Coronary artery freezing catheter

Abstract

A vacuum tube is arranged between a sealing component and a tube body of an outer tube, and a second pressure sensor is integrated in the vacuum tube and used for detecting the gas pressure in the vacuum tube; the air inlet pipe extends into the balloon from the near end of the ablation mechanism, and an opening is formed in the outer surface of the air inlet pipe and used for releasing cold air to the balloon; a second temperature sensor is integrated on the surface of the air inlet pipe and used for detecting the temperature in the balloon, and the working temperature in the balloon is maintained by monitoring the temperature in the balloon in real time and adjusting the air inlet rate of cold air; a third pressure sensor is integrated at a port of the air return pipe and used for detecting the air pressure in the balloon, and the air inlet rate of cold air is adjusted according to the air pressure in the balloon monitored in real time so that the air pressure in the balloon can be kept within a safe range.

Description

Technical Field

[0001] The invention relates to a coronary catheter, in particular to a coronary freezing catheter, and belongs to the technical field of medical devices. Background Art

[0002] Coronary heart disease is usually caused by atherosclerotic lesions in the coronary arteries, which can lead to vascular stenosis or blockage, and may cause myocardial ischemia, hypoxia, and even necrosis. For this disease, coronary intervention is usually used clinically to clear the narrowed or occluded coronary artery lumen, thereby improving myocardial blood perfusion. In the coronary intervention method, a guide wire and a hollow catheter are introduced into the coronary artery in turn, and gas is injected into the balloon on the hollow catheter to expand the balloon to support the blood vessel, and then a stent is built in the blood vessel, and the stent is used to restore the smoothness of the blood vessel. After the stent is built, the balloon is deflated, and finally the hollow catheter and guide wire are withdrawn from the blood vessel in turn.

[0003] During coronary intervention, as the time of stent implantation increases, vascular proliferation will occur, leading to vascular damage and restenosis. During balloon dilatation and stent implantation, the blood vessels are temporarily in a relatively blocked state, the blood flow is relatively slow, and the surgeon has no effective plan to predict the blood flow dynamics in advance, which may cause intraoperative thrombosis.

[0004] Currently, CT angiography is used clinically to detect blood flow velocity using the principle of X-ray development. However, the above method has a certain impact on the human body and makes the surgical operation cumbersome. At the same time, the injection of contrast agents poses certain risks to patients, and long-term X-ray exposure also poses certain risks to patients' health. Summary of the invention

[0005] In view of the above analysis, the present application aims to provide a coronary cryoablation catheter to solve the problems existing in the prior art: 1) As the time of stent implantation increases, vascular proliferation will occur, leading to vascular damage and restenosis. 2) During the process of balloon dilatation and stent implantation, since the blood vessels are temporarily in a relatively blocked state during this period, the use of CT angiography technology to detect blood flow velocity using the principle of X-ray development has a certain impact on the human body and makes the surgical operation cumbersome. At the same time, the injection of contrast agents poses certain risks to patients, and long-term X-ray exposure also poses certain risks to the health of patients.

[0006] The present invention adopts the following technical solutions:

[0007] A coronary cryocatheter, comprising an ablation mechanism 1, an outer tube 2, an operating mechanism 3, a connecting mechanism 4, and a blood flow monitoring structure 5; the ablation mechanism 1 comprises a balloon 14, and at least two first pressure sensors 143 and two first temperature sensors 144 are integrated on the surface of the balloon 14; the outer tube 2 has a guide wire cavity 15 sealed by a sealing component 23, an air inlet tube 16, an air return tube 17, and a sensor signal cable 24; a vacuum tube 18 is provided between the sealing component 23 and the tube body 25 of the outer tube 2, and a second pressure sensor 143 is integrated in the vacuum tube 18. The device 181 is used to detect the gas pressure inside the vacuum tube 18; the guidewire cavity 15, the air inlet tube 16, and the air return tube 17 extend into the balloon 14, the distal ends of the balloon 14 and the guidewire cavity 15 are fixed together at the distal end 11 of the ablation mechanism, and the proximal ends of the balloon 14, the guidewire cavity 15, the air inlet tube 16, and the air return tube 17 are fixed together at the proximal end 19 of the ablation mechanism; the air inlet tube 16 extends from the proximal end 19 of the ablation mechanism into the balloon 14, and the outer surface of the air inlet tube 16 is provided with an opening 161 for releasing cold air to the balloon 14; the air inlet tube 16 The second temperature sensor 162 is integrated on the surface of the 6, which is used to detect the temperature inside the balloon 14, and adjust the intake rate of cold air by real-time monitoring the temperature inside the balloon to maintain the working temperature inside the balloon; the third pressure sensor 171 is integrated on the port of the return air pipe 17, which is used to detect the gas pressure inside the balloon 14, and adjust the intake rate of cold air by real-time monitoring the gas pressure inside the balloon to maintain the gas pressure inside the balloon within a safe range; the connecting mechanism 4 includes a gas pipeline connector 41, a sensor signal connector 42, and Y-type valve 43; the air inlet pipe 16, the air return pipe 17 and the vacuum tube 18 pass through the outer tube 2 and the operating mechanism 3 respectively, and are finally fixed to the gas pipeline connector 41; the gas pipeline connector 41 is connected to the matching cryoablation equipment, the equipment provides cold air to the air inlet pipe 16, and collects the gas discharged from the air return pipe 17; the cryoablation equipment also draws back the gas through the vacuum tube 18 to maintain the vacuum degree between the sealing component 23 and the tube body 25; the blood flow monitoring mechanism 5 is arranged at any position of the distal end of the ablation catheter close to the balloon and the outer surface of the balloon.

[0008] Preferably, a thermally conductive coating 141 with high thermal conductivity is attached to the surface of the balloon 14, and the material of the thermally conductive coating 141 includes one of graphene, nanographene, gel, and carbon fiber; a hydrophilic coating 142 is attached to the surface of the thermally conductive coating 141, and the hydrophilic coating 142 includes one of water-based epoxy resin, polydimethylsiloxane, hydrophilic polymer, siloxane monomer, and ether monomer; the two first pressure sensors 143 are integrated on the surface of the hydrophilic coating 142 to detect the contact pressure between the balloon 14 and the lesion tissue; according to the contact pressure value detected in real time, it is ensured that the balloon and the lesion tissue are in good contact; the two first temperature ... The temperature sensor 144 is integrated on the surface of the hydrophilic coating 142, and is used to detect the temperature of the lesion tissue, and ensure that the lesion tissue has a good freezing temperature based on the real-time detected temperature value; the first pressure sensor 143 is one of a resistive, capacitive, piezoelectric, and strain pressure sensor; the first temperature sensor 144 includes one of a thermocouple, a thermistor, a silicon diode temperature sensor, an infrared temperature sensor, a bimetallic temperature sensor, a laser temperature sensor, and a platinum resistance sensor; the third pressure sensor 171 is one of a resistive strain sensor, a capacitive sensor, a piezoelectric sensor, a resonant sensor, and a semiconductor piezoresistive sensor.

[0009] Preferably, the second pressure sensor 181 includes one of a resistive strain sensor, a capacitive sensor, a piezoelectric sensor, a resonant sensor, and a semiconductor piezoresistive sensor; the second temperature sensor 162 includes one of a thermocouple, a thermistor, a silicon diode temperature sensor, an infrared temperature sensor, a bimetallic temperature sensor, a laser temperature sensor, and a platinum resistance sensor.

[0010] Preferably, the air inlet tube 16 extends from the proximal end 19 of the ablation mechanism to the center of the balloon 14 , and uniform openings 161 are provided on the outer surface of the air inlet tube 16 for releasing cold air into the balloon 14 .

[0011] Preferably, the outer tube 2 is composed of a tube body 25, a bending adjustment hole 21 and a bending adjustment wire 22. The outer tube 2 is a hollow tube with a bidirectional bending function. The outer tube 2 contains polyetheramide and polytetrafluoroethylene materials. There is a bending control component 31 on the operating mechanism 3. The bending control component 31 can be turned to the right to control the outer tube 2 to bend in one direction, and the bending control component 31 can be turned to the left to control the outer tube 2 to bend in another direction.

[0012] Furthermore, the signal lines corresponding to the first pressure sensor 143, the first temperature sensor 144, the second temperature sensor 162, the third pressure sensor 171 and the second pressure sensor 181 respectively pass through the outer tube 2 and the operating mechanism 3, and are finally integrated into the sensor signal connector 42; the sensor signal connector 42 is connected to the matching cryoablation equipment, and the cryoablation equipment processes these detection signals and performs closed-loop regulation of the supply and flow rate of cold air accordingly.

