Vascular intervention catheter for brain protection, intravascular cooling system and cooling method

Abstract

The invention provides a vascular intervention catheter for brain protection, an intravascular cooling system and a cooling method. The vascular intervention catheter comprises a catheter seat, a catheter body, an injection extension tube and a vacuum extension tube, one end of the tube body is connected with one end of the conduit seat; the injection extension tube and the vacuum extension tube are arranged on the conduit seat; a main intervention pipe, a cooling medium injection pipe and a vacuum cavity are arranged in the pipe body; the main intervention tube extends in the axial direction of the tube body, and the vacuum cavity is formed between the outer side wall of the main intervention tube and the inner side wall of the tube body; the vacuum cavity is communicated with the vacuum extension pipe, and the injection extension pipe is communicated with the vacuum cavity through the cooling medium injection pipe. The device can be used for protecting cranial nerves of a stroke patient, and has the advantages of high cooling efficiency, simplicity in operation, safety, reliability and the like.

Description

Technical Field

[0001] The present invention relates to the field of medical device technology, and in particular, to a vascular intervention catheter, an intravascular cooling system and a cooling method for brain protection, and in particular to an intravascular catheter, a selective intravascular cooling system and a selective brain cooling method for sub-hypothermia brain protection. Background Art

[0002] Mild hypothermia therapy is an effective neuroprotective measure that can be used to treat a variety of neurological diseases such as stroke and craniocerebral injury. It has been confirmed in animal experiments and clinical trials that it has a protective effect on ischemic brain damage. Existing mild hypothermia treatment methods mainly include whole-body cooling and selective brain cooling. Whole-body cooling is achieved through cooling of the body surface, body cavity, and blood. There are problems such as slow cooling speed and easy to cause chills and other adverse reactions. In order to avoid the adverse reactions of whole-body cooling, researchers have developed a variety of selective cooling catheters.

[0003] The cooling blood perfusion catheter, such as the TwinFlo catheter, adopts a double-lumen design, extracts blood from the aorta and cools it in vitro, and then perfuses the cooled blood into the carotid artery to achieve selective brain cooling. This method can quickly achieve deep brain cooling, but it requires the establishment of an extracorporeal circulation system, which is complicated to operate, and during the process of extracorporeal circulation cooling of autologous blood, blood cells are prone to lysis due to sudden changes in temperature and interference from a mechanical pump, and the cooled blood is easily heated by the surrounding environment during the process of being input back into the blood vessel. The patent document with publication number US8109897 discloses a selective cooling catheter, which is a double-lumen catheter and is provided with a blood flow blocking device at the distal end. After blocking the blood flow, body temperature blood enters from the distal end of the first lumen and is cooled by the cooling device at the proximal end of the catheter, and then enters from the proximal end of the second lumen and is injected back into the blood vessel from the distal end of the second lumen. The patent document with publication number US8353942 discloses a selective cooling catheter comprising three lumens, wherein the main lumen is used to inject cooling blood into the blood vessel, and the two side lumens are used to circulate cooling liquid, so that the cooling blood is kept at a low temperature during the input process.

[0004] The cooling saline perfusion catheter achieves local cooling by perfusing cold saline. For example, the Khione catheter wall is made of insulating material to reduce the degree to which the saline is heated by the surrounding blood during the process of being injected from the proximal end of the catheter to the distal end. This method is relatively simple to operate, but directly injecting cold saline into the blood vessels may aggravate cerebral edema, and the saline is easily heated by the surrounding environment during transportation.

[0005] The closed heat exchange catheter achieves cooling by delivering coolant through a closed circulation system. The patent document with publication number CN220193319 discloses a sub-hypothermic central venous balloon catheter, which has a main cavity and two side cavities. The coolant enters the balloon at the distal end of the catheter through one of the side cavities and flows back to the proximal end of the catheter through the other side cavity. Based on a similar cooling principle, the patent document with publication number CN115212027 discloses a low-temperature brain protection catheter comprising multiple internal heat exchange balloons. This type of catheter has a complex structure, and the balloons may affect blood flow. The patent document with publication number US20220226150 discloses a cooling catheter, along which a cavity for circulating cooling medium is arranged. The coolant contains a liquid and a solid with a melting point below 37°C mixed in the liquid. The heat of the blood flow around the catheter is taken away by melting the solid.

[0006] Therefore, it is urgent to develop an efficient, simple and safe selective brain cooling device. An ideal cooling catheter should have the following characteristics: 1) It can quickly and effectively achieve local cooling; 2) Avoid injecting extra fluid into the blood vessel; 3) It has a simple and reliable structure; 4) It has little effect on blood flow. The present invention provides a new intravascular cooling catheter based on the phase change cooling principle, which can overcome the shortcomings of the existing technology. Summary of the invention

[0007] In view of the defects in the prior art, an object of the present invention is to provide a vascular intervention catheter, an intravascular cooling system and a cooling method for brain protection.

[0008] A vascular intervention catheter for brain protection provided by the present invention comprises: a catheter seat, a tube body, an injection epitaxial tube and a vacuum epitaxial tube;

[0009] One end of the tube body is connected to one end of the catheter seat, and the injection epitaxial tube and the vacuum epitaxial tube are arranged on the catheter seat;

[0010] The tube body is provided with a main intervention tube, a cooling medium injection tube and a vacuum chamber; the main intervention tube extends along the axial direction of the tube body, and the vacuum chamber is formed between the outer side wall of the main intervention tube and the inner side wall of the tube body;

[0011] The vacuum chamber is in communication with the vacuum epitaxial tube, and the injection epitaxial tube is in communication with the vacuum chamber through the cooling medium injection tube;

[0012] The cooling medium is injected from outside the body through the injection extension tube, transported to the vacuum chamber through the cooling medium injection tube, spontaneously changes phase in the vacuum chamber, and uses the phase change to take away the blood flow heat around the catheter.

[0013] Preferably, the two ends of the tube body are respectively a proximal end and a distal end;

[0014] The proximal end is connected to the catheter seat; one end of the cooling medium injection tube is connected to the injection extension tube, and the other end of the cooling medium injection tube is located in the vacuum chamber at the distal end;

[0015] The cooling medium is injected from outside the body through the injection extension tube and transported to the vacuum chamber located at the distal end through the cooling medium injection tube.

[0016] Preferably, the main intervention tube extends into the catheter seat;

[0017] An injection buffer cavity is provided in the catheter seat, and the injection buffer cavity is formed between the outer side wall of the main intervention tube and the inner side wall of the catheter seat;

[0018] The injection epitaxial tube is communicated with the injection buffer chamber, and the injection buffer chamber is communicated with the vacuum chamber through the cooling medium injection tube.

