CN115956997A - Intravascular radio frequency/laser ablation probe - Google Patents

Abstract

The invention relates to an intravascular radio frequency/laser ablation probe, and belongs to the field of biomedical equipment. The invention aims to solve the problems of limited radio frequency ablation precision and limited guide mode resolution and provides an intravascular radio frequency/laser ablation probe. Compared with the traditional radio frequency ablation, the ablation of large-area thrombus or tumor tissues in blood vessels can be met, the ablation of residual diseased tissues can be performed by utilizing a laser ablation technology, the defect that the precision of the traditional single radio frequency ablation technology is limited is effectively overcome, the ablation precision is obviously improved, the focus is completely ablated, and normal tissues or cells are effectively protected. In addition, the invention realizes the sharing of components such as light paths, sound paths, circuits and the like among all modules of the ablation system, effectively reduces the size and the cost of the probe and improves the practical value of the probe.

Description

Intravascular radio frequency/laser ablation probe

Technical Field

The invention relates to an intravascular radio frequency/laser ablation probe, and belongs to the field of biomedical equipment.

Background

The ablation technology is an important minimally invasive treatment mode in the current medical treatment, and is mainly used in the clinical fields of beautifying, removing freckles, regulating arrhythmia, inactivating tumor cells and the like. The basic principle is that local focal tissues or cells are denatured and necrotized due to the thermal effect through a certain physical mode (such as exciting high-frequency current, high-power laser and the like) so as to achieve the purpose of healing. The common methods comprise radio frequency ablation, cold ablation, pulse ablation, laser ablation, ultrasonic ablation and the like, and compared with simple drug therapy, the ablation technology can completely eradicate the focus of infection, thereby fundamentally achieving the effect of curing diseases.

The radio frequency ablation method is the most common ablation technology for treating cardiovascular internal diseases at present, and has the advantages of small side effect, high real-time performance, small wound and the like. In the technical aspect, the radiofrequency ablation is generally used for positioning a focus in an external CT or B-ultrasonic imaging mode, an ablation needle is conveyed to an affected part in a puncture mode after a target position is determined so that a surface electrode is fully attached to a tissue, and finally, radiofrequency current is introduced to the electrode so that the tissue undergoes coagulative necrosis. Li Yanjun et al (Li Tingjun, fu Yahui, wu Hui, zheng Wenjian, gao Wei, for example, for detecting and clearing, zhang Dong. 100 cases of hepatic hemangioma treatment by radiofrequency ablation [ J ]. Hepatobiliary pancreas surgery journal, 2019,31 (09): 540-544.) were subjected to treatment experience summary for 100 cases of hepatic hemangioma treatment by radiofrequency, wherein 88 of 101 nodules were completely destroyed after RFA, the complete destruction rate was 87.1%, the ablation rate for hemangioma could be 92.1%, and the cure effect was good; wang Shiwei et al (Wang Shiwei, koreand, qin Mian, zhang Jingyan, mei Lixia) in ziqihaer's first hospital clinical research on the treatment of thromboangiitis obliterans by radio frequency ablation in blood vessels [ J ] Chinese sanitary standard management, 2019,10 (20): 31-32.) tests the efficacy of radio frequency ablation on thromboangiitis obliterans, and experiments show that the ABI index (0.90 +/-0.16) after operation of a patient is obviously better than that before operation (0.31 +/-0.07), and the radio frequency ablation effect is more obvious.

However, simple radiofrequency ablation also has several drawbacks:

first, the omission of thrombus mass or tumor cells and erroneous killing of normal tissue are major potential risks of rf ablation. The radiofrequency ablation is mainly based on the ablation energy applied by a surface electrode attached to a focus, and the size of the electrode determines the precision of the radiofrequency ablation. Due to the narrow space in the blood vessel, the probe cannot be provided with a surface electrode with small lower electrode area and large array scale, so the precision of radio frequency ablation cannot reach the micron level. This has the consequence of inaccurate ablation of the lesion margins.

Secondly, the form of fusion with imaging needs further improvement. The current commonly used positioning means for radiofrequency ablation mainly comprises two imaging technologies of in vitro CT or B-ultrasound, the resolution ratio is millimeter to sub-millimeter magnitude, so that the positioning accuracy of the radiofrequency ablation in the guided intravascular ablation is greatly insufficient, the result of 'misalignment' can be brought by the 'invisible' guiding mode, and the improvement of the ablation accuracy is limited.

Disclosure of Invention

The invention aims to solve the problems of limited radio frequency ablation precision and limited guide mode resolution and provides an intravascular radio frequency/laser ablation probe. Compared with the traditional radio frequency ablation, the ablation of large-area thrombus or tumor tissues in blood vessels can be met, the ablation of residual diseased tissues can be performed by utilizing a laser ablation technology, the defect that the precision of the traditional single radio frequency ablation technology is limited is effectively overcome, the ablation precision is obviously improved, the focus is completely ablated, and normal tissues or cells are effectively protected. And.

The purpose of the invention is realized by the following technical scheme.

The intravascular radio frequency/laser ablation probe provided by the invention integrates various intravascular imaging technologies, including imaging functions of OCT, ultrasound, photoacoustic, thermal chromatography and the like, can realize high-resolution image guidance, solves the defect that the traditional in-vitro imaging guidance mode is not clear, and further realizes alignment dual-mode ablation. In addition, the invention has the outstanding advantages of high integration and small volume, and the invention carries out optical, acoustic and electrical common-path design on a plurality of diagnosis and treatment functions, greatly reduces the size of the probe while ensuring multiple functions, and has the obvious characteristics of strong realizability, high resolution, high ablation precision and the like.

