System for monitoring ablation size

The present disclosure relates to systems and methods that can be used in tissue ablation procedures. More specifically, the present disclosure relates to systems and methods for monitoring ablation scale during real-time tissue ablation procedures.

In the treatment of diseases such as cancer, it has been found that certain types of cancer cells degenerate at elevated temperatures (temperatures that are usually slightly lower than the temperatures normally harmful to healthy cells). These types of treatments, commonly known as hyperthermia, typically utilize electromagnetic radiation to heat affected cells to temperatures above 41 ° C, while avoiding irreversible cell destruction. Maintain healthy cells adjacent to low temperatures. Cauterization of tissue can be mentioned as a treatment using electromagnetic radiation to heat the tissue.

Microwave ablation procedures, such as those performed for polycystic ovary, are typically performed to ablate the target tissue and denature or kill the tissue. Many procedures and a wide variety of devices that utilize electromagnetic radiation therapy are known in the art. Such microwave therapy is typically used in the treatment of tissues and organs such as the prostate, heart, and liver.

One non-invasive procedure generally involves the treatment of tissue beneath the skin (eg, a tumor) through the use of microwave energy. Microwave energy can penetrate the skin non-invasively and reach the underlying tissues. However, this non-invasive procedure can result in unwanted heating of healthy tissue. Therefore, the non-invasive use of microwave energy requires a great deal of control.

Currently, there are several systems and methods for monitoring the size of the ablation area. In some cases, one or more sensors (or other suitable equipment) are operably associated with the microwave ablation equipment. For example, in a microwave ablation device that includes a unipolar antenna configuration, the extended microwave conductor may be operationally communicative with the sensor exposed at the end of the microwave conductor. This type of sensor is sometimes surrounded by a dielectric shaft sheath.

Typically, one or more of the above types of sensors will work if the microwave ablation device is not working, i.e. not radiating (eg, in a control device for controlling the output of a power source). It is configured to provide feedback). That is, the aforementioned sensors do not work in real time. Typically, the power source is power when the sensor provides feedback (eg, tissue temperature) to a controller and / or one or more other devices configured to control the power source. Cuts off (or the pulse stops).

The present disclosure provides a system for monitoring the scale of ablation in real time. The system includes a power source that includes a microprocessor to execute one or more control algorithms. Microwave antennas are configured to carry microwave energy from a power source to the tissue to form a cautery zone. The ablation zone control module operatesly communicates with the storage device associated with the power source. The storage includes one or more data reference tables that contain data related to control curves that change over time and that represent one or more electrical parameters associated with the microwave antenna. A point along the control curve corresponds to the value of that electrical parameter, and if a given threshold of one or more electrical parameters is measured corresponding to the radius of the ablation zone, the ablation zone control module signals. cause.

The disclosure also provides a microwave antenna adapted to connect to a power source configured to perform a cauterization procedure. Microwave antennas include radiating parts that are configured to carry microwave energy from a power source to the tissue and form a cautery zone. The ablation zone control module operatesly communicates with the storage device associated with the power source. The storage includes one or more data reference tables that contain data related to control curves that change over time and that represent one or more electrical parameters associated with the microwave antenna. A point along the control curve corresponds to the value of one or more electrical parameters, and if a given threshold of at least one electrical parameter is measured corresponding to the radius of the ablation zone, then the ablation zone control module. Causes a signal.

The disclosure also provides a method for monitoring the temperature of tissue undergoing cauterization. The method involves the first step of transferring microwave energy from a power source to a microwave antenna to form a cauterized area of tissue. One step in the method is to measure the reflexes associated with the microwave antenna as the cauterized area of the tissue forms. One step of the method is to transmit a control signal to a power source when the microwave antenna reaches a predetermined reflection force. Adjusting the amount of microwave energy from a power source to its microwave antenna is another step in the method.