[0019] Preferably, the distal end is provided with a distal sealing ring, and the distal sealing ring is located between the outer side wall of the main intervention tube and the inner side wall of the tube body;

[0020] A vacuum sealing ring is provided in the catheter seat at a position adjacent to the vacuum extension tube, and the vacuum sealing ring is located between the outer side wall of the main intervention tube and the inner side wall of the catheter seat;

[0021] An injection sealing ring is provided in the catheter seat at a position adjacent to the injection extension tube, and the sealing ring is located between the outer side wall of the main intervention tube and the inner side wall of the catheter seat;

[0022] The cavity space between the distal sealing ring and the vacuum sealing ring is the vacuum cavity, and the cavity space between the vacuum sealing ring and the injection sealing ring is the injection buffer cavity.

[0023] Preferably, the vascular intervention catheter further comprises: a main lumen extension tube;

[0024] The main cavity extension tube is connected to the other end of the catheter seat.

[0025] Preferably, the size of the main interventional cavity is suitable for accommodating a guidewire, a microcatheter and an intermediate catheter;

[0026] And / or, the distal sealing ring, the vacuum sealing ring and the injection sealing ring are made of one or more materials selected from the group consisting of silicone, polyurethane, polytetrafluoroethylene and adhesive;

[0027] And / or, the cooling medium injection pipe is provided with one or more injection holes on the pipe body at the distal end; the distal end is provided with a developing ring, and the developing ring is arranged at the axial position of the injection hole;

[0028] And / or, the outer surface of the tube body of the cooling medium injection tube at the distal position is provided with a hydrophilic coating; the hydrophilic coating is one or more of polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide materials.

[0029] Preferably, the cooling medium comprises physiological saline; the pressure maintained in the vacuum chamber is capable of reducing the boiling point of the cooling medium to below the physiological temperature;

[0030] And / or, the cooling medium injection pipe is made of PEEK;

[0031] And / or, the tube body is provided with a temperature sensor located at the distal end, and the temperature sensor is used to monitor the local temperature;

[0032] And / or, an anticoagulant layer is provided on the outer surface of the tube body; the anticoagulant layer is one of heparin, citrate, and hydrogel;

[0033] And / or, the inner and outer surfaces of the distal end are provided with a texture structure, and the texture structure is used to increase the surface area to improve the heat transfer efficiency.

[0034] Preferably, the catheter seat is provided with a first externally threaded Luer connector and a first internally threaded Luer connector;

[0035] The injection epitaxial tube and the vacuum epitaxial tube are provided with a second internally threaded Luer connector for connecting to the first externally threaded Luer connector;

[0036] The main cavity extension tube is provided with a second externally threaded Luer connector for connecting to the first internally threaded Luer connector.

[0037] The present invention also provides an intravascular cooling system for brain protection, comprising the above-mentioned vascular intervention catheter for brain protection;

[0038] It also includes: a cooling medium conveying device and a negative pressure device;

[0039] The cooling medium conveying device is connected to the cooling medium injection pipe through the injection extension pipe;

[0040] The negative pressure device is connected to the vacuum chamber through the vacuum epitaxial tube;

[0041] The cooling medium injection tube and the vacuum chamber are fluidly connected at the distal end of the tube body;

[0042] The main intervention tube is fluidically isolated from the cooling medium injection tube and the vacuum chamber;

[0043] The cooling medium injection tube and the vacuum chamber are isolated from the blood fluid outside the catheter.

[0044] The present invention also provides a cooling method for brain protection, using the above intravascular cooling system for brain protection, specifically comprising the following steps:

[0045] Step S1: advancing the vascular intervention catheter to the designated cerebral artery;

[0046] Step S2: connecting the vacuum extension tube on the catheter seat to the negative pressure device, so that the vacuum cavity in the catheter is connected to the negative pressure device, and forming a low-pressure space at the distal end of the catheter;

[0047] Step S3: connecting the injection extension tube on the catheter seat to the cooling medium delivery device, so that the cooling medium injection tube is in communication with the cooling medium delivery device;

[0048] Step S4: injecting cooling medium into the vacuum chamber through the cooling medium injection pipe, inducing the cooling medium to gasify under low pressure conditions, and generating local cooling.

[0049] Compared with the prior art, the present invention has the following beneficial effects:

[0050] 1. The present invention adopts a vacuum chamber structure in combination with a cooling medium injection tube design, and utilizes a low-pressure environment to cause the cooling medium to spontaneously vaporize at the distal end of the catheter and absorb heat from the blood flow around the catheter, thereby avoiding the risk of aggravating cerebral edema caused by directly injecting cooling saline into the blood vessels with a traditional cooling catheter or the risk of blood cell lysis caused by injecting cooling blood.

[0051] 2. The cooling medium of the present invention is transported through the cooling intervention tube and enters the vacuum chamber only at the distal end of the catheter. Therefore, the phase change cooling of the catheter of the present invention only occurs at the distal end of the catheter, avoiding the problem of cooling saline or blood in traditional cooling catheters being heated by the surrounding environment during the transportation process from the proximal end to the distal end of the catheter. It has higher cooling efficiency and also reduces the impact on other tissues to achieve precise local cooling.

[0052] 3. The main intervention tube, vacuum cavity and cooling medium injection tube in the catheter of the present invention are isolated from each other by a sealing ring, which avoids the leakage of cooling medium into the blood vessels and the connection between the blood vessels and the vacuum environment. At the same time, the main intervention tube can be used for the delivery of guide wires and catheters, which does not affect the progress of existing vascular interventional surgery. It is expected that the catheter of the present invention can be delivered to the distal cerebral blood vessels to achieve more localized selective hypothermic brain protection. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Other features, objects and advantages of the present invention will become more apparent from the detailed description of non-limiting embodiments made with reference to the following drawings:

[0054] Figure 1It is a schematic structural diagram of the vascular intervention catheter of the present invention;

[0055] Figure 2 is a radial cross-sectional view of the vascular intervention catheter of the present invention at the distal end;

[0056] Figure 3 The axial section of the vascular intervention catheter of the present invention is Figure 1 ;

[0057] Figure 4 The axial section of the vascular intervention catheter of the present invention is Figure 2 ;

[0058] Figure 5 for Figure 4 Partial axial section of section A in the middle;

[0059] Figure 6 for Figure 4 Partial axial section of the middle B section;

[0060] Figure 7 for Figure 4 Partial axial section of the middle C section;

[0061] Figure 8 for Figure 4 Partial axial section of the middle D section;

[0062] Fig. 9 for Figure 4 Partial axial section of the middle E section;

[0063] Fig.10 It is a schematic diagram of the cooling working principle of the vascular intervention catheter of the present invention;

[0064] Fig.11 It is a schematic diagram of the cooling calculation results of the vascular intervention catheter of the present invention.

