An intravascular radiofrequency / laser ablation probe

Abstract

The present application relates to a kind of intravascular radio frequency / laser ablation probe, belong to the field of biological medical instrument.The purpose of the present application is to solve the problem of limited precision of radio frequency ablation, limited resolution of guide mode, provide a kind of intravascular radio frequency / laser ablation probe.Compared with traditional radio frequency ablation, not only can meet the ablation of large area thrombus or tumor tissue in blood vessel, but also can utilize laser ablation technology to ablate residual lesion tissue, effectively solve the limited precision of traditional pure radio frequency ablation technology, significantly improve the precision of ablation, ensure that lesion is completely ablated and effectively protect normal tissue or cell.The present application realizes that the light path, sound path, circuit and other components between each module of ablation system are shared, effectively reduces the size and cost of probe, and improves its practical value.

Description

TECHNICAL FIELD

[0001] The present application relates to an intravascular radiofrequency / laser ablation probe, belonging to the field of biological medical devices. BACKGROUND

[0002] Ablation technology is an important minimally invasive treatment method in current medical treatment, which is commonly used in clinical fields such as cosmetic freckle removal, arrhythmia regulation and tumor cell inactivation. Its basic principle is to make local lesion tissues or cells denature and necrosis due to thermal effect through certain physical methods (such as exciting high-frequency current, high-power laser, etc.), so as to achieve the purpose of cure. Common methods include radiofrequency ablation, cold ablation, pulse ablation, laser ablation and ultrasonic ablation, etc. Compared with simple drug treatment, ablation technology can completely eradicate the lesion and fundamentally achieve the effect of curing the disease.

[0003] Radiofrequency ablation is the most commonly used ablation technology for treating cardiovascular diseases at present, which has the advantages of small side effects, high real-time performance and small trauma. In terms of technology, radiofrequency ablation usually adopts the imaging method of in-vitro CT or B-ultrasound to locate the lesion, determines the target position, and then sends the ablation needle to the affected area through puncture to make the surface electrode fully adhere to the tissue, and finally passes the radiofrequency current to the electrode to make the tissue coagulative necrosis. Li Yanjun et al. (Li Tingjun, Fu Yahui, Wu Hui, Zheng Wenjian, Gao Wei, Lu Qingzhong, Zhang Dong. Analysis of 100 cases of radiofrequency ablation for liver hemangioma [J]. Journal of Hepatobiliary and Pancreatic Surgery, 2019, 31(09): 540-544.) summarized the treatment experience of 100 cases of radiofrequency treatment of liver hemangioma. Among the 101 nodules, 88 nodules were completely destroyed after RFA, with a complete destruction rate of 87.1%, and the ablation rate of hemangioma reached 92.1%, with good cure effect; Wang Shiwei et al. (Wang Shiwei, Han Jingang, Qin Mian, Zhang Jingyan, Mei Lixia. Clinical study on intravascular radiofrequency ablation for thromboangiitis obliterans [J]. China Health Standard Management, 2019, 10(20): 31-32.) tested the efficacy of radiofrequency ablation for thromboangiitis obliterans. The experiment showed that the ABI index of patients after operation (0.90±0.16) was significantly better than that before operation (0.31±0.07), and the effect of radiofrequency ablation was more significant.

[0004] However, there are several defects in simple radiofrequency ablation:

[0005] Firstly, the omission of thrombus or tumor cells and the false killing of normal tissues are the main potential risks of radiofrequency ablation. Radiofrequency ablation is mainly based on the application of ablation energy by surface electrodes in contact with lesions, and the size of the electrode determines the accuracy of radiofrequency ablation. Due to the narrow space in the blood vessel, it is impossible to arrange surface electrodes with small electrode area and large array size, so the accuracy of radiofrequency ablation is difficult to reach micrometer level. This results in the consequence of inaccurate ablation of the lesion edge.

[0006] Secondly, the image fusion form needs to be further improved. The current positioning method commonly used in radiofrequency ablation is mainly based on two imaging technologies of in-vitro CT or B-ultrasound, and the resolution is in millimeter to sub-millimeter level, which makes the positioning accuracy in guiding intravascular ablation face great deficiency. This "unclear" guiding mode will bring the consequence of "misalignment", which also limits the improvement of ablation accuracy. SUMMARY

[0007] The purpose of the present application is to solve the problems of limited radiofrequency ablation accuracy and limited resolution of guiding mode, and to provide an intravascular radiofrequency / laser ablation probe. Compared with traditional radiofrequency ablation, the intravascular radiofrequency / laser ablation probe can not only meet the ablation of large area thrombus or tumor tissue in blood vessels, but also can use laser ablation technology to ablate residual lesion tissue, effectively solve the limited precision of traditional pure radiofrequency ablation technology, significantly improve the ablation accuracy, and ensure that the lesion is completely ablated and the normal tissue or cells are effectively protected.

[0008] The purpose of the present application is achieved by the following technical solutions.

[0009] The intravascular radiofrequency / laser ablation probe provided by the present application integrates various intravascular imaging technologies, including OCT, ultrasound, photoacoustic and thermal tomography imaging functions, can realize high-resolution image guidance, solve the "unclear" disadvantage of the traditional in-vitro imaging guiding mode, and realize "accurate" dual-mode ablation. In addition, the present application has the outstanding advantages of high integration and small size. In the present application, various diagnosis and treatment functions are designed in optical, acoustic and electrical common paths, which greatly reduces the size of the probe while ensuring multifunction, and has the remarkable characteristics of strong realizability, high resolution and high ablation accuracy.

