A flexible cryoablation probe

Abstract

The flexible cryoablation probe disclosed by the present invention belongs to the technical field of medical devices and includes a probe body, a handle part, a protective outer tube, and a gas delivery tube; the probe body is connected to the handle part; the handle part is connected to the protective outer tube; the probe body includes a cryoprobe, a throttle tube, a medical plastic catheter, a temperature-measuring thermocouple wire, and a return tube; the front end of the return tube is connected to the cryoprobe, the temperature-measuring thermocouple wire is spirally wound around the outer surface of the return tube, and a medical plastic catheter is sleeved on the outer surface of the temperature-measuring thermocouple wire; a heat insulation layer is formed between the medical plastic catheter and the return tube; the throttle tube is arranged inside the return tube, and the front end of the throttle tube is close to the front end of the return tube, and the rear end of the throttle tube extends into the handle part; the gas delivery tube is arranged inside the protective outer tube, and the gas delivery tube is communicated with the throttle tube. The probe of the present invention can reach the whole lung of the lung cancer lesion through the bronchus, has better safety and minimally invasive property, and can better realize the ablation treatment of lung cancer.

Description

Technical Field

[0001] The present invention relates to the technical field of medical devices, and particularly to a flexible cryoablation probe that can be used for lung cancer ablation treatment. Background Art

[0002] Lung cancer is currently the malignant tumor with the first morbidity and mortality rates in China. Early detection and early diagnosis of lung cancer are one of the fundamental strategies to improve the survival rate of lung cancer patients. Surgical operation and stereotactic radiotherapy are considered as the first-line techniques for the treatment of early lung cancer. However, some lung cancer patients cannot tolerate surgery or are not suitable for radiotherapy, making interventional treatment one of the important treatment means. In recent years, great progress has been made in the interventional respiratory medicine technology via bronchoscope and the precise navigation system for pulmonary nodules. The ablation treatment of peripheral lung cancer / early lung cancer via bronchoscope has gradually emerged, and it has more definite curative effects especially in patients with lung cancer with a diameter less than 2 cm, showing good application prospects. At the same time, ablation treatment through natural body cavities can reduce the risks of pneumothorax, bleeding, etc.

[0003] The ablation techniques for peripheral lung cancer via bronchoscope mainly include radiofrequency, microwave and cryotherapy. Compared with the traditional radiofrequency and microwave ablation, cryoablation has some advantages. The ablation ranges of radiofrequency and microwave are ellipsoidal, while the ablation formed by cryoablation is nearly spherical, and it has better protection for blood vessels and nerves. In addition, cryoablation itself has an analgesic effect, which can reduce the occurrence of pain and complications during the operation compared with the traditional radiofrequency and microwave ablation. The traditional cryoablation treatment reaches the lung cancer lesion through a percutaneous approach, with risks such as trauma, pneumothorax and skin frostbite. Summary of the Invention

[0004] In order to solve the problem that the traditional cryoablation treatment for lung cancer reaches the lung cancer lesion through a percutaneous approach, with risks such as trauma, pneumothorax and skin frostbite, the present invention provides a flexible cryoablation probe that can be used for lung cancer ablation treatment, including a probe body, a handle part, a protective outer tube and an air supply tube; the probe body is connected to the handle part; the handle part is connected to the protective outer tube; the probe body includes a cryoprobe, a throttle tube, a medical plastic catheter, a temperature-measuring thermocouple wire and a return tube; the front end of the return tube is connected to the cryoprobe, the temperature-measuring thermocouple wire is spirally wound around the outer surface of the return tube, and the outer surface of the temperature-measuring thermocouple wire is sleeved with the medical plastic catheter; an insulating layer is formed between the medical plastic catheter and the return tube; the throttle tube is arranged inside the return tube, and the front end of the throttle tube is close to the front end of the return tube, and the rear end of the throttle tube extends into the inside of the handle part; the air supply tube is arranged inside the protective outer tube, and the air supply tube is communicated with the throttle tube.