[0065] The figure shows:

[0066] 1. Catheter seat; 2. Tube body; 3. Injection epitaxial tube; 4. Vacuum epitaxial tube; 5. Main cavity epitaxial tube; 21. Main intervention tube; 22. Cooling medium injection tube; 23. Distal sealing ring; 24. Vacuum sealing ring; 25. Injection sealing ring; 31. Injection buffer cavity; 41. Vacuum cavity; 201. Proximal end of tube body; 202. Distal end of tube body; 211. Main intervention cavity; 221. Injection hole. DETAILED DESCRIPTION

[0067] The present invention is described in detail below in conjunction with specific embodiments. The following embodiments will help those skilled in the art to further understand the present invention, but are not intended to limit the present invention in any form. It should be noted that, for those of ordinary skill in the art, several changes and improvements can also be made without departing from the concept of the present invention. These all belong to the protection scope of the present invention.

[0068] Embodiment 1:

[0069] like Figure 1-11 As shown, this embodiment provides a vascular intervention catheter for brain protection, including: a catheter seat 1, a tube body 2, an injection epitaxial tube 3 and a vacuum epitaxial tube 4; one end of the tube body 2 is connected to one end of the catheter seat 1, and the injection epitaxial tube 3 and the vacuum epitaxial tube 4 are arranged on the catheter seat 1; the tube body 2 is provided with a main intervention tube 21, a cooling medium injection tube 22 and a vacuum cavity 41; the main intervention tube 21 extends along the axial direction of the tube body 2, and the vacuum cavity 41 is formed between the outer wall of the main intervention tube 21 and the inner wall of the tube body 2; the vacuum cavity 41 is connected to the vacuum epitaxial tube 4, and the injection epitaxial tube 3 is connected to the vacuum cavity 41 through the cooling medium injection tube 22; the cooling medium is injected from the outside of the body through the injection epitaxial tube 3, and is transported to the vacuum cavity 41 through the cooling medium injection tube 22, and spontaneously changes phase in the vacuum cavity 41, and uses the phase change to take away the blood flow heat around the catheter. The vascular intervention catheter also includes: a main cavity epitaxial tube 5; the main cavity epitaxial tube 5 is connected to the other end of the catheter seat 1.

[0070] The catheter seat 1 is provided with a first externally threaded Luer connector and a first internally threaded Luer connector; the injection extension tube 3 and the vacuum extension tube 4 are provided with a second internally threaded Luer connector for connecting to the first externally threaded Luer connector; the main cavity extension tube 5 is provided with a second externally threaded Luer connector for connecting to the first internally threaded Luer connector.

[0071] The size of the main intervention cavity 211 is suitable for accommodating a guide wire, a microcatheter, and an intermediate catheter. The cooling medium injection tube 22 is provided with one or more injection holes 221 on the tube body at the distal end 202; the distal end 202 is provided with a developing ring, which is arranged at the axial position of the injection hole 221. The cooling medium includes physiological saline; the pressure maintained in the vacuum cavity 41 can reduce the boiling point of the cooling medium to below the physiological temperature. The material of the cooling medium injection tube 22 is PEEK.

[0072] The two ends of the tube body 2 are respectively a proximal end 201 and a distal end 202; the proximal end 201 is connected to the catheter seat 1; one end of the cooling medium injection tube 22 is connected to the injection extension tube 3, and the other end of the cooling medium injection tube 22 is located in the vacuum chamber 41 at the distal end 202; the cooling medium is injected from the body through the injection extension tube 3, and is transported to the vacuum chamber 41 at the distal end 202 through the cooling medium injection tube 22. The main intervention tube 21 extends into the catheter seat 1; the catheter seat 1 is provided with an injection buffer chamber 31, which is formed between the outer wall of the main intervention tube 21 and the inner wall of the catheter seat 1; the injection extension tube 3 is connected to the injection buffer chamber 31, and the injection buffer chamber 31 is connected to the vacuum chamber 41 through the cooling medium injection tube 22. The outer surface of the tube body of the cooling medium injection tube 22 at the distal end 202 is provided with a hydrophilic coating; the hydrophilic coating is one or more of polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethyleneimine, polyacrylamide, polyacrylic acid or polysaccharide materials.

[0073] The distal end 202 is provided with a distal sealing ring 23, which is located between the outer wall of the main intervention tube 21 and the inner wall of the tube body 2; a vacuum sealing ring 24 is provided at a position adjacent to the vacuum extension tube 4 in the catheter seat 1, which is located between the outer wall of the main intervention tube 21 and the inner wall of the catheter seat 1; an injection sealing ring 25 is provided at a position adjacent to the injection extension tube 3 in the catheter seat 1, which is located between the outer wall of the main intervention tube 21 and the inner wall of the catheter seat 1; the cavity space between the distal sealing ring 23 and the vacuum sealing ring 24 is a vacuum cavity 41, and the cavity space between the vacuum sealing ring 24 and the injection sealing ring 25 is an injection buffer cavity 31. The materials of the distal sealing ring 23, the vacuum sealing ring 24 and the injection sealing ring 25 are one or more of silicone, polyurethane, polytetrafluoroethylene, and adhesive;

[0074] The tube body 2 is provided with a temperature sensor at the distal end 202, and the temperature sensor is used to monitor the local temperature. The outer surface of the tube body 2 is provided with an anticoagulant layer; the anticoagulant layer is one of heparin, citrate, and hydrogel. The inner and outer surfaces of the distal end 202 are provided with a texture structure, and the texture structure is used to increase the surface area to improve the heat transfer efficiency.

[0075] The present embodiment also provides an intravascular cooling system for brain protection, comprising the above-mentioned vascular intervention catheter for brain protection; and also comprising: a cooling medium delivery device and a negative pressure device; the cooling medium delivery device is connected to the cooling medium injection tube 22 via the injection extension tube 3; the negative pressure device is connected to the vacuum chamber 41 via the vacuum extension tube 4; the cooling medium injection tube 22 and the vacuum chamber 41 are fluidically connected at the distal end 202 of the tube body 2; the main intervention tube 21 is fluidically isolated from the cooling medium injection tube 22 and the vacuum chamber 41; the cooling medium injection tube 22 and the vacuum chamber 41 are fluidically isolated from the blood outside the catheter.