<figref num="1">It is a perspective view of the system for monitoring the cauterization scale according to one Embodiment of this disclosure.</figref><figref num="2">It is a functional block diagram of a power source for use with the system depicted in Figure 1.</figref><figref num="3A">It is a schematic plan view of the tip of the microwave antenna depicted in FIG. 1, exemplifying a radiative cauterization region having a spherical configuration.</figref><figref num="3B">FIG. 5 is a schematic plan view of the tip of the microwave antenna depicted in FIG. 1, exemplifying a radiative cauterization region with an elliptical configuration.</figref><figref num="4A">Reflective power (P_r) It is a graph drawing of the time (t) curve.</figref><figref num="4B">Corresponding reflex power (P_r) Anti-cauterization radius (A)_r) It is a graph depiction of a curve.</figref><figref num="4C">Reflective power (P_r) Derivative coefficient of the time (t) curve (dP_rIt is a graph depiction of / dt).</figref><figref num="5">It is a flow chart which illustrates the method for monitoring the temperature of the tissue to be cauterized according to this disclosure.</figref>

The above and other aspects, features, and advantages of the present disclosure, in combination with the accompanying drawings below, will become more apparent in view of the embodiments for carrying out the invention below.

Embodiments of the systems and methods disclosed herein are described in detail with reference to constructions that identify elements with similar or identical reference numbers. As used herein and as conventional, the term "distal" refers to the part farthest from the user and the term "proximal" refers to the part closest to the user. .. In addition, terms such as "upper", "lower", "forward", "rear", etc. refer to the positioning or orientation of the components of the figure and are used only for convenience of depiction.

With reference to Figure 1, the system for monitoring the ablation scale is designated as 10. System 10 includes an electrosurgical power source, eg, one or more control devices 300, and, in some cases, a fluid supply pump 40, or an operational communication, RF and / or microwave (MW) generation. Includes a microwave antenna 100 adapted to connect to a vessel 200. Briefly, the microwave antenna 100 is a cooling set having an elongated mandrel 112, an introducer 116 having an elongated mandrel 112 and a radioactive or conductive portion or tip 114 operably located inside the elongated mandrel 112, and a cooling sheath 121. It includes a solid 120, a handle 118, a cooling fluid supply device 122 and a cooling fluid return device 124, and an electrosurgical energy connector 126. The connector 126 connects the microwave antenna 100 to an electrosurgical power source 200, eg, a generator or source of radio frequency energy and / or microwave energy, and transfers the electrosurgical energy to the distance of the microwave antenna 100. It is configured to supply to the place part. The conductive tip 114 and the elongated mandrel 112 extend from the proximal end of the microwave antenna 100 and are inside the mandrel 112 and at the conductive or radioactive tip 114 (see, eg, FIG. 3A). Electrical communication with connector 126 through an internal coaxial cable 126a (see, eg, FIG. 3A) containing the tip of an internal conductor that is operationally connected to an adjacent, operably arranged radiator 138. To do. As is common in the art, the internal coaxial cable 126a includes a dielectric material and an external conductor that surrounds the tip of the internal conductor and the dielectric material, respectively. The connection hub (not shown) located at the proximal end of the microwave antenna 100 has the connector 126 on the internal coaxial cable 126a and the cooling fluid supply device 122 and the cooling fluid return device 124 on the cooling assembly 120. Connect operably. The radiating section 138 via the conductive tip 114 (or, in some cases, having no conductive tip 114) is in (bipolar or unipolar mode). It is configured to deliver radio frequency energy (of which) or microwave energy (having a frequency of about 500 MHz to about 10 GHz) to the target tissue site. An elongated mandrel 112 and a conductive tip 114 can be formed from suitable conductive materials including, but not limited to, copper, gold, silver, or other conductive metals having similar conductivity values. .. Alternatively, the elongated mandrel 112 and / or the conductive tip 114 can be constructed from stainless steel, or plated with other materials, such as other conductive materials such as gold or silver, to identify Properties can be improved, for example, conductivity can be improved, energy loss can be reduced, and the like. In one embodiment, the conductive tip can be deployed from an elongated mandrel 112. In one specific embodiment, the microwave antenna 100 may include an introducer 116 having an elongated mandrel 112 and a non-conductive tip 114. In this case, the tip 114 can be made from non-conductive materials such as ceramics, plastics and the like.

