Radiofrequency ablation probe system capable of conformal thermal ablationTechnical Field
The invention relates to the technical field of radio frequency ablation probe systems, in particular to a conformal heat ablation radio frequency ablation probe system.
Background
According to data published by WHO in 2018, tumors have become the second leading cause of death worldwide. In China, among newly-increased cancer patients, lung cancer is the first, and gastric cancer, liver cancer, breast cancer, esophageal cancer and the like follow; among patients who die of cancer, lung cancer is also the first, and gastric cancer, liver cancer, esophageal cancer, colorectal cancer and the like follow.
In recent years, with the development of medical image guidance technology, the local thermal physical treatment of tumors is started to follow another technical development peak due to the minimal invasion and effectiveness, and an effective treatment scheme is provided for the recurrence and metastasis of solid tumors. Under the guidance of images such as CT, MRI and the like, the ablation probe can be directly punctured into or around a tumor through percutaneous puncture, a radio frequency electric field is formed in tissues by applying radio frequency current and/or voltage of a specific frequency band within a certain power range, and polar molecule high-frequency oscillation and other related physical changes are induced through the interaction of the radio frequency electric field and the tumor tissues, so that tumor ablation can be finally realized.
However, in actual clinical practice, due to the complex biological properties of the tumor and surrounding tissues, the tumor often appears irregularly shaped, which is especially prominent in malignant tumors. In order to completely destroy the in-situ tumor and avoid the potential risks of tumor metastasis, recurrence and the like, ablation range is usually expanded or multiple/multi-needle ablation is usually adopted. However, it is worth noting that the enlargement of the ablation range also causes unnecessary damage to the normal tissues around the tumor, and multiple ablations and/or multiple needle ablations prolong the treatment time, additionally cause trauma and increase the burden on the patient. Furthermore, in radio frequency ablation, often due to the nature of the tissue and the practical handling problems during the procedure, the needle is rarely inserted exactly in the center of the tumor, so that to achieve a complete ablation of the tumor, sometimes even two treatments may be required, which not only increases the complexity of the treatment, but also causes too much damage to the health. How to design the structure of the puncture type ablation probe and realize the conformal ablation of the tumor through the precise control of the radio frequency energy becomes the main technical bottleneck of the current invention innovation.
The Chinese patent publication No. CN101006939A discloses a conformal radio-frequency ablation electrode suitable for prostate cancer, wherein a plurality of micro hollow sub-needles with memory function extend out of a hollow catheter, form a curvature of 15-30 degrees with the catheter, are distributed in an umbrella shape, are relatively close to the left and right side lobes of the prostate, form broad bean-shaped ablation regions in the ablation process, and avoid thermal injury to normal tissues such as urethra and the like while completely covering the lesion regions. However, it is worth noting that 3-7 sub-needles are welded at the tail end of the catheter, when the catheter is pushed, all the sub-needles synchronously extend out of the catheter, the sub-needles are not independent in structure and electric field distribution, an ablation region has high axial symmetry, the cross section of the ablation region is in a regular ellipse shape in the direction perpendicular to the puncture direction, and an asymmetric ablation region with remarkable directivity cannot be formed.
Chinese patent publication No. CN110179537A discloses an umbrella-shaped conformal rf ablation probe, in which an electromagnet coil is wound on each electrode, and a magnetic field is used to make a plurality of electrodes close to or away from each other, so as to change the central symmetry of the umbrella-shaped distribution of the electrodes to a certain extent, and improve the degree of adaptability of an ablation region in a direction perpendicular to a puncture direction, but in a direction parallel to the puncture direction, the depth of rf ablation cannot be changed.