The invention provides an intravascular radio frequency/laser ablation probe which comprises a circular fixing column, a transparent shell, a visible-near infrared optical fiber, a far infrared optical fiber, a GRIN lens, a prism, an ultrasonic transducer, insulating liquid, a fixing base, a high-elasticity flexible balloon, a radio frequency electrode, a metal guide wire, an ultrasonic transducer lead wire, a flexible catheter, a radio frequency electrode lead wire, a liquid catheter and a radio frequency cable. The concrete connection mode is as follows: the round fixing column is fixed on the inner side of the transparent shell, is matched with the inner diameter of the transparent shell and is used for fixing the visible-near infrared optical fiber and the far infrared optical fiber; the GRIN lens is used for collimating and focusing optical signals transmitted by the two optical fibers, is fixed on the fixed base, is provided with a prism with the same size at the output end, can reflect light beams to vascular tissues at the side of the probe, and is closely attached to the visible-near infrared optical fiber and the far infrared optical fiber at the input end; the prism is positioned at the front end of the GRIN lens; the ultrasonic transducer is closely attached to the prism and used for transmitting and receiving ultrasonic signals; the fixed base is internally provided with a hollow structure and used for placing a transducer cable; the metal guide wire is connected with the front end of the fixed base and can be used for adjusting the relative position of the fixed base in the probe cavity; the internal components of the probe are sealed by a transparent shell, so that the permeability of optical signals and acoustic signals and the sealing property of the internal components are ensured; the flexible saccule is uniformly wrapped on the transparent shell, and the surface of the flexible saccule is provided with annular radio frequency array electrodes which are uniformly distributed along the axial direction; the interior of the flexible saccule contains a liquid conduit for transmitting cooling liquid such as high-purity cold water and the like; a flexible catheter is connected to the front end of the probe for carrying the metal guidewire, transducer leads and fluid catheter.

Furthermore, the visible-near infrared optical fiber can perform two functions, namely, transmitting and receiving optical signals for OCT imaging and transmitting photoacoustic imaging, and transmitting optical signals for laser ablation. The far-infrared optical fiber is used for transmitting a far-infrared optical signal of thermal tomography. The optical fibers are fixed in the probe by a round fixing column, and the radius of the round fixing plate is matched with the inner diameter of the transparent shell. Two circular holes with different radiuses are formed in the circular fixing column and used for fixing the two optical fibers, and the side face of the circular fixing column is connected with a fixing base and used for fixing components such as a prism, a GRIN lens and an ultrasonic transducer.

Further, the GRIN lens is used for collimating and focusing the optical signals transmitted by the two optical fibers, so that the optical signals are transmitted in an axial focusing manner.

Further, the ultrasonic transducer can utilize the positive and negative piezoelectric effect to complete the functions of transmitting ultrasonic wave signals of ultrasonic imaging and receiving ultrasonic imaging and photoacoustic imaging acoustic echo signals. The interior of the ultrasonic transducer is composed of a sensitive element, an electrode material, a sound absorption backing and a packaging material. The sensitive element can be made of a piezoelectric composite material, a relaxation single crystal material, a piezoelectric film and the like with high bandwidth and proper pore size so as to meet the requirements of stable sound wave emission and high-sensitivity sound wave receiving.

Furthermore, the fixed base is arranged in the probe and used for realizing the fixed placement of the optical element and the acoustic element and supporting the components. The fixing base is internally provided with a hollow structure for placing a cable of the transducer. And the optical element, the acoustic element 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 an external displacement control system. The method can be used for adjusting the relative position of the fixed base in the probe cavity, so that the transmitting position and the receiving position of optical signals and acoustic signals in the blood vessel can be flexibly adjusted and controlled, and the imaging and laser ablation quality can be improved.

Furthermore, the internal components of the probe are sealed by a transparent shell, so that the permeability of various optical signals and acoustic signals can be ensured, and the sealing performance of the internal components can be ensured. Insulating liquid such as glycerin, silicone oil and the like is filled in the probe cavity to ensure the internal insulation of the probe, the acoustic impedance is matched, and the friction is reduced.

Furthermore, the outer side of the transparent shell of the probe is coated with a high-elasticity flexible saccule, and the surface of the saccule is provided with annular radio frequency array electrodes which are uniformly distributed along the axial direction. After the imaging is finished and the positioning is finished, the saccule is opened, the electrode array element (covering electrode) covering the focus is accurately positioned by utilizing high-resolution imaging, and the high temperature for inactivating the thrombus block or tumor cells is generated by opening the covering electrode, so that the tissue is subjected to coagulative necrosis. The array elements of the array electrode are independently connected through the leads so as to meet the independent controllability of the array elements, and a user can selectively drive the array elements of the radio-frequency electrode according to the appearance of the thrombus or tumor cells. A multi-core cable is arranged in the balloon and used for loading the radio-frequency electrode lead.

Furthermore, a liquid catheter is arranged in the flexible balloon, and after the ablation operation is started, cooling liquid can be injected into the balloon through the liquid catheter so as to prevent normal vascular endothelial cells from being damaged by ablation high temperature. The structure of the balloon can be expanded by the injection amount until the structure is tightly attached to the inner wall of the blood vessel; after ablation is finished, cooling liquid in the saccule can be pumped out through the liquid catheter, so that the saccule is attached to the surface of the transparent shell of the probe after being contracted. It should be noted that, in addition to the cooling function, the cooling liquid should also be electrically insulating to satisfy the electrical insulation between the rf electrodes on the inner surface of the balloon.

Furthermore, the front end of the probe is connected with a flexible catheter, the transducer cable, the optical fiber, the metal guide wire, the radio frequency cable and the liquid catheter are loaded in the flexible catheter, and the other end of the flexible catheter is connected with the in-vitro displacement controller, so that the probe can be pushed, retracted and rotationally scanned in a blood vessel.

The invention provides an in-vitro multi-module system for the probe, and an ablation system is formed by the in-vitro multi-module system and the probe. The in vitro multi-module system consists of a control module, a displacement control system, an imaging module and an ablation module.

The control module controls each path of output in a synchronous time division multiplexing mode, has three functions, and is respectively used for (1) controlling the displacement control system to realize the omnibearing scanning function of the probe in the blood vessel; (2) Controlling the laser emission, the receiving and the electric pulse emission of the imaging module; and (3) controlling the emission of radio frequency signals.

The displacement control system is used for controlling the advancing, withdrawing and rotating of the probe in the blood vessel, the output end of the displacement control system is connected with the flexible catheter, and a guide wire in a fixed base in the probe is controlled.