[0010] The intravascular radiofrequency / laser ablation probe provided by the application is composed of a circular fixing column, a transparent shell, a visible-near infrared fiber, a far infrared fiber, a GRIN lens, a prism, an ultrasonic transducer, an insulating liquid, a fixing base, a high-elastic flexible balloon, a radiofrequency electrode, a metal guide wire, an ultrasonic transducer lead, a flexible catheter, a radiofrequency electrode lead, a liquid conduit and a radiofrequency cable. The specific connection mode is as follows: the circular fixing column is fixed to the inner side of the transparent shell and matches the inner diameter of the transparent shell, and is used for fixing the visible-near infrared fiber and the far infrared fiber; the GRIN lens is used for collimating and focusing the light signals transmitted through the two fibers, is fixed to the fixing base, and is provided with a prism with a size corresponding to the output end, so that the light beam can be reflected to the vascular tissue on the side of the probe; the input end is in close contact with the visible-near infrared fiber and the far infrared fiber; the prism is located at the front end of the GRIN lens; the ultrasonic transducer is placed in close contact with the prism and is used for emitting and receiving ultrasonic signals; the fixing base is internally hollow and is used for placing the transducer cable; the metal guide wire is connected with the front end of the fixing base and can be used for adjusting the relative position of the fixing base in the probe cavity; the internal components of the probe are sealed by a transparent shell, so as to ensure the permeability of the light signals and the acoustic signals and the sealing property of the internal components; the flexible balloon is uniformly wrapped on the transparent shell, and the surface of the flexible balloon is provided with annular radiofrequency array electrodes which are uniformly distributed along the axial direction; the flexible balloon internally contains a liquid conduit which is used for transmitting cooling liquids such as high-purity cold water; the flexible catheter is connected with the front end of the probe and is used for loading the metal guide wire, the transducer lead and the liquid conduit.

[0011] Further, the visible-near infrared fiber can complete two functions, one is used for transmitting the light signals for emitting and receiving OCT imaging and emitting photoacoustic imaging, and the other is used for transmitting the light signals for emitting laser ablation. The far infrared fiber is used for transmitting the far infrared light signals for thermal tomography. The fibers are fixed in the probe by a circular fixing column, and the radius of the circular fixing plate should match the inner diameter of the transparent shell. The circular fixing column is internally provided with two circular holes with different radii, which are used for fixing the two fibers, and the side of the circular fixing column is connected with a fixing base which is used for fixing the prism, the GRIN lens, the ultrasonic transducer and other components.

[0012] Further, the GRIN lens is used for collimating and focusing the light signals transmitted through the two fibers, so that the light signals are transmitted along the axial direction.

[0013] Further, the ultrasonic transducer can utilize the positive and negative piezoelectric effect to complete the functions of emitting ultrasonic wave signals for ultrasonic imaging and receiving ultrasonic echo signals for ultrasonic imaging and photoacoustic imaging. The ultrasonic transducer is internally composed of a sensitive element, an electrode material, an acoustic absorption backing and a packaging material. The sensitive element can be made of piezoelectric composite material, relaxor single crystal material, piezoelectric film and the like with higher bandwidth and appropriate aperture size, so as to meet the requirements of stable sound wave emission and high-sensitivity sound wave reception.

[0014] Further, the fixed base is installed inside the probe for fixed placement of optical elements, acoustic elements, and supporting the components. The fixed base is hollow inside for placing the transducer cable. The optical elements, acoustic elements, and other components are fixed on the upper surface of the fixed base. The front end of the fixed base is connected with a stretchable guide wire, and the other end of the guide wire is connected with the displacement control system outside the body. This method can be used to adjust the relative position of the fixed base in the probe cavity, so as to realize flexible adjustment of the emission position and receiving position of the optical signal and acoustic signal in the blood vessel, so as to improve the imaging and laser ablation quality.

[0015] Further, the internal components of the probe are sealed by a transparent shell, which not only ensures the permeability of various optical signals and acoustic signals, but also ensures the sealing of the internal components. The probe cavity is filled with insulating liquid such as glycerol and silicone oil to ensure the insulation and acoustic impedance matching of the probe interior and reduce friction.

[0016] Further, the transparent shell of the probe is coated with a high-elasticity flexible balloon on the outside, and the surface of the balloon has a ring-shaped radio frequency array electrode uniformly distributed along the axial direction. When the imaging is completed and positioned, the balloon is opened and the electrode array elements (covering electrodes) covering the lesion are precisely positioned by high-resolution imaging, and high temperature is generated by turning on the covering electrodes to inactivate the embolic or tumor cells, so that the tissue undergoes coagulative necrosis. Each array element of the array electrode is independently connected by a lead wire to meet the independent controllability of the array element. The user can selectively drive the array elements of the radio frequency electrode according to the morphology of the embolic or tumor cells. The balloon is provided with a multi-core cable for loading the radio frequency electrode lead wire.

[0017] Further, the flexible balloon contains a liquid conduit. After the ablation work starts, cooling liquid can be injected into the balloon through the liquid conduit to prevent ablation high temperature from damaging normal vascular endothelial cells. The structure of the balloon will expand by the amount of liquid injection until it tightly adheres to the inner wall of the blood vessel; when the ablation is completed, the cooling liquid in the balloon can be extracted through the liquid conduit, so that the balloon shrinks and is attached to the surface of the transparent shell of the probe. It should be noted that when selecting the cooling liquid, in addition to having cooling function, it should also have electrical insulation to ensure electrical insulation between the radio frequency electrodes on the inner surface of the balloon.

[0018] Further, the front end of the probe is connected with a flexible catheter, and the flexible catheter is loaded with the transducer cable, optical fiber, metal guide wire, radio frequency cable, and liquid conduit on the inside, and the other end is connected with the above-mentioned extracorporeal displacement controller, which can realize the advancement, retreat, and rotary scanning of the probe in the blood vessel.

[0019] The application provides an in-vitro multi-module system for the probe, which forms an ablation system with the probe. The in-vitro multi-module system comprises a control module, a displacement control system, an imaging module and an ablation module.

[0020] The control module controls each output in a synchronous time division multiplexing mode, and comprises three functions, which are respectively used for (1) controlling the displacement control system to realize the omnibearing scanning function of the probe in a blood vessel; (2) controlling the laser emission, reception and electric pulse emission of the imaging module; and (3) controlling the radio frequency signal emission.

[0021] The displacement control system is used for controlling the propulsion, withdrawal and rotation of the probe in the blood vessel, and the output end of the displacement control system is connected with the flexible catheter and controls the guide wire in the fixed base in the probe.

