Blood purification central venous catheter provided with two-way valves and capable of reducing recirculation rate

Abstract

The invention relates to the technical field of vascular pathways for blood purification treatment, and provides a blood purification central venous catheter with a two-way valve and capable of reducing recirculation rate, which comprises a catheter body, two relatively independent cavities are arranged in an inner cavity of the catheter body, a catheter seat is fixed at one end of the catheter body, an inner cavity of the catheter seat is communicated with the two relatively independent cavities, and the catheter body is fixed on the catheter seat. Two groups of two-way valves are arranged on the tube body, each group of two-way valves comprises at least one blood return valve and at least one blood guide valve, and the distance between the blood return valve and the blood guide valve is greater than 80mm. The blood guiding and returning cavity is freely switched through the two cavities due to different blood guiding and returning pressures, no fixed blood guiding and returning cavity exists, the problem of reverse connection and recycling is structurally avoided, meanwhile, the effect that tube sealing liquid is stably located in the inner cavity of the tube body after the catheter is sealed is achieved, it is guaranteed that the tube sealing liquid cannot leak into the blood vessel, and the sealing effect is good. And blood is prevented from flowing back into the tube body to cause thrombus and even tube blockage.

Description

Technical Field

[0001] The invention relates to the technical field of vascular access for blood purification treatment, in particular to a central venous catheter for blood purification with a bidirectional valve capable of reducing the recirculation rate. Background Art

[0002] The central venous catheter commonly used in clinical blood purification, whether it is a polyester sheathed catheter (TCC) or a non-polyester sheathed catheter (NCC), is structurally divided into a blood-intake end (red end) and a blood-return end (blue end). The opening position of the blood-intake end determines its best access path: the opening of the blood-intake end is located at the distal end of the middle and rear section of the catheter, and the opening of the blood-return end is located at the proximal end of the front section of the catheter. During the blood purification treatment, blood is drawn out from the distal end and returns to the proximal end after purification, thereby reducing the recirculation rate of the treatment process. The distal end of the middle and rear section of the catheter, so most catheters have side openings or are close to side openings. The side opening blood drawing process can easily cause it to adhere to the inner wall of the blood vessel due to the influence of fluid mechanics, causing poor blood drawing and thus interrupting the blood purification treatment. The emergency solution is to reverse the blood drawing and blood return end. After reversing, during blood purification treatment, the blood at the proximal end is drawn out and returned to the distal end after purification. With the flow of blood in the blood vessel, the purified blood will be drawn out again into the blood purification equipment, which will greatly increase the recirculation rate, thereby reducing the therapeutic effect of blood purification.

[0003] In addition, the openings of the arteriovenous ends of the commonly used clinical catheters are straight-through open. The slight pressure in the patient's venous blood vessels will cause blood to "escape" into the catheter or the sealing fluid in the catheter to "escape" into the blood vessels. This may affect the patient's coagulation function or cause thrombosis in the catheter to block the catheter. Patients with acute and chronic renal injury, hyperlipidemic pancreatitis, sepsis, etc. all need vascular access for blood purification treatment. Usually, a central venous double-lumen catheter is used for blood purification. One chamber is used to draw the blood that needs to be purified into the purification equipment, and the other chamber is used to return the blood purified by the purification equipment to the body, thereby completing the blood purification treatment. Therefore, the function of the catheter directly affects the therapeutic effect of blood purification.

[0004] A Chinese utility model patent with authorization announcement number CN206138564U discloses a deep vein double-lumen catheter for blood purification, including a catheter with a pointed end, wherein the catheter is provided with a blood return cavity and a blood drainage cavity which are independent of each other, wherein the tip of the blood return cavity is provided with a first bleeding hole, and the side wall of the blood drainage cavity is provided with at least one blood drainage hole, and the distance between the blood drainage hole closest to the tip and the first bleeding hole is not less than 75 mm.

[0005] The above-mentioned existing technical solutions have the following defects: the vascular access needs to be effectively sealed at the end of treatment. The types and concentrations of sealing solutions vary greatly in clinical practice. High-concentration sealing solutions will increase the risk of bleeding in patients, while low-concentration sealing solutions may increase the risk of thrombosis in the catheter and catheter failure. After the existing vascular access is sealed, a "escape" phenomenon will occur, and part of the sealing solution will enter the patient's body, which will increase the risk of bleeding for patients at high risk of bleeding.

[0006] The Chinese utility model patent with authorization announcement number CN213432500U discloses a three-way valve with a complex structure, which avoids the escape of the sealing fluid, but the production process is extremely difficult and not convenient for market promotion. It cannot effectively avoid the problem of recirculation after changing the blood inlet and blood return access position.