Chinese patent publication No. CN1032027728A discloses a single-needle multi-action-point microwave ablation probe, in which the surface of a needle body is divided into several sections by multiple sections of insulating media to realize spherical or columnar ablation zones. It is worth noting that the single microwave coaxial cable in the invention penetrates through the whole needle body and is directly connected with the transmitting front electrode, and the transmitting front electrode is directly connected with the ablation needle body, so that the equal potential is formed on the surface of the needle body. Although the needle body is segmented by a plurality of insulating media to form a plurality of action points, the electric potential on each action point is the same, and the action points are supplied with power by microwave coaxial cables and cannot work independently. Therefore, in the cross section perpendicular to the puncture direction, the ablation cross section is still a regular circle, and an irregular boundary cannot be formed. And once the insulating medium is processed, the probe is shaped, and the shape of the boundary of the formed ablation area cannot be changed by the shaping in the direction parallel to the puncture direction. When the conformal ablation is used for the tumor with different long-axis diameters, an ablation probe with specific characteristics is selected for ablation, and the variability of the ablation range in the direction parallel to the puncture direction is not available, which obviously influences the conformal ablation capability.
Chinese patent publication No. CN109303602A discloses a multi-stage rf ablation catheter formed by multiple electrode rings arranged at intervals in the axial direction on the outer wall of the catheter, the catheter is composed of two rf power sources, each electrode ring is connected with the positive electrode or the negative electrode of one of the rf power sources through an rf wire, and different positive and negative electrode pairs are formed between the electrode rings by arrangement and combination, thereby forming different electric field loops. By changing the selection of the electrode ring connected with the cathode of the radio frequency power source, one or two spherical or columnar ablation areas with the size influenced by the power of the radio frequency power source can be formed in the depth direction parallel to the catheter. It is noted that the cross-section of the ablation region in the direction perpendicular to the depth of the catheter is still a regular circle, and no irregular boundaries can be formed. Meanwhile, the electrode ring used by the invention is wound on the surface of the catheter and cannot be used for percutaneous puncture.
Chinese patent publication No. CN105555362A discloses an interstitial ultrasound disposable applicator for conformal treatment of uneven tumor lesions, in which a plurality of capacitive micromachined ultrasonic transducer arrays are arranged to form a pseudo-cylindrical shape, and focus parameters of independent transducer elements are controlled by electronic drive to realize conformal volume ablation in axial and radial directions. It is worth noting that the ablation technology is based on ultrasound, and for lung tumors, due to the existence of a large amount of air in alveoli, the ultrasonic energy is obviously attenuated, the ablation range is limited, and the application is not suitable. For bone tumor, due to the high tissue density, ultrasound is easy to attenuate, and the reflection occurs at the tissue interface, so that the sound field distribution is difficult to predict, and conformal ablation is affected.
In summary, the existing puncture type radio frequency ablation probe has a low conformal degree in an ablation region, and is usually dedicated to conformal ablation along a single axial or radial direction of the radio frequency ablation probe, and the ablation effect only generates a columnar or spherical ablation form, and cannot adapt to the three-dimensional irregular shape of a solid tumor; the ablation target area in the prior art is often a single tumor, synchronous ablation of a plurality of nearby in-situ tumors is not considered, and multiple-needle insertion or multi-needle cooperative ablation usually prolongs the operation time, increases the operation complexity and causes additional burden to a patient; in the prior art, due to the axisymmetric ablation volume formed by radio frequency ablation, in clinical practice, it is difficult to accurately puncture an ablation probe to an axisymmetric center of a set position through a single puncture operation, so that the probe is often required to be plugged and pulled for multiple times to match a preoperative planning result, but the operation time is prolonged by plugging and pulling the probe for multiple times, and additional trauma is caused to a patient; the prior art does not consider conformal ablation of structures such as blood vessels, nerves and the like on the periphery of a tumor and a puncture path, has potential risks when being used for ablation of intracranial tumors, spinal tumors, liver tumors and the like, and has limited types of indications.
Therefore, those skilled in the art are dedicated to develop a probe system capable of performing three-dimensional volume conformal radio frequency ablation on irregular tumors and conformal ablation after insertion and deflection, which solves the problems of applicability and operability of the prior art.
Disclosure of Invention
In view of the defects in the prior art, the technical problem to be solved by the present invention is how to provide a conformal thermal ablation rf ablation probe system for three-dimensional volume conformal thermal ablation of solid tumors, which realizes irregular ablation matching with the actual puncture path.