[0022] The imaging module can realize four kinds of imaging modules of OCT, ultrasound, photoacoustic and thermal tomography, and its structure is composed of laser light source, visible-near infrared fiber, far infrared fiber, 90:10 coupler, reference arm (composed of collimating mirror, lens and mirror), circulator, 50:50 coupler, photodetector, far infrared detector, pulse transmitter / receiver, data processing and image reconstruction module and image display module. The specific connection mode is as follows: the input end of the laser light source is connected with the control module for receiving and reading the synchronization signal of the control module, and the output end is connected with a 90:10 coupler for splitting the optical signal to form reference arm signal and sample arm signal; the 90:10 coupler has two output ports of reference arm and sample arm, and is respectively connected with a circulator for positioning the optical signal of OCT; the reference arm is composed of collimating mirror, lens and mirror, and is connected with the output end of the circulator for adjusting the reference arm signal; the circulator located in the sample arm has an input end and two output ends, the input end is connected with the output port of the 90:10 coupler for receiving the sample arm signal and PA signal of OCT emitted by the laser light source; one output port of the circulator located in the sample arm is connected with the probe, which can be used for transmission and reception of OCT and PA signals; the input end of the 50:50 coupler is respectively connected with the output ends of the two circulators located in the reference arm and the sample arm for coherently superimposing the sample arm and reference arm signals; the output end of the 50:50 coupler is connected with a photodetector for receiving and reading the OCT signal; the input end of the signal processing and image reconstruction module is connected with the photodetector, and the output end is connected with the display module, which respectively realizes the functions of photoelectric signal conversion and image display of the detection system; the input end of the pulse transmitter / receiver is connected with the control module, and the output end is connected with the lead wire of the ultrasonic transducer, which can provide pulse signals for the ultrasonic transducer in the probe; the far infrared detector is used for receiving and reading the thermal radiation information in the blood vessel, and then transmitting the information to the data processing and image reconstruction module for three-dimensional temperature field inversion, the input end of the far infrared detector is connected with the far infrared fiber in the probe, and the output end is connected with the data processing and image reconstruction module.

[0023] Further, the OCT module is composed of laser light source, visible-near infrared fiber, 90:10 coupler, reference arm, circulator, 50:50 coupler, photodetector, data processing and image reconstruction module and image display module. When the instruction of the control module is issued, the laser light source will generate near-infrared light signal, the light source is split by the 90:10 coupler to form a sample arm with power of 90% and a reference arm with power of 10%, the light signal of the sample arm is directed by the circulator and shot into the blood vessel by the probe. After the signal reflected by the blood vessel tissue, the signal is combined with the reference arm with power of 10% in the 50:50 coupler and then transmitted to the photodetector for reading.

[0024] Further, the ultrasound imaging module is composed of a pulse emitter / receiver, a data processing and image reconstruction module, and an image display module. The ultrasound module realizes the conversion of acoustic and electric signals through the ultrasound transducer inside the probe. When the control module sends instructions to the pulse emitter / receiver, the pulse emitter / receiver controls the ultrasound transducer to emit ultrasound signals. The echo signals reflected by the blood vessel tissue are received by the ultrasound transducer and then transmitted to the pulse emitter / receiver for reading.

[0025] Further, the photoacoustic imaging module shares the laser light source, visible-near infrared fiber, and 90:10 coupler of the OCT module, and shares the pulse emitter / receiver, data processing and image reconstruction module, and image display module of the ultrasound imaging module.

[0026] Further, the thermal tomography imaging module is composed of a far-infrared fiber, a far-infrared detector, a data processing and image reconstruction module, and an image display module. The far-infrared fiber is used to transmit far-infrared light signals carrying thermal information. The temperature field inversion is realized by using the far-infrared detector and the data processing and image reconstruction module. Finally, the thermal tomography imaging in the blood vessel is realized by the display module, and further information such as the type of thrombus / tumor cells and the physiological function of the lesion site can be obtained. The user can accurately control the ablation temperature and ablation mode according to the information.

[0027] The ablation module is composed of a radio frequency ablation module and a laser ablation module.

[0028] Further, the radio frequency ablation module includes a radio frequency signal emitter, the input end of which is connected to the control module, and the output end of which is connected to the probe balloon electrode. After imaging is completed, the control module controls the radio frequency signal emitter to generate a radio frequency current, which reaches the balloon electrode through the lead wire for ablation.

[0029] Further, the laser ablation module shares the same light emission system with the OCT imaging. After the radio frequency ablation is completed, the user can image the local blood vessel again, and after the positioning information is confirmed to be correct, the control module controls the laser light source to generate a hot laser pulse to continue laser ablation on the residual lesion.

[0030] The present application provides a new method of intravascular radio frequency / laser ablation. By using the intravascular radio frequency / laser ablation probe and the extracorporeal multi-module system, the synergistic effect of the two ablation methods in the blood vessel can be realized, and the outstanding advantages of large ablation range and high ablation precision can be achieved. The specific steps are as follows:

[0031] Step one, control the imaging module to obtain the three-dimensional topographic information (OCT imaging, ultrasound imaging, and photoacoustic imaging) and functional information (thermal tomography imaging) in the blood vessel;

[0032] Step two, according to the image information provided in step one, the lesion area is preliminarily positioned;

[0033] Step three, the lesion area is analyzed in terms of morphology, size, composition and other elements, and a proper ablation scheme is formulated;

[0034] Step four, inject cooling liquid into the balloon through the liquid conduit to inflate the balloon to fully adhere the surface electrode to the lesion;

[0035] Step five, control the imaging module to image the lesion at high resolution to determine the electrode array element number that fully adheres to the lesion;

[0036] Step six, control the radio frequency ablation module to turn on the fully adhered electrode array element to ablate the lesion, while observing the morphological changes of the lesion using the imaging module until most of the emboli or tumor cells are inactivated, then turn off the radio frequency ablation module;

[0037] Step seven, control the imaging module to accurately position the lesion area that is not completely treated in step six;

[0038] Step eight, control the laser ablation module to laser ablate the residual lesion in step six, and observe the morphological changes of the lesion in real time until the lesion tissue is completely inactivated, then turn off the laser ablation module;

[0039] Step nine, use the liquid conduit to drain the cooling liquid in the balloon to make the balloon shrink inward and adhere to the surface of the probe transparent shell.