[0013] Preferably, the blood flow monitoring mechanism 5 is an electromagnetic induction sensor, and the iron ion electromagnetic induction coil 501 included in the blood flow monitoring mechanism 5 is arranged in a ring shape on the outer wall of the catheter 2 at the proximal end of the cryoballoon 14, the iron ion electromagnetic induction coil 501 is coaxial with the catheter 2, and a sufficiently large gap is designed between the iron ion electromagnetic induction coil 501 and the outer wall of the catheter 2 to allow the flowing blood to pass through; blood passing through the iron ion electromagnetic induction coil 501 can generate electromagnetic induction, and the electromagnetic induction can generate an electrical signal; the iron ion electromagnetic induction coil 501 is provided with an electrical signal lead wire 506; the electrical signal can be electrically connected to the cryoablation device through the signal lead wire 506; the electrical signal can be converted into a blood flow velocity v through the built-in electrical signal converter of the cryoablation device and displayed on the human-computer interaction module of the cryoablation device; when the cryoballoon is inflated, blood will flow out of the balloon 14 The blood flows between the outer wall and the inner wall of the blood vessel 28, and the blood flow monitoring mechanism 5 uses the iron ion electromagnetic induction coil 501 to sense the iron ions flowing in the blood of the measured part to generate a measured magnetic induction electric signal; the signal acquisition module set up in the cryoablation equipment extracts data information from the measured induced electric signal, and obtains blood flow data according to the extracted data information; the signal acquisition module extracts current / voltage amplitude data from the measured induced electric signal, and converts the extracted current / voltage amplitude data into the blood flow velocity v in the blood vessel; the blood flow velocity v measured by the blood flow monitoring mechanism 5 is correlated with the flow state of the blood, specifically: for different occlusion states, the induced electric signals corresponding to the different dynamic pressure values ​​generated by the blood flow are respectively extracted for data information, and the blood flow data corresponding to the electric signals corresponding to the different dynamic pressure values ​​are obtained according to the extracted data information, so as to judge the state of balloon occlusion. During the cryoablation process, the catheter enters the human body. When there is no blood flow, the blood flow velocity v=0, and the blood dynamic pressure Pdynamic=0, indicating that there is no blood flow and the blood flow is well blocked. When the blood flow is not well blocked, the blood is flowing, v>0, and the blood dynamic pressure Pdynamic>0, and there is blood flow blockage at the blood flow monitoring mechanism 5, that is, the pressure here increases, and the blood flow monitoring mechanism 5 feeds back relevant information as a reminder according to the operator's needs.

[0014] Furthermore, the probe of the third temperature sensor 504 configured by the blood flow monitoring mechanism 5 is fixed on the outer surface of the catheter 2 close to the balloon end, and the probe of the fourth temperature sensor 505 is fixed on the outer surface of the catheter 2 farther from the balloon end than the third temperature sensor 504. The third temperature sensor 504 and the fourth temperature sensor 505 are inserted into the blood vessel together with the cryoballoon catheter during the operation. The arrangement of the third temperature sensor 504 and the fourth temperature sensor 505 uses heat transfer as a reference basis, and according to the correlation between blood temperature change and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor, and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module of the cryoablation device. The control module of the cryoablation device calculates the flow state of blood in the blood vessel according to the temperature signal, and displays it to the human-computer interaction module of the cryoablation device, thereby assisting in judging the effect of blood flow.

[0015] Preferably, the blood flow monitoring mechanism 5 is configured as a fiber optic sensor, and the fiber optic sensor 508 components used in the blood flow monitoring mechanism 5 include a helium-neon laser, a Bragg box, a beam splitter, a photodiode, a spectrum analyzer, and a control module located inside the cryoablation device, as well as a single-mode optical fiber 506 and a fiber optic probe 510 located on the surface of the cryoballoon 14; the blood flow monitoring mechanism 5 is equipped with a third temperature sensor 504 and a third temperature sensor 505 for auxiliary monitoring; the fiber optic sensor 508 utilizes the principle of the Doppler effect; the fiber optic sensor 508 has an outer diameter of several tens of μm, is disposed at the apex of the cryoballoon 14, and is inserted into the blood vessel with the balloon during the operation; the fiber optic sensor 508 measures the light beam that enters the blood flow to be measured through the fiber optic probe 510, is scattered by the red blood cells inside the blood vessel 28, and a part of it The light returns along the original path to obtain a Doppler frequency shift signal f+Δf, and a part of it enters a Bragg box (frequency shifter) with a driving frequency of f1=40MHz to obtain a reference light signal with a frequency of f-f1; the optical fiber sensor 508 transmits the obtained light signal to the control module of the cryoablation device through the single-mode optical fiber 506; the control module of the cryoablation device mixes the reference light signal with the Doppler frequency shift signal through the photodiode in the cryoablation device, and the light signal is converted into a photocurrent and sent to the spectrum analyzer to obtain the Doppler frequency shift spectrum (velocity spectrum) corresponding to the blood flow velocity. According to the velocity spectrum, the refractive index n of the blood, the angle θ between the optical fiber axis and the blood vessel axis, and the laser wavelength λ, the blood flow velocity v in the blood vessel is calculated according to formula 1-1, and the blood flow state is displayed to the human-computer interaction module of the cryoablation device:

[0016]

[0017] The blood flow velocity v measured by the blood flow monitoring mechanism 5 is correlated with the flow state of the blood, specifically: data information is extracted for the induced electrical signals corresponding to different dynamic pressure values ​​generated by different blockage leaks, and blood flow data corresponding to the electrical signals corresponding to the different dynamic pressure values ​​are obtained based on the extracted data information, so as to judge the size of the blockage leak; during the cryoablation process, the catheter enters the human body, when there is no blood flow, the blood flow velocity v=0, and the blood dynamic pressure Pdynamic=0 at this time, indicating that there is no blood flow at this time and the blood flow blockage is good; when the blood flow blockage is not good, the blood is flowing, v>0, the blood dynamic pressure Pdynamic>0, and the blood flow detection There is blood flow blockage at the detection mechanism, that is, the pressure here increases, and the blood flow detection mechanism can feedback relevant information according to the needs of the operator; the third temperature sensor 504 probe configured by the blood flow monitoring mechanism 5 is fixed on the outer surface of the distal end of the freezing balloon 14, and the fourth temperature sensor 505 probe is fixed on the outer surface position of the freezing balloon 14 compared to the proximal end of the third temperature sensor 504; the third temperature sensor 504 and the fourth temperature sensor 505 are inserted into the blood vessel together with the freezing balloon catheter during the operation; the arrangement of the third temperature sensor 504 and the fourth temperature sensor 505 uses heat transfer as a reference, based on According to the correlation between blood temperature changes and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module inside the cryoablation device. The cryoablation device control module calculates the flow state of blood in the blood vessel according to the temperature signal and displays it to the human-computer interaction module, thereby assisting in judging the flow state of blood during the operation; the temperature changes of the third temperature sensor 504 and the fourth temperature sensor 505 are correlated with the flow state of blood, specifically: during the cryoablation process, the catheter enters the human body, when the blood flow is blocked Good, when there is no blood flow, an ice ball is formed on the surface of the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, an ice ball is formed on the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the freezing balloon in the blood vessel determines the flow rate of the blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. The third temperature sensor 504 and the fourth temperature sensor 505 can assist in judging the blood flow dynamics according to the different time consumptions under the same temperature change value.

[0018] Preferably, the blood flow monitoring mechanism 5 is a turbine speed sensor; the turbine speed sensor 512 component used in the blood flow monitoring mechanism 5 includes a tachometer located inside the cryoablation device, a signal conversion module, a control module, a turbine 513 located at the distal end of the cryoballoon, blades 514, a signal generator 515, and a signal lead 506; the turbine 513 is arranged at the distal end of the cryoballoon 14; the blood or other fluid flowing through the blood vessel 28 causes the blades 514 of the turbine 513 to rotate; the turbine 513 is mechanically coupled to the signal generator 515, which generates a signal indicating the rotation speed of the turbine 513, and the rotation speed depends at least in part on the blood flowing through the blood vessel 28; a tachometer inside the cryoablation device determines the blood flow state in the blood vessel according to the rotation speed of the turbine 513; in some cases, the blades 514 are collapsible to reduce the diameter of the turbine 513, thereby facilitating the insertion of the cryoballoon 14 into the blood vessel 28; the turbine 513 is close to the distal end of the cryoballoon 14 and includes at least one blade 514, and the at least one blade 514 is configured to rotate relative to the cryoballoon 14 in response to the fluid flow through the blood vessel and rotate at a rotation speed that depends at least in part on the speed of the fluid flow through the blood vessel; a signal generator 515 is mechanically coupled to the turbine 513 and configured to generate an indication of the at least one a rotation speed signal of the blade 514; and a signal lead 506, which is configured to transmit a rotation speed signal indicating the at least one blade 514, the signal lead 506 being connected to the signal generator 515 and extending along the cryoballoon 14 and the catheter 2; the signal generator 515 includes a Hall effect sensor, a magnet and a coil, wherein the magnet is configured to rotate relative to the coil of the signal generator 515 in response to the rotation of the at least one blade 514, wherein the magnet is configured to rotate relative to the Hall effect sensor of the signal generator 515 in response to the rotation of the at least one blade 514 and generate an electrical signal of current / voltage; the signal generator 515, electrically connected to the control module of the cryoablation device through the signal lead 506, the control module converts the electric signal of current / voltage into the blood flow velocity v and displays it to the human-computer interaction module; the blood flow velocity v measured by the blood flow monitoring mechanism 5 is correlated with the flow state of the blood, specifically: data information is extracted for the induced electric signals corresponding to the different dynamic pressure values ​​generated by different blockage leaks, and blood flow data corresponding to the electric signals corresponding to the different dynamic pressure values ​​are obtained according to the extracted data information, so as to judge the size of the blockage leak; during the cryoablation process, the catheter enters the human body, when there is no blood flow, the blood flow velocity v=0, and the blood dynamic pressure P dynamic=0 at this time, indicating that there is no blood flow at this time and the blood flow blockage is good;When the blood flow is not blocked well, the blood is flowing, v>0, the blood dynamic pressure Pdynamic>0, and the blood flow is blocked at the blood flow detection mechanism, that is, the pressure here increases; the third temperature sensor 504 probe configured by the blood flow monitoring mechanism 5 is arranged on the outer surface of the distal end 11 of the ablation mechanism, and the fourth temperature sensor 505 probe is fixed at the apex position of the front end face of the cryoballoon 14. The third temperature sensor 504 and the fourth temperature sensor 505 are inserted into the blood vessel together with the catheter during the operation; the arrangement of the third temperature sensor 504 and the fourth temperature sensor 505 uses heat transfer as a reference basis, and according to the correlation between blood temperature change and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor, and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module of the cryoablation device. The control module calculates the flow state of the blood in the blood vessel according to the temperature signal, and displays it to the human-computer interaction module, thereby assisting in judging the balloon blocking effect and enhancing the reliability of the application of a cryoablation system for detecting blood flow state; the third temperature sensor 504 and the fourth temperature sensor 5 The temperature change of 05 is correlated with the flow state of blood. Specifically, during the cryoablation process, the catheter enters the human body. When the blood flow is well blocked, when there is no blood flow, an ice ball is formed on the balloon surface. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, the balloon forms an ice ball. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the freezing balloon in the blood vessel determines the flow speed of the blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. The third temperature sensor 504 and the fourth temperature sensor 505 can assist in judging the blood flow dynamics according to the different time consumption under the same temperature change value. ;