The imaging module can realize OCT, supersound, optoacoustic and thermal chromatography four kinds of imaging module, its structure by laser source, visible-near infrared optic fibre, far infrared optic fibre, 90 couplers, reference arm (by collimating mirror, lens and speculum constitution), circulator, 50 couplers, photoelectric detector, far infrared detector, pulse transmission/receiver, data processing and image reconstruction module and image display module constitute. The specific connection mode is as follows: the input end of the laser light source is connected with the control module and used for receiving and reading the synchronous signal of the control module, and the output end of the laser light source is connected with a 90; the 90; the reference arm consists of a collimating mirror, a lens and a reflecting mirror, is connected to the output end of the circulator and is used for adjusting a reference arm signal; the circulator positioned on the sample arm comprises an input end and two output ends, wherein the input end of the circulator is connected with the output port of the 90; one output port of the circulator positioned on the sample arm is connected with the probe and can be used for transmitting and receiving OCT and PA signals; the input ends of the 50; the output end of the 50; the input end of the signal processing and image reconstruction module is connected with the photoelectric detector, and the output end of the signal processing and image reconstruction module is connected with the display module, so that the photoelectric signal conversion and image display functions of the detection system are respectively realized; the input end of the pulse transmitting and receiving device is connected with the control module, and the output end of the pulse transmitting and receiving device is connected with the lead of the ultrasonic transducer, so that a pulse signal can be provided for the ultrasonic transducer in the probe; the far infrared detector is used for receiving and reading heat radiation information in the blood vessel, 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 optical fiber in the probe, and the output end of the far infrared detector is connected with the data processing and image reconstruction module.

Further, the OCT module is composed of a laser light source, a visible-near infrared optical fiber, a 90. When the instruction of the control module is sent out, the laser light source generates a near infrared light signal, the light source is divided into a sample arm with 90% of power and a reference arm with 10% of power after beam splitting by a coupler of 90. The signal reflected by the vascular tissue and the reference arm with 10% of power are transmitted into a photoelectric detector for reading after a 50.

Furthermore, the ultrasonic imaging module is composed of a pulse transmitting/receiving device, a data processing and image reconstruction module and an image display module. The ultrasonic module realizes the conversion of sound and electricity signals through an ultrasonic transducer in the probe, and after the control module sends an instruction to the pulse transmitter/receiver, the pulse transmitter/receiver controls the ultrasonic transducer to transmit ultrasonic signals. Echo signals reflected by vascular tissues are received by the ultrasonic transducer and then transmitted into the pulse transmitting/receiving device again for reading.

Further, the photoacoustic imaging module shares the laser light source, the visible-near infrared optical fiber, and the 90.

Further, the thermal chromatography imaging module is composed of a far infrared optical fiber, a far infrared detector, a data processing and image reconstruction module and an image display module. The far-infrared optical fiber is used for transmitting far-infrared optical signals carrying thermal information, the far-infrared detector and the data processing and image reconstruction module are used for realizing temperature field inversion, and finally, the display module is used for performing thermal chromatography imaging on the blood vessel, so that the cell functional information such as the type of thrombus/tumor cells of a lesion part, physiology and the like can be further obtained. The user can accurately control the ablation temperature and the ablation mode according to the information.

The ablation module consists of a radio frequency ablation module and a laser ablation module.

Furthermore, the radio frequency ablation module comprises a radio frequency signal transmitter, the input end of the radio frequency signal transmitter is connected with the control module, and the output end of the radio frequency signal transmitter is connected with the probe balloon electrode. After imaging is completed, the control module controls the radio-frequency signal transmitter to generate radio-frequency current, and the radio-frequency current reaches the balloon electrode through the lead wire for ablation.

Further, the laser ablation module and the OCT imaging share the same light emission system. After the radiofrequency ablation is completed, the user can image the local part of the blood vessel again, and after the positioning information confirms that the positioning information is correct, the control module controls the laser light source to generate a scorching laser pulse to continue laser ablation on the residual focus.

The invention provides a novel intravascular radio frequency/laser ablation method, which can realize the synergistic effect of two ablation modes in a blood vessel by adopting the intravascular radio frequency/laser ablation probe and an in-vitro multi-module system, thereby achieving the outstanding advantages of large ablation range and high ablation precision, and comprising the following specific steps:

the method comprises the following steps of firstly, controlling an imaging module to acquire three-dimensional topography information (OCT imaging, ultrasonic imaging and photoacoustic imaging) and functional information (thermal chromatography imaging) in a blood vessel;

secondly, performing primary positioning on the focus area according to the image information provided in the first step;

step three, performing feature analysis on the focus area, such as appearance, size, components and the like, and formulating a proper ablation scheme;

injecting cooling liquid into the balloon through a liquid catheter to enable the balloon to be expanded until the surface electrode is fully attached to the focus;

step five, controlling an imaging module to carry out high-resolution imaging on the focus, and determining the electrode array element number completely attached to the focus;

controlling a radio frequency ablation module, opening the completely attached electrode array element, ablating the focus, observing the shape change of the focus by using an imaging module at the same time, and closing the radio frequency ablation module until most of the thrombus blocks or tumor cells are inactivated;

step seven, controlling an imaging module to accurately position the untreated clean focus area in the step six;

step eight, controlling a laser ablation module, performing laser ablation on the residual focus in the step six, and observing the shape change of the focus in real time until focus tissues are completely inactivated, and then closing the laser ablation module;

and step nine, pumping the cooling liquid in the balloon by using a liquid catheter to dry, and enabling the balloon to contract inwards and be pasted on the surface of the transparent shell of the probe.

Step ten, according to the actual situation, the ablation of the next focus in the blood vessel is carried out or the catheter is withdrawn to the outside of the body of the patient to finish the ablation process.

Has the advantages that:

1. the intravascular radio frequency/laser ablation probe disclosed by the invention realizes the cooperation and fusion of two ablation technologies of radio frequency ablation and laser ablation aiming at thrombus blocks or tumor cells in a blood vessel for the first time, fully utilizes the advantages of large radio frequency ablation range and high laser ablation precision, realizes the advantages of exerting the advantages and filling up short plates for simple radio frequency ablation and simple laser ablation, can greatly improve the inactivation rate of focus cells, avoids the defect that the normal tissues are damaged due to incomplete or excessive inactivation of focuses by the traditional simple radio frequency ablation technology, and improves the ablation precision.