[0040] Step ten, according to the actual situation, ablate the next lesion in the blood vessel or withdraw the catheter to the outside of the patient's body to end the ablation process.

[0041] Beneficial effects:

[0042] 1. The blood vessel radio frequency / laser ablation probe disclosed in the present application first realizes the synergy and fusion of radio frequency ablation and laser ablation technologies for emboli or tumor cells in blood vessels, fully utilizes the advantages of large radio frequency ablation range and high laser ablation precision, realizes the advantages of pure radio frequency ablation and pure laser ablation, greatly improves the inactivation rate of lesion cells, avoids the disadvantages of traditional pure radio frequency ablation technology, such as incomplete inactivation of lesions or excessive inactivation of normal tissues, and improves the ablation accuracy.

[0043] 2. The blood vessel radio frequency / laser ablation probe disclosed in the present application uses multiple imaging methods to obtain blood vessel morphology and functional information, which not only can accurately provide three-dimensional morphological information of blood vessel tissue, but also can provide cell functional information, which can further improve the accuracy of lesion positioning and the accuracy of temperature control during ablation.

[0044] 3. The intravascular radiofrequency / laser ablation probe disclosed in the application realizes the sharing of optical path, acoustic path, circuit and other components among the modules of the ablation system, effectively reduces the size and cost of the probe, and improves the practical value thereof.

[0045] 4. The in-vitro multi-functional system disclosed in the application has high automation characteristics, and the displacement control system, the imaging module and the ablation module can be automatically controlled by the computer through the synchronous control module, and the received signals are processed and displayed, which effectively reduces the operation difficulty and saves the labor cost. BRIEF DESCRIPTION OF DRAWINGS

[0046] Figure 1 The probe internal structure cross-sectional view (transparent shell part) provided by the application;

[0047] Figure 2 The probe internal structure cross-sectional view (non-transparent shell part) provided by the application;

[0048] Figure 3 The three-dimensional structure view of the probe provided by the application;

[0049] Figure 4 The working schematic diagram of the probe after the balloon is opened in the blood vessel (when the left edge of the laser ablation lesion is ablated);

[0050] Figure 5 The working schematic diagram of the probe after the balloon is opened in the blood vessel (when the right edge of the laser ablation lesion is ablated);

[0051] Figure 6 The in-vitro multi-module system scheme principle diagram suitable for the probe of the application (OCT, ultrasound, photoacoustic, thermal chromatography, radiofrequency ablation, laser ablation);

[0052] Figure 7 The in-vitro multi-module system scheme principle diagram suitable for the probe of the application (OCT, radiofrequency ablation, laser ablation);

[0053] Figure 8 The in-vitro multi-module system scheme principle diagram suitable for the probe of the application (OCT, thermal chromatography, radiofrequency ablation, laser ablation);

[0054] In the figure, 1 is a circular fixed column, 2 is a transparent shell, 3 is a near-infrared optical fiber, 4 is a far-infrared optical fiber, 5 is a GRIN lens, 6 is a prism, 7 is an ultrasonic transducer, 8 is an insulating liquid, 9 is a fixed base, 10 is a high-elasticity flexible balloon, 11 is a radiofrequency electrode, 12 is a metal guide wire, 13 is an ultrasonic transducer lead, 14 is a flexible catheter, 15 is a radiofrequency electrode lead, 16 is a liquid catheter, and 17 is a radiofrequency cable. DETAILED DESCRIPTION

[0055] In order to make the purpose, technical scheme and advantages of the present application clearer, the present application will be further described in detail below with specific examples and drawings.

[0056] Example 1

[0057] As shown in Figure 1 and Figure 2 , the present application provides an intravascular radiofrequency / laser ablation probe which is composed of a circular fixed column 1, a transparent shell 2, a visible-near infrared fiber 3, a far infrared fiber 4, a GRIN lens 5, a prism 6, an ultrasonic transducer 7, an insulating liquid 8, a fixed base 9, a high-elasticity flexible balloon 10, a radiofrequency electrode 11, a metal guide wire 12, an ultrasonic transducer lead 13, a flexible catheter 14, a radiofrequency electrode lead 15, a liquid catheter 16 and a radiofrequency cable 17. The circular fixed column 1 is fixed inside the transparent shell 2 and matches the inner diameter of the transparent shell 2, which is used to fix the visible-near infrared fiber 3 and the far infrared fiber 4; the GRIN lens is fixed on the fixed base 9, the input end of which is placed closely with the two kinds of fibers 3 and 4, which plays a role in directing and focusing the light signal; the prism 6 is located at the front end of the GRIN lens for reflecting the OCT imaging, photoacoustic imaging and laser ablation light signals to the blood vessel tissue; the ultrasonic transducer 7 is placed closely with the prism 6, which is used to emit and receive ultrasonic signals; the lead 13 can be led out through the fixed base 9, the inside of which is a hollow structure which can be used to place the ultrasonic transducer cable. Figure 3 A three-dimensional structure diagram of the intravascular radiofrequency / laser ablation probe provided by the present application can be used to meet the structural design of Figure 1 and Figure 2 . The metal guide wire 12 is connected with the front end of the fixed base 9, which can be used to adjust the relative position of the fixed base 9 in the probe cavity; the internal components of the probe are sealed by a transparent shell 2, which ensures the permeability of the light signal and the acoustic signal and the sealing property of the internal components; the high-elasticity flexible balloon 10 is uniformly wrapped on the transparent shell, the surface of which has a ring-shaped radiofrequency array electrode 11 which is uniformly distributed along the axial direction; the high-elasticity flexible balloon 10 contains a liquid catheter 16 inside, which is used to transmit cooling liquids such as high-purity cold water; the flexible catheter 14 is connected with the front end of the probe, which is used to load the metal guide wire 12, the transducer lead 13 and the liquid catheter 16.

[0058] As shown in Figure 4 and Figure 5 , for the edge processing of the lesion area, the present application gives a set of radiofrequency ablation and laser ablation collaborative scheme, the specific steps are as follows:

[0059] Step one, determination of the lesion position. After the lesion area is positioned by the imaging module, high-purity pure water or cooling liquid is injected into the flexible balloon 10 through the liquid catheter 16 until the radiofrequency electrode 11 of the flexible balloon 10 is closely attached to the intravascular lesion.

