A variable stiffness vascular interventional catheter and its manufacturing method

Abstract

The present invention relates to a variable-stiffness vascular interventional catheter and a manufacturing method thereof. Among them, the variable-stiffness vascular interventional catheter includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter, and a low-melting-point alloy with a melting point of 43-45 degrees is sealed between the outer catheter and the inner catheter. In this solution, a low-melting-point alloy with a melting point of 43-45 degrees is sealed between the outer catheter and the inner catheter, and the stiffness of the catheter can be adjusted by injecting normal saline at different temperatures into the working channel, so as to adapt to different operations during the surgery and facilitate the normal progress of the surgery.

Description

Technical Field

[0001] The present invention relates to the field of medical technology, and in particular, to a variable-stiffness vascular interventional catheter and a manufacturing method thereof. Background Art

[0002] A vascular interventional catheter is a tool for medical diagnosis and treatment, which is achieved by placing a flexible tube inside the human body. These catheters are usually soft and bendable, and can be inserted into the patient's vascular system for operation. The use of vascular interventional catheters can reduce trauma, improve surgical precision, and reduce the patient's recovery time. The following are some common uses of vascular interventional catheters:

[0003] Angioplasty: Vascular interventional catheters can be used to treat arterial stenosis or occlusion, usually in the treatment of coronary artery disease and peripheral artery disease. The catheter carries an inflatable balloon, and when the catheter reaches the stenotic site, the balloon is inflated to help dilate the blood vessel and increase blood flow.

[0004] Stent implantation: In the case of vascular stenosis, a stent can be placed at the stenotic site to keep the blood vessel unobstructed. The catheter carries the stent, and once the catheter reaches the stenotic site, the stent will unfold and stabilize inside the blood vessel to prevent re-occlusion.

[0005] Embolization therapy: Vascular interventional catheters are used to treat tumors, vascular malformations, abnormal bleeding or thrombolysis. Under the guidance of the catheter, a doctor can send embolic agents (such as micro-particles or coils) into abnormal blood vessels to block their blood flow, or send thrombolytic drugs into the blood vessels to dissolve thrombi and restore blood flow.

[0006] Performing minimally invasive surgery using a vascular interventional catheter has many advantages. Minimally invasive interventional surgery only requires a very small incision or puncture. Compared with traditional open surgery, the patient has a smaller wound, less tissue damage and bleeding, less surgical trauma, less pain and discomfort felt by the patient, and a shorter recovery time; due to the smaller incision, the risk of infection in minimally invasive interventional surgery is lower and the postoperative complications are fewer; only local anesthesia or mild general anesthesia is required, compared with larger open surgeries, reducing the use of anesthesia and related risks. In recent decades, minimally invasive vascular interventional surgery has developed rapidly and has become one of the main clinical methods for treating vascular diseases.

[0007] However, current vascular interventional catheters are usually rigid or soft, which is inconvenient for surgical operation. Summary of the Invention

[0008] In order to solve the defect that the existing catheter is inconvenient for normal surgical operation, the present invention provides a variable-stiffness vascular interventional catheter and a manufacturing method thereof, which can change the stiffness of the catheter during the operation to facilitate the surgical operation.

[0009] The present invention provides a variable stiffness vascular intervention catheter, which includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter, and a low melting point alloy with a melting point of 43-45 degrees is sealed between the outer catheter and the inner catheter.

[0010] Preferably, the inner catheter is disposed inside the outer catheter, and the centers of the inner catheter and the outer catheter are the same.

[0011] Preferably, the inner catheter has an inner diameter of 1 mm and an outer diameter of 1.6 mm; the outer catheter has an inner diameter of 2.4 mm and an outer diameter of 3 mm, and the average gap of the interlayer between the inner catheter and the outer catheter is 0.4 mm.

[0012] Preferably, the low melting point alloy is a bismuth-indium-lead-tin-cadmium alloy.

[0013] Preferably, the proportions of the respective elements in the low melting point alloy are as follows: bismuth accounts for 45%, indium accounts for 19%, lead accounts for 23%, tin accounts for 8%, and cadmium accounts for 5%.

