue to be cauterized.

The system then sets a threshold that determines when the end point is reached (420). These thresholds can be determined by measurements such as impedance, current, voltage, energy, power, and temperature. Thresholds can also work in relation to the time element. Therefore, when the threshold is reached, the system can continue to operate for a certain length of time to ensure that it reaches the appropriate end point for the cauterization to complete. In some embodiments, the power generator channels assigned to the electrodes of the tissue portion that have reached the end point reassign the tissue to the electrodes that are still cauterizing, providing additional power to the process. This can speed up the end.

Power is applied to the electrosurgical device to initiate cauterization (425). The system monitors two or more parameters during this process to determine when a threshold is reached (430). When the threshold is reached, the end point procedure (435) is performed. This end point procedure can be as simple as gradually reducing the power, or it can be accompanied by the setting of a timer. It is important to note that the application of power can be adjusted during the cauterization process so that the power curve is applied for surgery, while the application of power is constant over a wide range of impedances. Since the present invention provides multiple power channels for multiple electrodes, some electrodes may reach the end point before other electrodes. In this case, the power to these electrodes is terminated, while the power continues to be applied to the other electrodes. Therefore, each of the electrodes can have a different power curve that is adjusted in real time. If all endpoints have not been reached (440), the process continues (445), and if so, the system is powered off (450) and the procedure completes.

The electrosurgical device incorporates sensors to acquire various process parameters in real time according to an algorithm. Therefore, impedance can be measured between selected electrode pairs or a set of electrodes. Temperature can be measured in relation to one or more physical transitions along the surface of the device. The effect of cauterization can be measured by a local strain gauge located along the longitudinal direction of one or both probe jaws (in this example, the strain gauge is also used to pre-calculate the cauterization profile. Can be used). In this regard, each of the electrodes can be thought of as a separate device that operates independently of a particular area along the surface of the tissue with which the probe jaws are in contact.

Although the present invention has been described in this document in connection with preferred embodiments, the uses described in this document may be replaced by other uses without departing from the concept and scope of the invention. What can be done will be easily understood by those skilled in the art. For example, in some embodiments, the power generator determines the presence or absence of tissue on each of the electrodes at the beginning of the cauterization cycle, impedance, pressure, or any combination of these and / or other parameters. , By measuring any of the above. If no tissue is present in any of the electrode pairs, the electrode pair is idle and instructional information for this situation is provided to the power generator operator. The power generator can also provide a status indicator for each of the electrode pairs, indicating whether the sealing cycle is in progress or completed for each of the electrode pairs. In this embodiment, each of the electrode pairs may include a mode status indicator (eg, LED) that indicates either an idle state, an active state, or a completed state after the cauterization cycle has begun.

Therefore, the present invention shall be limited only by the claims.

<figref num="1">It is a conceptual diagram of the system and method of this invention using a plurality of rigid plate electrodes.</figref><figref num="2">As the structure of the electrode structure, an electrosurgical probe is shown in which each of the electrode structures has a plurality of active surfaces that are electrically insulated.</figref><figref num="3">It is a schematic block diagram which shows the electric power generator by this invention.</figref><figref num="4">It is a flow chart which shows the algorithm of the power adjustment by this invention.</figref>

Code description

10 system 12 First composite electrode 14 Second electrode 16 High frequency power supply T organization 50 Electrosurgical probe 56 Joe 58 end 60 Front end 62 Handle assembly 64 lever assembly 300 system 302, 304 Electrode structure 310 Conductive piece 330 microprocessor 340 profile 350 control electronic circuit 355 Conductive path 360 return route 365 smart card reader