[0019] Preferably, the Y-shaped valve 43 includes a liquid channel 431, an instrument channel 432, and an instrument channel seal 433, and the Y-shaped valve 43 is connected to the guidewire cavity 15. Heparin saline or contrast agent can be delivered to the distal end 11 of the ablation mechanism by the liquid channel 431 and through the guidewire cavity 15, for flushing and exhausting the catheter, and for angiography; the guidewire is delivered to the distal end 11 of the ablation mechanism by the instrument channel 432 and through the guidewire cavity 15, for guiding and supporting the catheter during the operation. During the process of flushing and exhausting the catheter, the instrument channel seal 433 can be tightened to exhaust the gas between the Y-shaped valve 43 and the distal end 11 of the ablation mechanism; the instrument channel seal 433 can then be loosened to exhaust the gas at the end of the Y-shaped valve 43; the instrument channel seal 433 is a press-type or knob-type structure.

[0020] Furthermore, the distance between the distal end of the bending hole 21 and the distal end of the outer tube 2 is substantially the same, and the proximal end of the bending hole 21 and the proximal end of the outer tube 2 are at a certain distance; the distal end of the bending wire 22 is fixed to the distal end of the outer tube 2, and the proximal end of the bending wire 22 extends from the proximal end of the bending hole 21 and is fixed to the bending control member 31; the bending wires 22 on both sides of the outer tube 2 are respectively fixed to both sides of the bending control member 31, and when the bending control member 31 is moved to one side, the bending wire 22 on one side of the outer tube 2 is straightened, so that the outer tube 2 Bend to one side; when the bending control part 31 is pushed to the other side, the bending wire 22 on the other side of the outer tube 2 will be straightened, so that the outer tube 2 bends to the other side, based on which the double bending function of the outer tube 2 is realized; a sealing component 23 is provided in the hollow part of the outer tube 2, and the sealing component 23 contains a guide wire cavity 15, an air inlet pipe 16, an air return pipe 17 and a sensor signal cable 24; the distal end of the sealing component 23 is fixed to the proximal end 19 of the ablation mechanism, and the proximal end of the sealing component 23 is fixed to the gas pipeline connector 41. The distal end of the outer tube 2 is fixed to the proximal end 19 of the ablation mechanism, and the proximal end of the outer tube 2 is fixed to the operating mechanism 3; there is a vacuum tube 18 between the sealing component 23 and the tube body 25; the cold air generated by the equipment acts on the balloon 14 through the air inlet pipe 16, and is discharged from the balloon 14 through the air return pipe 17 and recovered to the equipment; the sealing component 23 ensures that the gas or liquid in the guide wire cavity 15, the air inlet pipe 16 and the air return pipe 17 will not leak to the balloon 14 through processes such as hot melting or welding; the vacuum tube 18 achieves the vacuum degree between the sealing component 23 and the tube body 25 by sucking back the gas at the device end, and the second pressure sensor 181 detects the gas pressure value at the vacuum tube 18 in real time to determine whether the sealing component 23 is damaged and causes gas leakage, and issues an alarm prompt.

[0021] Preferably, the signal lines corresponding to the first pressure sensor 143, the first temperature sensor 144, the second temperature sensor 162, the third pressure sensor 171 and the second pressure sensor 181 are gathered together to the sensor signal cable 24, and the sensor signal cable 24 passes through the outer tube 2 and the operating mechanism 3 respectively, and is finally integrated into the sensor signal connector 42, which is used to provide the measured pressure information and temperature information to the equipment, so as to realize closed-loop control of the cold air supply and the cold air flow rate.

[0022] Furthermore, the thermal conductive coating 141 is uniformly covered on the surface of the balloon 14 in a woven manner in a horizontal and vertical manner; alternatively, the thermal conductive coating 141 can also uniformly and completely cover the surface of the balloon 14; alternatively, the thermal conductive coating 141 can also uniformly cover the surface of the balloon 14 in a horizontal or vertical manner with a certain spacing.

[0023] The beneficial effects of the present invention are:

[0024] 1) The ablation catheter uses cryogenic energy to ablate the lesion tissue. Compared with the existing technology of restoring the smoothness of blood vessels by balloon dilatation and stent implantation, the method proposed by the present invention can effectively remove plaques at the narrowed part of the blood vessels, and no foreign matter will remain in the body after the operation, and there will be no rejection reaction and restenosis of the blood vessels.

[0025] 2) The surface of the balloon of the present invention is attached with a thermally conductive coating having high thermal conductivity, and the surface of the thermally conductive coating is attached with a hydrophilic coating. Compared with the common balloons in the prior art, during the cryotherapy process, the hydrophilic coating attached to the surface of the balloon of the present application can make the blood in the coronary artery flow more easily and is less likely to cause the formation of thrombus during the operation. In addition, since the surface of the balloon is attached with a thermally conductive coating having high thermal conductivity, during the cryotherapy process, the cold air in the balloon can reach the lesion tissue more efficiently, making the plaque removal more thorough, while improving the treatment effect and safety.

[0026] 3) The guidewire cavity, air inlet pipe, air return pipe and sensor signal cable of the present invention are sealed by a sealing component. A vacuum tube is provided between the sealing component and the body of the outer tube. A pressure sensor is integrated inside the vacuum tube. The ablation mechanism also integrates multiple pressure sensors and temperature sensors. The vacuum tube can maintain the vacuum degree between the sealing component and the body of the outer tube to ensure that the cold air in the air inlet pipe can be maintained at a relatively low temperature during the pipeline transmission process, thereby ensuring the efficiency of cryoablation; in addition, the gas pressure in the vacuum tube can be monitored in real time during ablation. If the maximum allowable pressure value is exceeded, the sealing component is leaking, and the operator is reminded to replace the ablation catheter, thereby ensuring the efficiency of cryoablation; multiple pressure sensors and temperature sensors work together to achieve closed-loop control of cold air supply and cold air flow rate, thereby improving the safety of the operation and the therapeutic effect.

[0027] 4) The outer tube of the present invention has a double bending function. When the ablation catheter reaches the lesion area, it can pass through the complex vascular pathway more smoothly, thereby improving the efficiency and safety of the operation.

[0028] 5) The balloon of the present invention is provided with a blood flow monitoring mechanism. By monitoring the blood dynamics, the operator can ensure that the cryoballoon is correctly placed without having to determine the balloon placement position through blood flow angiography, thereby reducing the blood flow blockage time and reducing the risk of cardiac ischemia. Real-time monitoring of blood flow can also help the operator evaluate the effect of cryoablation and adjust the surgical strategy in time, avoid unnecessary damage to surrounding tissues, reduce complications such as vascular damage or thrombosis, improve the success rate of the operation, and reduce the chance of thrombosis during the operation and the chance of restenosis after the operation. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a structural diagram of the coronary cryoablation catheter.

[0030] Figure 2 An embodiment of a coronary cryoablation catheter blood flow monitoring mechanism using an electromagnetic induction sensor.

[0031] Figure 3 An embodiment of a coronary cryoablation catheter blood flow monitoring mechanism using an optical fiber sensor is disclosed.

[0032] Figure 4 An embodiment of a turbine speed sensor is provided for a coronary cryoablation catheter blood flow monitoring mechanism.

[0033] Figure 5 This is a cross-sectional view of the outer tube.

[0034] Fig. 6A This is a front view of the ablation mechanism.

[0035] Figure 6B This is a side view of the ablation mechanism.

[0036] Figure 7 A structural diagram of a thermal conductive coating.

[0037] Reference numerals:

[0038] 1. Ablation mechanism; 2. Outer tube; 3. Operating mechanism; 4. Connecting mechanism; 5. Blood flow monitoring mechanism; 11. Distal end of ablation mechanism; 14. Balloon; 15. Guidewire cavity; 16. Air inlet tube; 17. Air return tube; 18. Vacuum tube; 19. Proximal end of ablation mechanism; 21. Bending hole; 22. Bending wire; 23. Sealing component; 24. Sensor signal cable; 25. Tube body; 31. Bending control component; 32. Handle; 41. Gas pipeline connector; 42. Sensor signal No. connector; 43. Y-type valve; 141. thermal conductive coating; 142. hydrophilic coating; 143. first pressure sensor; 144. first temperature sensor; 161. opening; 162. second temperature sensor; 171. third pressure sensor; 181. second pressure sensor; 431. liquid channel; 432. instrument channel; 433. instrument channel seal; 501. electromagnetic induction coil, 504. third temperature sensor, 505. fourth temperature sensor. DETAILED DESCRIPTION

[0039] The present invention is further described below in conjunction with the accompanying drawings and specific embodiments.

[0040] In order to make the objectives, technical solutions and advantages of the present application more clearly understood, the present application is further described in detail below with reference to the accompanying drawings and examples.