In order to achieve the above object, the present invention provides a conformal heat ablation rf ablation probe system, which includes an rf ablation probe and an rf generation unit array, wherein the rf ablation probe includes a solid metal tip, a lateral rf electrode set, an rf signal transmission line bundle, a temperature sensor set, a temperature signal transmission line bundle, an insulating layer, a push tube, and a system interface;
the solid metal needle tip and the lateral radio frequency electrode group are connected with the radio frequency signal transmission line cluster, and the temperature measuring sensor group is connected with the temperature signal transmission line cluster; the lateral radio frequency electrode group and the temperature measuring sensor group are positioned in the circumferential direction of the radio frequency ablation probe, and the temperature signal transmission line cluster and the radio frequency signal transmission line cluster are distributed in the circumferential direction and the center of the inside of the radio frequency ablation probe;
the insulating layer is connected with and separates the solid metal needle tip, the lateral radio frequency electrode group and the temperature measuring sensor group, and the push pipe is positioned at the end part of the insulating layer;
the system interface is positioned at the end part of the radio frequency ablation probe, the radio frequency generation unit array is arranged in an upper computer, and the radio frequency signal transmission line bundle and the temperature signal transmission line bundle are connected with the radio frequency generation unit array through the system interface.
Further, the insulating layer is a stretchable structure.
Further, the lateral radio frequency electrode group comprises a plurality of mutually independent electrodes.
Furthermore, the temperature sensor group consists of one or more temperature sensors.
Further, the electrodes of the lateral radiofrequency electrode group are arranged at intervals in the circumferential direction and the axial direction of the radiofrequency ablation probe to form an array.
Furthermore, each electrode of the lateral radio frequency electrode group is connected to the radio frequency generating unit array one by one through the transmission lines in the radio frequency signal transmission line cluster.
Furthermore, each temperature measuring sensor of the temperature measuring sensor group is connected to the radio frequency generating unit array one by one through a transmission line in the temperature signal transmission line cluster.
Further, the radio frequency generation unit array is composed of one or more radio frequency generation units with mutually independent frequencies and/or voltages and a ground level.
Further, the radio frequency generation unit array further comprises a many-to-many control port, and the radio frequency generation unit and the ground level are connected to the many-to-many control port.
Further, each electrode of the lateral radiofrequency electrode group applies a different voltage or current.
The invention has at least the following beneficial technical effects:
1. the conformal thermal ablation radio frequency probe system provided by the invention realizes the three-dimensional conformal thermal ablation on irregular tumors through the array distribution of a plurality of lateral radio frequency electrode groups and the combination of the independent solid metal needle points, and gives consideration to the irregular degrees of the tumors in the axial direction and the radial direction of the puncture probe.
2. According to the radiofrequency ablation probe system capable of conformal thermal ablation, the insulating layer with adjustable length realizes accurate regulation and control of the distance between the solid metal needle tip and the lateral radiofrequency electrode group and the distance between the lateral radiofrequency electrode group and the electrodes, the two can be regulated and controlled independently or jointly, and the conformal ablation capability of the ablation probe is improved.
3. According to the conformal heat ablation radio frequency ablation probe system provided by the invention, the radio frequency electrodes can be controlled to work independently, so that synchronous ablation of a plurality of adjacent in-situ tumors is realized; by adjusting the radio frequency electrode voltage and/or the current control strategy and/or the radio frequency, the path deviation caused by the actual puncture operation is made up, and the ablation probe is prevented from being plugged again.
4. The conformal thermal ablation radio frequency ablation probe system provided by the invention can avoid important structures such as blood vessels and nerves possibly existing around a solid tumor in a planning puncture path through a radio frequency signal control strategy.
5. The conformal heat ablation radio frequency ablation probe system provided by the invention enhances the puncture capability of the radio frequency ablation probe by virtue of the solid metal needle tip.
The conception, the specific structure and the technical effects of the present invention will be further described with reference to the accompanying drawings to fully understand the objects, the features and the effects of the present invention.