[0076] This embodiment also provides a cooling method for brain protection, using the above-mentioned intravascular cooling system for brain protection, and specifically comprising the following steps:

[0077] Step S1: advancing the vascular intervention catheter to the designated cerebral artery;

[0078] Step S2: connecting the vacuum extension tube 4 on the catheter seat 1 to the negative pressure device, so that the vacuum cavity 41 in the catheter 2 is connected to the negative pressure device, and a low-pressure space is formed at the distal end 202 of the catheter 2;

[0079] Step S3: Connect the injection extension tube 3 on the catheter seat 1 to the cooling medium delivery device, so that the cooling medium injection tube 22 is connected to the cooling medium delivery device;

[0080] Step S4: injecting the cooling medium into the vacuum chamber 41 through the cooling medium injection pipe 22, inducing the cooling medium to gasify under low pressure conditions, thereby generating local cooling.

[0081] This embodiment provides an intravascular sub-hypothermic brain protection catheter using phase change cooling, comprising a catheter seat and a tube body mounted on the catheter seat, an injection epitaxial tube, a vacuum epitaxial tube, a main cavity epitaxial tube, a sealing ring distributed along the axial direction of the tube body, and a vacuum cavity and an injection buffer cavity formed by the isolation of the sealing ring, wherein an axially extending main intervention tube and one or more injection tubes are arranged inside the tube body. The main cavity epitaxial tube is used to transport a guide wire, a microcatheter or other interventional instruments.

[0082] When performing sub-hypothermic brain protection, an extracorporeal vacuum source is connected to the catheter through a vacuum epitaxial tube, a vacuum cavity is created in the catheter, and a cooling medium is injected from the outside of the body through the injection epitaxial tube, transported to the distal end of the catheter through the injection tube, and spontaneously changes phase in the vacuum cavity. The phase change is used to take away the heat of the blood flow around the catheter, and the blood flow temperature around the catheter is reduced, thereby achieving the purpose of selective brain cooling. The catheter can avoid directly injecting cooling liquid into the blood, reducing the risk of cerebral edema. This embodiment can be used to protect the cranial nerves of stroke patients, and has the advantages of high cooling efficiency, simple operation, safety and reliability.

[0083] Embodiment 2:

[0084] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0085] This embodiment provides a vascular intervention catheter for sub-hypothermic brain protection, comprising: a catheter seat 1 and a tube body 2 with a proximal end and a distal end, an injection epitaxial tube 3, a vacuum epitaxial tube 4, and a main cavity epitaxial tube 5 installed on the catheter seat 1. The injection epitaxial tube 3, the vacuum epitaxial tube 4, and the main cavity epitaxial tube 5 are all arranged on one side of the catheter seat 1, and the proximal end 201 of the tube body 2 is connected to the other side of the catheter seat 1. The temperature range of sub-hypothermia is 28-35°C.

[0086] The tube body 2 is internally provided with an axially extending main intervention tube 21; a vacuum chamber 41 which is isolated from the main intervention tube 21 and the blood fluid outside the catheter and is fluidly connected to the vacuum extension tube 4; and one or more cooling medium injection tubes 22 which are isolated from the main intervention tube 21 and the blood fluid outside the catheter, fluidly connected to the vacuum chamber 41, and fluidly connected to the injection extension tube 3.

[0087] The vascular intervention catheter further includes a distal sealing ring 23 located at the distal end 202 of the tube body, a vacuum sealing ring 24 located inside the catheter seat 1 and at the proximal end of the vacuum extension tube 4, and an injection sealing ring 25 located inside the catheter seat 1 and at the proximal end of the injection extension tube 3. The distal sealing ring 23 and the vacuum sealing ring 24 form a vacuum cavity 41 in the catheter cavity, which is fluidically connected to the vacuum extension tube 4 at the distal end 202 of the tube body and fluidically isolated from the main intervention cavity 211 inside the main intervention tube 21. The vacuum sealing ring 24 and the injection sealing ring 25 form an injection buffer cavity 31 in the catheter seat 1, which is fluidically connected to the injection extension tube 3 and fluidically isolated from the main intervention cavity 21.

[0088] The main intervention lumen 211 is sized to accommodate a guidewire, a microcatheter, and an intermediate catheter.

[0089] The materials of the distal sealing ring 23, the vacuum sealing ring 24 and the injection sealing ring 25 are one or more of silicone, polyurethane, polytetrafluoroethylene and adhesive.

[0090] The distal end of the cooling medium injection pipe 22 includes one or more injection holes 221 .

[0091] The distal end of the cooling medium injection tube 22 is provided with a hydrophilic coating, which is one or more of polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide materials.

[0092] The cooling medium includes physiological saline. The vacuum chamber 41 maintains sufficient pressure to reduce the boiling point of the cooling medium to below physiological temperature.

[0093] The cooling medium injection pipe 22 is made of PEEK.

[0094] The tube body 2 further comprises a temperature sensor located at the distal end 202 of the tube body for monitoring the local temperature.

[0095] The tube body 2 is provided with an anticoagulant layer on its surface, wherein the anticoagulant layer is one of heparin, citrate and hydrogel.

[0096] The tube body distal end 202 is provided with a developing ring. The tube body 2 is provided with a developing ring at the axial position of the injection hole (221).

[0097] The inner and outer surfaces of the distal end 202 of the tube body include textures and structures that increase the surface area to improve heat transfer efficiency.

[0098] The catheter seat 1 also includes an externally threaded Luer connector and an internally threaded Luer connector. The injection epitaxial tube 3, the vacuum epitaxial tube 4, and the main cavity epitaxial tube 5 are respectively provided with the externally threaded Luer connector and the internally threaded Luer connector.

[0099] This embodiment also provides a selective intravascular cooling system, comprising:

[0100] A multi-lumen catheter having a main intervention tube 21, a cooling medium injection tube 22 and a vacuum chamber 41;

[0101] a cooling medium delivery device connected to the cooling medium injection pipe 22;

[0102] A vacuum source connected to the vacuum chamber 41;

[0103] The cooling medium injection tube 22 and the vacuum chamber 41 are fluidically connected at the distal end 202 of the tube body;

[0104] The main intervention tube 21 is fluidically isolated from the cooling medium injection tube 22 and the vacuum chamber 41 .

[0105] The cooling medium injection tube 22 and the vacuum chamber 41 are isolated from the blood fluid outside the catheter.

[0106] The intravascular cooling system also includes a pressure sensor for monitoring the vacuum level.

[0107] The intravascular cooling system also includes a control mechanism for regulating the vacuum pressure and the flow rate of the cooling medium.

[0108] The intravascular cooling system also includes a temperature feedback control system.