2. The intravascular radio frequency/laser ablation probe disclosed by the invention adopts multiple imaging modes to acquire the intravascular topography and functional information, can accurately provide the three-dimensional topography information of vascular tissues, can also provide the cell functional information, and can further improve the accuracy of positioning a focus area and the accuracy of temperature control in an ablation process.

3. The intravascular radio frequency/laser ablation probe disclosed by the invention realizes the sharing of components such as a light path, an acoustic path, a circuit and the like among all modules of an ablation system, effectively reduces the size and the cost of the probe and improves the practical value of the probe.

4. The in-vitro multifunctional system disclosed by the invention has higher automation characteristics, can realize automatic control of the displacement control system, the imaging module and the ablation module by utilizing the computer through the synchronous control module, and performs data processing and image display on the received signals, thereby effectively reducing the operation difficulty of personnel and saving the labor cost.

Drawings

FIG. 1 is a cross-sectional view of the internal structure of the probe (transparent shell portion) provided by the present invention;

FIG. 2 is a cross-sectional view of the internal structure of the probe according to the present invention (non-transparent shell portion);

FIG. 3 is a three-dimensional structural view of a probe provided by the present invention;

FIG. 4 is a schematic representation of the operation of the probe of the present invention after the endovascular balloon has been opened (laser ablation of the left margin of the lesion);

FIG. 5 is a schematic representation of the operation of the probe of the present invention after the endovascular balloon has been opened (laser ablation of the right margin of the lesion);

FIG. 6 is a schematic diagram of an in vitro multi-module system scheme (OCT, ultrasound, photoacoustic, thermal tomography, RF ablation, laser ablation) suitable for use with the probe of the present invention;

FIG. 7 is a schematic diagram of an in vitro multi-module system scheme (OCT, RF ablation, laser ablation) suitable for use with the probe of the present invention;

FIG. 8 is a schematic diagram of an in vitro multi-module system scheme (OCT, thermal chromatography, RF ablation, laser ablation) suitable for use with the probe of the present invention;

in the figure, 1-round fixed column, 2-transparent shell, 3-near infrared optical fiber, 4-far infrared optical fiber, 5-GRIN lens, 6-prism, 7-ultrasonic transducer, 8-insulating liquid, 9-fixed base, 10-high elastic flexible saccule, 11-radio frequency electrode, 12-metal guide wire, 13-ultrasonic transducer lead wire, 14-flexible conduit, 15-radio frequency electrode lead wire, 16-liquid conduit, 17-radio frequency cable.

Detailed Description

To make the objects, technical solutions and advantages of the present invention more apparent, the present invention will be further described in detail with reference to the accompanying drawings of specific embodiments.

Example 1

Referring to fig. 1 and 2, the intravascular radio frequency/laser ablation probe provided by the invention comprises a circular fixing column 1, a transparent shell 2, a visible-near infrared optical fiber 3, a far infrared optical fiber 4, a GRIN lens 5, a prism 6, an ultrasonic transducer 7, an insulating liquid 8, a fixing base 9, a high-elasticity flexible balloon 10, a radio frequency electrode 11, a metal guide wire 12, an ultrasonic transducer lead 13, a flexible catheter 14, a radio frequency electrode lead 15, a liquid catheter 16 and a radio frequency cable 17. The round fixing column 1 is fixed on the inner side of the transparent shell 2, is matched with the inner diameter of the transparent shell 2 and is used for fixing the visible-near infrared optical fiber 3 and the far infrared optical fiber 4; the GRIN lens is fixed on a fixed base 9, and the input end of the GRIN lens is closely attached to the two optical fibers 3 and 4 to play a role in directing and focusing optical signals; the prism 6 is positioned at the front end of the GRIN lens and is used for reflecting optical signals of OCT imaging, photoacoustic imaging and laser ablation to vascular tissues; the ultrasonic transducer 7 is closely attached to the prism 6 and used for transmitting and receiving ultrasonic signals; the lead 13 can be led out through the fixing base 9, wherein the inside of the base 9 is a hollow structure for placing the ultrasonic transducer cable. Fig. 3 is a three-dimensional block diagram of an intravascular rf/laser ablation probe according to the present invention, which can be used to meet the structural design of fig. 1 and 2. The metal guide wire 12 is connected with the front end of the fixed base 9 and can be used for adjusting 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, so that the permeability of optical signals and acoustic signals and the sealing property of the internal components are ensured; the high-elasticity flexible saccule 10 is uniformly wrapped on the transparent shell, and the surface of the high-elasticity flexible saccule is provided with annular radio frequency array electrodes 11 which are uniformly distributed along the axial direction; the high-elasticity flexible saccule 10 is internally provided with a liquid conduit 16 for transmitting cooling liquid such as high-purity cold water and the like; a flexible catheter 14 is attached to the front end of the probe for carrying the metal guidewire 12, transducer leads 13 and fluid conduit 16.

Referring to fig. 4 and 5, for the edge processing of the focal zone, the present invention provides a set of cooperative schemes of radio frequency ablation and laser ablation, which specifically includes the following steps:

step one, determining the position of a focus. After the focus area is positioned according to the imaging module, high-purity pure water or cooling liquid is injected into the flexible saccule 10 through the liquid catheter 16 until the radio-frequency electrode 11 of the flexible saccule 10 is tightly attached to the focus in the blood vessel.

And step two, selecting the serial number of the radio frequency electrode and carrying out radio frequency ablation. And determining the number of the complete radio frequency electrode attached to the focus by using a high-resolution imaging module, then carrying out radio frequency ablation on the focus, and simultaneously observing the shape change of the focus by using the imaging module until most of the thrombus blocks or tumor cells are inactivated, and then closing the radio frequency ablation module.