Drawings
FIG. 1A is a schematic view of a needle module in accordance with a preferred embodiment of the present invention;
FIG. 1B is a schematic diagram of a probe connection line structure according to a preferred embodiment of the present invention;
FIG. 2 is a system architecture diagram of a preferred embodiment of the present invention;
FIG. 3 is a schematic cross-sectional view Z-4 of a preferred embodiment of the present invention;
FIG. 4 is a left side view of the system interface of a preferred embodiment of the present invention;
FIG. 5A is a schematic cross-sectional view Z-1 of a preferred embodiment of the present invention;
FIG. 5B is a schematic cross-sectional view Z-2 of a preferred embodiment of the present invention;
FIG. 5C is a schematic cross-sectional view taken along line Z-3 of a preferred embodiment of the present invention;
FIG. 6A is a schematic view of conformal ablation simulation of another preferred embodiment of the present invention;
FIG. 6B is a schematic diagram showing a simulation of very short lateral RF electrode spacing in accordance with another preferred embodiment of the present invention;
FIG. 6C is a schematic diagram showing a simulation of lateral RF electrode spacing extreme length in accordance with another preferred embodiment of the present invention;
FIGS. 7A, 7B and 7C are schematic diagrams showing simulation of the insulation layer length adjustment effect according to another preferred embodiment of the present invention;
FIGS. 8A and 8B are schematic views of a corrected ablation simulation of penetration bias in accordance with another preferred embodiment of the present invention;
FIGS. 9A and 9B are schematic views of a three-dimensional conformal ablation simulation of another preferred embodiment of the present invention;
FIG. 10 is a schematic view of a dual tumor ablation simulation in accordance with another preferred embodiment of the present invention.
Wherein: 1-solid metal needle tip, 2-insulating layer, 3-temperature sensor group, 4-lateral radio frequency electrode group, 5-temperature signal transmission line bundle, 6-radio frequency signal transmission line bundle, 7-push tube, 8-system interface, 9-radio frequency ablation 60 ℃ isothermal line, 10-conventional radio frequency ablation probe ablation zone shape, 11-radio frequency ablation probe, 12-radio frequency generation unit array and 121-many-to-many control port.
Detailed Description
The technical contents of the preferred embodiments of the present invention will be more clearly and easily understood by referring to the drawings attached to the specification. The present invention may be embodied in many different forms of embodiments and the scope of the invention is not limited to the embodiments set forth herein.
In the drawings, structurally identical elements are represented by like reference numerals, and structurally or functionally similar elements are represented by like reference numerals throughout the several views.
As shown in fig. 1A, 1B, 3, 4, 5A, 5B, and 5C, the present embodiment discloses a conformable thermal ablation rf ablation probe, which includes asolid metal tip 1, an insulatinglayer 2, athermometric sensor group 3, a lateralrf electrode group 4, a temperature signaltransmission line bundle 5, an rf signaltransmission line bundle 6, apush tube 7, and asystem interface 8.
The solidmetal needle point 1 is connected with the insulatinglayer 2 and the radio frequency signaltransmission line cluster 6, the temperature measuringsensor group 3 is connected with the temperature signaltransmission line cluster 5, the insulatinglayer 2 is simultaneously connected with thepush tube 7 to form an integrated structure, and the solidmetal needle point 1 has the percutaneous puncture capability and can puncture the epidermis and subcutaneous tissues of a human body to reach the inside or the periphery of the solid tumor.
The insulatinglayer 2 isolates the electric conduction between the solidmetal needle tip 1 and the lateral radiofrequency electrode group 4 and between the lateral radiofrequency electrode group 4, ensures the independence between radio frequency signals, is of a telescopic structure, can adjust the length of the insulatinglayer 2 by moving thepush tube 7, and can independently adjust the distance between the solidmetal needle tip 1 and the lateral radiofrequency electrode group 4 and the distance between the lateral radiofrequency electrode group 4 and also adjust the distance in a combined manner, so as to adapt to the conformal ablation requirements of different irregular solid tumors.