With reference to FIG. 2, a schematic block diagram of the generator 200 is illustrated. The generator 200 includes a control device 300 having one or more modules (eg, a cauterization area control module 332 (AZCM332), a power supply device 237, and a microwave output stage 238). In this case, the generator 200 is described for carrying microwave energy. The power supply device 237 converts the DC force into microwave energy and provides the DC force to the microwave output stage 238 that transports the microwave energy to the radiation unit 138 of the microwave antenna 100. The controller 300 may include analog and / or logic circuits for processing the senses provided by AZCM332 and measuring the control signals sent through the microprocessor 335 to the generator 200 and / or the supply pump 40. The controller 300 (or the components operably associated with the controller) has a reflective force P associated with the microwave antenna 100 when the microwave antenna is radiating energy._rAccepts one or more measurement signals indicating.

One or more modules of controller 300, such as AZCM332, analyze its measurement signal and the threshold reflex force P._r, For example, P_r1Is satisfied. Reflective force P of the threshold_r1If the condition is met, then the AZCM332, microprocessor 335, and / or the controller instructs the generator 200 to appropriately adjust the microwave output stage 238 and / or the power supply 237. In addition, controller 300 may also signal the supply pump to regulate the amount of cooling fluid relative to the microwave antenna 100 and / or surrounding tissue. The control device 200 includes a microprocessor 335 having a storage device 336 that can be a volatile storage device (eg, RAM) and / or a non-volatile storage device (eg, flash medium, disk medium, etc.). In the illustrated embodiment, the microprocessor 335 is a power supply device that allows the microprocessor 335 to control the output of the generator 300 according to either an open and / or closed control loop array. Operatively communicates with 237 and / or microwave output stage 238. The microprocessor 335 can execute software instructions for processing the data received by the AZCM 332 and software instructions for appropriately outputting control signals to the generator 300 and / or the supply pump 40. Software instructions that can be executed by the control device 300 are stored in the storage device 336.

One or more electrical characteristics (eg, voltage, current, power, impedance, etc.) associated with the signal (or pulse) generated by the generator 200 can be monitored and measured. More specifically, the electrical characteristics associated with the anterior and reflective parts of the signal generated by the generator 200 are monitored and measured. For example, in one specific embodiment, the forward and reflected power of the signal for cauterizing the tissue, P._fAnd P_rIs measured by the AZCM332, controller 300, microprocessor 337, or other suitable module associated with generator 200 and / or controller 300, respectively.

One or more control algorithms for predicting the ablation scale of the tissue are performed by the controller 300. More specifically, the reflective force P associated with a particular microwave antenna, eg, microwave antenna 100._rCan be used to indicate tissue death or necrosis using the concept of correlating with a cauterization area "A" having a radius "r". More specifically, the reflective force P associated with the microwave antenna 100_rChanges over the ablation cycle due to the complex permeability changes of the tissue caused by increased temperature (see, eg, Figures 4A and 4B). Reflective force P as a function of time, according to the control curve illustrated in Figure 4A._rThe relationship is expressed. Similarly, according to the control curve illustrated in Figure 4B, the reflectivity P as a function of cauterization scale._rThe relationship is expressed. The control curves represented by FIGS. 4A and 4B are the model functions f (t) and captured during the cauterization procedure performed with the microwave antenna 100, controller 300, and / or generator 200. Reflective power P_rBased on known measurements of. In accordance with the present disclosure, the reflex force P of a specific threshold is used using the control curves (and / or mathematically related equations) depicted in FIGS. 4A and 4B._r(For example, reflex power P_r1-ss) Is t_ssWithin a specific time range that does not exceed (eg, t₁~ t_ss), That is, the time that the microwave antenna 100 and the ablated tissue are in steady state conditions can be calculated and / or verified, see, for example, FIG. 4A or FIG. 4B. The significance of the microwave antenna 100 and the ablated tissue in steady state conditions is described in more detail below.