[0007] In view of the shortcomings of existing products, the patent of the present invention solves the problem of blood and sealing fluid escaping to the inner side of the catheter and the blood side by changing the catheter structure. It also avoids the problem of increased recirculation when the catheter is reversed due to poor blood drainage due to catheter wall adhesion, which affects the blood purification treatment effect. At the same time, it can also avoid clinical operation errors that may cause the blood return end to affect the treatment effect, thereby improving the fault tolerance rate of human operation.

[0008] The Chinese invention patent with the authorization announcement number CN115944789B discloses an antibacterial and anticoagulant nano-copper-fluorinated graphene coated dialysis catheter. The surface of the traditional catheter is specially treated to be antibacterial and anticoagulant, reducing the formation of blood clots and the adhesion of bacteria. However, there is no essential change in the structure, so the sealing fluid and blood can still escape freely from inside and outside the catheter, and it cannot solve the recirculation problem when reverse connection occurs. Summary of the invention

[0009] In view of the deficiencies of the prior art, the present invention provides a central venous catheter for blood purification with a bidirectional valve capable of reducing the recirculation rate.

[0010] To achieve the above objectives, the present invention is implemented through the following technical solutions: a central venous catheter for blood purification with a bidirectional valve that can reduce the recirculation rate, comprising a tube body, the inner cavity of the tube body is provided with two relatively independent cavities, a tube seat is fixed at one end of the tube body, and the inner cavity of the tube seat is connected with the two relatively independent cavities, and two groups of two bidirectional valves are arranged on the tube body, each group of bidirectional valves includes at least one blood return valve and at least one blood drainage valve, the distance between the blood return valve and the blood drainage valve is greater than 80 mm, and a catheter tip is arranged at the end of the tube body, the blood return valve is located inside the catheter tip, the blood return valve is used to connect one of the independent cavities with the space outside the tube body, and the blood drainage valve is used to connect the other independent cavity with the space outside the tube body, and whether the two independent cavities are used for the blood drainage cavity or the blood return cavity depends on the pressure difference between the intraluminal pressure and the intravascular pressure.

[0011] Preferably, the two relatively independent cavities are a blood return cavity and a blood drainage cavity, and the blood return cavity and the blood drainage cavity are identical in structure.

[0012] Preferably, the blood return valve is used to connect the blood return cavity with the space outside the tube body, and the blood drainage valve is used to connect the blood drainage cavity with the space outside the tube body.

[0013] Preferably, it also includes a tear-off sheath used in conjunction with the catheter body, the sheath is used to assist in the process of inserting the catheter body into the human body, the sheath includes a sheath body and a sheath seat, the inner diameter of the sheath body is larger than the catheter body, the outer wall of the sheath body is provided with tear-off marks for tearing the sheath in half from the middle, and the seat is provided with tear wings.

[0014] Preferably, the sheath tube body contains a hollow sheath tube core, the hollow area allows the guide wire to pass through, the sheath tube core structure is a "D"-shaped structure with a narrowed front end, the sheath tube core and the sheath tube are sleeved together to form a whole, and a threaded device is used to lock them together at the tube seat position. The cross-sectional area of ​​the outer side of the sheath tube core as a whole is rectangular in the rear section, and gradually narrows and becomes thinner at the front section 2 to 3 cm, and its overall length is 10 to 15 cm. The sheath tube as a whole extends from the tube seat to the front end and stops at the position where the sheath tube core begins to narrow. When the sheath tube and the sheath tube core are sleeved together, they are tight and have no gaps.

[0015] Preferably, a catheter fixing wing is provided on one side of the outer wall of the tube body located at the tube seat, and fixing wire holes are provided on both sides of the catheter fixing wing.

[0016] Preferably, the outer wall of the blood vessel is provided with a pipeline clamp, and the end of the blood vessel is provided with an interface.

[0017] The invention provides a central venous catheter for blood purification with a bidirectional valve capable of reducing the recirculation rate.

[0018] It has the following beneficial effects:

[0019] 1. The present invention uses two cavities to freely switch the blood introduction and return chamber due to different blood introduction and return pressures. There is no fixed blood introduction and return chamber, which avoids the problem of reverse connection and recirculation from a structural perspective.

[0020] 2. After the blood purification is completed, the tube lumens on both sides are sealed respectively. When there is no positive or negative pressure in the two cavities, the four valves of the double cavities are all closed to isolate the outside of the catheter from the inside of the catheter, which has the effect of keeping the sealing liquid stably located in the inner cavity of the tube body after the blood vessel is sealed, ensuring that the sealing liquid will not leak into the body and avoiding blood reflux into the tube body to cause thrombosis or even blockage.