[0005] Further, the handle portion includes a first handle housing, a second handle housing, a first diameter reducer, an inner tube of the handle vacuum interlayer, an outer tube of the handle vacuum interlayer, a heat exchanger, an electric heating wire, a second diameter reducer, and a filter; one end of the first handle housing is connected to the probe body, and the other end of the first handle housing is connected to the second handle housing; the rear end of the return pipe passes through the first handle housing and extends into the interior of the second handle housing; the first handle housing is connected to the inner tube of the handle vacuum interlayer through the first diameter reducer, both ends of the outer tube of the handle vacuum interlayer are connected to the inner tube of the handle vacuum interlayer, and a handle vacuum interlayer is formed between the inner tube of the handle vacuum interlayer and the outer tube of the handle vacuum interlayer; the rear end of the throttle pipe is connected to the air outlet of the heat exchanger; the filter is arranged inside the heat exchanger, the outlet of the filter is connected to the air outlet of the heat exchanger, the inlet of the filter is connected to the air inlet of the heat exchanger, and the air delivery pipe is connected to the air inlet of the heat exchanger; the electric heating wire is spirally wound on the outer surface of the heat exchanger; the inner tube of the handle vacuum interlayer is connected to the protective outer tube through the second diameter reducer; the second handle housing is connected to the protective outer tube.

[0006] Preferably, the heat exchanger is a micro fin heat exchanger, and the material of the micro fin heat exchanger is red copper.

[0007] Preferably, the filter is a copper sintered filter, and the copper sintered filter is sintered from copper powder.

[0008] Preferably, the throttle pipe is a stainless steel capillary with an inner diameter of 0.2 mm - 0.3 mm.

[0009] Preferably, the return pipe is a medical stainless steel capillary with a diameter of 1 mm - 2 mm softened by heat treatment and can be bent arbitrarily.

[0010] Preferably, the temperature measuring thermocouple wire is a T-type thermocouple wire.

[0011] Preferably, the air delivery pipe is a metal capillary.

[0012] Preferably, the material of the freezing probe is medical stainless steel; the material of the medical plastic catheter is medical trifluoro or high molecular polyethylene.

[0013] Preferably, the material of the first handle housing is silica gel; the material of the second handle housing is ABS resin; the vacuum degree of the handle vacuum interlayer is 10 -4 Pa; the electric heating wire is a nickel-chromium, tungsten or carbon fiber heating wire; the material of the first diameter reducer is stainless steel; the material of the second diameter reducer is metal or plastic; the material of the protective outer tube is silica gel or PVC.

[0014] The flexible cryoablation probe provided by the present invention can reach the whole lung of the lung cancer lesion through the probe body, the handle part, the protective outer tube and the gas delivery tube via the bronchus, has better safety and minimally invasive properties, and its ablation range that is nearly spherical can better achieve the cryoablation treatment of lung cancer, ensuring the safe ablation range and having good clinical application prospects. BRIEF DESCRIPTION OF THE DRAWINGS

[0015] Figure 1 It is a schematic structural view of the flexible cryoablation probe provided by an embodiment of the present invention. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0016] The technical solution of the present invention will be further described below in conjunction with the drawings and embodiments.

[0017] The flexible cryoablation probe provided by an embodiment of the present invention can meet the cryoablation treatment of lung cancer through a bronchoscope, thereby achieving the whole lung arrival of the lung cancer lesion and realizing safe and efficient ablation treatment, providing a new type of lung cancer interventional treatment technology for medical clinics. Refer to Figure 1 The flexible cryoablation probe provided by an embodiment of the present invention that can be used for the cryoablation treatment of lung cancer includes a probe body, a handle part, a protective outer tube 16 and a gas delivery tube 17; the probe body is connected to the handle part; the handle part is connected to the protective outer tube 16; the probe body includes a cryoprobe 1, a throttle tube 2, a medical plastic catheter 3, a temperature-measuring thermocouple wire 4 and a return tube 5; the front end of the return tube 5 is connected to the cryoprobe 1, the temperature-measuring thermocouple wire 4 is wound around the outer surface of the return tube 5 in a spiral shape, and a medical plastic catheter 3 is sleeved on the outer surface of the temperature-measuring thermocouple wire 4; a heat-insulating layer is formed between the medical plastic catheter 3 and the return tube 5; the throttle tube 2 is arranged inside the return tube 5, and the front end of the throttle tube 2 is close to the front end of the return tube 5, and the rear end of the throttle tube 2 extends into the handle part; the gas delivery tube 17 is arranged inside the protective outer tube 16, and the gas delivery tube 17 is communicated with the throttle tube 2.