And step three, laser ablation treatment of the residual edges of the focus. Laser ablation treatment is carried out on the focus residues left after the radio frequency ablation by utilizing the laser ablation, and the focusing position of the optical signal in the laser ablation is superposed with the observation point of the imaging module, so that the laser ablation can be carried out while imaging observation is realized. Therefore, the imaging and ablation of the probe internal imaging module and the laser ablation module can be realized by the displacement control system while mechanical scanning, and the steps are described as follows by way of example:

(1) And (3) carrying out laser ablation treatment on the left edge of the focus, and starting a laser ablation module as shown in figure 4. Near-infrared laser is emitted from the visible-near-infrared optical fiber 3, is converged by the GRIN lens 5 and is reflected to the left side edge of the focus residues through the prism 6, and then laser ablation treatment can be carried out on the focus residues left after radio frequency ablation.

(2) Laser ablation treatment of the right margin of the lesion, as shown in fig. 5. After the residues on the left edge of the focus are completely treated, closing the laser ablation module; controlling a displacement control system to push a metal guide wire 12, so that the fixing base 9 is pushed along the head of the probe until the right edge of the focus is observed and stops; and starting the laser ablation module again to perform laser ablation treatment on the residues on the right edge of the focus.

And step four, observing the shape of the focus residue until the residue is completely ablated. The cooperative ablation of the radio frequency ablation and the laser ablation realized by the probe can treat various intravascular lesions with complex shapes cleanly, and can effectively avoid the defect that the normal tissues are damaged due to incomplete or excessive inactivation of the lesions by the traditional radio frequency ablation technology.

Example 2

Referring to fig. 6, the present invention designs a set of external multi-module ablation system scheme suitable for intravascular rf/laser ablation probe.

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 free movement and rotation of the probe in a blood vessel of a patient by controlling the displacement control system, the imaging module finishes one or more modes of OCT imaging, ultrasonic imaging, photoacoustic imaging and thermal chromatography imaging by scanning of the probe, and is mainly used for providing three-dimensional topography information and functional information in the blood vessel for the ablation module, and the ablation module covers a radio frequency ablation and laser ablation dual-mode and is used for inactivating a target focus area.

Specifically, the control module is connected with the input end of a laser light source, the laser light source can excite visible-near infrared light signals for OCT imaging and photoacoustic imaging after adjustment, and the 90; and the 50.

The data processing and image reconstruction module is internally combined by functional modules such as an A/D converter, a noise reduction filter, a numerical control microcomputer, a data acquisition card, an RGB (red, green and blue) code converter and the like. When in use, the A/D converter and the noise reduction filter are responsible for carrying out noise reduction pretreatment on the received analog signal so as to improve the signal quality; the numerical control microcomputer is used for transmitting and feeding back signals of the synchronous control module in real time so as to adjust the positions of the probe and the metal guide wire 12 and the wavelength of the laser light source; the data acquisition card is used for recording three-dimensional coordinate information of OCT, ultrasound and optoacoustic, so as to provide inversion premise for thermal chromatography imaging, and then can store information such as position, morphology and components of a focus in a blood vessel, so as to facilitate orderly ablation work; the RGB transcoder is used for realizing multi-mode (pseudo) color imaging in blood vessels, and the appearance in the blood vessels is clearly shown in a two-dimensional or three-dimensional graph mode. According to fig. 6, the output ends of the photoelectric detector, the far infrared detector, the pulse transmitting receiver and the control module are all connected with the module, so that synchronous processing of all paths of information is realized, and the image display module can perform real-time imaging when ablation is performed; the radio frequency signal transmitter is used for controlling an electrode carrying array element codes on the outer side of the probe, a radio frequency electrode lead is connected with the radio frequency signal transmitter through a displacement control system, and selective driving can be achieved according to electrode numbers attached to focus positions after imaging is completed. The ablation process is detailed below in conjunction with the fig. 6 structure:

first, the control imaging module acquires three-dimensional topographic information (OCT imaging, ultrasound imaging, photoacoustic imaging) and functional information (thermal tomography) in the vessel.

Specifically, this step can simultaneously generate OCT, ultrasound, photoacoustic and thermal tomography signals in a synchronized time-division multiplexed manner by the control module of the ablation system described above, wherein the optical signal is generated by the control module controlling the laser light source and the ultrasound signal is generated by the control module controlling the pulse transmitter/receiver. The OCT optical signal and the ultrasonic and photoacoustic signals returned by the vascular tissue are respectively received and read by the photoelectric detector and the pulse transmitting/receiving device, the thermal chromatography optical signal is read by the far infrared detector, at the moment, the three-dimensional shape 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 three-dimensional shape information of the blood vessel for a user. In particular, thermal tomography performs temperature field inversion, and performs calculation by using topographic coordinate information, so that a user can select (one or more imaging modes) for imaging according to the size of a lesion area to obtain thermal tomography images of different depths (one or more types), thereby providing vascular functional information for the user.

Secondly, performing primary positioning on a focus area according to the provided image information;

specifically, the probe is continuously controlled by the displacement control system via the flexible catheter 14, and the catheter displays an image of the embolus or tumor cells in the visual area of the image display module during free movement in the blood vessel.

Thirdly, analyzing the features of the focus area, such as appearance, size, components and the like, and formulating a proper ablation scheme;

specifically, thermal tomography inverts the thermal information of the blood vessel in the form of temperature field distribution, so that the temperature of local thrombus and tumor tissue is different from that of surrounding normal tissue, and a user can select an ablation scheme according to the acquired lesion morphology and components. The ablation scheme comprises an appropriate ablation temperature and an ablation mode, a user can obtain appropriate temperature information after fully considering the body temperature, cell function tolerance and the like of a patient by combining functional information provided by thermal tomography, the selection of the ablation mode needs the user to fully consider the three-dimensional morphological characteristics of a lesion in a blood vessel, and in the embodiment, the detailed description is carried out by taking an irregular large-volume thrombus block in the blood vessel as an ablation object.

The analysis and ablation plan generation process may be performed manually or may be analyzed using simulation or computational software.

Fourthly, injecting cooling liquid into the balloon through a liquid catheter to enable the balloon to be expanded until the surface electrode is fully attached to the focus;

specifically, after the lesion location, composition and ablation plan are sufficiently confirmed, a liquid catheter 16 is used to inject a cooling liquid into the flexible balloon 10 to make the outer side surface of the balloon 10 sufficiently fit with the lesion area, wherein the temperature of the cooling liquid should correspond to the ablation plan in the third step.