[0041] The “proximal end” mentioned in the present application refers to the end close to the surgical operator, and the “distal end” mentioned in the present application refers to the end far away from the surgical operator.

[0042] like Figure 1As shown, a coronary cryoablation catheter is composed of an ablation mechanism 1, an outer tube 2, an operating mechanism 3, a connecting mechanism 4 and a blood flow monitoring structure 5. The ablation mechanism 1 includes a balloon 14, wherein a thermal conductive coating 141 with high thermal conductivity is attached to the surface of the balloon 14, and the thermal conductive coating 141 includes but is not limited to graphene, nanographene, gel, carbon fiber and other materials. A hydrophilic coating 142 is attached to the surface of the thermal conductive coating 141, and the hydrophilic coating 142 includes but is not limited to water-based epoxy resin, polydimethylsiloxane, hydrophilic polymer, siloxane monomer and ether monomer. At least two pressure sensors 143 are integrated on the surface of the hydrophilic coating 142 to detect the contact pressure between the balloon 14 and the lesion tissue, and according to the contact pressure value detected in real time, to ensure that the balloon and the lesion tissue are in good contact, thereby improving the surgical treatment effect. The pressure sensor 143 includes a resistive, capacitive, piezoelectric, strain gauge pressure sensor and the like. At least two temperature sensors 144 are integrated on the surface of the hydrophilic coating 142 to detect the temperature of the lesion tissue, and ensure that the lesion tissue has a good freezing temperature according to the real-time detected temperature value, thereby improving the surgical treatment effect. The temperature sensor 144 includes a thermocouple, a thermistor, a silicon diode temperature sensor, an infrared temperature sensor, a bimetallic temperature sensor, a laser temperature sensor, a platinum resistance sensor, etc.

[0043] The guidewire cavity 15, the air inlet tube 16, the air return tube 17 and the sensor signal cable 24 are sealed by a sealing component 23. A vacuum tube 18 is provided between the sealing component 23 and the tube body 25 of the outer tube 2. A pressure sensor 181 is integrated inside the vacuum tube 18 to detect the gas pressure inside the vacuum tube 18. The pressure sensor 181 includes a resistance strain type, a capacitance type, a piezoelectric type, a resonance type, a semiconductor piezoresistance type sensor, etc. The balloon 14 has a guidewire cavity 15, an air inlet tube 16, and an air return tube 17 inside. The distal ends of the balloon 14 and the guidewire cavity 15 are fixed together at the distal end 11 of the ablation mechanism, and the proximal ends of the balloon 14, the guidewire cavity 15, the air inlet tube 16 and the air return tube 17 are fixed together at the proximal end 19 of the ablation mechanism. The air inlet tube 16 extends from the proximal end 19 of the ablation mechanism to the center of the balloon 14, and uniform openings 161 are provided on the outer surface of the air inlet tube 16 to release cold air to the balloon 14. The surface of the air inlet pipe 16 is integrated with a temperature sensor 162, which is used to detect the temperature inside the balloon 14. By real-time monitoring of the internal temperature of the balloon and adjusting the intake rate of cold air, the working temperature inside the balloon is maintained, thereby improving the treatment effect. The temperature sensor 162 includes a thermocouple, a thermistor, a silicon diode temperature sensor, an infrared temperature sensor, a bimetallic temperature sensor, a laser temperature sensor, a platinum resistance sensor, etc. The port of the return air pipe 17 is integrated with a pressure sensor 171, which is used to detect the gas pressure inside the balloon 14. According to real-time monitoring of the gas pressure inside the balloon, the intake rate of cold air is adjusted to maintain the gas pressure inside the balloon within a safe range, thereby improving the safety of the operation. The pressure sensor 171 includes a resistive strain sensor, a capacitive sensor, a piezoelectric sensor, a resonant sensor, a semiconductor piezoresistance sensor, etc.

[0044] The outer tube 2 is composed of a tube body 25, a bending hole 21 and a bending wire 22. The outer tube 2 has a bidirectional bending function. The outer tube 2 contains materials such as polyetheramide and polytetrafluoroethylene. The operating mechanism 3 is provided with a bending control member 31. The bending control member 31 can be turned right to control the outer tube 2 to bend in one direction, and the bending control member 31 can be turned left to control the outer tube 2 to bend in another direction. The connecting mechanism 4 includes a gas pipeline connector 41, a sensor signal connector 42, and a Y-type valve 43. The air inlet pipe 16, the air return pipe 17 and the vacuum pipe 18 pass through the outer tube 2 and the operating mechanism 3 respectively, and are finally fixed to the gas pipeline connector 41. The gas pipeline connector 41 is connected to the matching cryoablation equipment, which provides cold air to the air inlet pipe 16 and collects the gas discharged from the air return pipe 17. The equipment can also withdraw gas through the vacuum pipe 18 to maintain the vacuum between the sealing component 23 and the tube body 25. The signal lines corresponding to the pressure sensor 143, temperature sensor 144, temperature sensor 162, pressure sensor 171 and pressure sensor 181 pass through the outer tube 2 and the operating mechanism 3 respectively, and are finally integrated into the sensor signal connector 42. The sensor signal connector 42 is connected to the matching cryoablation device, and the device processes these detection signals and performs closed-loop regulation of the supply and flow rate of cold air accordingly. The blood flow monitoring mechanism 5 is arranged at any position of the distal end of the ablation catheter close to the balloon and the outer surface of the balloon.

[0045] In a coronary cryoablation catheter embodiment of the present invention, the blood flow monitoring mechanism 5 is configured as an electromagnetic induction sensor. The specific implementation is as follows:

[0046] The iron ion electromagnetic induction coil 501 included in the blood flow monitoring mechanism 5 is arranged in a ring shape on the outer wall of the catheter 2 at the proximal end of the cryoballoon 14. The iron ion electromagnetic induction coil 501 is coaxial with the catheter 2, and a sufficiently large gap is designed between the iron ion electromagnetic induction coil 501 and the outer wall of the catheter 2 to allow the flowing blood to pass through. The blood can generate electromagnetic induction through the iron ion electromagnetic induction coil 501, and the electromagnetic induction can generate an electrical signal. The iron ion electromagnetic induction coil 501 is provided with an electrical signal lead-out line 506. The electrical signal can be electrically connected to the cryoablation device through the signal lead-out line 506. The electrical signal can be converted into a blood flow velocity v through the built-in electrical signal converter of the cryoablation device and displayed to the human-computer interaction module of the cryoablation device.

[0047] When the cryoballoon is inflated, blood will flow between the outer wall of the balloon 14 and the inner wall of the blood vessel 28. The blood flow monitoring mechanism 5 uses the iron ion electromagnetic induction coil 501 to sense the iron ions flowing in the blood of the measured part, generating a measured magnetic induction electric signal; the signal acquisition module set by the cryoablation device extracts data information from the measured induced electric signal, and obtains blood flow data based on the extracted data information. The signal acquisition module extracts current / voltage amplitude data from the measured induced electric signal, and converts the extracted current / voltage amplitude data into the blood flow velocity v in the blood vessel.

[0048] The blood flow velocity v measured by the blood flow monitoring mechanism 5 is correlated with the flow state of the blood, specifically:

[0049] For different blocking states, the induced electrical signals corresponding to the different dynamic pressure values ​​generated by the blood flow are respectively extracted for data information, and the blood flow data corresponding to the electrical signals corresponding to the different dynamic pressure values ​​are obtained based on the extracted data information, so as to judge the state of balloon blocking. During the cryoablation process, the catheter enters the human body. When there is no blood flow, the blood flow rate v=0, and the blood dynamic pressure Pdynamic=0 at this time, indicating that there is no blood flow at this time and the blood flow is well blocked; when the blood flow is not well blocked, the blood flows, v>0, the blood dynamic pressure Pdynamic>0, and there is blood flow blockage at the blood flow monitoring mechanism 5, that is, the pressure here increases, and the blood flow monitoring mechanism 5 can feedback relevant information reminders according to the needs of the operator.

[0050] The temperature sensor 504 probe configured by the blood flow monitoring mechanism 5 is fixed on the outer surface of the catheter 2 close to the balloon end, and the temperature sensor 505 probe is fixed on the outer surface of the catheter 2 farther from the balloon end than the temperature sensor 504. The temperature sensors 504 and 505 are inserted into the blood vessel together with the cryoballoon catheter during the operation. The arrangement of the temperature sensors 504 and 505 uses heat transfer as a reference basis. According to the correlation between blood temperature change, blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module of the cryoablation device. The control module of the cryoablation device calculates the flow state of blood in the blood vessel according to the temperature signal and displays it to the human-computer interaction module of the cryoablation device, thereby assisting in judging the effect of blood flow and enhancing the reliability of the application of a cryoablation system for detecting blood flow state.

[0051] The temperature change of the temperature sensors 504 and 505 is correlated with the flow state of the blood, specifically:

[0052] During the cryoablation process, the catheter enters the human body. When there is no blood flow, an ice ball is formed on the surface of the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, an ice ball is formed on the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the freezing balloon in the blood vessel determines the flow rate of blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. Temperature sensors 504 and 505 can assist in judging the blood flow dynamics according to the different time consumptions under the same temperature change value, thereby enhancing the reliability of the application of a cryoablation system for detecting blood flow status.

[0053] In another embodiment of the coronary cryoablation catheter of the present invention, the blood flow monitoring mechanism 5 is configured as an optical fiber sensor. The specific implementation is as follows:

[0054] The fiber optic sensor 508 component used in the blood flow monitoring mechanism 5 includes a helium-neon laser, a Bragg cell, a beam splitter, a photodiode, a spectrum analyzer, a control module located inside the cryoablation device, and a single-mode optical fiber 506 and an optical fiber probe 510 located on the surface of the cryoballoon 14. The blood flow monitoring mechanism 5 is equipped with temperature sensors 504 and 505 for auxiliary monitoring to enhance the reliability of the blood flow state detection results. The fiber optic sensor 508 uses the principle of the Doppler effect. The outer diameter of the fiber optic sensor 508 is about tens of μm, and it can be set at the top position of the cryoballoon 14 and inserted into the blood vessel with the balloon during the operation.