Referring here to FIGS. 4A and 4B, there is an impedance mismatch between the microwave antenna 100 and the tissue when the microwave antenna 100 is first inserted into the unheated tissue. This impedance mismatch is due to the impedance of 50Ω associated with the internal cable 126a, which is inconsistent with the impedance of the radiating section 118 and / or the conductive tip 114. Impedance mismatch is a non-zero reflex force P at the start of the ablation procedure_ri(See, for example, Figures 4A and 4B). In the course of the ablation procedure, time t until the optimum impedance matching between the microwave antenna 100 and the tissue is reached (combined with Figure 4B on the ablation scale with a radius "r" equal to 2 cm).₂(See Figure 4A at a time equal to), the tissue in the "near-field" warms up and the reflex force P (at non-linear velocity)_rConsequently results in a reduction in (see, eg, Figure 4A). That is, the total impedance Z of the microwave antenna 100 and the tissue in the "near field"_tIs approximately equal to 50Ω. The microwave antenna 100 and tissue in the "near field" remain at this optimum impedance for a short time. Time t₂At a later time, the microwave antenna 100 and tissue in the near field diverge from its optimal impedance matching (at non-linear velocities). Finally, if the microwave antenna 100 was heating the tissue to the maximum reachable temperature, then the corresponding radius "r" (eg r)_ss) Is formed (see, eg, FIG. 3A in combination with FIGS. 4A and 4B). At this maximum temperature, the dielectric constant and conductivity associated with the ablated tissue is the steady-state reflectivity P associated with the microwave antenna 100._rss(Hereafter, simply P_rssThe steady-state condition (this steady-state condition is called time t) corresponding to (called)_ssTo reach). That is, since the cauterized tissue is in the "near-field" of the microwave antenna 100, the cauterized tissue is essentially part of the microwave antenna 100. Therefore, when the dielectric constant and conductivity associated with the ablated tissue reach steady-state conditions, the reflectivity P at the microwave antenna 100_rAlso in steady-state conditions, for example, P in Figure 4A._rssTo reach.

As mentioned above, the control algorithm described above includes one or more model functions f (t) representing the model curves illustrated in FIGS. 4A and 4B. Model function f (t), model curve depicted in Figures 4A and 4B, and / or reflectivity P_rKnown measurements of the reflex force P so that real-time monitoring of the cautery area can be achieved._rUsed to obtain information related to. More specifically, the measurement result of the gradient of the tangent at a point along any of the control curves (eg, the curve illustrated in FIG. 4A) is the derivative (dP) of the curve at that point._rEqual to / dt). The calculation result of the differential coefficient at a specific point along one or more curves is the reflective force P._rProvide information about. More specifically, the reflex force P with respect to time_rRate of change, more specifically, reflective force P_rThe vector quantity of the rate of change (ie, the direction (positive or negative) and the magnitude of the rate of change) is calculated from one or more control curves depicted in FIGS. 4A-4C. Reflective force against time P_rUtilizing this rate of change related to, for example, the reflex force P_rIt is possible to distinguish between rising and falling. More specifically, the points along the control curves depicted in FIGS. 4A and 4B are the reflective forces P._r, For example, reflex power P_r1And P_r3Corresponds to the value of, which corresponds to the corresponding time t, eg, time t₁And t₃With radius "r", for example radius r₁And r₃Corresponds to the ablation area "A" with. Reflective value, eg P_r1Is more than one radius of the cautery area, eg r₁And r₃Please note that it corresponds to.