[0021] 3. The use of the tear-off sheath of the present invention avoids major changes to the traditional catheterization process, which is convenient for clinical operation. It also avoids the damage to the catheter valve structure caused by the guide wire directly passing through the catheter, thereby changing the catheter function. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 This is a structural diagram of the blood-drawing valve of the present invention;

[0024] Figure 3 It is a schematic diagram of the blood return valve of the present invention;

[0025] Figure 4 For the present invention Figure 1 Cross-sectional area view at positions II and IV.

[0026] Among them, 1. tube body; 2. tube seat; 3. catheter fixing wing; 4. blood vessel; 5. interface; 6. pipeline clamp; 7. fixing thread hole; 8. blood return valve; 9. blood guide valve; 10. catheter tip. DETAILED DESCRIPTION

[0027] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0028] Example:

[0029] Please see attached Figure 1-Figure 4The embodiment of the present invention is a central venous catheter for blood purification with a bidirectional valve that can reduce the recirculation rate, including a tube body 1, an outer wall of the tube body 1 is provided with a catheter fixing wing 3 on one side of a tube seat 2, and both sides of the catheter fixing wing 3 are provided with a fixing thread hole 7, the inner cavity of the tube body 1 is provided with two relatively independent cavities, a tube seat 2 is fixed at one end of the tube body 1, and the inner cavity of the tube seat 2 is connected to two relatively independent blood return cavities and blood drainage cavities, and the blood return cavities and blood drainage cavities have the same structure, and two groups of two bidirectional valves are provided on the tube body 1, and each group of bidirectional valves includes at least one return cavities. The blood valve 8 and at least one blood extraction valve 9, the distance between the return blood valve 8 and the blood extraction valve 9 is greater than 80 mm, and the end of the tube body 1 is provided with a catheter tip 10, the return blood valve 8 is located inside the catheter tip 10, the return blood valve 8 is used to connect the return blood cavity with the space outside the tube body 1, and the extraction blood valve 9 is used to connect the extraction blood cavity with the space outside the tube body 1. Whether the two independent lumens are used for the extraction blood cavity or the return blood cavity depends on the pressure difference between the inner pressure of the lumen and the inner pressure of the blood vessel 4. The outer wall of the blood vessel 4 is provided with a pipeline clamp 6, and the end of the blood vessel 4 is provided with an interface 5

[0030] By adopting the above technical solution, after the part of the tube body 1 in which each lumen is provided with the return blood valve 8 and the blood guide valve 9 is placed in the human blood vessel, the lumen is connected with the tube seat 2. When used for blood guide, when the pressure in the lumen is lower than the human blood pressure, the blood in the blood vessel 4 can exert pressure on the blood guide valve 9, so that the blood guide valve 9 is opened, and the blood in the blood vessel 4 enters the lumen. At the same time, the blood in the blood vessel 4 can exert pressure on the return blood valve 8, so that the return blood valve 8 is closed. At this time, the lumen is a blood guide lumen; when the pressure in the lumen is the same as the human blood pressure, the blood guide valve 9 and the return blood valve 8 are both closed.

[0031] The other lumen is connected to the tube seat 2 and is affected by the blood return pressure. When the pressure in the blood return chamber is greater than the human blood pressure, the blood in the catheter can exert pressure on the blood return valve 8 to open the blood return valve 8, and the blood in the catheter enters the blood vessel 4. At the same time, the blood in the catheter can exert pressure on the blood extraction valve 9 to close the blood extraction valve 9. At this time, the chamber is the blood return chamber; when the pressure in the chamber is the same as the human blood pressure, the blood extraction valve 9 and the blood return valve 8 are both closed.

[0032] After blood purification is completed, the tube lumens on both sides are sealed respectively. After sealing, the double-lumen four valves are closed, and the tube body 1 is filled with sealing liquid to ensure that the sealing liquid will not leak into the body and prevent blood from flowing back into the tube body 1 to cause thrombosis or even blockage.