[0060] Step two, select the radio frequency electrode number and carry out radio frequency ablation. The complete radio frequency electrode number which is in contact with the lesion is determined by using the high resolution imaging module, and then the radio frequency ablation is carried out on the lesion, and the imaging module is used to observe the morphological changes of the lesion until most of the embolus or tumor cells are inactivated, and then the radio frequency ablation module is turned off.

[0061] Step three, laser ablation treatment of the residual edge of the lesion. Laser ablation is used to treat the residual lesion left by radio frequency ablation. Since the focusing point of the light signal in laser ablation coincides with the observation point of the imaging module, laser ablation can be carried out while imaging is observed. Therefore, the internal imaging module and laser ablation module of the probe can be mechanically scanned while imaging and ablation are carried out by using the displacement control system. The following is an example of this step:

[0062] (1) Laser ablation treatment of the left edge of the lesion. The laser ablation module is turned on, as shown in Figure 4 . Near-infrared laser is emitted from the visible-near-infrared optical fiber 3, converged through the GRIN lens 5, reflected to the left edge of the lesion residue through the prism 6, and then laser ablation treatment of the residual lesion left by radio frequency ablation can be carried out.

[0063] (2) Laser ablation treatment of the right edge of the lesion, as shown in Figure 5 . After the left edge of the lesion is treated, the laser ablation module is turned off; the displacement control system is controlled to advance the metal guide wire 12, so that the fixed base 9 advances along the probe head until the right edge of the lesion is observed, and then the laser ablation module is turned on again to carry out laser ablation treatment of the right edge of the lesion.

[0064] Step four, observe the morphology of the lesion residue until the residue is completely ablated. The cooperative ablation of radio frequency ablation and laser ablation realized by the probe of the present application can completely treat various complex intravascular lesions, and can also effectively avoid the disadvantages of traditional radio frequency ablation technology, such as incomplete inactivation of the lesion or excessive inactivation of the lesion which damages normal tissues.

[0065] Example 2

[0066] Please refer to Figure 6 , the present application designs a set of in vitro multi-module ablation system scheme suitable for intravascular radio frequency / laser ablation probe.

[0067] The ablation system is composed of a control module, a displacement control system, an imaging module and an ablation module. The control module can realize the free movement and rotation of the probe in the patient's blood vessel by controlling the displacement control system. The imaging module completes one or more ways of OCT imaging, ultrasonic imaging, photoacoustic imaging and thermal tomography imaging through the scanning of the probe, which is mainly used to provide the three-dimensional topography information and functional information of the blood vessel for the ablation module. The ablation module covers the dual-mode of radio frequency ablation and laser ablation, which is used to inactivate the target lesion area.

[0068] Specifically, the control module is connected with the input end of the laser light source. After adjustment, the laser light source can excite visible to near-infrared light signals for OCT imaging and photoacoustic imaging. A 90:10 coupler is used to split the OCT signal into the sample arm and the reference arm. A 50:50 coupler is used to combine the detected OCT signal with the reference arm into a photodetector for identification and reading. The read information is transmitted to the data processing and image reconstruction module in the form of electrical signals for A / D conversion, storage and calculation.

[0069] The data processing and image reconstruction module internally uses functional modules such as A / D converter, noise reduction filter, numerical control microcomputer, data acquisition card and RGB encoding converter for combination. When in use, the A / D converter and the noise reduction filter are responsible for noise reduction preprocessing of the received analog signal to improve the signal quality; the numerical control microcomputer is used for real-time transmission and feedback of the signals of the synchronous control module, so as to adjust the position of the probe and the metal guide wire 12 and the wavelength of the laser light source; the data acquisition card is used to record the three-dimensional coordinate information of OCT, ultrasonic and photoacoustic, so as to provide the inversion premise for thermal tomography, and secondly, it can store the position, morphology and composition of the lesion in the blood vessel, so as to facilitate the orderly progress of the ablation work; the RGB encoding converter is used to realize the (pseudo) color imaging of the multi-mode in the blood vessel, and the morphology in the blood vessel is clearly displayed through two-dimensional or three-dimensional graph. According to Figure 6 , the output ends of the photodetector, the far-infrared detector, the pulse emitter-receiver and the control module are connected with the module, realizing the synchronous processing of various information, so as to ensure that the image display module can realize real-time imaging during ablation; the radio frequency signal transmitter is used to control the electrode with array element code carried on the outside of the probe. The radio frequency electrode lead is connected with the radio frequency signal transmitter through the displacement control system. After imaging is completed, selective driving can be realized according to the electrode number attached to the lesion. Figure 6 The structure details the ablation process:

[0070] Firstly, the control imaging module acquires the three-dimensional topography information (OCT imaging, ultrasonic imaging, photoacoustic imaging) and functional information (thermal tomography) in the blood vessel.

[0071] Specifically, the step can be simultaneously generated by the control module of the ablation system described above in a synchronous time-division multiplexing manner, wherein the OCT, ultrasound, photoacoustic and thermal tomography signals are generated by the control module controlling the laser light source, the ultrasound signal is generated by the control module controlling the pulse emitter / receiver. The OCT light signal returned by the blood vessel tissue and the ultrasound, photoacoustic signal are respectively received and read by the photodetector and the pulse emitter / receiver, and the thermal tomography light signal is read by the far-infrared detector. At this time, the three-dimensional topographic information of the blood vessel is recorded in the data processing and image reconstruction module for operation and storage, and finally the digital image is transmitted to the display module to provide the user with the three-dimensional topographic information of the blood vessel. In particular, the temperature field inversion of thermal tomography imaging will use topographic coordinate information for operation, and the user can select imaging (one or more imaging methods) according to the size of the lesion area to obtain thermal tomography images of different depths (one or more) to provide the user with vascular functional information.

[0072] Second, according to the provided image information, the lesion area is preliminarily positioned;

[0073] Specifically, the probe is continuously controlled by the displacement control system through the flexible catheter 14, and the catheter displays the embolus or tumor cell image in the field of view of the image display module during free movement in the blood vessel.