The solidmetal needle tip 1 and the lateral radiofrequency electrode group 4 are used as radio frequency electrodes for emitting radio frequency energy to solid tumors or used as a negative electrode and a positive electrode respectively to form a closed loop.
The radio frequency signal transmission lines in the radio frequency signaltransmission line bundle 6 are connected with the solidmetal needle tips 1 and the lateral radiofrequency electrode groups 4 one by one and used for transmitting radio frequency treatment signals from an upper computer of the system to the radio frequency ablation probes so as to realize three-dimensional volume conformal thermal ablation of solid tumors.
Thetemperature sensor group 3 has the characteristics of high precision and low time delay, can convert temperature signals into electric signals in real time within an acceptable error range, and is used for acquiring and monitoring the temperature of different positions on the surface and/or inside the radio frequency ablation probe; the temperature measuringsensor group 3 is connected with temperature signal transmission lines in the temperature signaltransmission line cluster 5 one by one, and transmits signals to the upper computer of the system in real time through the temperature signaltransmission line cluster 5. The temperature signaltransmission line bundle 5 is used for transmitting temperature signals to a system upper computer and is used for functions including but not limited to real-time temperature display, real-time radio frequency voltage and/or radio frequency current adjustment and the like.
The temperature signaltransmission line cluster 5 and the radio frequency signaltransmission line cluster 6 are distributed and arranged in the circumferential direction and the center in the radio frequency ablation probe, the temperature signaltransmission line cluster 5 and the radio frequency signaltransmission line cluster 6 are flexibly packaged through electric isolation to form a signal cluster, and a probe connecting line can be conveniently and freely bent according to specific conditions in actual operation and is connected with an upper computer through asystem interface 8.
As shown in fig. 2, the rf generating unit array 12 is composed of one or more rf generating units with mutually independent frequencies and/or voltages and a ground level, and can output rf signals with specific frequencies and/or voltages independently under the control of the system main control end; the array of radio frequency generating units 12 further comprises a many-to-many control port 121. The signal bundle of the radiofrequency ablation probe 11 is connected with the radio frequency generating unit array 12 through the many-to-many control ports 121, and under the control of the system master control end, any radio frequency signal transmission line can be connected with any radio frequency generating unit or ground level at any time, so that the solidmetal needle tip 1 and the lateral radiofrequency electrode group 4 can independently emit specific radio frequency energy to solid tumors, or respectively serve as a negative electrode and a positive electrode to form a closed loop.
The lateral radiofrequency electrode group 4 is composed of a plurality of electrodes, the electrodes are arranged on the surface of the insulatinglayer 2 of the radio frequency ablation probe in a non-contact way, the size is customized according to the special calculation design of the position where the solid tumor is located, and M (M is more than or equal to 2) electrodes are arranged along the circumferential direction of the radio frequency ablation probe to form a section; n (N is more than or equal to 2) electrode segments are axially arranged along the radiofrequency ablation probe, and the spacing is designed and customized according to the special calculation of the part where the solid tumor is located, so that the radiofrequency ablation electrode array is formed. In a preferred embodiment of the present invention, 2 (number M) of electrodes that are not in contact with each other are arranged along the circumference of the rf ablation probe to form a "segment", and 3 (number N) segments of electrodes are arranged at a certain interval along the axial direction of the rf ablation probe to form a 2 × 3 array.
In the synchronous ablation of single and/or multiple in-situ tumors, the temperature-measuringsensor group 3 comprehensively monitors the temperature field distribution around the radio-frequency ablation probe in real time and is used for the real-time independent closed-loop control of the voltage and/or the current of the solidmetal needle tip 1 and the lateral radio-frequency electrode group 4.
Under the condition that the actual puncture path deviates from the preoperative planned trajectory, the correction of the ablation region is realized through the real-time independent closed-loop control on the voltage and/or the current. The upper computer of the system can independently control the voltage and/or the current of each electrode of the solidmetal needle point 1 and the lateral radiofrequency electrode group 4 through the radio frequency signaltransmission line bundle 6.
