400 results about "Catheter sheath" patented technology

Systems, methods, and devices allow intravascular or percutaneous mapping, orientation and / or ablation, in bodily cavities or lumens. A device includes elongate members, moveable between an unexpanded configuration and an expanded or fanned configuration. The elongate members form a stack in the unexpanded configuration to fit through a catheter sheath. The elongate members follow respective arcuate or curvilinear paths as advanced from the sheath into the bent or coiled stack configuration, adopting volute, scroll or rho shapes, and may be nested. The elongated members are fanned or radially spaced circumferentially with respect to one another into the expanded or fanned configuration. Transducer elements carried by elongate members sense various physiological characteristics of or proximate tissue, and / or may apply energy to or proximate tissue. The elongate members are rotatable in groups or as a group in the expanded configuration. The device is retractable.

The invention discloses a shock wave forming device with a valve blood perfusion function, which relates to the technical field of medical instruments and comprises a catheter sheath, a shock wave forming balloon group, a shock wave generating component, a handle and a magnetic flexible net opening and closing structure. A guide wire is slidably arranged in the catheter sheath; the shock wave forming balloon set comprises a plurality of shock wave balloons, one ends of the shock wave balloons are connected with the end of the guide wire through flexible net-shaped structures, and the other ends of the shock wave balloons are connected with the end of the catheter sheath through flexible rod-shaped structures. The shock wave generating assembly comprises an axial shock wave generating electrode pair and a circumferential shock wave generating electrode pair; and the magnetic type flexible net opening and closing structure is arranged between the guide wire end part and the flexible net-shaped structure. The blood vessel can be mechanically supported or loosened; through the axial shock wave generation electrode pair and the circumferential shock wave generation electrode pair, the blocking plaque can be opened in the forward direction, and shock waves can be emitted in the circumferential direction to crack or crush calcium deposits; in addition, broken calcified plaques or aortic plaques, thrombus and the like can be captured.

The invention relates to the technical field of medical equipment, in particular to a bidirectional bending-adjustable handle and a bending-adjustable catheter sheath, the medical equipment comprises an adjusting tube, a restraint plate, a pull rope, an adjusting handle, a pushing block and a bending tube sleeve; an operator pulls different pull ropes to enable the adjusting tube to be bent at different positions, so that in the using process of the adjusting tube, even if the adjusting tube is inserted into a branch blood vessel in a staggered mode, the adjusting tube can exit from selection again and then is adjusted to a correct path; the adjusting handle can bend the adjusting pipe in different directions by controlling the rotating direction of the adjusting ring, control and adjustment of bending of the front section of the adjusting pipe are achieved, good practicability and economical efficiency are achieved, and application and popularization of equipment are facilitated.

A catheter configured for placement within a bodily lumen, comprises: a catheter sheath defining a first lumen for medical tools; and an exchange segment defining a second lumen for a guidewire. A proximal end of the exchange segment is joined with a distal end of the catheter sheath in a lengthwise direction forming an angle therebetween, such that the second lumen is laterally offset by a distance and angled with respect to the first lumen. When the catheter is placed within a patient's anatomy, the catheter sheath and / or the exchange segment straightens out so that the axis of the second lumen and the axis of the first lumen become substantially parallel to each other. The offset distance between the axes of sheath and exchange segment depends mainly on the diameter of the guidewire to be used, on the diameter of the sheath, and the angle of the junction.

The invention provides a central venous catheter assembly, which comprises a puncture needle, a central venous catheter, a central venous catheter and a central venous catheter, the puncture needle is sleeved with the catheter, and the needle tip of the puncture needle is exposed out of the front end of the catheter; the blood stop valve is arranged at the rear end of the catheter, the blood stop valve is connected with a branch pipe, the branch pipe is provided with a Robert clamp, and a three-way connector is arranged at the tail end of the branch pipe; the standard Luer taper is connected to the tail end of the puncture needle, the standard Luer taper is connected with the blood stop valve, and the standard Luer taper is connected with an external injector or a plug; the needle holder is arranged on the catheter and used for clamping the catheter in the catheter pushing process; and the sensor module is arranged on the catheter and is used for monitoring the physical sign data, processing the physical sign data, comparing the processed physical sign data with a standard threshold value, and generating a warning signal when a preset threshold value is reached. Whether the catheter displaces or leaks liquid or not can be monitored in real time, and therefore a clinician can find complications caused by catheter displacement as soon as possible.

The invention discloses a guiding device for cardiovascular interventional operation guide wire insertion, and belongs to the technical field of guide wire guiding. The guide wire guiding and twisting assembly comprises a guiding seat, the guide wire guiding and twisting assembly comprises a sliding block, a positioning pin is elastically inserted into the sliding block in a sliding mode, the sliding block is rotationally connected with a second shifting wheel, and the second shifting wheel is elastically connected with a first shifting wheel; the guide wire is clamped by the first dial wheel and the second dial wheel, the first dial wheel and the second dial wheel are both of a fan-shaped structure and form a round wheel, and the guide wire is inserted into the catheter sheath along the guide seat through the round wheel which is shifted in a reciprocating mode. The first poking wheel and the second poking wheel are poked and arranged at the sliding block, and the round wheel clamps the guide wire; a positioning pin is extruded by a second poking wheel and inserted into a guide seat for positioning, so that the situation that the hands, the guide wire and the catheter sheath of a doctor are polluted due to the fact that blood in the catheter sheath flows out is avoided, and the guide wire stored in a guide wire storage tube is poked in a reciprocating mode through a guide wire guide twisting assembly and inserted into the catheter sheath; and the problem that blood vessels are scratched due to the fact that the guide wire is pulled out of the catheter sheath by mistake is solved.