Fifthly, controlling an imaging module to carry out high-resolution imaging on the focus, determining the number of an electrode array element completely attached to the focus, then controlling a radio frequency ablation module to ablate the focus, and observing the change of the focus by using the imaging module at the same time until most of the thrombus blocks or tumor cells are inactivated, and then closing the radio frequency ablation module;

specifically, the control module controls the radio-frequency signal transmitter to discharge to the radio-frequency electrode 11 to generate high temperature, and the part, attached to the tissue, of the flexible balloon 10 on the probe is subjected to ablation treatment. After the system starts the radio frequency ablation work, a user can check the inactivation degree of the tissue through the image display module, the temperature of the cooling liquid can be changed according to the inactivation condition of the focus to neutralize the local high temperature, the control module can be operated by a person or a computer to close the work of the radio frequency transmitter until the focus area in the visual area is inactivated in a large quantity, and the radio frequency ablation module is closed.

Sixthly, observing real-time imaging in the blood vessel, and locating and finding out the untreated clean focus area in the fifth step;

specifically, the user can repeat the first step to image the area after the radio frequency ablation, then control the probe to move in the blood vessel through the displacement control system to find the untreated clean thrombus block or tumor cell, and transmit the position information to the control module.

Seventhly, starting a laser ablation module to perform laser ablation on the residual region of the focus in the sixth step, observing the shape change of the focus, and closing the laser ablation module until the focus region is completely inactivated;

specifically, the control module controls a laser light source to generate high-temperature laser pulses, the high-temperature laser pulses are transmitted to a prism 6 in the probe through a visible-near infrared optical fiber and are emitted, and the laser pulses are acted on the residual focus. During laser ablation, a user can obtain the treatment condition of the residual focus by observing the image display module until the residues are completely removed, and then the synchronous control module is controlled to adjust the laser wavelength or close the laser light source to finish the laser ablation.

And eighthly, pumping the cooling liquid in the balloon by using a liquid catheter to ensure that the balloon is contracted on the surface of the transparent shell of the probe.

Specifically, after the two types of ablation are completed, the user judges according to the disease focus condition of the image display module, and after the disease focus is inactivated fully, the inactivation of the disease focus area is completed. After the system stops the ablation work, the liquid in the balloon 10 is pumped out by the liquid conduit 16, and the pumping-out mode can be realized by connecting a vacuum liquid pump, so that the balloon 10 is tightly attached to the surface of the transparent shell of the probe again.

And ninthly, ablating the next focus in the blood vessel or withdrawing the catheter to the outside of the patient body according to the requirements of the user to complete the ablation work.

Specifically, when the flexible balloon 10 is tightly attached to the outer side of the probe, the flexible catheter 14 will recover its stretching function, and the user can repeat the first step to the eighth step to sequentially ablate other lesion areas in the blood vessel of the patient, so as to completely ablate the lesion areas.

Example 3

Referring to fig. 7, in another alternative embodiment, the present invention provides a system connection scheme suitable for OCT, rf ablation, and laser ablation. The system comprises a control module, a laser light source, a 90 coupler, a circulator, a reference arm, a 50 coupler, a visible-near infrared optical fiber, a photoelectric detector, a displacement control system, a data processing and image reconstruction module, an image display module and a radio frequency signal transmitter, can realize high-resolution OCT imaging and radio frequency/laser dual-mode ablation functions, has local high-resolution characteristics in OCT imaging, has axial resolution of about 10 mu m, and can be used for displaying high-resolution characteristic information of a focal region in a blood vessel.

Specifically, the control module is connected to the input end of the laser light source, and the adjusted light source can excite a near-infrared light signal of about 1310nm for OCT imaging, and the signal is split in a 90. The light signal entering the sample arm is emitted into the vascular tissue through the probe, and the position of the probe can be adjusted through the displacement controller in the process so as to complete the OCT positioning of the vascular lesion. The reflected light signals pass through the circulator, then enter a coupler of 50 percent and interfere with a 10 percent reference arm signal, and finally enter the photodetector to read the signals, the read information is transmitted to the data processing and image reconstruction module in an electric signal form to be subjected to A/D conversion, storage and calculation, and an OCT image can be presented to the image display module. The details are described below with reference to specific examples:

first, the control module is turned on to make the laser source emit near infrared light, so that the system of this embodiment generates OCT imaging at the lesion.

Secondly, performing primary positioning on a focus area according to the provided OCT information;

thirdly, determining an ablation scheme, and delivering the probe balloon electrode part to the vascular lesion;

fourthly, injecting cooling liquid into the balloon through a liquid catheter to enable the balloon to be expanded until the surface electrode is fully attached to the focus;

fifthly, determining the electrode array element number completely attached to the focus, then controlling a radio frequency ablation module to ablate the focus, and simultaneously observing the difference change of the focus appearance by an image display module until most of the plug blocks or tumor cells are inactivated, and then closing the radio frequency ablation module;

sixthly, observing the real-time imaging in the blood vessel, finding out the untreated clean focus area in the fifth step and positioning;

seventhly, starting a laser ablation module to perform laser ablation on the residual region of the focus in the sixth step, observing the shape change of the focus, and closing the laser ablation module until the focus region is completely inactivated;

and eighthly, pumping the cooling liquid in the saccule by using a liquid catheter to ensure that the saccule is contracted on the surface of the probe glass shell.

And ninthly, ablating the next focus in the blood vessel or separating the catheter from the body of the patient to complete the ablation according to the requirements of the user.

Example 4

Referring to fig. 8, in another alternative embodiment, the present invention provides a system connection scheme suitable for OCT, thermal tomography, rf ablation, and laser ablation. The thermal tomography is used for providing functional information of the intravascular lesion, and a user can conveniently and better judge the characteristics of the lesion area to select the ablation temperature and the ablation mode. The real-time monitoring of temperature field distribution by thermal tomography and the high-resolution monitoring of morphology change by OCT imaging are combined, so that the real-time monitoring of the ablation process is realized, the precise implementation of an ablation scheme is ensured, and the purposes of controllable temperature and controllable morphology are achieved.