[0074] Third, the lesion area is analyzed in terms of topography, size, composition and other elements, and an appropriate ablation scheme is developed;

[0075] Specifically, thermal tomography imaging will invert the thermal information of the blood vessel in the form of temperature field distribution, so the temperature of the local embolus and tumor tissue will differ from the surrounding normal tissue. The user can select the ablation scheme according to the obtained lesion topography and composition. The ablation scheme should include the ablation temperature and the ablation mode. The user should fully consider the patient's body temperature, cell function tolerance, etc. to obtain the appropriate temperature information according to the functional information provided by the thermal tomography imaging. The selection of the ablation mode requires the user to fully consider the three-dimensional topographic characteristics of the lesion in the blood vessel. In this embodiment, an irregular large-volume embolus in the blood vessel is taken as the ablation object for detailed description.

[0076] The above analysis and ablation scheme development process can be performed manually or with the help of simulation or calculation software.

[0077] Fourth, cooling liquid is injected into the balloon through the liquid catheter to make the balloon expand to fully adhere to the lesion;

[0078] Specifically, after the location, composition and ablation scheme of the lesion are fully confirmed, cooling liquid is injected into the flexible balloon 10 through the liquid catheter 16 to make the outer surface of the balloon 10 fully adhere to the lesion area, wherein the temperature of the cooling liquid should correspond to the ablation scheme in the third step.

[0079] Fifth, control the imaging module to high-resolution imaging of the lesion, determine the electrode array number complete with the lesion, and then control the radiofrequency ablation module to ablate the lesion, while using the imaging module to observe the changes in the lesion, until most of the embolus or tumor cells are inactivated, then turn off the radiofrequency ablation module;

[0080] Specifically, the control module controls the radiofrequency signal transmitter to discharge the radiofrequency electrode 11 to generate high temperature, and the part of the flexible balloon 10 on the probe that is in contact with the tissue will be ablated. After the system radiofrequency ablation work starts, the user can view the inactivation degree of the tissue through the image display module, and can change the cooling liquid temperature to neutralize the local high temperature according to the inactivation of the lesion, until the lesion area in the visual field is inactivated to a large extent, and then the radiofrequency transmitter can be turned off by manual or computer control.

[0081] Sixth, observe the intravascular real-time imaging to locate the lesion area that is not completely treated in the fifth step;

[0082] Specifically, the user can repeat the first step to image the area after radiofrequency ablation, and then control the displacement control system to move the probe in the blood vessel to find the embolus or tumor cells that are not completely treated, and transmit the position information to the control module.

[0083] Seventh, turn on the laser ablation module to ablate the residual lesion area in the sixth step, and observe the morphological changes of the lesion until the lesion area is completely inactivated, then turn off the laser ablation module;

[0084] Specifically, the control module controls the laser light source to generate high-temperature laser pulses, which are transmitted to the prism 6 in the probe through the visible-near infrared optical fiber, and then emitted to act on the residual lesion. During laser ablation, the user can obtain the treatment condition of the residual lesion through the image display module, and then adjust the wavelength of the laser or turn off the laser light source to complete the laser ablation when the residue is completely removed.

[0085] Eighth, use the liquid conduit to pump out the cooling liquid in the balloon, so that the balloon shrinks on the surface of the probe transparent shell.

[0086] Specifically, after the two ablations are completed, the user can judge the lesion condition according to the image display module, and when the lesion is inactivated sufficiently, the inactivation of the lesion area is completed. After the system stops ablation, the liquid in the balloon 10 is pumped out through the liquid conduit 16, and the pumping out can be realized by connecting a vacuum liquid pump, so that the balloon 10 is tightly attached to the surface of the probe transparent shell again.

[0087] Ninth, according to the user's needs, the next lesion in the blood vessel is ablated or the catheter is withdrawn to the outside of the patient's body to complete the ablation work.

[0088] Specifically, when the flexible balloon 10 is tightly attached to the outside of the probe, the flexible catheter 14 will restore its stretching function, and the user can repeat the first to eighth steps to ablate other lesion areas in the patient's blood vessels in turn, so as to achieve complete ablation of the lesion area.

[0089] Embodiment 3

[0090] Please refer to Figure 7 In another optional embodiment, the present application provides a system connection scheme suitable for OCT, radio frequency ablation, and laser ablation. The system is composed of a control module, a laser light source, a 90:10 coupler, a circulator, a reference arm, a 50:50 coupler, a visible-near infrared fiber, a photodetector, a displacement control system, a data processing and image reconstruction module, an image display module, and a radio frequency signal transmitter, which can realize high-resolution OCT imaging and radio frequency / laser dual-mode ablation functions. Since OCT imaging has a local high-resolution feature, its axial resolution can reach about 10 μm, which can be used to display high-resolution feature information of the lesion area in the blood vessel.

[0091] Specifically, the control module is connected to the input end of the laser light source. After adjustment, the light source can excite a near-infrared light signal of about 1310 nm for OCT imaging. This signal is split in the 90:10 optical coupler, of which 10% power is injected into the reference arm (composed of a collimator, a lens, and a mirror), and 90% power is injected into the sample arm. The light signal entering the sample arm is injected into the blood vessel tissue through the probe. During this process, the position of the probe can be adjusted by the displacement controller to complete the OCT positioning of the blood vessel lesion. The reflected light signal passes through the circulator and then enters the 50:50 coupler to interfere with the 10% reference arm signal and finally enters the photodetector to read the signal. The read information is transmitted to the data processing and image reconstruction module in the form of an electrical signal for A / D conversion, storage, and calculation. The OCT image can be presented to the image display module. The following will be described in detail in combination with specific embodiments:

[0092] First, turn on the control module to make the laser light source emit a near-infrared light, so that the system of the present embodiment generates an OCT image of the lesion.