[0018] Refer to Figure 1, the handle part of the embodiment of the present invention further includes a first handle housing 6, a second handle housing 7, a first diameter reducer 8, an inner tube of the handle vacuum interlayer 9, an outer tube of the handle vacuum interlayer 10, a heat exchanger 12, an electric heating wire 13, a second diameter reducer 14 and a filter 15. One end of the first handle housing 6 is connected to the probe body, and the other end of the first handle housing 6 is connected to the second handle housing 7; the rear end of the return pipe 5 passes through the first handle housing 6 and extends into the interior of the second handle housing 7; the first handle housing 6 is connected to the inner tube of the handle vacuum interlayer 9 through the first diameter reducer 8, and both ends of the outer tube of the handle vacuum interlayer 10 are connected to the inner tube of the handle vacuum interlayer 9, and a handle vacuum interlayer 11 is formed between the inner tube of the handle vacuum interlayer 9 and the outer tube of the handle vacuum interlayer 10; the rear end of the throttle tube 2 is connected to the air outlet of the heat exchanger 12; a filter 15 is arranged inside the heat exchanger 12, the outlet of the filter 15 is connected to the air outlet of the heat exchanger 12, the inlet of the filter 15 is connected to the air inlet of the heat exchanger 12, and the gas transmission pipe 17 is connected to the air inlet of the heat exchanger 12; the electric heating wire 13 is spirally wound on the outer surface of the heat exchanger 12; the inner tube of the handle vacuum interlayer 9 is connected to the protective outer tube 16 through the second diameter reducer 14; the second handle housing 7 is connected to the protective outer tube 16.

[0019] In practical applications, the heat exchanger 12 can be a micro fin heat exchanger, which is used for heat exchange of the gas flowing through its interior and exterior. The material of the micro fin heat exchanger is red copper; the filter 15 is a copper sintered filter, which is sintered from copper powder and is used to filter out tiny particles in the gas to prevent blockage of the throttle tube 2. At the same time, the copper material has a high thermal conductivity, and together with the tiny pores, it can effectively improve the gas heat exchange efficiency; the throttle tube 2 is a stainless steel capillary tube with an inner diameter of 0.2 mm - 0.3 mm, and high-pressure gas (high-pressure argon or high-pressure helium) is sprayed during operation; the cryoprobe 1 is a cryoablation area, and the material of the cryoprobe 1 is medical stainless steel; the material of the medical plastic catheter 3 is a low-temperature resistant material, such as medical trifluoride or high molecular polyethylene; the temperature measuring thermocouple wire 4 is a T-type thermocouple wire, which is used to measure the temperature of the cryoprobe 1 and support the medical plastic catheter 3, so as to form a heat insulation interlayer between the medical plastic catheter 3 and the return pipe 5; the return pipe 5 is a heat-treated and softened medical stainless steel capillary tube with a diameter of 1 mm - 2 mm and can be bent arbitrarily; the material of the first handle housing 6 is silica gel; the material of the second handle housing 7 is ABS resin; the vacuum degree of the handle vacuum interlayer 11 is 10 -4Pa is used for heat insulation; the electric heating wire 13 is a nickel-chromium, tungsten or carbon fiber heating wire, which is used to heat the heat exchanger 12 to improve the heating rate and save helium; the first reduced diameter 8 is made of stainless steel and is used for welding and sealing the reflux pipe 5 and the inner layer pipe 9 of the handle vacuum interlayer, and at the same time fixing the first handle housing 6 and the second handle housing 7; the second reduced diameter 14 is made of metal or plastic and is used for fixing the second handle housing 7 and protecting the outer pipe 16; the protecting outer pipe 16 is made of silica gel or PVC; the gas transmission pipe 17 is a metal capillary tube and is welded to the heat exchanger 12.