[0109] This embodiment also provides a method for selective brain cooling, comprising:

[0110] Advance the intravascular catheter into the designated cerebral artery;

[0111] The vacuum chamber 41 in the catheter is connected to a negative pressure device to form a low-pressure space at the distal end of the catheter;

[0112] Injecting cooling medium into the vacuum chamber 41 through the cooling medium injection pipe 22;

[0113] Inducing the cooling medium to vaporize under low pressure conditions to produce local cooling;

[0114] The main intervention tube 21 is kept fluidically isolated from the vacuum chamber 41 and the cooling medium injection tube 22 .

[0115] Brain cooling methods also include monitoring local temperature.

[0116] The method of brain cooling also includes adjusting vacuum pressure and cooling medium injection flow based on temperature feedback.

[0117] The method of brain cooling also includes maintaining cooling for a predetermined treatment time.

[0118] Embodiment 3:

[0119] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0120] The purpose of this embodiment is to provide an intravascular sub-hypothermic brain protection catheter using phase change cooling to solve the problems existing in the prior art. To achieve this purpose, this embodiment adopts the following technical solutions:

[0121] The present embodiment provides a multi-lumen catheter for intravascular sub-hypothermic brain protection using phase change cooling, including a catheter seat and a tube body mounted on the catheter seat, an injection epitaxial tube, a vacuum epitaxial tube, and a main cavity epitaxial tube. The tube body is provided with an axially extending main intervention tube, a vacuum cavity isolated from the main intervention tube fluid and connected to the vacuum epitaxial tube fluid, and one or more cooling medium injection tubes isolated from the main intervention tube fluid and connected to the injection epitaxial tube fluid. The cooling medium injection tube is isolated from the vacuum cavity fluid at the proximal end of the catheter to prevent the cooling medium from being sucked into the vacuum epitaxial tube at the proximal end of the catheter. The cooling medium is injected into the vacuum cavity at the distal end of the catheter through the cooling medium injection tube, and the vacuum is used to reduce the boiling point of the cooling medium, so that the cooling medium undergoes a phase change and takes away heat from the surrounding environment, thereby achieving local cooling.

[0122] Furthermore, the fluid isolation of the main intervention tube, the vacuum cavity and the cooling medium injection tube is achieved by three sealing rings distributed along the axial direction of the tube body: a distal sealing ring located at the distal end of the tube body, a vacuum sealing ring located inside the catheter seat and at the proximal end of the vacuum extension tube, and an injection sealing ring located inside the catheter seat and at the proximal end of the injection extension tube. The distal sealing ring and the vacuum sealing ring form a vacuum cavity in the tube body, and the vacuum sealing ring and the injection sealing ring form an injection buffer cavity in the catheter seat.

[0123] Further, the outer diameter of the catheter is 0.09 to 0.13 inches, and the inner diameter of the main interventional tube is 0.04 to 0.10 inches, which is suitable for navigation to the internal carotid artery and beyond, and can be used to deliver guidewires, microcatheters or other interventional devices.

[0124] Furthermore, the distal sealing ring, vacuum sealing ring and injection sealing ring are made of one or more of silicone, polyurethane, polytetrafluoroethylene, and adhesive, which are used to ensure fluid isolation between the vacuum cavity and the main intervention tube and fluid isolation between the cooling medium injection tube and the main intervention tube.

[0125] Furthermore, the distal end of the cooling medium injection tube comprises a plurality of injection holes isolated from each other, which are used to increase the vaporization area of ​​the physiological saline solution and improve the efficiency of phase change heat absorption.

[0126] Furthermore, a hydrophilic coating is provided on the distal surface of the cooling medium injection tube to reduce the contact angle of the outer surface of the cooling medium injection tube, increase the vaporization area of ​​the cooling medium, and improve the efficiency of phase change heat absorption. The hydrophilic coating is one of polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide materials.

[0127] Furthermore, the cooling medium is sterile saline.

[0128] Furthermore, the vacuum chamber maintains a sufficiently low pressure to reduce the boiling point of the cooling medium to below physiological temperature. For example, when physiological saline is used, the vacuum chamber needs to maintain a pressure of less than 6 kPa.

[0129] Furthermore, the cooling medium injection tube is made of PEEK, which has excellent biocompatibility and excellent processing performance, and can be used to manufacture the cooling medium injection tube with an outer diameter less than 0.01 inches and to process redundant injection holes on the cooling medium injection tube.

[0130] Furthermore, the distal end of the tube body also includes a temperature sensor for temperature feedback control, which adjusts the vacuum chamber pressure and the cooling medium injection flow rate according to the current temperature and the preset temperature.

[0131] Furthermore, an anticoagulant layer is provided on the outer surface of the tube body to prevent the catheter from causing blood coagulation during the process of cooling the blood. The anticoagulant layer is one of heparin, citrate, and hydrogel.

[0132] Furthermore, a developing ring is provided at the distal end of the tube body for displaying the distal end position of the catheter of the present invention during the intervention process.

[0133] Furthermore, the tube body is provided with a developing ring at the proximal end of the injection hole, which is used to display the cooling area of ​​the catheter of the present invention during the intervention process.

[0134] Furthermore, the inner and outer surfaces of the distal end of the tube body include textures that increase the surface area, such as waves, array patterns, etc., which are used to increase the heat conduction area with the vacuum cavity and the blood outside the catheter, thereby improving the cooling efficiency.

[0135] Furthermore, the catheter seat also includes an externally threaded Luer connector and an internally threaded Luer connector, and the injection epitaxial tube, vacuum epitaxial tube, and main cavity epitaxial tube are respectively provided with the externally threaded Luer connector and the internally threaded Luer connector, which are used for quick connection with instrument interfaces such as syringes, vacuum pumps, saline pumps, and hemostatic valves.

[0136] Furthermore, the sub-hypothermic brain protection catheter is connected to the cooling medium reservoir and the vacuum source through a catheter seat to form a selective brain cooling system. A temperature sensor is installed at the distal end of the catheter to detect the temperature of the blood around the distal end of the catheter. According to the temperature, the system can adjust the injection flow of the cooling medium reservoir to the catheter and the pressure provided by the vacuum source to achieve the control of the cooling power and cooling temperature.

[0137] This embodiment adopts a vacuum chamber structure in conjunction with the design of a cooling medium injection tube, and utilizes a low-pressure environment to cause the cooling medium to spontaneously vaporize at the distal end of the catheter and absorb heat from the blood flow around the catheter, thereby avoiding the risk of aggravating cerebral edema caused by directly injecting cooling saline into the blood vessels with a traditional cooling catheter or the risk of blood cell lysis caused by injecting cooling blood.

[0138] In addition, since the cooling medium is transported through the cooling intervention tube and enters the vacuum chamber only at the distal end of the catheter, the phase change cooling of the catheter of the present invention only occurs at the distal end of the catheter, avoiding the problem of cooling saline or blood being heated by the surrounding environment during transportation from the proximal end to the distal end of the catheter in traditional cooling catheters. It has higher cooling efficiency and also reduces the impact on other tissues to achieve precise local cooling.