The system comprises a laser light source, a 90 coupler, a circulator, a visible-near infrared optical fiber, a far infrared detector, a displacement control system, a data processing and image reconstruction module and an image display module, wherein the laser light source is arranged in the center of the circulator, and the displacement control system comprises a data processing and image reconstruction module and an image display module. The details are described below with reference to specific examples:

first, the control module is turned on to make the laser source emit near infrared light, so that the system of this embodiment generates OCT imaging at the focus.

Secondly, performing primary positioning on a focus area according to the provided OCT information;

thirdly, determining an ablation scheme, and delivering the probe balloon electrode part to the vascular lesion;

fourthly, cooling liquid is injected into the saccule through the liquid catheter, so that the saccule is expanded until the surface electrode is fully attached to the focus;

fifthly, determining the number of the electrode array element completely attached to the focus, and then controlling a radio frequency ablation module to ablate the focus;

sixthly, the high temperature generated in the ablation process causes the temperature change at the focus, the system of the embodiment inverts the intravascular temperature field according to the three-dimensional topography information and the heat source information of the intravascular focus, and the image display module presents an intravascular thermal tomography image and an OCT image at the moment. Observing the difference change of the focus appearance, temperature and components through an image display module until most of the thrombus blocks or tumor cells are inactivated and then closing a radio frequency ablation module;

seventhly, observing real-time imaging in the blood vessel, finding out and positioning the untreated clean focus area in the fifth step;

eighthly, starting a laser ablation module to perform laser ablation on the residual region of the focus in the sixth step, observing the shape change of the focus in the image display module during ablation, and closing the laser ablation module until the focus region is completely inactivated;

and ninthly, pumping the cooling liquid in the saccule by using a liquid catheter to ensure that the saccule is contracted on the surface of the transparent shell of the probe.

And tenth, ablating the next focus in the blood vessel or withdrawing the catheter to the outside of the patient body according to the requirements of the user to complete the ablation work.

The above detailed description is intended to illustrate the objects, aspects and advantages of the present invention, and it should be understood that the above detailed description is only exemplary of the present invention and is not intended to limit the scope of the present invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims (6)

1. An intravascular radio frequency/laser ablation probe, comprising: the method comprises the following steps: the device comprises a circular fixing column, a transparent shell, a visible-near infrared optical fiber, a far infrared optical fiber, a GRIN lens, a prism, an ultrasonic transducer, insulating liquid, a fixing base, a high-elasticity flexible balloon, a radio-frequency electrode, a metal guide wire, an ultrasonic transducer lead, a flexible catheter, a radio-frequency electrode lead, a liquid catheter and a radio-frequency cable;

the round fixing column is fixed on the inner side of the transparent shell, is matched with the inner diameter of the transparent shell and is used for fixing the visible-near infrared optical fiber and the far infrared optical fiber; the GRIN lens is used for collimating and focusing optical signals transmitted by the two optical fibers, is fixed on the fixed base, is provided with a prism with the same size at the output end and is used for reflecting light beams to vascular tissues at the side of the probe, and the input end of the GRIN lens is closely attached to the visible-near infrared optical fiber and the far infrared optical fiber; the prism is positioned at the front end of the GRIN lens; the ultrasonic transducer is closely attached to the prism and used for transmitting and receiving ultrasonic signals; the fixed base is internally provided with a hollow structure and used for placing a transducer cable; the metal guide wire is connected with the front end of the fixed base and is used for adjusting the relative position of the fixed base in the probe cavity; the internal components of the probe are sealed by adopting a transparent shell so as to ensure the permeability of optical signals and acoustic signals and the sealing property of the internal components; the flexible saccule is uniformly wrapped on the transparent shell, and the surface of the flexible saccule is provided with annular radio frequency array electrodes which are uniformly distributed along the axial direction; the flexible saccule contains a liquid conduit for transmitting high-purity cold water cooling liquid; a flexible catheter is connected to the front end of the probe for carrying the metal guidewire, transducer leads and fluid catheter.

2. The intravascular rf/laser ablation probe of claim 1, wherein:

the visible-near infrared optical fiber can complete two functions, namely, the visible-near infrared optical fiber is used for transmitting, transmitting and receiving optical signals for OCT imaging and transmitting photoacoustic imaging, and is used for transmitting optical signals for laser ablation; the far infrared optical fiber is used for transmitting far infrared optical signals of thermal chromatography imaging; the optical fibers are fixed in the probe by a round fixing column, and the radius of the round fixing plate is matched with the inner diameter of the transparent shell; two circular holes with different radiuses are formed in the circular fixing column and used for fixing the two optical fibers, and the side face of the circular fixing column is connected with a fixing base and used for fixing a prism, a GRIN lens and an ultrasonic transducer component;

the GRIN lens is used for collimating and focusing the optical signals transmitted by the two optical fibers, so that the optical signals are transmitted in an axial focusing manner;

the ultrasonic transducer can utilize the positive and negative piezoelectric effect to complete the functions of transmitting ultrasonic wave signals of ultrasonic imaging and receiving ultrasonic imaging and photoacoustic imaging acoustic echo signals; the interior of the ultrasonic transducer consists of a sensitive element, an electrode material, a sound absorption backing and a packaging material; the sensitive element can be made of a piezoelectric composite material, a relaxation single crystal material and a piezoelectric film which are high in bandwidth and suitable in aperture size, so that the requirements of stable sound wave emission and high-sensitivity sound wave receiving are met;

the fixed base is arranged in the probe and used for realizing the fixed placement of the optical element and the acoustic element and supporting the components; the fixing base is internally provided with a hollow structure and used for placing a cable of the transducer; the optical element and the acoustic element are fixed on the upper surface of the fixed base; the front end of the fixed base is connected with the stretchable guide wire, and the other end of the guide wire is connected with an external displacement control system; the method can be used for adjusting the relative position of the fixed base in the probe cavity, thereby realizing the flexible regulation and control of the transmitting position and the receiving position of optical signals and acoustic signals in the blood vessel so as to improve the imaging and laser ablation quality;

the internal components of the probe are sealed by the transparent shell, so that the permeability of various optical signals and acoustic signals can be ensured, and the sealing performance of the internal components can be ensured; glycerin and silicone oil insulating liquid are filled in the probe cavity to ensure the internal insulation of the probe, the acoustic impedance is matched and the friction is reduced;