More specifically, the reflective force P depicted in FIGS. 4A and 4B._rA typical control curve for is the initial value, eg, P, at the start of the ablation procedure._iReflective force P_rIs illustrated. Reflective power P_rReflection force P until is approximately equal to 0, i.e., when the total impedance of the microwave antenna 100 and tissue in the "near field" is approximately equal to 50Ω._rDecreases. If the total impedance of the microwave antenna 100 and the tissue in the "near field" is not equal to 50Ω, then time t₂In the time after, the reflex P_rWill increase. Therefore, the reflex force P along the control curve_rThe measured value of reflects force P, indicating one or more cauterization areas "A" with the corresponding radius "r"._rProvide one or more numbers for. For example, time t₁Reflective force in P_rMeasured value, for example, P_r1Is a radius r approximately equal to 1 cm₁Corresponds to the ablation area "A" with (see Figures 4A and 4B together). Similarly, time t₃Reflective force in P_rMeasured value, for example, P_r1Is a radius r approximately equal to 2.2 cm₃Corresponding to the ablation area "A" with, see Figures 4A and 4B together.

According to the present disclosure, selection points along the control curve (eg, radius r).₁And r₃Corresponding point and / or time t₁And t₃The sample of the differential coefficient taken at (the point corresponding to) is the reflective force P with respect to the control curve._rProvides information related to the exact location of the (eg, ascending or descending portion of the control curve).

More specifically, and as best seen, for example, in Figure 4C, the reflective force P_rSince the gradient of is decreasing, the reflex force P_rIs P_r1Approximately equal time t₁The differential coefficient taken at the point along the control curve in is negative. In this case, the reflex force P_r1Can be considered to have a negative value and is assigned a negative value to one or more modules associated with the controller 300 and / or the generator 200, eg, AZCM332, with a reflective force P._r1This value of is the radius r₁Indicates a cauterization area "A" with and corresponds to. Similarly, as best seen in Figure 4C, reflectivity P_rSince the gradient of is increasing, the reflex force P_rIs P_r1Approximately equal time t₃The sample of differential coefficients taken at points along the control curve in is positive. In this case, the reflex force P_r1Can be considered to have a positive value and is assigned a positive value to one or more modules associated with the controller 300 and / or the generator 200, eg, AZCM332, with a reflective force P._r1This value of is the radius r₃Indicates a cauterization area "A" with and corresponds to.

By executing a control algorithm that utilizes the calculation result of the differential coefficient taken at a point on the control curve, it becomes easy to determine the exact scale of the ablation region "A". That is, one or more modules associated with controller 300 and generator 200, eg, AZCM332, have a radius "r" of which cauterization region, eg radius r.₁Or r₂However, the reflex power P_r, For example, the measured reflex force P_r1It is possible to identify whether it corresponds to. Furthermore, when a large number of ablation areas "A" are placed adjacent to each other, the tissue impedance of the unheated tissue in the vicinity of the ablation area "A" can result in a measurement of reflectivity Pr. More specifically, the tissue impedance of unheated tissue in near-field may be slightly higher or lower (depending on the particular adjacent ablation zone "A"), which, as well, Reflective power P more than expected_rCan be higher or lower at the beginning of the ablation procedure. Therefore, the initial reflective force P_iIs P_r4When approximately equal to, the calculation of the derivative taken at a point on the control curve indicates that the microwave antenna 100 is placed adjacent to the heated or cauterized tissue. That is, P_r4The positive initial value is the reflex force P_rIs increasing, and therefore the steady-state condition is approaching, that is, the derivative calculation results show the measured reflex force P._rIs within the rising part of the control curve, and the reflex force P_rIndicates that 0, that is, the total impedance associated with the microwave antenna 100 and the tissue adjacent to the near-field does not approach a point on the control curve that is approximately equal to 50Ω.