In a preferred embodiment of the present invention, during the rf ablation of the solid tumor, the length of the insulatinglayer 2 can be adjusted in advance according to the treatment plan, and after the rf ablation probe is inserted into the solid tumor, the length of the insulatinglayer 2 can be adjusted twice according to the actual puncturing operation result. Under the control of a radio frequency signal control strategy, radio frequency signals are transmitted to the solidmetal needle tip 1 and the lateral radiofrequency electrode group 4 through the radio frequency signaltransmission line bundle 6 at certain time intervals, and the three-dimensional conformal thermal ablation of the body tumor is realized.
In another preferred embodiment of the present invention, an electrode array of M × N ═ 2 × 2 is used, and conformal ablation conditions when using a radio frequency signal control strategy in constant voltage output mode are studied by multi-physical field simulation when the insulatinglayer 2 is at different lengths.
As shown in FIG. 6A, two sections of the lateralRF electrode groups 4 are arranged in the parallel probe puncture direction at the same insulation interval as the length of the electrodes of the lateralRF electrode groups 4, and the interval between the solidmetal needle tip 1 and the adjacent lateralRF electrode groups 4 is the same as the length of the electrodes of the lateralRF electrode groups 4. And (3) alternately applying 15V constant radio frequency voltage by taking 5s as an electrode alternate working interval, wherein the total action time of each electrode is 10min, and a gourd-shaped conformal ablation area is formed due to the action of the needle point.
As shown in fig. 6B, two segments of the lateral rf electrode sets 4 are arranged in the parallel puncturing direction with an insulation distance of 0.3 times the electrode length of the lateral rf electrode set 4, and the electrode distance between the solidmetal needle tip 1 and the adjacent lateral rf electrode set 4 is consistent with the electrode length of the lateralrf electrode set 4. And 5s is taken as an electrode alternate working interval, 15V constant radio frequency voltage is applied alternately, the total action time of each electrode is 10min, and due to the excessively short electrode distance, the two lateral electrodes generate the same columnar ablation area with a single electrode when acting simultaneously, so that the three-dimensional conformal purpose cannot be achieved. However, at this distance, the two lateral electrodes are used separately, and the ablation size in the length direction of the electrodes can be adjusted by selecting the length of the electrodes more than that of the connected single electrodes.
As shown in fig. 6C, two segments of the lateral rf electrode sets 4 are arranged in the parallel probe penetration direction at an insulation distance of 1.36 times the electrode length of the lateral rf electrode set 4, and the electrode distance between thesolid metal tip 1 and the adjacent lateral rf electrode set 4 is the same as the electrode length of the lateralrf electrode set 4. And 5s is taken as an electrode alternate working interval, 15V constant radio frequency voltage is applied alternately, the total action time of each electrode is 10min, and the lateral radiofrequency electrode group 4 cannot show the synergistic effect due to the overlong electrode distance. More importantly, the temperature of the needle wall in the middle part of the two lateral electrodes can not reach 60 ℃, and the risk of tumor tissue metastasis is brought to the needle pulling process.
As shown in fig. 7A, 7B and 7C, the two sections of lateral rf electrode sets 4 are arranged in the parallel probe piercing direction at the same insulation distance as the length of the electrodes of the lateral rf electrode sets 4, and the length of theinsulation layer 2 is adjusted by thepush tube 7, so that the electrode distances between the solidmetal needle tip 1 and the adjacent lateral rf electrode sets 4 are respectively 0.2 times, 0.5 times and 1.2 times of the length of the electrodes of the lateral rf electrode sets 4. And (3) alternately applying 15V constant radio frequency voltage by taking 5s as an electrode alternate working interval, wherein the total action time of each electrode is 10min, and obtaining ablation areas with different lengths in the parallel probe puncture direction.