[0055] The optical fiber sensor 508 measuring light beam enters the measured blood flow through the optical fiber probe 510, and is scattered by the red blood cells inside the blood vessel 28. A part of the light returns along the original path to obtain a Doppler frequency shift signal f+Δf, and a part enters a Bragg box (frequency shifter) with a driving frequency of f1=40MHz to obtain a reference light signal with a frequency of f-f1. The optical fiber sensor 508 transmits the obtained light signal to the control module of the cryoablation device through the single-mode optical fiber 506. The control module of the cryoablation device mixes the reference light signal with the Doppler frequency shift signal through the photodiode in the cryoablation device, and the light signal is converted into a photocurrent and sent to the spectrum analyzer to obtain the Doppler frequency shift spectrum (velocity spectrum) corresponding to the blood flow velocity. According to the velocity spectrum, the refractive index n of the blood, the angle θ between the optical fiber axis and the blood vessel axis, and the laser wavelength λ, the blood flow velocity v in the blood vessel is calculated according to formula (1-1), and the blood flow state is displayed to the human-computer interaction module of the cryoablation device.

[0056]

[0057] The blood flow velocity v measured by the blood flow monitoring mechanism 5 is correlated with the flow state of the blood, specifically:

[0058] Data information is extracted from the induced electrical signals corresponding to different dynamic pressure values ​​generated by different blocked leaks, and blood flow data corresponding to the electrical signals corresponding to different dynamic pressure values ​​are obtained based on the extracted data information, so as to judge the size of the blocked leak. During the cryoablation process, the catheter enters the human body. When there is no blood flow, the blood flow rate v=0, and the blood dynamic pressure Pdynamic=0, indicating that there is no blood flow at this time and the blood flow is well blocked; when the blood flow is not well blocked, the blood flows, v>0, the blood dynamic pressure Pdynamic>0, and there is blood flow blockage at the blood flow detection mechanism, that is, the pressure here increases. The blood flow detection mechanism can feedback relevant information according to the needs of the operator.

[0059] The temperature sensor 504 probe configured by the blood flow monitoring mechanism 5 is fixed on the outer surface of the distal end of the cryoballoon 14, and the temperature sensor 505 probe is fixed on the outer surface position of the cryoballoon 14 compared to the proximal end of the temperature sensor 504. The temperature sensors 504 and 505 are inserted into the blood vessel together with the cryoballoon catheter during the operation. The arrangement of the temperature sensors 504 and 505 uses heat transfer as a reference basis. According to the correlation between blood temperature change and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module inside the cryoablation device. The cryoablation device control module calculates the flow state of blood in the blood vessel according to the temperature signal and displays it to the human-computer interaction module, thereby assisting in judging the flow state of blood during the operation and enhancing the reliability of the application of a cryoablation system for detecting blood flow state.

[0060] The temperature change of the temperature sensors 504 and 505 is correlated with the flow state of the blood, specifically:

[0061] During the cryoablation process, the catheter enters the human body. When the blood flow is well blocked, when there is no blood flow, an ice ball is formed on the balloon surface. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, an ice ball is formed on the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the freezing balloon in the blood vessel determines the flow rate of the blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. The temperature sensors 504 and 505 can assist in judging the blood flow dynamics according to the different time consumptions under the same temperature change value, thereby enhancing the reliability of the application of a cryoablation system for detecting blood flow status.

[0062] Another coronary cryoablation catheter blood flow monitoring mechanism 5 of the present invention is configured as a turbine speed sensor. The specific implementation is as follows:

[0063] The turbine speed sensor 512 assembly used in the blood flow monitoring mechanism 5 includes a tachometer located inside the cryoablation device, a signal conversion module, a control module, a turbine 513 located at the distal end of the cryoballoon, blades 514, a signal generator 515, and a signal lead 506. The turbine 513 is arranged at the distal end of the cryoballoon 14. The blood or other fluid flowing through the blood vessel 28 causes the blades 514 of the turbine 513 to rotate. The turbine 513 is mechanically coupled to the signal generator 515, which generates a signal indicating the rotation speed of the turbine 513, which rotation speed depends at least in part on the speed of the fluid flowing through the blood vessel 28. The tachometer inside the cryoablation device determines the blood flow state in the blood vessel according to the rotation speed of the turbine 513. In some cases, the blades 514 are collapsible to reduce the diameter of the turbine 513, thereby facilitating the insertion of the cryoballoon 14 into the blood vessel 28.

[0064] A turbine 513, which is proximate to the distal end of the cryoballoon 14 and includes at least one blade 514, wherein the at least one blade 514 is configured to rotate relative to the cryoballoon 14 in response to the fluid flow through the blood vessel and to rotate at a rotational speed that depends at least in part on the speed of the fluid flow through the blood vessel; a signal generator 515, which is mechanically coupled to the turbine 513 and is configured to generate a rotational speed signal indicative of the at least one blade 514; and a signal lead 506, which is configured to transmit a rotational speed signal indicative of the at least one blade 514, the signal lead 506 being connected to the signal generator 515 and extending along the cryoballoon 14 and the catheter 2.

[0065] The signal generator 515 includes a Hall effect sensor, a magnet and a coil, wherein the magnet is configured to rotate relative to the coil of the signal generator 515 in response to the rotation of the at least one blade 514, wherein the magnet is configured to rotate relative to the Hall effect sensor of the signal generator 515 in response to the rotation of the at least one blade 514, and generate an electric current / voltage signal. The signal generator 515 is electrically connected to the control module of the cryoablation device through the signal lead 506, and the control module converts the electric current / voltage signal into the blood flow velocity v and displays it to the human-computer interaction module.

[0066] The blood flow velocity v measured by the blood flow monitoring mechanism 5 is correlated with the flow state of the blood, specifically:

[0067] Data information is extracted from the induced electrical signals corresponding to different dynamic pressure values ​​generated by different blocked leaks, and blood flow data corresponding to the electrical signals corresponding to different dynamic pressure values ​​are obtained based on the extracted data information, so as to judge the size of the blocked leak. During the cryoablation process, the catheter enters the human body. When there is no blood flow, the blood flow rate v=0, and the blood dynamic pressure Pdynamic=0, indicating that there is no blood flow at this time and the blood flow is well blocked; when the blood flow is not well blocked, the blood flows, v>0, the blood dynamic pressure Pdynamic>0, and there is blood flow blockage at the blood flow detection mechanism, that is, the pressure here increases. The blood flow detection mechanism can feedback relevant information according to the needs of the operator.

[0068] The temperature sensor 504 probe configured by the blood flow monitoring mechanism 5 is arranged on the outer surface of the distal end 11 of the ablation mechanism, and the temperature sensor 505 probe is fixed at the apex position of the front end face of the cryoballoon 14. The temperature sensors 504 and 505 are inserted into the blood vessel together with the catheter during the operation. The arrangement of the temperature sensors 504 and 505 uses heat transfer as a reference basis. According to the correlation between blood temperature change and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module of the cryoablation device. The control module calculates the flow state of blood in the blood vessel according to the temperature signal and displays it to the human-computer interaction module, thereby assisting in judging the balloon blocking effect and enhancing the reliability of the application of a cryoablation system for detecting blood flow status.

[0069] The temperature change of the temperature sensors 504 and 505 is correlated with the flow state of the blood, specifically:

[0070] During the cryoablation process, the catheter enters the human body. When the blood flow is well blocked, when there is no blood flow, an ice ball is formed on the balloon surface. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, an ice ball is formed on the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the freezing balloon in the blood vessel determines the flow rate of the blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. The temperature sensors 504 and 505 can assist in judging the blood flow dynamics according to the different time consumptions under the same temperature change value, thereby enhancing the reliability of the application of a cryoablation system for detecting blood flow status.

[0071] The Y-type valve 43 includes a liquid channel 431, an instrument channel 432, and an instrument channel seal 433, and the Y-type valve 43 is connected to the guidewire cavity 15. Heparin saline or contrast agent can be delivered to the distal end 11 of the ablation mechanism by the liquid channel 431 and through the guidewire cavity 15, which is used for flushing and exhausting the catheter and performing angiography. The guidewire is delivered to the distal end 11 of the ablation mechanism by the instrument channel 432 and through the guidewire cavity 15, which is used for guiding and supporting the catheter during the operation. During the process of flushing and exhausting the catheter, the instrument channel seal 433 can be tightened to exhaust the gas between the Y-type valve 43 and the distal end 11 of the ablation mechanism; then the instrument channel seal 433 can be loosened to exhaust the gas at the end of the Y-type valve 43. The instrument channel seal 433 can be a press-type or knob-type structure.