Any suitable configuration (eg, width "w" and length "l") such as spherical (Fig. 3A), hemispherical, oval (Fig. 3B where the cauterization area is designated as "A-2"). The microwave antenna 100 of the present disclosure can be configured to create a cauterized region "A" with ")" (see, eg, FIG. 3). In one specific embodiment, the microwave antenna 100 is configured to create a cautery region "A" that is spherical (FIG. 3A). As mentioned above, when the microwave antenna 100 heats the tissue in the "proximity field" to maximum temperature, the dielectric constants and conductivity associated with the ablated tissue are the steady-state reflections associated with the microwave antenna 100. Power P_rssReach the steady state corresponding to. P associated with the microwave antenna 100 with a cauterized structure (ie, a cauterized structure whose dielectric constant and conductivity are in steady-state conditions)._rssBy correlating the ablation zone "A" with a particular magnitude (eg radius r)_ss) And shape (eg, sphere) are shown. Therefore, the P associated with the microwave antenna 100_rssThe measured value of is the radius r, for example r_ssCorresponds to the ablation area "A" with. The control algorithm of the present disclosure predicts the cautery region using known steady-state reflectivity associated with a particular microwave antenna of a particular radius. That is, the reflective force P associated with a particular microwave antenna, eg, microwave antenna 100._r, For example, P_rss, And the corresponding radius, eg r_ssIs edited in one or more reference tables "D", stored in storage, such as storage 336, and can be recalled by microprocessor 335 and / or AZCM332. Therefore, the measured reflectivity of a particular microwave antenna, eg, microwave antenna 100, is P._rssUpon reaching, one or more modules associated with the controller 300, eg, AZCM332, commands the controller 200 to appropriately adjust the output to the microwave antenna 100. The combination of this event is r_ssWill provide a cautery area "A" with a radius approximately equal to.

In one embodiment, for a given microwave antenna, eg, microwave antenna 100, t_ssEarlier time, eg time t₁~ t₄The reflection force measurement can be started at. In this case, the reflective force associated with the microwave antenna 100, eg P_r1~ P_r4Is measured from the center of the cauterization area "A", the radius r₁~ r₄It can be correlated with the ablation region "A" defined by multiple concentric ablation regions (collectively called the radius r). More specifically, the reflective force P_r1~ P_r4And the corresponding radius "r", P_rssAnd r_ssCan be correlated with each other in the manner described above (see, eg, FIG. 3A in combination with FIGS. 4A and 4B). In this case, a particular reflective force, eg P₃When is satisfied, one or more modules associated with the controller 300, eg, AZCM332, commands the controller 200 to appropriately adjust the output to the microwave antenna 100.

Reflection force P associated with microwave antenna 100_rNote that can vary with a given microwave antenna. Specific reflectivity P for a given microwave antenna_rFactors that can contribute to the production of microwave antennas (or related parts, such as radiation), such as dimensions associated with microwave antennas (eg, length, width, etc.), copper, silver, etc. The type of material used to do this, the composition of the radiating part (bipolar, unipolar, etc.), and / or the conductive tip associated with the microwave antenna (eg, sharp, dull, bent, etc.). However, it is not limited to these. Specific reflectivity P for a given microwave antenna_rOther factors that can contribute to are, for example, the type of microwave antenna (eg, microwave antenna configured for use in treating lungs, kidneys, liver, etc.), the type of tissue to be treated (eg). For example, lungs, kidneys, liver, heart, etc.), tumor size, etc.