[0020] See Figure 1 , the flexible cryoablation probe of the embodiment of the present invention needs to be used in cooperation with a bronchoscope. The probe is inserted along the working hole of the bronchoscope, reaches the target tumor position of the bronchus through the bronchoscope, and starts cryoablation treatment. The specific process is as follows:

[0021] 1. Freezing mode: High-pressure argon gas enters the inner hole of the heat exchanger 12 through the gas transmission pipe 17, then enters the throttle pipe 2 through the filter 15 ( Figure 1 solid arrow), and is ejected from the port of the throttle pipe 2 to become low-pressure argon gas. At the same time, due to the Joule-Thomson principle, the argon gas cools down; the low-pressure and low-temperature argon gas returns to the outside fins of the heat exchanger 12 through the channel between the reflux pipe 5 and the throttle pipe 2, and spirally flows out along the fins to between the protecting outer pipe 16 and the gas transmission pipe 17, and then is discharged into the atmosphere ( Figure 1 hollow arrow); when the low-temperature and low-pressure argon gas flows through the fins of the heat exchanger 12, it pre-cools the newly flowing high-pressure argon gas in the inner pipe of the heat exchanger 12 through the heat exchange structure. The pre-cooled high-pressure argon gas is ejected from the port of the throttle pipe 2, so as to further cool down. Such a cycle continues to cool down until the boiling point of liquid argon is reached; since there is a certain resistance when the reflux gas passes through the heat exchanger 12, the pressure of the reflux low-pressure argon gas is about 1-2 MPa. Therefore, the lowest temperature of the cryoprobe 1 is about -150 °C; the heat insulation interlayer between the medical plastic catheter 3 and the reflux pipe 5 is supported by the temperature measuring thermocouple wire 4, which plays a role in heat insulation, prevents frostbite and improves the utilization rate of cold energy, so that all the cold energy is concentrated in the freezing working area of the cryoprobe 1.

[0022] 2. Heating mode: High-pressure helium flows into the inner hole of the heat exchanger 12 through the gas pipeline 17, then enters the throttle tube 2 through the filter 15, and is ejected from the port of the throttle tube 2 to become low-pressure helium. At the same time, due to the Joule-Thomson principle, the helium heats up; the low-pressure and high-temperature helium flows back to the outer fins of the heat exchanger 12 through the channel between the return pipe 5 and the throttle tube 2, and spirally flows out along the fins to the space between the protective outer tube 16 and the gas pipeline 17, and then is discharged into the atmosphere; when the low-pressure and high-temperature helium flows through the fins of the heat exchanger 12, it preheats the high-pressure helium newly flowing into the inner tube of the heat exchanger 12 through the heat exchange structure, and the preheated high-pressure helium is ejected from the port of the throttle tube 2, thereby further heating up, and the temperature continuously rises in such a cycle. However, due to the high price of helium and the doctor's hope for rapid heating, an electric heating wire 13 is wound around the root of the fins of the heat exchanger 12. When the heating mode is started, the heat exchanger 12 is heated by supplying power to the electric heating wire 13 to generate heat. In this way, under the dual action of electric heating and helium throttling heating, the probe can be heated from minus 150 degrees to 0 degrees within a few seconds, realizing thawing, the probe is separated from the target tissue, and helium is saved.

[0023] The flexible cryoablation probe provided by the embodiment of the present invention can meet the requirements of cryoablation treatment for lung cancer through a bronchoscope. The flexible cryoablation probe reaches the lung cancer lesion through the working channel of the bronchoscope under the guidance of a navigation system or image-guided positioning, forming an ablation range in the shape of an almost sphere with a central temperature of -150 °C. The outer diameter of the flexible cryoablation probe provided by the embodiment of the present invention is only 1.5 mm, which has a high reachability to the lesion. It can reach bronchi beyond grade 7, can achieve full-lung access through natural body cavities, and perform cryoablation for lung cancer; compared with percutaneous cryoablation, it reduces the risks of pneumothorax, bleeding, skin frostbite, etc. The outer diameter of the flexible cryoablation probe of the embodiment of the present invention is only 1.5 mm, which can more easily form a spherical ablation range, and has more advantages than the ellipsoidal ablation range of traditional radiofrequency and microwave ablation, and has better protection for blood vessels and nerves. In addition, cryoablation itself has an analgesic effect, and can reduce the occurrence of intraoperative pain complications compared with traditional radiofrequency and microwave ablation. In clinical applications, the flexible cryoablation probe provided by the embodiment of the present invention can achieve full-lung access to lung cancer lesions through the bronchus, has better safety and minimal invasiveness, and its almost spherical ablation range can better achieve lung cancer ablation treatment, ensuring a safe ablation range, and has good clinical application prospects.