[0139] The main intervention tube, vacuum cavity and cooling medium injection tube in the catheter of this embodiment are isolated from each other by a sealing ring, which avoids the leakage of cooling medium into the blood vessels and the connection of blood vessels with the vacuum environment. At the same time, the main intervention tube can be used for the delivery of guide wires and catheters without affecting the progress of existing vascular interventional surgery. It is expected that the catheter of the present invention can be delivered to the distal cerebral blood vessels to achieve more localized selective hypothermic brain protection.

[0140] Embodiment 4:

[0141] Those skilled in the art may understand this embodiment as a more specific description of Embodiment 1.

[0142] The "proximal end" and "distal end" in this embodiment refer to the near and far end relative to the operator. When in use, the end close to the doctor or operator is the "proximal end", that is, the end where the catheter seat is located, and the end away from the doctor or operator is the "distal end", that is, the end where the cooling medium injection hole is located.

[0143] like Figure 1-11As shown, the multi-lumen interventional catheter of this embodiment includes a catheter seat 1, a tube body 2 installed on the distal end of the catheter seat 1, and an injection epitaxial tube 3, a vacuum epitaxial tube 4, and a main lumen epitaxial tube 5 installed on the proximal end of the catheter seat 1. The tube body 2 is provided with a main interventional tube 21 and one or more cooling medium injection tubes 22 extending axially from the proximal end 201 of the tube body to the distal end 202 of the tube body. The main lumen epitaxial tube 5 is fluidically connected to the main interventional tube 21 for conveying other interventional devices such as guide wires, microcatheters, stents, and releasing materials such as contrast agents, embolic agents, and coolants.

[0144] The space formed by the main intervention tube 21 in the tube body 2 and the outside of the cooling medium injection tube 22 is a vacuum chamber 41. The vacuum chamber 41 is fluidically connected to the vacuum extension tube 4, and a low-pressure environment is created in the vacuum chamber 41 by connecting a vacuum source outside the body. The injection extension tube 3 is fluidically connected to the cooling medium injection tube 22, and the cooling medium is transported to the cooling medium injection tube 22 through a cooling medium delivery device connected outside the body, and enters the vacuum chamber 41 through the injection hole 221 located at the far end of the cooling medium injection tube 22. In a low-pressure environment, the boiling point of the cooling medium can be reduced to below the physiological temperature of 37°C, so that the cooling medium spontaneously vaporizes in the vacuum chamber and takes away heat from the blood flow around the tube body 2, thereby achieving the purpose of low-temperature brain protection.

[0145] In order to maintain the low pressure environment in the vacuum chamber 41 and prevent the low pressure from leaking into the blood vessel, a distal sealing ring 23 located at the distal end of the tube body 2 and a vacuum sealing ring 24 located at the proximal end of the vacuum epitaxial tube 4 are also provided inside the tube body 2 and are distributed along the axial direction of the tube body 2 .

[0146] In some instances, the catheter further includes an injection seal ring 25 located at the proximal end of the catheter seat 1. The injection seal ring 25 and the vacuum seal ring 24 form an injection buffer chamber 31 in the catheter seat 1 that is fluidically isolated from the vacuum chamber 41. The injection buffer chamber 31 is fluidically connected to the proximal end of the cooling medium injection tube 22. The cooling medium enters the injection buffer chamber 31 through the injection extension port 3, enters the cooling medium injection tube 22 through the proximal end of the cooling medium injection tube 22, and finally enters the distal end of the vacuum chamber 41 through the injection hole 221 for phase change cooling. Such a design helps the operator to conveniently deliver the cooling medium into the small cooling medium injection tube 22. In other instances, the injection seal ring 25 may not be provided, and the cooling medium injection tube 22 may directly extend out of the catheter seat 1 and be fluidically connected to an in vitro cooling medium delivery device.

[0147] In some examples, the outer diameter of the tube body 2 refers to the long sheath commonly used in neurointervention such as Benchmark The inner diameter of the main interventional tube is 0.09 to 0.13 inches, and the inner diameter of the main interventional tube should generally be greater than 0.04 inches to accommodate the loach guidewire and microcatheter commonly used in neurointervention to facilitate navigation to the internal carotid artery and beyond.

[0148] In some examples, the distance between the distal end of the cooling medium injection tube 22 and the distal end of the tube body 2 is less than 1 cm, and the distal end of the cooling medium injection tube 22 is provided with a plurality of injection holes 221 arranged along the axial direction, and these injection holes 221 form a cooling zone located at the distal end of the tube body 2 with an axial length of about 10 cm. The cooling medium enters the vacuum chamber 41 through these injection holes 221, so that phase change cooling occurs concentratedly in the cooling zone, preventing large-scale brain cooling. The above-mentioned 10 cm cooling zone length is roughly equal to the length from the proximal end of the internal carotid artery to the middle cerebral artery. Through this setting, it is possible to selectively achieve cooling of one side of the brain and reduce the impact on the contralateral brain function.

[0149] In some examples, the tube body 2 is provided with a developing ring at the distal end 202 of the tube body and at a position axially corresponding to the injection hole 221, so as to facilitate the operator to identify the position of the catheter end and the above-mentioned cooling zone during the intervention process.

[0150] In some examples, the cooling medium injection tube 22 is made of PEEK. PEEK has excellent biocompatibility and excellent bending resistance and pushing performance. It can be processed into an ultra-thin wall catheter by hot extrusion, and the cooling medium injection tube 22 with an outer diameter of less than 0.01 inches can be manufactured. In the case where the outer diameter of the tube body 2 is limited, reducing the cooling medium injection tube 22 is beneficial to the main intervention tube 21 having a sufficiently large inner diameter to deliver instruments such as guide wires. The injection hole 221 set on the cooling medium injection tube 22 can be obtained by laser processing.

[0151] In some examples, the cooling medium can be water, a water-based mixture, or other liquids whose phase transition temperature is lower than the physiological temperature under low pressure. Furthermore, the cooling medium used must not produce toxic side effects to the human body when accidentally leaking into the blood vessels, such as sterile saline. Under the condition of using sterile saline, the vacuum source should maintain the absolute pressure in the vacuum chamber 41 at least below 6kPa. At this pressure, the boiling point of saline is 37°C, which will spontaneously vaporize in the vacuum chamber 41 and take away heat from the blood outside the catheter to cool the blood. Cooling power P = ρQL, where ρ is density, L is specific latent heat of about 2500kJ / kg, and Q is injection flow rate. For all existing cooling saline perfusion catheters, blood cooling is achieved by transferring the internal energy of blood to cooling saline through thermal mixing, and its cooling power P = ρQΔTCp, where ΔT is the temperature difference between cooling saline and blood, and Cp is the specific heat of saline, about 3.7kJ / kgoC. Calculations show that the heat absorbed by vaporizing 1 mL of normal temperature saline is 18 times that of injecting 1 mL of 0°C cooling saline into the blood. Therefore, the vacuum-induced phase change cooling mechanism adopted in this embodiment can avoid directly injecting cooling liquid into the blood vessels, reduce the risk of cerebral edema, and achieve the purpose of efficient cooling at the same time.