The AZCM332 may be a module separate from the microprocessor 335, or the AZCM332 may include a microprocessor 335. In one embodiment, the AZCM332 can be operably placed on the microwave antenna 100. The AZCM332 may include a control circuit that receives information from one or more control modules and / or one or more impedance sensors (not shown) and provides that information to controller 300 and / or microprocessor 335. In this case, the AZCM332, microprocessor 335, and / or controller 300 calls reference table "D" and a particular cauterization area (eg, radius r)._ssThe specific reflectivity associated with the microwave assembly 100 (eg, P), corresponding to the specific cautery region with_rss) Satisfies, and then the generator 200 can be instructed to adjust the amount of microwave energy carried to the microwave antenna. In one specific embodiment, reference table "D" can be stored in a storage device (not shown) associated with the microwave antenna 100. More specifically, reference table "D" can be stored in a storage device that is operationally associated with the handle 118 and / or connector 126 of the microwave antenna 100, and the microprocessor 335 and / or storage. It can be downloaded, read, saved in device 336, and then recalled and used as described above. This would eliminate the need to reprogram the generator 200 and / or controller 300 for a particular microwave antenna. The storage device can also be configured to include information related to the microwave antenna 100. For example, storing information such as the type of microwave antenna, the type of tissue that the microwave antenna is configured to treat, the type of cauterized area desired, etc. in the storage equipment associated with the microwave antenna. Can be done. In this case, use with a microwave antenna configured to create a cauterization zone "A" different from that of the microwave antenna 100 configured to create a cauterization zone "A", for example, a cauterization zone "A-2". The generator 200 and / or the controller 300 of the system 10 can be adapted for this purpose.

In the embodiments illustrated in FIGS. 1-4, the generator is shown operably coupled to the fluid supply pump 40. The feed pump 40 is similarly operably coupled to the feed tank 44. In an embodiment, the microprocessor 335 is operatedly communicated with, thereby opening, the supply pump 40 through one or more suitable types of interfaces, eg, ports 240, which are operationally located on the generator 200. And / or according to any of the closed control loop arrangements, the microprocessor 335 can control the output of the cooling fluid from the feed pump 40 to the microwave antenna 100. The control device 300 can send a signal to the supply pump 40 to control the output of the cooling fluid from the supply tank 44 to the microwave antenna 100. In this way, the cooling fluid 42 is automatically circulated to the microwave antenna 100 and returned to the supply pump 40. In certain embodiments, the clinician can manually control the feed pump 40 to expel the cooling fluid 42 from the microwave antenna 100 into and / or near the surrounding tissue.

The operation of System 10 is described here. In the following description, the loss associated with the connector 126 and / or the cable 126a is negligible and therefore the reflectivity of the microwave antenna 100 adjacent to the cautery area during the cauterization procedure is calculated and / Or it is assumed that it is not needed when making a decision. First, the microwave antenna 100 is connected to the generator 200. In one specific embodiment, the generator 200 and / or one or more modules associated with the controller 300, eg, AZCM332, is the data from the storage equipment associated with the antenna 100, eg, the type of microwave antenna. , Read and / or download the type of tissue to be treated, etc. The microwave antenna 100 can then be placed adjacent to the tissue (Fig. 3A). The generator 200 can then be activated to supply microwave energy to the radiating section 138 of the microwave antenna 100 so that the tissue can be cauterized. During tissue cauterization, the microwave antenna 100 has a predetermined reflective force, eg, P._rssUpon reaching, the AZCM332 instructs the generator 200 to adjust the microwave energy appropriately. In the sequence of events described above, the AZCM332 functions in real time and has an appropriate proportion of uniform cauterization (eg radius r)._ssThe amount of microwave energy relative to the ablation zone is controlled so that the ablation zone "A") with is formed with minimal or no damage to adjacent tissue.

With reference to FIG. 5, a method 400 for monitoring the temperature of a cauterized tissue is illustrated. In step 402, the microwave energy from the generator 200 is transmitted to the microwave antenna 100 adjacent to the ablation site of the tissue. In step 404, the reflection force P associated with the microwave antenna_rIs monitored. In step 406, the predetermined reflective force P_rWhen the microwave antenna 100 reaches, the detection signal is transmitted to the generator 200. In step 408, the amount of microwave energy from the generator 200 to the microwave antenna 100 can be adjusted.

From the above and with reference to the various constructions, one of ordinary skill in the art will appreciate that certain modifications can be made to this disclosure without departing from the scope of this disclosure. For example, one or more directional couplers (not shown) are operatedly associated with the generator 200, controller 300, and / or AZCM332, and the forward power, reflected power, of the sampled output signal (or pulse), And / or the load power portion can be configured to point towards the AZCM332. More specifically, the directional coupler provides a sample of forward and reflected signals (or pulses) generated by the generator 200. The power, magnitude, and phase of the generated output signal can be obtained or calculated from the forward and reflected signals measured by conventional algorithms using one or more suitable equations.