the outer side of a transparent shell of the probe is coated with a high-elasticity flexible saccule, and the surface of the transparent shell is provided with annular radio frequency array electrodes which are uniformly distributed along the axial direction; after the imaging is finished and positioned, opening the saccule, accurately positioning an electrode array element (covering electrode) covering a focus by utilizing high-resolution imaging, and generating high temperature for inactivating the thrombus block or tumor cells by opening the covering electrode to enable the tissue to generate coagulative necrosis; according to the array electrode, each array element of the array electrode is independently connected through the lead wire so as to meet the independent controllability of the array elements, and a user can selectively drive the array elements of the radio-frequency electrode according to the appearance of the thrombus or tumor cells; a multi-core cable is arranged in the balloon and used for loading a radio-frequency electrode lead;

the flexible saccule is internally provided with a liquid catheter, and after the ablation operation is started, cooling liquid can be injected into the saccule through the liquid catheter so as to prevent ablation high temperature from damaging normal vascular endothelial cells; the structure of the balloon can be expanded by the injection amount until the balloon is tightly attached to the inner wall of the blood vessel; after ablation is finished, cooling liquid in the saccule can be pumped out through the liquid catheter, so that the saccule is attached to the surface of the transparent shell of the probe after being contracted; it should be noted that, when the cooling liquid is selected, besides the cooling function, the cooling liquid should also have electrical insulation to satisfy the 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, the transducer cable, the optical fiber, the metal guide wire, the radio frequency cable and the liquid catheter are loaded in the flexible catheter, the other end of the flexible catheter is connected with the in-vitro displacement controller, and the probe can be pushed, retracted and rotationally scanned in a blood vessel.

3. An ablation system is formed by the imaging probe and the in-vitro multi-module system according to claim 1, and is characterized in that: the in vitro multi-module system consists of a control module, a displacement control system, an imaging module and an ablation module;

the control module controls each path of output in a synchronous time division multiplexing mode, has three functions, and is respectively used for (1) controlling the displacement control system to realize the omnibearing scanning function of the probe in the blood vessel; (2) Controlling the laser emission, the receiving and the electric pulse emission of the imaging module; (3) controlling the emission of radio frequency signals;

the displacement control system is used for controlling the advancing, withdrawing and rotating of the probe in the blood vessel, the output end of the displacement control system is connected with the flexible catheter, and a guide wire in a fixed base in the probe is controlled;

the imaging module can realize OCT, ultrasonic, photoacoustic and thermal chromatography four imaging modules,

the ablation module consists of a radio frequency ablation module and a laser ablation module.

4. The system of claim 3, wherein: the imaging module consists of a laser light source, a visible-near infrared optical fiber, a far infrared optical fiber, a 90; the specific connection mode is as follows: the input end of the laser light source is connected with the control module and used for receiving and reading the synchronous signal of the control module, and the output end of the laser light source is connected with a 90; the 90; the reference arm consists of a collimating mirror, a lens and a reflecting mirror, is connected to the output end of the circulator and is used for adjusting a reference arm signal; the circulator positioned on the sample arm comprises an input end and two output ends, the input end of the circulator is connected with the output port of the 90; one output port of the circulator positioned on the sample arm is connected with the probe and is used for transmitting and receiving OCT and PA signals; the input ends of the 50; the output end of the 50; the input end of the signal processing and image reconstruction module is connected with the photoelectric detector, and the output end of the signal processing and image reconstruction module is connected with the display module, so that the photoelectric signal conversion and image display functions of the detection system are realized respectively; the input end of the pulse transmitting and receiving device is connected with the control module, and the output end of the pulse transmitting and receiving device is connected with an ultrasonic transducer lead wire and can provide pulse signals for an ultrasonic transducer in the probe; the far infrared detector is used for receiving and reading heat radiation information in the blood vessel, 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 optical fiber in the probe, and the output end of the far infrared detector is connected with the data processing and image reconstruction module.

5. The system of claim 3, wherein:

the radio frequency ablation module comprises a radio frequency signal transmitter, the input end of the radio frequency signal transmitter is connected with the control module, and the output end of the radio frequency signal transmitter is connected with the probe balloon electrode; after imaging is finished, the control module controls the radio-frequency signal transmitter to generate radio-frequency current, and the radio-frequency current reaches the balloon electrode through a lead wire for ablation;

the laser ablation module and the OCT imaging share the same light emission system; after the radiofrequency ablation is completed, the user can image the local part of the blood vessel again, and after the positioning information confirms that the positioning information is correct, the control module controls the laser light source to generate a scorching laser pulse to continue laser ablation on the residual focus.

6. A method of intravascular RF/laser ablation using the ablation system of claim 3, 4 or 5, wherein: the method comprises the following steps:

the method comprises the following steps that firstly, an imaging module is controlled to acquire three-dimensional topography information in a blood vessel, namely OCT imaging, ultrasonic imaging, photoacoustic imaging and functional information;

secondly, performing primary positioning on a focus area according to the three-dimensional topography information provided in the first step;

step three, performing feature analysis on the shape, the size and the components of the focus area to formulate an ablation scheme;

injecting cooling liquid into the balloon through the liquid catheter to enable the balloon to be expanded until the surface electrode is fully attached to the focus;

step five, controlling an imaging module to carry out high-resolution imaging on the focus, and determining the electrode array element number completely attached to the focus;

controlling a radio frequency ablation module, starting the completely attached electrode array element, ablating the focus, observing the shape change of the focus by using an imaging module at the same time, and closing the radio frequency ablation module until most focus tissues are inactivated;

step seven, controlling an imaging module to accurately position the untreated clean focus area in the step six;

step eight, controlling a laser ablation module, performing laser ablation on the residual focus in the step six, and observing the shape change of the focus in real time until focus tissues are completely inactivated, and then closing the laser ablation module;

step nine, pumping cooling liquid in the saccule by using a liquid catheter to dry, and enabling the saccule to contract inwards and be pasted on the surface of the transparent shell of the probe;

step ten, according to the actual situation, the ablation of the next focus in the blood vessel is carried out or the catheter is withdrawn to the outside of the body of the patient to finish the ablation process.

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