[0072] Figure 5 It is a cross-sectional view of the outer tube. The outer tube 2 is composed of a tube body 25, a bending adjustment hole 21 and a bending adjustment wire 22. The outer tube 2 is a hollow tube, and its constituent materials include but are not limited to polyetheramide or polytetrafluoroethylene and other biocompatible materials with a certain elasticity. There is a bending adjustment hole 21 on both sides of the outer tube 2, and there is a bending adjustment wire 22 inside each bending adjustment hole 21. The distance between the distal end of the bending adjustment hole 21 and the distal end of the outer tube 2 is basically the same, and the proximal end of the bending adjustment hole 21 is at a certain distance from the proximal end of the outer tube 2. The distal end of the bending adjustment wire 22 is fixed to the distal end of the outer tube 2, and the proximal end of the bending adjustment wire 22 extends from the proximal end of the bending adjustment hole 21 and is fixed to the bending control component 31. The bending wires 22 on both sides of the outer tube 2 are fixed to both sides of the bending control member 31 respectively. When the bending control member 31 is moved to one side, the bending wire 22 on one side of the outer tube 2 will be straightened, so that the outer tube 2 is bent to one side; when the bending control member 31 is moved to the other side, the bending wire 22 on the other side of the outer tube 2 will be straightened, so that the outer tube 2 is bent to the other side, thereby realizing the double bending function of the outer tube 2. Based on the double bending function of the outer tube 2, in the process of the catheter from subcutaneous puncture to the coronary lesion area, it will be able to pass through the complex vascular pathway more smoothly, thereby improving the efficiency and safety of the operation.

[0073] The hollow part of the outer tube 2 is provided with a sealing component 23, and the sealing component 23 contains a guide wire cavity 15, an air inlet pipe 16, an air return pipe 17 and a sensor signal cable 24. The distal end of the sealing component 23 is fixed to the proximal end 19 of the ablation mechanism, and the proximal end of the sealing component 23 is fixed to the gas pipeline connector 41. The distal end of the outer tube 2 is fixed to the proximal end 19 of the ablation mechanism, and the proximal end of the outer tube 2 is fixed to the operating mechanism 3. A vacuum tube 18 is provided between the sealing component 23 and the tube body 25. The cold air generated by the device acts on the balloon 14 through the air inlet pipe 16, and is discharged from the balloon 14 through the air return pipe 17 and recovered to the device; the sealing component 23 ensures that the gas or liquid in the guidewire cavity 15, the air inlet pipe 16 and the air return pipe 17 will not leak into the balloon 14 through processes such as hot melting or welding; the vacuum tube 18 realizes the vacuum degree between the sealing component 23 and the tube body 25 by withdrawing the gas at the end of the device, and the pressure sensor 181 detects the gas pressure value at the vacuum tube 18 in real time to determine whether the sealing component 23 is damaged and causes gas leakage, and issues an alarm prompt. Through the above measures, the cold air in the air inlet pipe can be maintained at a relatively low temperature during the pipeline transmission process to the greatest extent, thereby ensuring the efficiency of cryoablation.

[0074] The signal lines corresponding to the pressure sensor 143, temperature sensor 144, temperature sensor 162, pressure sensor 171 and pressure sensor 181 are gathered together to the sensor signal cable 24. The sensor signal cable 24 passes through the outer tube 2 and the operating mechanism 3 respectively, and is finally integrated into the sensor signal connector 42, which is used to provide the measured pressure information and temperature information to the equipment, so as to realize closed-loop control of the cold air supply and the cold air flow rate.

[0075] Fig. 6A The front view of the ablation mechanism. The surface of the balloon 14 in the present application is attached with a thermal conductive coating 141 with high thermal conductivity, and the surface of the thermal conductive coating is attached with a hydrophilic coating 142. The surface of the hydrophilic coating is integrated with a pressure sensor 143 and a temperature sensor 144. The pressure sensor 143 is used to detect the contact pressure between the balloon 14 and the lesion tissue. The number of the pressure sensors 143 is at least 2, and they are evenly distributed on the surface of the balloon 14 (such as Figure 6B As shown in the figure, the pressure sensor 143 is located at the position where the outer diameter of the balloon 14 is the largest, that is, the middle part of the balloon. Usually, the best place for the balloon 14 to abut against the lesion tissue is at the place where the outer diameter of the balloon is the largest. Therefore, the integrated pressure sensor 143 at this place can best measure the abutment of the lesion tissue and the balloon to ensure that the balloon and the lesion tissue have good abutment, thereby improving the surgical treatment effect. The temperature sensor 144 is used to detect the temperature at the lesion tissue, and according to the temperature value detected in real time, it is ensured that the lesion tissue has a good freezing temperature, thereby improving the surgical treatment effect.

[0076] Figure 71 is a structural diagram of a thermal conductive coating. As one embodiment, the thermal conductive coating 141 is uniformly covered on the surface of the balloon 14 in a woven manner. In addition, the thermal conductive coating 141 can also be uniformly and completely covered on the surface of the balloon 14. The thermal conductive coating 141 can also be uniformly covered on the surface of the balloon 14 in a horizontal or vertical manner with a certain spacing.

[0077] In the interventional treatment of coronary artery stenosis, the smoothness of the stenotic part of the blood vessel is restored by balloon dilatation and stent implantation. This method usually has some problems. For example, long-term medication is required to overcome the body's rejection reaction; in addition, as the stent implantation time increases, the problem of vascular hyperplasia will also occur, leading to restenosis of the blood vessel. The coronary cryoablation catheter described in the present application, through the cold air generated by the device end, enters the balloon 14 through the opening 161 set on the outer surface of the air inlet pipe 16, and acts on the plaque at the stenotic part of the coronary artery by heat conduction. The cold air includes but is not limited to CO2, N20, Freon, nitrogen or argon. Based on the ultra-low temperature freezing energy, the plaque in the blood vessel can be effectively removed, and the stenosis can be fundamentally restored to the original size and elasticity of the blood vessel, thereby preventing the problem of vascular hyperplasia and restenosis caused by long-term implantation of the stent, and improving the safety after surgery. In addition, since there is no foreign body left in the body after cryoablation, it will not cause rejection reaction of the human body after surgery, thereby avoiding the problem of long-term medication after surgery and improving the quality of life of patients after surgery.

[0078] For coronary interventional treatment, during balloon dilatation and stent implantation, since the blood vessels are temporarily in a relatively blocked state during this period, the blood flow rate is relatively slow, which may cause the formation of thrombus during the operation. In the coronary cryoablation catheter described in the present application, the surface of the balloon 14 is attached with a thermally conductive coating 141 with high thermal conductivity, and the surface of the thermally conductive coating is attached with a hydrophilic coating 142. During the cryoablation process, the hydrophilic coating 142 can reduce the resistance between the blood and the balloon 14, so that a relatively smoother blood circulation rate can be maintained, thereby reducing the probability of intraoperative thrombus formation and improving the safety of the operation. In addition, the thermally conductive coating 141 has a high thermal conductivity. During the cryotherapy process, the cold air in the balloon can reach the lesion tissue more efficiently. Under the condition of the same cold air intake rate, the intravascular plaque can be removed more thoroughly, thereby improving the effect of surgical treatment. Compared with ordinary balloons, based on the hydrophilic coating 142 with high thermal conductivity described in the present application, a relatively lower cold air intake rate can be controlled to achieve the same plaque removal effect. The lower cold air intake rate means that the gas pressure in the balloon is lower, thereby also improving the safety of the operation.

[0079] The above are preferred embodiments of the present invention. A person skilled in the art may make various changes or improvements on this basis. Without departing from the general concept of the present invention, these changes or improvements should fall within the scope of protection claimed by the present invention.

Claims

1. A coronary cryocatheter, characterized in that: It comprises an ablation mechanism (1), an outer tube (2), an operating mechanism (3), a connecting mechanism (4), and a blood flow monitoring structure (5); The ablation mechanism (1) comprises a balloon (14), and at least two first pressure sensors (143) and two first temperature sensors (144) are integrated on the surface of the balloon (14); The outer tube (2) has a guide wire cavity (15) sealed by a sealing component (23), an air inlet pipe (16), an air return pipe (17) and a sensor signal cable (24) inside, a vacuum tube (18) is provided between the sealing component (23) and the tube body (25) of the outer tube (2), and a second pressure sensor (181) is integrated inside the vacuum tube (18) for detecting the gas pressure inside the vacuum tube (18); The guidewire cavity (15), the air inlet tube (16), and the air return tube (17) extend into the interior of the balloon (14); the distal ends of the balloon (14) and the guidewire cavity (15) are fixed to the distal end (11) of the ablation mechanism; and the proximal ends of the balloon (14), the guidewire cavity (15), the air inlet tube (16), and the air return tube (17) are fixed to the proximal end (19) of the ablation mechanism; The air inlet tube (16) extends from the proximal end (19) of the ablation mechanism into the balloon (14), and an opening (161) is provided on the outer surface of the air inlet tube (16) for releasing cold air into the balloon (14); a second temperature sensor (162) is integrated on the surface of the air inlet tube (16) for detecting the temperature inside the balloon (14), and by real-time monitoring the temperature inside the balloon and adjusting the air intake rate of the cold air, the working temperature inside the balloon is maintained; The return air pipe (17) port is integrated with a third pressure sensor (171) for detecting the gas pressure inside the balloon (14), and adjusting the intake rate of cold air according to real-time monitoring of the gas pressure inside the balloon to maintain the gas pressure inside the balloon within a safe range; The connecting mechanism (4) includes a gas pipeline connector (41), a sensor signal connector (42), and a Y-type valve (43); the air inlet pipe (16), the air return pipe (17), and the vacuum tube (18) respectively pass through the outer tube (2) and the operating mechanism (3), and are finally fixed to the gas pipeline connector (41); the gas pipeline connector (41) is connected to a matching cryoablation device, the device provides cold air to the air inlet pipe (16), and collects the gas discharged from the air return pipe (17); the cryoablation device also draws back the gas through the vacuum tube (18) to maintain the vacuum between the sealing component (23) and the tube body (25); The blood flow monitoring mechanism (5) is arranged at any position of the distal end of the ablation catheter close to the balloon and the outer surface of the balloon.