[0024] The specific embodiments described above further elaborate on the purpose, technical solutions, and beneficial effects of the present invention. It should be understood that the above are only specific embodiments of the present invention and are not used to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principles of the present invention shall be included within the protection scope of the present invention.

Claims

1. A flexible cryoablation probe, characterized in that, It is used in conjunction with a bronchoscope. The flexible cryoablation probe is inserted along the working hole of the bronchoscope, reaches the target tumor position in the bronchus through the bronchoscope, and starts cryoablation. The flexible cryoablation probe includes a probe body, a handle part, a protective outer tube, and a gas delivery tube; the probe body is connected to the handle part; the handle part is connected to the protective outer tube; the probe body includes a cryoprobe, a throttle tube, a medical plastic catheter, a thermocouple wire, and a return tube; the return tube is a medical stainless steel capillary softened by heat treatment and can be bent arbitrarily; the front end of the return tube is connected to the cryoprobe, the thermocouple wire is wound around the outer surface of the return tube in a spiral shape, and the medical plastic catheter is sleeved on the outer surface of the thermocouple wire; an insulating layer is formed between the medical plastic catheter and the return tube, and the insulating layer between the medical plastic catheter and the return tube is supported by the thermocouple wire to play an insulating role; the throttle tube is arranged inside the return tube, and the front end of the throttle tube is close to the front end of the return tube, and the rear end of the throttle tube extends into the handle part; the gas delivery tube is arranged inside the protective outer tube, and the gas delivery tube is communicated with the throttle tube.

2. The flexible cryoablation probe according to claim 1, wherein, The handle part includes a first handle housing, a second handle housing, a first reducer, an inner tube of the handle vacuum interlayer, an outer tube of the handle vacuum interlayer, a heat exchanger, an electric heating wire, a second reducer, and a filter; one end of the first handle housing is connected to the probe body, and the other end of the first handle housing is connected to the second handle housing; the rear end of the return tube passes through the first handle housing and extends into the second handle housing; the first handle housing is connected to the inner tube of the handle vacuum interlayer through the first reducer, both ends of the outer tube of the handle vacuum interlayer are connected to the inner tube of the handle vacuum interlayer, and a handle vacuum interlayer is formed between the inner tube of the handle vacuum interlayer and the outer tube of the handle vacuum interlayer; the rear end of the throttle tube is connected to the air outlet of the heat exchanger; the filter is arranged inside the heat exchanger, the outlet of the filter is connected to the air outlet of the heat exchanger, the inlet of the filter is connected to the air inlet of the heat exchanger, and the gas delivery tube is connected to the air inlet of the heat exchanger; the electric heating wire is wound around the outer surface of the heat exchanger in a spiral shape; the inner tube of the handle vacuum interlayer is connected to the protective outer tube through the second reducer; the second handle housing is connected to the protective outer tube.

3. The flexible cryoablation probe according to claim 2, wherein The heat exchanger is a micro fin heat exchanger, and the material of the micro fin heat exchanger is copper.

4. The flexible cryoablation probe according to claim 2, wherein The filter is a copper sintered filter, and the copper sintered filter is sintered from copper powder.

5. The flexible cryoablation probe according to claim 2, wherein The throttle tube is a stainless steel capillary with an inner diameter of 0.2 mm - 0.3 mm.

6. The flexible cryoablation probe according to claim 2, wherein The diameter of the return tube is 1 mm - 2 mm.

7. The flexible cryoablation probe according to claim 2, characterized in that, The thermocouple wire is a T-type thermocouple wire.

8. The flexible cryoablation probe according to claim 2, wherein, The gas delivery tube is a metal capillary.

9. The flexible cryoablation probe according to claim 2, wherein, The material of the cryoprobe is medical stainless steel; the material of the medical plastic catheter is medical trifluoride or high molecular polyethylene.

10. The flexible cryoablation probe according to claim 2, wherein, The material of the first handle housing is silicone; the material of the second handle housing is ABS resin; the vacuum degree of the handle vacuum interlayer is 10 -4 Pa; the electric heating wire is a nickel-chromium, tungsten or carbon fiber heating wire; the material of the first reduced diameter part is stainless steel; the material of the second reduced diameter part is metal or plastic; the material of the protective outer tube is silicone or PVC.

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