[0152] It should be made clear that the vaporization heat absorption mentioned in the above working principle is only a type of phase change cooling. The melting point of the cooling medium from solid to liquid state and the sublimation point from solid to gas state can decrease with the decrease of pressure. For example, water is in solid state under normal pressure of 0℃. When the pressure is lower than 0.6kPa, it can directly sublimate from solid to gas and take away a lot of heat. Therefore, in addition to liquid, the cooling medium can also be in the form of hydrogel.

[0153] In some embodiments of the invention, the outer surface of the tube body 2 may be provided with an anti-coagulation layer, which may be one or more of heparin, citrate, and hydrogel, to prevent blood in direct contact with the outer surface of the tube body 2 from coagulating when cooled. Figure 5 As shown, the catheter of the present invention injects a cooling medium (such as sterile saline) into the vacuum chamber 41 in the catheter through the cooling medium injection tube 22, and uses the cooling medium to absorb heat from the blood outside the tube body 2 due to spontaneous phase change due to the decrease in boiling point under low pressure conditions, thereby achieving the purpose of selective hypothermic brain protection. The heat is transferred from the blood to the outer wall of the catheter by thermal convection, and then transferred from the outer wall of the catheter to the inner wall of the catheter by thermal conduction. The efficiency of heat transfer is determined by the outer diameter D of the catheter. o , inner diameter of the catheter D i , the cooling area length L, the heat convection coefficient h and the catheter wall heat conductivity coefficient K. Take a catheter with an outer diameter of 0.130 inches, an inner diameter of 0.126 inches, an outer tube material of Pebax, and a cooling area length of 10 cm as an example. When placed in the internal carotid artery for low-pressure induced phase change cooling, assuming that the blood flow rate is 300 mL / min, when the injection flow rate of the cooling medium is 1 mL / min, the equivalent cooling power is about 41 W, and 37°C blood flowing through the catheter is cooled to about 35°C. At this time, the temperature of the outer wall of the catheter is about -11°C. Therefore, in this type of operating environment, it is necessary to provide the above-mentioned anticoagulant layer on the surface of the tube body 2. In some instances, a temperature sensor can be installed on the distal surface of the tube body 2 to detect the temperature of the blood after cooling.

[0154] In some examples, the vacuum source further includes a pressure sensor and a pressure control device. When the cooling power needs to be increased, the vacuum source can further reduce the pressure in the vacuum chamber 41. In other examples, the vacuum source also includes a timing function to maintain cooling for a predetermined treatment time.

[0155] In some examples, the cooling medium delivery device further includes a flow control device to increase the injection flow of the cooling medium when the cooling power needs to be increased. In other examples, the flow control device also includes a timing function to maintain cooling for a predetermined treatment time.

[0156] In some examples, the outer surface of the cooling medium injection tube 22 may be provided with a hydrophilic coating to reduce the contact angle between the cooling medium and the outer surface of the cooling medium injection tube 22, so as to increase the vaporization area of ​​the cooling medium and improve the cooling efficiency. The hydrophilic coating may be one or more of polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethyleneimine, polyacrylamide, polyacrylic acid or polysaccharide materials commonly used in hydrophilic coatings of vascular intervention catheters. Similarly, the number of injection holes 221 provided on the cooling medium injection tube 22 may also be increased to increase the vaporization area of ​​the cooling medium to improve the cooling efficiency.

[0157] In some instances, the injection extension tube 3, the vacuum extension tube 4, and the main cavity extension tube 5 may be provided with external or internal threaded Luer connectors, respectively, for rapid fluid connection and disassembly with vacuum sources, cooling medium delivery devices, and other equipment commonly used in interventional hemostatic valves.

[0158] The following is an introduction to the operation steps of the catheter of the present invention for low-temperature brain protection, taking the use of physiological saline as a cooling medium as an example. When in use, the tube body 2 is delivered to the carotid artery or a more distal position of the intracranial blood vessels through the guide wire and microcatheter in the main intervention tube 21. When low-temperature brain protection is required, the vacuum epitaxial tube 4 is first connected to the vacuum source, and the negative pressure is set to maintain the pressure in the vacuum chamber 41 less than 6kPa. Then, the cooling medium delivery device is connected through the injection epitaxial tube 3, and the cooling medium input flow rate is set. Physiological saline is delivered to the injection tube 22, and enters the vacuum chamber 41 through the injection hole 221. Under the action of negative pressure, the physiological saline is vaporized in the vacuum chamber 41 located at the distal end 202 of the catheter, taking away the heat of the blood around the tube body 2, and achieving local brain cooling.

[0159] In some examples, the temperature of the blood after cooling can be monitored by a temperature sensor located at the distal end of the tube body 2, and the injection flow rate of the cooling medium and the negative pressure of the vacuum source can be adjusted in real time. When the blood temperature is lower than a preset value, the injection amount of the cooling medium is reduced or the vacuum source pressure is increased, or a combination of the two; when the blood temperature is higher than a preset value, the injection amount of the cooling medium is increased or the vacuum source pressure is reduced, or a combination of the two.

[0160] The present invention can be used to protect the brain nerves of stroke patients and has the advantages of high cooling efficiency, simple operation, safety and reliability.

[0161] In the description of the present application, it should be understood that the terms "up", "down", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inside", "outside", etc., indicating orientations or positional relationships, are based on the orientations or positional relationships shown in the accompanying drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the referred device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be understood as a limitation on the present application.

[0162] The above describes the specific embodiments of the present invention. It should be understood that the present invention is not limited to the above specific embodiments, and those skilled in the art can make various changes or modifications within the scope of the claims, which does not affect the essence of the present invention. In the absence of conflict, the embodiments of the present application and the features in the embodiments can be combined with each other arbitrarily.