2. The coronary cryocatheter according to claim 1, characterized in that: A thermally conductive coating (141) with high thermal conductivity is attached to the surface of the balloon (14), and the material of the thermally conductive coating (141) includes one of graphene, nanographene, gel, and carbon fiber; a hydrophilic coating (142) is attached to the surface of the thermally conductive coating (141), and the hydrophilic coating (142) includes one of water-based epoxy resin, polydimethylsiloxane, hydrophilic polymer, siloxane monomer, and ether monomer; The two first pressure sensors (143) are integrated on the surface of the hydrophilic coating (142) and are used to detect the contact pressure between the balloon (14) and the lesion tissue; according to the contact pressure value detected in real time, it is ensured that the balloon and the lesion tissue are in good contact with each other; The two first temperature sensors (144) are integrated on the surface of the hydrophilic coating (142) and are used to detect the temperature of the lesion tissue, and ensure that the lesion tissue has a good freezing temperature according to the temperature value detected in real time; The first pressure sensor (143) is one of a resistive, capacitive, piezoelectric, and strain gauge pressure sensor; The first temperature sensor (144) includes one of a thermocouple, a thermistor, a silicon diode temperature sensor, an infrared temperature sensor, a bimetallic temperature sensor, a laser temperature sensor, and a platinum resistance sensor; The third pressure sensor (171) is one of a resistive strain sensor, a capacitive sensor, a piezoelectric sensor, a resonant sensor, and a semiconductor piezoresistive sensor.

3. The coronary cryocatheter according to claim 1, characterized in that: The second pressure sensor (181) includes one of a resistive strain sensor, a capacitive sensor, a piezoelectric sensor, a resonant sensor, and a semiconductor piezoresistive sensor; the second temperature sensor (162) includes one of a thermocouple, a thermistor, a silicon diode temperature sensor, an infrared temperature sensor, a bimetallic temperature sensor, a laser temperature sensor, and a platinum resistance sensor.

4. The coronary cryocatheter according to claim 1, characterized in that: The air inlet tube (16) extends from the proximal end (19) of the ablation mechanism to the center of the balloon (14), and the outer surface of the air inlet tube (16) is provided with uniform openings (161) for releasing cold air into the balloon (14).

5. The coronary cryocatheter according to claim 1, characterized in that: The outer tube (2) is composed of a tube body (25), a bending hole (21) and a bending wire (22); the outer tube (2) is a hollow tube and has a bidirectional bending function; the outer tube (2) contains polyetheramide and polytetrafluoroethylene materials; the operating mechanism (3) is provided with a bending control member (31); the bending control member (31) can be turned rightward to control the outer tube (2) to bend in one direction; the bending control member (31) can be turned leftward to control the outer tube (2) to bend in another direction.

6. The coronary cryocatheter according to claim 2, characterized in that: The signal lines corresponding to the first pressure sensor (143), the first temperature sensor (144), the second temperature sensor (162), the third pressure sensor (171) and the second pressure sensor (181) respectively pass through the outer tube (2) and the operating mechanism (3), and are finally integrated into the sensor signal connector (42); the sensor signal connector (42) is connected to the matching cryoablation equipment, and the cryoablation equipment processes these detection signals and performs closed-loop regulation of the supply and flow rate of cold air accordingly.

7. The coronary cryocatheter according to claim 1, characterized in that: The blood flow monitoring mechanism (5) is an electromagnetic induction sensor. The iron ion electromagnetic induction coil (501) included in the blood flow monitoring mechanism (5) is arranged in a ring shape on the outer wall of the catheter (2) at the proximal end of the cryoballoon (14). The iron ion electromagnetic induction coil (501) and the catheter (2) are coaxial. A sufficiently large gap is designed between the iron ion electromagnetic induction coil (501) and the outer wall of the catheter (2) to allow flowing blood to pass through. Blood passing through the iron ion electromagnetic induction coil (501) can generate electromagnetic induction, and the electromagnetic induction can generate an electrical signal. The iron ion electromagnetic induction coil (501) is provided with an electrical signal lead wire (506). The electrical signal can be electrically connected to the cryoablation device through the signal lead wire (506). The electrical signal can be converted into a blood flow velocity v through an electrical signal converter built into the cryoablation device and displayed on the human-computer interaction module of the cryoablation device. When the cryoballoon is inflated, blood will flow between the outer wall of the balloon (14) and the inner wall of the blood vessel (28), and the blood flow monitoring mechanism (5) uses the iron ion electromagnetic induction coil (501) to sense the iron ions flowing in the blood of the measured part, generating a measured magnetic induction electric signal; the signal acquisition module provided in the cryoablation device extracts data information from the measured induced electric signal, and obtains blood flow data based on the extracted data information; the signal acquisition module extracts current / voltage amplitude data from the measured induced electric signal, and converts the extracted current / voltage amplitude data into the blood flow velocity v in the blood vessel; The blood flow velocity v measured by the blood flow monitoring mechanism (5) is correlated with the flow state of the blood, specifically: For different blocking states, the induced electrical signals corresponding to the different dynamic pressure values ​​generated by the blood flow are respectively extracted for data information, and the blood flow data corresponding to the electrical signals corresponding to the different dynamic pressure values ​​are obtained according to the extracted data information, so as to judge the state of balloon blocking. During the cryoablation process, the catheter enters the human body. When there is no blood flow, the blood flow velocity v=0, and the blood dynamic pressure Pdynamic=0 at this time, indicating that there is no blood flow at this time and the blood flow blocking is good; when the blood flow blocking is not good, the blood flows, v>0, the blood dynamic pressure Pdynamic>0, and there is blood flow blocking at the blood flow monitoring mechanism 5, that is, the pressure here increases, and the blood flow monitoring mechanism (5) feedbacks relevant information reminders according to the needs of the operator.

8. The coronary cryocatheter according to claim 7, characterized in that: The third temperature sensor (504) probe configured by the blood flow monitoring mechanism (5) is fixed on the outer surface of the catheter (2) close to the balloon end, and the fourth temperature sensor (505) probe is fixed on the outer surface of the catheter (2) farther from the balloon end than the third temperature sensor (504). The third temperature sensor (504) and the fourth temperature sensor (505) are inserted into the blood vessel together with the cryoballoon catheter during the operation. The arrangement of the third temperature sensor (504) and the fourth temperature sensor (505) uses heat transfer as a reference. According to the correlation between blood temperature changes, blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor and the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module of the cryoablation device. The control module of the cryoablation device calculates the flow state of blood in the blood vessel based on the temperature signal and displays it to the human-computer interaction module of the cryoablation device, thereby assisting in judging the effect of blood flow.

9. The coronary cryocatheter according to claim 1, characterized in that: The blood flow monitoring mechanism (5) is configured as an optical fiber sensor. The optical fiber sensor (508) component used by the blood flow monitoring mechanism (5) includes a helium-neon laser, a Bragg box, a beam splitter, a photodiode, a spectrum analyzer, a control module located inside the cryoablation device, and a single-mode optical fiber (506) and an optical fiber probe (510) located on the surface of the cryoballoon (14); the blood flow monitoring mechanism (5) is configured with a third temperature sensor (504) and a third temperature sensor (505) for auxiliary monitoring; the optical fiber sensor (508) utilizes the principle of the Doppler effect; the optical fiber sensor (508) has an outer diameter of several tens of μm, is disposed at the top position of the cryoballoon (14), and is inserted into the blood vessel along with the balloon during the operation; The optical fiber sensor (508) measures a light beam which enters the blood flow to be measured through an optical fiber probe (510), is scattered by red blood cells inside the blood vessel (28), and a portion of the light returns along the original path to obtain a Doppler frequency shift signal f+Δf, and a portion of the light enters a Bragg box (frequency shifter) with a driving frequency of f1=40MHz to obtain a reference light signal with a frequency of f-f1; the optical fiber sensor (508) transmits the obtained light signal to the control module of the cryoablation device through a single-mode optical fiber (506); the control module of the cryoablation device mixes the reference light signal with the Doppler frequency shift signal through a photodiode inside the cryoablation device, and converts the light signal into a photocurrent and sends it to a spectrum analyzer to obtain a Doppler frequency shift spectrum (velocity spectrum) corresponding to the blood flow velocity; based on the velocity spectrum, the refractive index n of the blood, the angle θ between the optical fiber axis and the blood vessel axis, and the laser wavelength λ, the blood flow velocity v in the blood vessel is calculated according to formula (1-1), and the blood flow state is displayed to the human-computer interaction module of the cryoablation device: The blood flow velocity v measured by the blood flow monitoring mechanism (5) is correlated with the flow state of the blood. Specifically, data information is extracted for the induced electrical signals corresponding to different dynamic pressure values ​​generated by different blocked leaks, and blood flow data corresponding to the electrical signals corresponding to the different dynamic pressure values ​​are obtained based on the extracted data information, so as to judge the size of the blocked leak; during the cryoablation process, the catheter enters the human body, when there is no blood flow, the blood flow velocity v=0, and the blood dynamic pressure Pdynamic=0 at this time, indicating that there is no blood flow at this time and the blood flow is well blocked; when the blood flow is not well blocked, the blood flows, v>0, the blood dynamic pressure Pdynamic>0, and there is blood flow blockage at the blood flow detection mechanism, that is, the pressure here increases, and the blood flow detection mechanism can feedback relevant information according to the needs of the operator; The third temperature sensor (504) probe configured by the blood flow monitoring mechanism (5) is fixed on the outer surface of the distal end of the cryoballoon (14), and the fourth temperature sensor (505) probe is fixed on the outer surface position of the cryoballoon (14) proximal to the third temperature sensor (504); the third temperature sensor (504, the fourth temperature sensor (505) are inserted into the blood vessel together with the cryoballoon catheter during the operation; the arrangement of the third temperature sensor (504) and the fourth temperature sensor (505) is based on the use of heat transfer as a reference basis, according to the correlation between blood temperature change and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor, the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module inside the cryoablation device, the cryoablation device control module calculates the flow state of blood in the blood vessel according to the temperature signal, and displays it to the human-computer interaction module, so as to assist in judging the flow state of blood during the operation; The temperature changes of the third temperature sensor (504) and the fourth temperature sensor (505) are correlated with the flow state of the blood, specifically: During the cryoablation process, the catheter enters the human body. When the blood flow is well blocked, when there is no blood flow, an ice ball is formed on the balloon surface. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, an ice ball is formed on the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the cryoballoon in the blood vessel determines the flow rate of the blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. The third temperature sensor (504) and the fourth temperature sensor (505) can assist in judging the blood flow dynamics according to the different time consumption under the same temperature change value.