As shown in FIG. 8A, two sections of the lateralRF electrode groups 4 are arranged in the parallel probe puncture direction at the same insulation interval as the length of the electrodes of the lateralRF electrode groups 4, and the interval between the solidmetal needle tip 1 and the adjacent lateralRF electrode groups 4 is the same as the length of the electrodes of the lateralRF electrode groups 4. The 5s is taken as an electrode alternate working interval, 18V constant radio frequency voltage is applied to one side electrode of the two sections of lateral radiofrequency electrode groups 4, 10V constant radio frequency voltage is applied to the other side electrode, 15V constant radio frequency voltage is applied to the solidmetal needle point 1, the total action time of each electrode is 10min, the central axis in the ablation area can deviate towards one side of the probe, and the ablation problem that the central axis of the probe and the central axis of the solid tumor have translation deviation due to puncture deviation can be solved.
As shown in fig. 8B, the two sections of the lateral rf electrode sets 4 are arranged in the direction parallel to the probe penetration direction with an insulation distance of 0.8 times the electrode length of the lateralrf electrode set 4. Taking 5s as an electrode alternate working interval, applying a 460kHz 15V radio frequency voltage to one side of a section of lateral electrode close to the solidmetal needle point 1, and not applying the radio frequency voltage to the other side; applying 1MHz radio frequency voltage to one side of the other section of lateral electrode, and not applying the radio frequency voltage to the other side; thesolid metal tip 1 is not applied with a radio frequency voltage. Finally, an ablation area surrounded by aradio frequency ablation 60℃ isotherm 9 is formed, and compared with theablation area shape 10 of a conventional radio frequency ablation probe, the long axis of the ablation area and the central axis of the probe can form a specific included angle so as to solve the ablation problem that the central axis of the probe and the central axis of the solid tumor have angle deviation due to puncture deviation.
As shown in fig. 9A and 9B, two segments of the lateral rf electrode sets 4 are arranged in the parallel probe penetration direction at the same insulation distance as the length of the electrodes of the lateral rf electrode set 4, and the distance between thesolid metal tip 1 and the adjacent lateral rf electrode set 4 is the same as the length of the electrodes of the lateralrf electrode set 4. 5s is taken as an electrode alternate working interval, 20V constant radio frequency voltage is applied to one side electrode of a section of lateral electrode close to the solidmetal needle point 1, and 8V constant radio frequency voltage is applied to the other side electrode; one side electrode of the other section of lateral electrode applies 8V constant radio frequency voltage, the other side applies 15V constant radio frequency voltage, the solidmetal needle point 1 applies 15V constant radio frequency voltage, the total action time of each electrode is 10min, and a three-dimensional irregular ablation area can be formed.
As shown in fig. 10, two segments of lateral rf electrode sets 4 are arranged in the parallel probe puncture direction at the same insulation distance as the length of the electrodes of the lateral rf electrode set 4, and the distance between the solidmetal needle tip 1 and the adjacent lateral rf electrode set 4 is 2 times the length of the electrodes of the lateral rf electrode set 4 through thepush tube 7. And (3) alternately applying 15V constant radio frequency voltage by taking 5s as an electrode alternate working interval, wherein the total action time of each electrode is 10min, so that two ablation areas, namely a large ablation area and a small ablation area, are obtained, and the synchronous ablation of the two in-situ tumors is realized.
The rf signal control strategy using the constant current output mode is similar to the above rf signal control strategy using the constant voltage mode.
The conformal heat-ablation radio frequency probe system provided by the invention realizes three-dimensional volume conformal heat ablation on irregular tumors by the array distribution of a plurality of lateral radio frequency electrode groups and the combination of independent solid metal needle points, and considers the irregular degrees of the tumors in the axial direction and the radial direction of the puncture probe; the insulating layer and the push tube with adjustable length realize independent and/or combined accurate regulation and control of the space between the solid metal needle tip and the lateral radio frequency electrode group and the space between the lateral radio frequency electrode group and the electrode, and improve the conformal ablation capability of the ablation probe. Therefore, the present invention has advantageous technical effects.
The foregoing detailed description of the preferred embodiments of the invention has been presented. It should be understood that numerous modifications and variations could be devised by those skilled in the art in light of the present teachings without departing from the inventive concepts. Therefore, the technical solutions available to those skilled in the art through logic analysis, reasoning and limited experiments based on the prior art according to the concept of the present invention should be within the scope of protection defined by the claims.