[0014] Preferably, the variable stiffness vascular intervention catheter includes a soft state and a rigid state, or includes a soft state, a rigid state and an intermediate state. The soft state is formed by injecting normal saline with a temperature of 45 degrees or above into the working channel. The rigid state is formed by injecting normal saline with a temperature of 43 degrees or below into the working channel. The intermediate state is a state with a stiffness between the soft state and the rigid state, and the intermediate state is formed by adjusting the temperature of the normal saline injected into the working channel.

[0015] The present invention also provides a manufacturing method of a variable stiffness vascular intervention catheter, which includes: inserting the inner catheter into the outer catheter; using silicone sealant to seal the first end of the interlayer between the outer catheter and the inner catheter; heating the low melting point alloy with a melting point of 43-45 degrees in a water bath to a liquid state; injecting the liquid low melting point alloy into the interlayer between the outer catheter and the inner catheter; using silicone sealant to seal the second end of the interlayer between the outer catheter and the inner catheter.

[0016] The present invention also provides a variable stiffness vascular intervention catheter, which includes at least two catheter segments. Each catheter segment includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter, and a low melting point alloy with a melting point of 43-45 degrees is sealed between the outer catheter and the inner catheter; the melting points of the low melting point alloys of each catheter segment are different.

[0017] The present invention also provides a variable stiffness vascular intervention catheter, which includes a first catheter and a second catheter. The first catheter includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low melting point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter; the second catheter includes a catheter in a rigid state.

[0018] The present invention also provides a variable stiffness vascular intervention catheter, which includes a first catheter and a second catheter. The first catheter includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low melting point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter; the second catheter includes a catheter in a soft state.

[0019] Compared with the prior art, the present invention has the following beneficial effects:

[0020] In the existing solutions, when a catheter with excessive rigidity passes through a curved or narrow blood vessel, it may cause trauma to the vascular intima, resulting in bleeding, hematoma, or vascular injury, spasm, etc. When a catheter with too little rigidity passes through a blood vessel bend, it may bend and cannot pass smoothly, and the working channel inside the catheter may be deformed or blocked, thus affecting the normal progress of the operation. That is, the rigidity of the existing single vascular intervention catheter cannot conform to the anatomical structure and lesion conditions of the blood vessel. It can be seen that the vascular intervention catheters in the existing solutions are usually either rigid or soft, which is not convenient for surgical operation. However, the solution of the present application provides a variable stiffness vascular intervention catheter, which includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low melting point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter. In this solution, a low melting point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter. The stiffness of the catheter can be adjusted by injecting normal saline at different temperatures into the working channel, so as to adapt to different operations during the operation and facilitate the normal progress of the operation. For example, normal saline with a temperature of 45 degrees or above can be injected into the working channel, so that the low melting point alloy in the variable stiffness vascular intervention catheter turns into a liquid state, thereby making the variable stiffness vascular intervention catheter become a soft state, so that when the catheter passes through a curved or narrow blood vessel, it will not cause trauma to the vascular intima and facilitate the operation. Normal saline with a temperature of 43 degrees or below can also be injected into the working channel, so that the low melting point alloy in the variable stiffness vascular intervention catheter turns into a solid state, thereby making the variable stiffness vascular intervention catheter become a soft state; enabling the catheter to pass smoothly through the blood vessel bend, and the working channel inside the catheter will not be squeezed and deformed or blocked, thus facilitating the normal progress of the operation. The stiffness of the catheter can also be adjusted by continuously adjusting the temperature of the normal saline injected into the working channel to make the catheter adapt to different requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] The present invention will be described in detail below in conjunction with embodiments and the accompanying drawings, where:

[0022] Figure 1 is a schematic structural diagram of a variable stiffness vascular interventional catheter;

[0023] Figure 2 is a schematic diagram of the stiffness change of the variable stiffness vascular interventional catheter at different temperatures;

[0024] Figure 3 is a schematic diagram of the manufacturing method of the variable stiffness vascular interventional catheter. Specific Embodiments

[0025] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be further described in detail below in conjunction with the accompanying drawings. Examples of the embodiments are shown in the drawings, where the same or similar reference numerals represent the same or similar components or components with the same or similar functions from beginning to end. The embodiments described below by referring to the drawings are exemplary and are only used to explain the present invention and should not be construed as limiting the present invention.