10. The coronary cryocatheter according to claim 1, characterized in that: The blood flow monitoring mechanism (5) is a turbine speed sensor; The turbine speed sensor (512) assembly used in the blood flow monitoring mechanism (5) includes a tachometer located inside the cryoablation device, a signal conversion module, a control module, a turbine (513) located at the distal end of the cryoballoon, blades (514), a signal generator (515), and a signal lead (506); the turbine (513) is arranged at the distal end of the cryoballoon (14); blood or other fluid flowing through the blood vessel (28) causes the blades (514) of the turbine (513) to rotate; the turbine (5 13) is mechanically coupled to a signal generator (515) that generates a signal indicative of a rotational speed of the turbine (513), the rotational speed being at least partially dependent on a speed of a fluid flowing through the blood vessel (28); a tachometer within the cryoablation device that determines a blood flow state within the blood vessel based on the rotational speed of the turbine (513); in some cases, the blades (514) are collapsible to reduce a diameter of the turbine (513) to facilitate insertion of the cryoballoon (14) into the blood vessel (28); a turbine (513) proximate the distal end of the cryoballoon (14) and comprising at least one blade (514), the at least one blade (514) being configured to rotate relative to the cryoballoon (14) in response to a fluid flow through the blood vessel and at a rotational speed that depends at least in part on the speed of the fluid flow through the blood vessel; a signal generator (515) being mechanically coupled to the turbine (513) and configured to generate a rotational speed signal indicative of the at least one blade (514); and a signal lead (506) configured to transmit a rotational speed signal indicative of the at least one blade (514), the signal lead (506) being connected to the signal generator (515) and extending along the cryoballoon (14) and the catheter (2); The signal generator (515) comprises a Hall effect sensor, a magnet and a coil, wherein the magnet is configured to rotate relative to the coil of the signal generator (515) in response to the rotation of the at least one blade (514), wherein the magnet is configured to rotate relative to the Hall effect sensor of the signal generator (515) in response to the rotation of the at least one blade (514) and generate an electric current / voltage signal; the signal generator (515) is electrically connected to a control module of the cryoablation device via a signal lead (506), and the control module converts the electric current / voltage signal into a blood flow velocity v and displays it to a human-computer interaction module; The blood flow velocity v measured by the blood flow monitoring mechanism (5) is correlated with the flow state of the blood, specifically: Data information is extracted from the induced electrical signals corresponding to different dynamic pressure values ​​generated by different blocked leaks, and blood flow data corresponding to the electrical signals corresponding to different dynamic pressure values ​​are obtained based on the extracted data information, so as to judge the size of the blocked leak; during the cryoablation process, the catheter enters the human body, when there is no blood flow, the blood flow rate v=0, and the blood dynamic pressure Pdynamic=0 at this time, indicating that there is no blood flow at this time and the blood flow is well blocked; when the blood flow is not well blocked, the blood flows, v>0, the blood dynamic pressure Pdynamic>0, and there is blood flow blockage at the blood flow detection mechanism, that is, the pressure increases here; The third temperature sensor (504) probe configured by the blood flow monitoring mechanism (5) is arranged on the outer surface of the distal end (11) of the ablation mechanism, and the fourth temperature sensor (505) probe is fixed at the apex position of the front end face of the cryoballoon (14). The third temperature sensor (504) and the fourth temperature sensor (505) are inserted into the blood vessel together with the catheter during the operation; the arrangement of the third temperature sensor (504) and the fourth temperature sensor (505) is based on the use of heat transfer as a reference basis, according to the correlation between blood temperature change and blood flow and time t, by measuring the temperature change difference ΔT before and after the temperature sensor, the temperature change time t, the signal collected by the temperature sensor is converted into an electrical signal and input into the control module of the cryoablation device, the control module calculates the flow state of blood in the blood vessel according to the temperature signal, and displays it to the human-computer interaction module, so as to assist in judging the balloon blocking effect and enhance the reliability of the application of a cryoablation system for detecting blood flow state; The temperature changes of the third temperature sensor (504) and the fourth temperature sensor (505) are correlated with the flow state of the blood, specifically: During the cryoablation process, the catheter enters the human body. When the blood flow is well blocked, when there is no blood flow, an ice ball is formed on the balloon surface. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t1; when there is blood flow, an ice ball is formed on the balloon. According to the heat transfer, the temperature change value before and after the sensor is ΔT, and the temperature change time is t2; the blocking state of the cryoballoon in the blood vessel determines the flow rate of the blood in the blood vessel, and also determines the different temperature change times t corresponding to the same temperature change ΔT before and after the sensor. The third temperature sensor (504) and the fourth temperature sensor (505) can assist in judging the blood flow dynamics according to the different time consumption under the same temperature change value.

11. The coronary cryocatheter according to claim 1, characterized in that: The Y-shaped valve (43) includes a liquid channel (431), an instrument channel (432), and an instrument channel seal (433), and the Y-shaped valve (43) is connected to the guidewire cavity (15). Heparin saline or contrast agent can be delivered to the distal end (11) of the ablation mechanism through the liquid channel (431) and the guidewire cavity (15) for flushing and exhausting the catheter and performing angiography; the guidewire is delivered to the distal end (11) of the ablation mechanism through the instrument channel (432) and the guidewire cavity (15) for guiding and supporting the catheter during the operation. During the process of flushing and exhausting the catheter, the instrument channel seal (433) can be tightened to exhaust the gas between the Y-shaped valve (43) and the distal end (11) of the ablation mechanism; thereafter, the instrument channel seal (433) can be loosened to exhaust the gas at the end of the Y-shaped valve (43); the instrument channel seal (433) is a press-type or knob-type structure.

12. The coronary cryocatheter according to claim 5, characterized in that: The distance between the distal end of the bending adjustment hole (21) and the distal end of the outer tube (2) is substantially the same, and the distance between the proximal end of the bending adjustment hole (21) and the proximal end of the outer tube (2) is certain; the distal end of the bending adjustment wire (22) is fixed to the distal end of the outer tube (2), and the proximal end of the bending adjustment wire (22) extends from the proximal end of the bending adjustment hole (21) and is fixed to the bending adjustment control member (31); the bending adjustment wires (22) on both sides of the outer tube (2) are respectively fixed to both sides of the bending adjustment control member (31); when the bending adjustment control member (31) is moved to one side, the bending adjustment wire (22) on one side of the outer tube (2) is straightened, thereby causing the outer tube (2) to bend to one side; when the bending adjustment control member (31) is moved to the other side, the bending adjustment wire (22) on the other side of the outer tube (2) is straightened, thereby causing the outer tube (2) to bend to the other side, thereby realizing the double bending function of the outer tube (2). A sealing component (23) is provided in the hollow portion of the outer tube (2), and the sealing component (23) contains a guide wire cavity (15), an air inlet pipe (16), an air return pipe (17) and a sensor signal cable (24); the distal end of the sealing component (23) is fixed to the proximal end (19) of the ablation mechanism, and the proximal end of the sealing component (23) is fixed to the gas pipeline connector (41). The distal end of the outer tube (2) is fixed to the proximal end (19) of the ablation mechanism, and the proximal end of the outer tube (2) is fixed to the operating mechanism (3); a vacuum tube (18) is provided between the sealing component (23) and the tube body (25); the cold air generated by the device acts on the balloon (14) through the air inlet pipe (16), and is discharged from the balloon (14) through the air return pipe (17) and recovered to the device; the sealing component (23) ensures that the gas or liquid in the guide wire cavity (15), the air inlet pipe (16) and the air return pipe (17) will not leak into the balloon (14) through processes such as hot melting or welding; the vacuum tube (18) realizes the vacuum degree between the sealing component (23) and the tube body (25) by means of gas back-drawing at the device end; the second pressure sensor (181) detects the gas pressure value at the vacuum tube (18) in real time to determine whether the sealing component (23) is damaged and causes gas leakage, and issues an alarm prompt.

13. The coronary cryocatheter according to claim 1, characterized in that: The signal lines corresponding to the first pressure sensor (143), the first temperature sensor (144), the second temperature sensor (162), the third pressure sensor (171) and the second pressure sensor (181) are collectively connected to a sensor signal cable (24). The sensor signal cable (24) passes through the outer tube (2) and the operating mechanism (3) respectively, and is finally integrated into a sensor signal connector (42) for providing the measured pressure information and temperature information to the device, so as to realize closed-loop control of the cold air supply and the cold air flow rate.

14. The coronary cryocatheter according to claim 2, characterized in that: The thermal conductive coating (141) is uniformly covered on the surface of the balloon (14) in a woven manner in both horizontal and vertical directions; alternatively, the thermal conductive coating (141) can also uniformly and completely cover the surface of the balloon (14); alternatively, the thermal conductive coating (141) can also uniformly cover the surface of the balloon (14) in a horizontal or vertical manner at a certain interval.

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