[0093] Second, according to the provided OCT information, preliminarily position the lesion area;

[0094] Third, determine the ablation scheme, and send the probe balloon electrode part to the blood vessel lesion;

[0095] Fourth, inject cooling liquid into the balloon through the liquid catheter, so that the balloon expands to the surface electrode and fully adheres to the lesion;

[0096] Fifth, determine the electrode array number which fits the lesion completely, then control the radio frequency ablation module to ablate the lesion, and observe the difference of the lesion morphology by the image display module until most of the embolus or tumor cells are inactivated, then turn off the radio frequency ablation module;

[0097] Sixth, observe the intravascular real-time imaging, find the lesion region which is not treated completely in the fifth step and locate it;

[0098] Seventh, turn on the laser ablation module to ablate the residual lesion region in the sixth step, and observe the morphology change of the lesion until the lesion region is completely inactivated, then turn off the laser ablation module;

[0099] Eighth, use the liquid catheter to drain the cooling liquid in the balloon, so that the balloon shrinks on the surface of the probe glass shell.

[0100] Ninth, according to the user's needs, ablate the next lesion in the blood vessel or separate the catheter to complete the ablation work in the patient's body.

[0101] Example 4

[0102] Please refer to Figure 8 In another optional embodiment, the present application provides a set of system connection scheme suitable for OCT, thermal chromatography, radio frequency ablation and laser ablation. The thermal chromatography imaging is used to provide the functional information of the intravascular lesion, so that the user can better judge the characteristics of the lesion region to select the ablation temperature and ablation mode. The combination of real-time monitoring of temperature field distribution by thermal chromatography imaging and high-resolution monitoring of morphology change by OCT imaging realizes real-time monitoring of the ablation process to ensure the accurate implementation of the ablation scheme, and achieves temperature controllable and morphology controllable.

[0103] The system structure includes laser light source, 90:10 coupler, circulator, visible-near infrared fiber, far infrared fiber, far infrared detector, displacement control system, data processing and image reconstruction module, and image display module. The following will be described in detail in combination with specific embodiments:

[0104] First, turn on the control module to make the laser light source emit near-infrared light, so that the OCT imaging of the lesion in the system of the embodiment is generated.

[0105] Second, according to the provided OCT information, the lesion region is preliminarily positioned;

[0106] Third, determine the ablation scheme, and send the probe balloon electrode part to the blood vessel lesion;

[0107] Fourth, inject cooling liquid into the balloon through the liquid catheter, so that the balloon is inflated to the surface electrode and the lesion are fully fitted;

[0108] Fifth, determine the electrode array number which is completely fitted with the lesion, and then control the radio frequency ablation module to ablate the lesion;

[0109] Sixth, the high temperature generated by the ablation process causes temperature change at the lesion, and the system according to the three-dimensional topography information and heat source information of the intravascular lesion inversely calculates the intravascular temperature field, and the image display module presents the intravascular thermal tomography image and OCT image. By observing the lesion topography, temperature and differential changes in composition through the image display module, the radio frequency ablation module is turned off after most of the embolus or tumor cells are inactivated;

[0110] Seventh, observe the real-time imaging in the blood vessel, find the lesion area which is not completely treated in the fifth step and locate it;

[0111] Eighth, turn on the laser ablation module to ablate the residual lesion area in the sixth step, and observe the lesion topography change in the image display module during the ablation, and then turn off the laser ablation module after the lesion area is completely inactivated;

[0112] Ninth, use the liquid catheter to pump out the balloon inner cooling liquid, so that the balloon shrinks on the surface of the probe transparent shell.

[0113] Tenth, according to the user's needs, ablate the next lesion in the blood vessel or withdraw the catheter to the outside of the patient's body to complete the ablation work.

[0114] The above specific description further details the purpose, technical solution and beneficial effects of the application. It should be understood that the above description is only a specific embodiment of the application and is not used to limit the protection scope of the application. Any modification, equivalent replacement, improvement, etc. within the spirit and principles of the application should be included in the protection scope of the application.

Claims

1. An intravascular radiofrequency / laser ablation probe, characterized by: Comprise: A circular fixed column, a transparent shell, a visible-near infrared fiber, a far infrared fiber, a GRIN lens, a prism, an ultrasonic transducer, an insulating liquid, a fixed base, a high-elastic flexible balloon, a radio frequency electrode, a metal guide wire, an ultrasonic transducer lead, a flexible catheter, a radio frequency electrode lead, a liquid conduit and a radio frequency cable; The circular fixed column is fixed inside the transparent shell, which is consistent with the inner diameter of the transparent shell, and is used to fix the visible-near infrared fiber and the far infrared fiber; the GRIN lens is used to collimate and focus the light signal transmitted through the two fibers, and is fixed on the fixed base, and the output end is provided with a prism with the same size, which is used to reflect the light beam to the blood vessel tissue on the side of the probe, and the input end is placed close to the visible-near infrared fiber and the far infrared fiber; the prism is located at the front end of the GRIN lens; the ultrasonic transducer is placed close to the prism and is used to emit and receive ultrasonic signals; the internal components of the probe are sealed by the transparent shell to ensure the permeability of the light signal and the acoustic signal and the sealing of the internal components; the flexible balloon is uniformly wrapped on the transparent shell, and the surface has a ring-shaped radio frequency array electrode uniformly distributed along the axial direction; the flexible balloon contains a liquid conduit for transmitting high-purity cold water cooling liquid; The flexible catheter is connected to the front end of the probe and is used to load the metal guide wire, the transducer lead and the liquid conduit; The fixed base is installed inside the probe and is used to realize the fixed placement of the optical and acoustic elements and support the components; the fixed base is hollow inside and is used to place the transducer cable; the optical and acoustic elements are fixed on the upper surface of the fixed base; the front end of the fixed base is connected with the metal guide wire, and the other end of the metal guide wire is connected with the displacement control system outside the body to adjust the relative position of the fixed base in the probe cavity, so as to realize the flexible adjustment of the emission position and the receiving position of the light signal and the acoustic signal in the blood vessel, thereby improving the imaging and laser ablation quality; Each array element of the ring-shaped radio frequency array electrode is independently connected through a lead to meet the independent controllability of the array element, and the user can selectively drive the array element of the ring-shaped radio frequency array electrode according to the morphology of the plug or tumor cells.