[0026] In the existing solutions, when a catheter with excessive rigidity passes through a curved or narrow blood vessel, it may cause trauma to the intima of the blood vessel, resulting in bleeding, hematoma, or blood vessel injury, spasm, etc. When a catheter with too little rigidity passes through a curved part of the blood vessel, it may bend and cannot pass through smoothly, and the working channel inside the catheter may be deformed or blocked, thereby affecting the normal progress of the operation. That is, the rigidity of the existing single vascular interventional catheter cannot conform to the anatomical structure and pathological conditions of the blood vessel. It can be seen that the vascular interventional catheters in the existing solutions are usually either rigid or soft, which is not convenient for the normal progress of the operation.

[0027] The solution of the present application proposes a variable stiffness vascular interventional catheter, as Figure 1 shown, including an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low melting point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter. Specifically, as an optional embodiment, the inner catheter is disposed inside the outer catheter, and the centers of the inner catheter and the outer catheter are the same. The centers of the inner catheter and the outer catheter may also be different, which can be specifically set according to requirements. Specifically, as an optional embodiment, the inner diameter of the inner catheter is 1 mm, the outer diameter is 1.6 mm; the inner diameter of the outer catheter is 2.4 mm, the outer diameter is 3 mm, and the average gap of the sandwich between the inner catheter and the outer catheter is 0.4 mm. It should be noted that the above dimensions are only an optional solution of the present scheme, and different dimensions can also be set according to requirements to correspond to different types of blood vessels, etc. Additionally, optionally, in order to avoid too small a gap between the outer catheter and the inner catheter, a support member can also be provided in the sandwich for support to prevent the gap from being too small.

[0028] Specifically, as an optional embodiment, the low-melting-point alloy is a bismuth-indium-lead-tin-cadmium alloy. Specifically, as an optional embodiment, the proportion of each element in the low-melting-point alloy is as follows: bismuth (element symbol Bi) accounts for 45%, indium (element symbol In) accounts for 19%, lead (element symbol Pb) accounts for 23%, tin (element symbol Sn) accounts for 8%, and cadmium (element symbol Cd) accounts for 5%.

[0029] As the state of the variable-stiffness vascular interventional catheter changes, the state of the variable-stiffness vascular interventional catheter can be divided into a soft state, a rigid state, and an intermediate state, etc. Specifically, as an optional embodiment, the variable-stiffness vascular interventional catheter includes a soft state, a rigid state, and an intermediate state. The soft state is formed by injecting normal saline at a temperature of 45 degrees or above into the working channel. The rigid state is formed by injecting normal saline at a temperature of 43 degrees or below into the working channel. The intermediate state is a state where the stiffness is between the soft state and the rigid state, and the intermediate state is formed by adjusting the temperature of the normal saline injected into the working channel.

[0030] In this solution, a low-melting-point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter. The stiffness of the catheter can be adjusted by injecting normal saline at different temperatures into the working channel, so as to adapt to different operations during the surgery and facilitate the normal progress of the surgery. For example, as Figure 2 shown, normal saline at a temperature of 43 degrees or below can be injected into the working channel, so that the low-melting-point alloy in the variable-stiffness vascular interventional catheter turns into a solid state, thereby increasing the stiffness of the variable-stiffness vascular interventional catheter and making the catheter become a rigid state; enabling the catheter to pass smoothly through the curved part of the blood vessel, and the working channel inside the catheter will not be squeezed, deformed, or blocked, thus facilitating the normal progress of the surgery. The stiffness of the catheter can also be adjusted by continuously adjusting the temperature of the normal saline injected into the working channel to make the catheter adapt to different requirements. Normal saline at a temperature of 45 degrees or above can also be injected into the working channel, so that the low-melting-point alloy in the variable-stiffness vascular interventional catheter turns into a liquid state, thereby reducing the stiffness of the variable-stiffness vascular interventional catheter and making the catheter become a soft state, so that the catheter will not cause trauma to the vascular intima when passing through curved or narrow blood vessels, facilitating the surgery.