[0033] It also includes a tear-off sheath tube used in conjunction with the catheter body, the sheath tube is used to assist the operation process of inserting the catheter body into the human body, the sheath tube includes a sheath tube body 1 and a sheath tube seat 2, the inner diameter of the sheath tube body 1 is larger than the catheter body, and the outer wall of the tube body 1 is provided with tear-off marks, which is used to tear the sheath tube from the middle into two, and the sheath tube seat 2 is provided with tearing wings; the sheath tube body 1 contains a hollow sheath tube core, the hollow area allows the guide wire to pass through, the sheath tube core structure is a "D"-shaped structure with a narrowed front end, the sheath tube core and the sheath tube body are sleeved together to form a whole, and a threaded device is locked together at the position of the tube seat 2, the cross-sectional area of ​​the outer side of the sheath tube core as a whole is a rectangular in the rear section, and gradually narrows and becomes thinner at the front section 2 to 3 cm, and its overall length is 10 to 15 cm, and the sheath tube as a whole extends from the tube seat 2 to the front end to the position where the sheath tube core begins to narrow and stops. When the sheath tube and the sheath tube core are sleeved together, there is no gap.

[0034] By adopting the above technical solution, when the catheter body is inserted into the human body, according to the traditional method, the guide wire is inserted into the blood vessel 4 using the Seldinger technique, and then the skin and blood vessels are expanded using a skin expander, and the sheath is put on the guide wire, and the sheath is inserted along the guide wire. After all the sheaths are inserted into the sheath, the sheath core is withdrawn from the sheath together with the guide wire, and then the catheter is sent into the sheath along the sheath. After reaching the predetermined position, the sheath is torn and the sheath is withdrawn while being torn until the sheath is completely withdrawn, and the catheter is inserted.

[0035] By adopting the above technical solution, the damage to the valve structure on the catheter when the traditional method of using a guide wire to directly pass through the catheter to guide the catheter into the blood vessel 4 is avoided, thereby ensuring the integrity of the catheter and the valve structure.

[0036] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate, comprising a tube body (1), wherein the inner cavity of the tube body (1) is provided with two relatively independent cavities, a tube seat (2) is fixed at one end of the tube body (1), and the inner cavity of the tube seat (2) is connected to the two relatively independent cavities, characterized in that: The tube body (1) is provided with two groups of two bidirectional valves, each group of bidirectional valves includes at least one blood return valve (8) and at least one blood drainage valve (9), the distance between the blood return valve (8) and the blood drainage valve (9) is greater than 80 mm, and the end of the tube body (1) is provided with a catheter tip (10), the blood return valve (8) is located inside the catheter tip (10), the blood return valve (8) is used to connect one of the independent cavities with the space outside the tube body (1), and the blood drainage valve (9) is used to connect the other independent cavity with the space outside the tube body (1), and whether the two independent cavities are used for the blood drainage cavity or the blood return cavity is determined by the pressure difference between the internal pressure of the cavity and the internal pressure of the blood vessel (4).

2. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate according to claim 1, characterized in that: The two relatively independent cavities are the blood return cavity and the blood drainage cavity, and the blood return cavity and the blood drainage cavity are identical in structure.

3. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate according to claim 2, characterized in that: The blood return valve (8) is used to connect the blood return cavity with the space outside the tube body (1), and the blood drainage valve (9) is used to connect the blood drainage cavity with the space outside the tube body (1).

4. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate according to claim 1, characterized in that: It also includes a tear-off sheath tube used in conjunction with the catheter body, the sheath tube is used to assist in the operation process of inserting the catheter body into the human body, and is characterized in that: the sheath tube includes a tube body (1) and a tube seat (2), the inner diameter of the tube body (1) is larger than that of the catheter body, and the outer wall of the tube body (1) is provided with tear-off marks for tearing the sheath tube into two from the middle, and the tube seat (2) is provided with tearing wings.

5. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate according to claim 4, characterized in that: The sheath tube contains a hollow sheath tube core, and the hollow area allows the guide wire to pass through. The sheath tube core structure is a "D"-shaped structure with a narrowed front end. The sheath tube core and the sheath tube are sleeved together to form a whole, and a threaded device is provided at the tube seat (2) to lock them together. The cross-sectional area of ​​the outer side surface of the sheath tube core as a whole is rectangular in the rear section, and gradually narrows and becomes thinner at the front section 2 to 3 cm, and its overall length is 10 to 15 cm. The sheath tube as a whole extends from the tube seat (2) to the front end and stops at the position where the sheath tube core begins to narrow. When the sheath tube and the sheath tube core are sleeved together, they are tight and have no gap.

6. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate according to claim 1, characterized in that: The outer wall of the tube body (1) is provided with a catheter fixing wing (3) on one side of the tube seat (2), and fixing thread holes (7) are provided on both sides of the catheter fixing wing (3).

7. A central venous catheter for blood purification with a bidirectional valve capable of reducing recirculation rate according to claim 1, characterized in that: The outer wall of the blood vessel (4) is provided with a pipeline clamp (6), and the end of the blood vessel (4) is provided with an interface (5).

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