Note that the energy value or parameter of the output pulse (eg, power, voltage, current, impedance, magnitude, or phase) is valid at the output of the generator 200. That is, as suggested above, the connector 126 and / or the internal cable 126a may include transmission line loss. Therefore, to obtain a more accurate interpretation and / or measurement of energy values or parameters that are carried to the microwave antenna 100 and / or reflected back to the generator 200, the connector 126 and / or the internal cable 126a You will need to know the actual transmission line loss associated with. Thus, in one embodiment, the loss information of the connector 126 and / or the internal cable 126a is determined and then stored in storage 336, eg, the calibration module (600), or other for later use. It can be called by one or more modules, such as the appropriate module (eg, AZCM332). Loss information for connector 126 and / or internal cable 126a can be determined by any suitable equipment and / or method. For example, loss information for connector 126 and / or internal cable 126a can be determined through network analyzer 602. In one specific embodiment, the network analyzer 602 can be an integral part of the generator 200 (eg, part of the calibration module 600), or alternative, the network analyzer 602 can be operational with the generator 200. It can be a separate handheld device that communicates with. The network analyzer 602 can be used to perform diagnostic tests on the connector 126 and / or the internal cable 126a. The network analyzer 602 can function in a manner similar to most conventional network analyzers known in the art available. That is, the network analyzer 602 has characteristics associated with the connector 126 and / or the internal cable 126a, more specifically, for example, the characteristic impedance of the connector 126 and / or the internal cable 126a._{o o}Such characteristics associated with the connector 126 and / or the internal cable 126a that affect the reflection and / or transmission of the output signal, such as, can be determined.

Known line loss information associated with connector 126 and / or internal cable 126a is stored in storage 336 and ablated by one or more modules associated with controller 300 and / or generator 200, such as AZCM332. Called during the procedure and then a predetermined threshold of reflex Pr, eg P_r1-ssCan be used to determine if is satisfied. More specifically, it uses the characteristic impedance associated with the connector 126 and / or the internal cable 126a to provide a more accurate or comprehensive reflectivity P._rThe measured value of can be determined. For example, using the following equation, a more accurate or comprehensive reflex P_rMeasurements can be determined:<maths num="1"><img id="000002" he="23" wi="159" file="JP5908058B2_D0001.tif" img-format="tif" img-content="drawing" /></maths> In the formula, Z_{o o}Is the characteristic impedance associated with the connector 126 and / or the internal cable 126a, Z_1-ssMicrowave antenna 100 is time t_1-ssThis is the impedance of the microwave antenna 100 when it is placed adjacent to the tissue in the "near-field"._swrCan be calculated using the following equation: Power standing wave ratio (P)_swr) Is:<maths num="2"><img id="000003" he="23" wi="159" file="JP5908058B2_D0001.tif" img-format="tif" img-content="drawing" /></maths> In the formula, P_fIs the power associated with the generated signal (ie, the forward signal), P_rIs the power associated with the reflected signal. Characteristic impedance Z_{o o}Is an accurate measurement of the impedance of the connector 126 and / or the internal cable 126a, taking into account the line loss associated with the connector 126 and / or the internal cable 126a. In this case, after all the necessary calculations have been done, the reflex force P_rAn accurate depiction of the AZCM332 (or any other suitable module associated with either the controller 300 or the generator 200) can be transmitted and measured thereby.

Although some embodiments of the present disclosure are shown in the drawings and / or are considered herein, the present disclosure is as broad as the art allows and is similarly interpreted herein. It is not intended to limit this disclosure to such embodiments. Therefore, the above description should be construed as merely an example of a specific embodiment, not as a limitation. Those skilled in the art will envision other amendments within the scope and intent of the claims attached herein.