[0031] In addition, in this solution, the thermal conductivity of the inner catheter and the outer catheter can also be changed by changing indicators such as the materials and thicknesses of the inner catheter and the outer catheter, so that when normal saline at the same temperature is introduced into the working channels in different segments of the catheter, different segments of the catheter have different stiffnesses, thus facilitating adaptation to the needs of the surgery. For example, if the catheter is divided into five segments, the thickness of the inner catheter in the second segment can be reduced, so that the low-melting-point alloy corresponding to the second segment of the catheter softens faster, facilitating bending of the second segment of the catheter to change the orientation of the first segment of the catheter. In addition, in some solutions, an extension tube can be provided, and the extension tube can extend into the working channel of the inner catheter, so that the temperature of the inner catheter can be changed by adding liquids at different temperatures into the extension tube. The thermal conductivity of different segments of the corresponding extension tube can also be different, which can be specifically set according to requirements.

[0032] Based on the above embodiments, the embodiment of the present application further provides a method for manufacturing a variable-stiffness vascular interventional catheter, as Figure 3 shown. The method includes: Step 1, inserting the inner catheter into the outer catheter; Step 2, using silicone sealant to seal the first end of the interlayer between the outer catheter and the inner catheter; Step 3, heating the low-melting-point alloy with a melting point of 43 - 45 degrees in a water bath to a liquid state; Step 4, injecting the liquid low-melting-point alloy into the interlayer between the outer catheter and the inner catheter; Step 5, using silicone sealant to seal the second end of the interlayer between the outer catheter and the inner catheter. In this solution, auxiliary components for facilitating the implementation of this manufacturing method can also be provided. For example, a bracket can be provided to support the inner catheter and the outer catheter, so that the interlayer between the inner catheter and the outer catheter maintains the required gap. Equipment for automatically encapsulating the catheter, equipment for automatically heating and injecting the alloy, etc. can also be provided, thus facilitating the implementation of the solution of the present application.

[0033] The variable-stiffness vascular interventional catheter of the solution of the present application can also be composed of multiple catheter segments with different melting points. Specifically, as an optional embodiment, the present application further provides a variable-stiffness vascular interventional catheter, including at least two catheter segments. Each catheter segment includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low-melting-point alloy with a melting point of 43 - 45 degrees is sealed between the outer catheter and the inner catheter; the melting points of the low-melting-point alloys of each catheter segment are different. Among them, the different melting points of the low-melting-point alloys of each catheter segment result in different stiffnesses of different catheter segments when normal saline at the same temperature is introduced into the working channels in different catheter segments of the catheter, thus facilitating adaptation to the needs of the surgery.

[0034] The variable stiffness vascular interventional catheter of the solution of the present application can also be connected to a catheter in a rigid state to meet different requirements. Specifically, as an optional embodiment, the present application also provides a variable stiffness vascular interventional catheter, which includes a first catheter and a second catheter. The first catheter includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low melting point alloy with a melting point of 43-45 degrees is sealed between the outer catheter and the inner catheter. The second catheter includes a catheter in a rigid state. One or more segments of the variable stiffness vascular interventional catheter can be connected to one or more segments of the catheter in a rigid state to meet the requirements.

[0035] The variable stiffness vascular interventional catheter of the solution of the present application can also be connected to a catheter in a soft state to meet different requirements. Specifically, as an optional embodiment, the present application also provides a variable stiffness vascular interventional catheter, which is characterized by including a first catheter and a second catheter. The first catheter includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A low melting point alloy with a melting point of 43-45 degrees is sealed between the outer catheter and the inner catheter. The second catheter includes a catheter in a soft state. One or more segments of the variable stiffness vascular interventional catheter can be connected to one or more segments of the catheter in a flexible state to meet the requirements. One or more segments of the variable stiffness vascular interventional catheter can also be connected to one or more segments of the catheter in a rigid state and one or more segments of the catheter in a flexible state to meet the requirements.

[0036] In the description of this specification, if terms such as "Embodiment 1", "this embodiment", "in one embodiment", etc. appear, it means that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the invention or the invention. In this specification, the schematic expressions of the above terms do not necessarily refer to the same embodiment or example; moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in an appropriate manner.