Claims

1. A vascular intervention catheter for brain protection, characterized in that: include: A catheter seat (1), a tube body (2), an injection epitaxial tube (3) and a vacuum epitaxial tube (4); One end of the tube body (2) is connected to one end of the catheter seat (1), and the injection epitaxial tube (3) and the vacuum epitaxial tube (4) are arranged on the catheter seat (1); The tube body (2) is provided with a main intervention tube (21), a cooling medium injection tube (22) and a vacuum chamber (41); the main intervention tube (21) extends along the axial direction of the tube body (2), and the vacuum chamber (41) is formed between the outer side wall of the main intervention tube (21) and the inner side wall of the tube body (2); The vacuum chamber (41) is connected to the vacuum epitaxial tube (4), and the injection epitaxial tube (3) is connected to the vacuum chamber (41) through the cooling medium injection tube (22); The cooling medium is injected from outside the body through the injection extension tube (3), transported to the vacuum chamber (41) through the cooling medium injection tube (22), and spontaneously changes phase in the vacuum chamber (41), thereby taking away the heat of the blood flow around the catheter by means of the phase change.

2. The vascular intervention catheter for brain protection according to claim 1, characterized in that: The two ends of the tube body (2) are respectively a proximal end (201) and a distal end (202); The proximal end (201) is connected to the catheter seat (1); one end of the cooling medium injection tube (22) is connected to the injection extension tube (3), and the other end of the cooling medium injection tube (22) is located in the vacuum chamber (41) at the distal end (202); The cooling medium is injected from outside the body through the injection extension tube (3) and transported to the vacuum chamber (41) located at the distal end (202) through the cooling medium injection tube (22).

3. The vascular intervention catheter for brain protection according to claim 2, characterized in that: The main intervention tube (21) extends into the catheter seat (1); An injection buffer cavity (31) is provided in the catheter seat (1), and the injection buffer cavity (31) is formed between the outer wall of the main intervention tube (21) and the inner wall of the catheter seat (1); The injection epitaxial tube (3) is in communication with the injection buffer chamber (31), and the injection buffer chamber (31) is in communication with the vacuum chamber (41) via the cooling medium injection tube (22).

4. The vascular intervention catheter for brain protection according to claim 3, characterized in that: The distal end (202) is provided with a distal sealing ring (23), and the distal sealing ring (23) is located between the outer wall of the main intervention tube (21) and the inner wall of the tube body (2); A vacuum sealing ring (24) is provided in the catheter seat (1) at a position adjacent to the vacuum extension tube (4), and the vacuum sealing ring (24) is located between the outer wall of the main intervention tube (21) and the inner wall of the catheter seat (1); An injection sealing ring (25) is provided in the catheter seat (1) at a position adjacent to the injection extension tube (3), and the sealing ring (25) is located between the outer side wall of the main intervention tube (21) and the inner side wall of the catheter seat (1); The cavity space between the distal sealing ring (23) and the vacuum sealing ring (24) is the vacuum cavity (41), and the cavity space between the vacuum sealing ring (24) and the injection sealing ring (25) is the injection buffer cavity (31).

5. The vascular intervention catheter for brain protection according to claim 4, characterized in that: The vascular intervention catheter further comprises: a main lumen extension tube (5); The main cavity extension tube (5) is connected to the other end of the catheter seat (1).

6. The vascular intervention catheter for brain protection according to claim 5, characterized in that: The size of the main intervention cavity (211) is suitable for accommodating a guide wire, a microcatheter and an intermediate catheter; And / or, the distal sealing ring (23), the vacuum sealing ring (24) and the injection sealing ring (25) are made of one or more materials selected from the group consisting of silicone, polyurethane, polytetrafluoroethylene and adhesives; And / or, the cooling medium injection pipe (22) is provided with one or more injection holes (221) on the pipe body at the distal end (202); the distal end (202) is provided with a developing ring, and the developing ring is arranged at an axial position of the injection hole (221); And / or, the outer surface of the cooling medium injection tube (22) at the distal end (202) is provided with a hydrophilic coating; the hydrophilic coating is one or more of polyvinyl pyrrolidone, polyvinyl alcohol, polyethylene glycol, polyethylene imine, polyacrylamide, polyacrylic acid or polysaccharide materials.

7. The vascular intervention catheter for brain protection according to claim 5, characterized in that: The cooling medium includes physiological saline; the pressure maintained in the vacuum chamber (41) is capable of reducing the boiling point of the cooling medium to below the physiological temperature; And / or, the material of the cooling medium injection pipe (22) is PEEK; And / or, the tube body (2) is provided with a temperature sensor located at the distal end (202), and the temperature sensor is used to monitor the local temperature; And / or, the outer surface of the tube body (2) is provided with an anti-coagulation layer; the anti-coagulation layer is one of heparin, citrate, and hydrogel; And / or, the inner and outer surfaces of the distal end (202) are provided with a texture structure, and the texture structure is used to increase the surface area to improve the heat transfer efficiency.

8. The vascular intervention catheter for brain protection according to claim 5, characterized in that: The catheter seat (1) is provided with a first externally threaded Luer connector and a first internally threaded Luer connector; The injection epitaxial tube (3) and the vacuum epitaxial tube (4) are provided with a second internally threaded Luer connector for connecting to the first externally threaded Luer connector; The main cavity extension tube (5) is provided with a second externally threaded Luer connector for connecting to the first internally threaded Luer connector.

9. An intravascular cooling system for brain protection, characterized in that: A vascular intervention catheter for brain protection comprising any one of claims 1 to 8; It also includes: a cooling medium conveying device and a negative pressure device; The cooling medium conveying device is connected to the cooling medium injection pipe (22) through the injection extension pipe (3); The negative pressure device is in communication with the vacuum chamber (41) via the vacuum epitaxial tube (4); The cooling medium injection pipe (22) and the vacuum chamber (41) are fluidically connected at the distal end (202) of the tube body (2); The main intervention tube (21) is fluidically isolated from the cooling medium injection tube (22) and the vacuum chamber (41); The cooling medium injection tube (22) and the vacuum chamber (41) are isolated from the blood fluid outside the catheter.

10. A cooling method for brain protection, characterized in that: Using the intravascular cooling system for brain protection according to claim 9 specifically comprises the following steps: Step S1: advancing the vascular intervention catheter to the designated cerebral artery; Step S2: connecting the vacuum extension tube (4) on the catheter seat (1) to the negative pressure device, so that the vacuum cavity (41) in the catheter (2) is connected to the negative pressure device, and a low-pressure space is formed at the distal end (202) of the catheter (2); Step S3: connecting the injection extension tube (3) on the catheter seat (1) to the cooling medium conveying device, so that the cooling medium injection tube (22) is in communication with the cooling medium conveying device; Step S4: injecting cooling medium into the vacuum chamber (41) through the cooling medium injection pipe (22), inducing the cooling medium to gasify under low pressure conditions, and generating local cooling.

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