2. The intravascular radio frequency / laser ablation probe of claim 1, wherein: The visible-near infrared fiber can complete two functions, one is used to transmit and receive the light signal for OCT imaging and photoacoustic imaging, and the other is used to transmit the light signal for laser ablation; the far infrared fiber is used to transmit the far infrared light signal for thermal tomography; the fibers are fixed in the probe by a circular fixed column, which is fixed inside the transparent shell and is consistent with the inner diameter of the transparent shell; the circular fixed column has two circular holes with different radii inside, which are used to fix the two fibers; the side of the circular fixed column is connected with a fixed base, which is used to fix the prism, the GRIN lens and the ultrasonic transducer components; The GRI N The lens is used for collimating and focusing the optical signal after transmission through two optical fibers, so that the optical signal is transmitted along the axial direction. The ultrasonic transducer can utilize the positive and negative piezoelectric effect to complete the functions of transmitting ultrasonic imaging signals and receiving ultrasonic imaging, photoacoustic imaging and acoustic echo signals; the ultrasonic transducer is internally composed of a sensitive element, an electrode material, an acoustic absorption backing and a packaging material; wherein the sensitive element is made of a piezoelectric composite material, a relaxor single crystal material or a piezoelectric film with a high bandwidth and a suitable aperture size to meet the requirements of stable sound wave transmission and high sensitivity sound wave reception; The internal components of the probe are sealed by a transparent shell, which not only ensures the permeability of various optical signals and acoustic signals, but also ensures the sealing of the internal components; the probe cavity is filled with glycerol and silicon oil insulating liquid to ensure the internal insulation and acoustic impedance matching of the probe and reduce friction; The transparent shell of the probe is coated with a high-elasticity flexible balloon; during use, the balloon can be opened and the elements of the ring-shaped radio frequency array electrode covering the lesion can be positioned by high-resolution imaging, and high temperature generated by turning on the elements of the ring-shaped radio frequency array electrode covering the lesion can inactivate the plug or tumor cells to cause coagulative necrosis of the tissue; a multi-core cable is arranged in the balloon for loading radio frequency electrode leads; After the ablation work starts, cooling liquid is injected into the balloon through the liquid conduit to prevent ablation high temperature from damaging normal vascular endothelial cells; the structure of the balloon will be inflated by the amount of liquid injection until it closely adheres to the inner wall of the blood vessel; after the ablation is completed, the cooling liquid in the balloon can be extracted through the liquid conduit to make the balloon shrink and adhere to the surface of the transparent shell of the probe; in addition to the cooling function, the cooling liquid should also have electrical insulation to ensure electrical insulation between the radio frequency electrodes on the inner surface of the balloon; The front end of the probe is connected with a flexible catheter, and the other end is connected with the displacement control system to realize the advancement, withdrawal and rotary scanning of the probe in the blood vessel; the flexible catheter internally loads the transducer cable, optical fiber, metal guide wire, radio frequency cable and liquid conduit.

3. An ablation system comprising a probe as claimed in claim 1 and an extracorporeal multi-module system, characterized in that: The extracorporeal multi-module system is composed of a control module, a displacement control system, an imaging module and an ablation module; The control module controls each output in a synchronous time division multiplexing manner and includes three functions, which are respectively used for (1) controlling the displacement control system to realize the full-range scanning function of the probe in the blood vessel; (2) controlling the laser emission, reception and electric pulse emission of the imaging module; and (3) controlling the radio frequency signal emission; The displacement control system is used to control the advancement, withdrawal and rotation of the probe in the blood vessel, and the output end thereof is connected with the flexible catheter to control the guide wire in the fixed base in the probe; The imaging module can realize OCT imaging, ultrasonic imaging, photoacoustic imaging and thermal tomographic imaging; The ablation module is composed of a radio frequency ablation module and a laser ablation module.

4. The system of claim 3, wherein: The imaging module is composed of a laser light source, a visible-near infrared fiber, a far infrared fiber, a 90:10 coupler, a reference arm, a circulator, a 50:50 coupler, a photodetector, a far infrared detector, a pulse emitter / receiver, a data processing and image reconstruction module and an image display module; the specific connection mode is as follows: the input end of the laser light source is connected to the control module for receiving and reading the synchronization signal of the control module, and the output end thereof is connected to a 90:10 coupler for splitting the optical signal to form a reference arm signal and a sample arm signal; the 90:10 coupler has two output ports of a reference arm and a sample arm, and is connected to the circulator for positioning the OCT optical signal; the reference arm is composed of a collimating mirror, a lens and a mirror, is connected to the output end of the circulator, and is used for adjusting the reference arm signal; the circulator located in the sample arm has an input end and two output ends, the input end is connected to the output port of the 90:10 coupler for receiving the sample arm signal and the PA signal of the OCT emitted by the laser light source; one output port of the circulator located in the sample arm is connected to the probe for emitting and receiving the OCT and PA signals; the input ends of the 50:50 coupler are respectively connected to the output ends of the two circulators located in the reference arm and the sample arm for coherently superimposing the sample arm and reference arm signals; the output end of the 50:50 coupler is connected to a photodetector for receiving and reading the OCT signal; the input end of the signal processing and image reconstruction module is connected to the photodetector, and the output end thereof is connected to the display module to respectively realize the functions of photoelectric signal conversion and image display; the input end of the pulse emitter / receiver is connected to the control module, and the output end thereof is connected to the lead wire of the ultrasonic transducer to provide a pulse signal for the ultrasonic transducer in the probe; the far infrared detector is used for receiving and reading the thermal radiation information in the blood vessel, and then transmitting the information to the data processing and image reconstruction module for three-dimensional temperature field inversion, the input end thereof is connected to the far infrared fiber in the probe, and the output end thereof is connected to the data processing and image reconstruction module.

5. The system of claim 3, wherein: The radio frequency ablation module comprises a radio frequency signal emitter, the input end of which is connected to the control module, and the output end thereof is connected to the annular radio frequency array electrode; the control module is used for controlling the radio frequency signal emitter to generate a radio frequency current, which reaches the annular radio frequency array electrode through the lead wire for ablation; The laser ablation module shares the same light emitting system with the OCT imaging; after the radio frequency ablation is completed, the user can image the local blood vessel again, and the control module is used for controlling the laser light source to generate a hot laser pulse for continuing laser ablation on the residual lesion.

Images