[0037] In the description of this specification, terms such as "connection", "installation", "fixation", "setting", "having", etc. are all understood in a broad sense. For example, "connection" can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present application can be understood according to specific circumstances.

[0038] In the description of this specification, relational terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any actual relationship or order between these entities or operations. Moreover, the terms "comprising", "including" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device comprising a series of elements not only includes those elements but also includes other elements not expressly listed, or elements inherent to such process, method, article or device. Without further limitation, an element defined by the statement "comprising an..." does not exclude the presence of additional identical elements in the process, method, article or device comprising the said element.

[0039] The above description of the embodiments is for the convenience of those of ordinary skill in the art to understand and apply the technology of this case. It is obvious that those who are familiar with the technology in this field can easily make various modifications to these examples and apply the general principles described here to other embodiments without creative labor. Therefore, this case is not limited to the above embodiments, and the following modifications should be within the protection scope of this case: ① A new technical solution implemented based on the technical solution of the present invention in combination with the existing common knowledge, and the technical effect produced by this new technical solution does not exceed the technical effect of the present invention; ② An equivalent replacement of some features of the technical solution of the present invention using well-known technologies, and the technical effect produced is the same as the technical effect of the present invention; ③ Expansion based on the technical solution of the present invention, and the substantial content of the expanded technical solution does not exceed the technical solution of the present invention; ④ An equivalent transformation made using the content of the specification and drawings of the present invention, directly or indirectly applied to other related technical fields.

Claims

1. A variable stiffness vascular intervention catheter, characterized in that, It includes at least two catheter segments. Each catheter segment includes an outer catheter and an inner catheter. A working channel is formed in the middle of the inner catheter. A support member is arranged between the outer catheter and the inner catheter, and a low-melting-point alloy with a melting point of 43 - 45 degrees is sealed therein. The variable stiffness vascular interventional catheter includes a soft state, a rigid state, and an intermediate state. The soft state is formed by injecting normal saline with a temperature of 45 degrees or above into the working channel. The rigid state is formed by injecting normal saline with a temperature of 43 degrees or below into the working channel. The intermediate state is a state with a stiffness between the soft state and the rigid state, and the intermediate state is formed by adjusting the temperature of the normal saline injected into the working channel. The thermal conductivities of the inner catheters of each catheter segment are not completely the same. The thickness of the inner catheter of the second catheter segment is less than the thickness of the inner catheter of the first catheter segment. The variable stiffness vascular interventional catheter is made by a manufacturing method, and the manufacturing method includes: Insert the inner catheter into the outer catheter and set up a bracket to support the inner catheter and the outer catheter. Seal the first end of the interlayer between the outer catheter and the inner catheter with silicone sealant. Heat the low-melting-point alloy with a melting point of 43 - 45 degrees in a water bath to the liquid state. Inject the liquid low-melting-point alloy into the interlayer between the outer catheter and the inner catheter. Seal the second end of the interlayer between the outer catheter and the inner catheter with silicone sealant.

2. The variable stiffness vascular intervention catheter according to claim 1, characterized in that, The inner catheter is arranged inside the outer catheter, and the centers of the inner catheter and the outer catheter are the same.

3. The variable stiffness vascular intervention catheter according to claim 1, characterized in that, The low-melting-point alloy adopts a bismuth-indium-lead-tin-cadmium alloy.

4. The variable stiffness vascular intervention catheter according to claim 3, characterized in that, The proportion of each element in the low-melting-point alloy is as follows: bismuth accounts for 45%, indium accounts for 19%, lead accounts for 23%, tin accounts for 8%, and cadmium accounts for 5%.

5. The variable stiffness vascular intervention catheter according to claim 1, characterized in that, The melting points of the low-melting-point alloys of each catheter segment are different.

6. The variable stiffness vascular intervention catheter according to claim 1, characterized in that, It includes at least two of the catheter segments and a second catheter. The second catheter includes a catheter in a rigid state.

7. The variable stiffness vascular intervention catheter according to claim 1, characterized in that, It includes at least two of the catheter segments and a second catheter. The second catheter includes a catheter in a soft state.

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