The utility model is suitable for the technical field related to medical instruments, and provides a valve auxiliary system sheath which comprises a shell assembly and a catheter sheath tube arranged on the shell assembly. The bending adjusting handle is used for adjusting the angle of the tail end of the catheter sheathing canal, and the bending adjusting handle is connected with the shell assembly; the catheter sheath is used for being matched with the catheter sheath tube to achieve introduction of an interventional instrument or conveying of an auxiliary instrument; the flushing valve is used for conveying medicaments, and the flushing valve is communicated with the catheter sheath through an extension tube body; the catheter sheath tube, the catheter sheath, the flushing valve and other components are arranged in a matched mode, so that the dilator can be always kept in the catheter sheath tube in the original position in the process that the catheter sheath tube enters the access blood vessel of a patient, blood cannot permeate out of a product, use is convenient, and the valve positioning accuracy and the operation safety are effectively improved.

The device for catheterization includes a catheter sheath support mounted on the catheterization device and holding a catheter sheath, a carriage supporting a guide needle, and a connector for removably engaging the catheter sheath support to the carriage. When the carriage is disengaged from the connector, it translates along an insertion axis of the guide needle independent of the catheter sheath support. An actuator controls the separation of the carriage from the catheter sheath support at a uniform speed in response to disengagement of the connector. The translation and separation may be automated. In response to detection of a vessel wall puncture, the carriage is automatically released from the catheter sheath support and retracts along the insertion axis at a uniform speed relative to the catheter sheath support, and the catheter sheath is automatically advanced along the insertion axis at a uniform speed into the target vessel while the carriage is retracted.

A device for catheterization includes a catheter sheath support mounted to a catheterization device and holding a catheter sheath, a carriage supporting a guide needle, and a connector to removably engage the catheter sheath support to the carriage. The carriage translates along an axis of insertion of the guide needle independent of the catheter sheath support when disengaged from the connector. An actuator controls separation of the carriage from the catheter sheath support at a uniform velocity in response to disengagement of the connector. Translation and separation may be automated. In response to detection of the vessel wall puncture, the carriage automatically releases from the catheter sheath support and retracts along the axis of insertion at the uniform velocity relative to the catheter sheath support, and the catheter sheath automatically advances into the target vessel along the axis of insertion at the uniform velocity while the carriage retracts.

The invention discloses a guide wire and catheter exchange blood vessel interventional instrument which comprises a catheter sheath assembly, a puncture needle, a guide wire and a catheter, and belongs to the field of medical instruments. Wherein the catheter sheath assembly is composed of an outer sheath tube and an expansion tube, the far ends of the outer sheath tube and the expansion tube are provided with gradient transition structures, and puncture resistance can be reduced; an exchange connector is arranged at the near end of the outer sheathing canal, an asymmetric structure is arranged in the outer sheathing canal, blood flowing resistance is increased, and when the outer sheathing canal works, through cooperation of all parts, the catheter is fed in the process of retracting the expansion tube, the tearable sheathing canal is blocked in advance, and intraoperative bleeding is reduced. The invention further provides a preparation method of the tearable sheathing canal, the axial pressure resistance, tearability and surface smoothness of the tearable sheathing canal can be adjusted by controlling the raw material ratio, the molecular weight and the processing technology, thrust is provided for clinical puncture, and puncture resistance is reduced; the tearable sheathing canal can reduce the displacement of the catheter after the catheter is indwelled; the expansion tube, the guide wire and the catheter are provided with identification points, and medical operation is facilitated.

The invention discloses an intravascular adjustable ultrasonic real-time navigation TIPS puncture instrument, and relates to the technical field of medical devices, the intravascular adjustable ultrasonic real-time navigation TIPS puncture instrument comprises a catheter sheath, a core-through needle catheter, a hollow core-through needle and a solid core-through needle; the core-through needle catheter penetrates through the interior of the catheter sheath; an operating handle is arranged at one end of the through core needle catheter, a traction mechanism is installed on the operating handle, and a pull wire is arranged in the catheter sheath. Real-time ultrasonic images are obtained through the ultrasonic probe, so that an operator can clearly see a needle point path, and key organs such as hepatic artery, bile duct and gall bladder are effectively avoided. The bending-adjustable puncture needle provides the capability of real-time correction in an operation, can easily cope with complex anatomical variation, can keep certain rigidity through the hardness adjusting chain after bending adjustment, improves the penetrating power of the puncture needle, prevents unpredictable mechanical deformation during liver cirrhosis liver puncture, enhances the controllability after bending adjustment, and improves the safety of liver cirrhosis. And accurate execution of the preset angle is ensured.

A modular catheter system including a sheath projecting distally from a delivery catheter having a main body module An inner core module carrying a stent thereon, the inner core being axially movable through the main body of the delivery catheter and the delivery catheter sheath, a handle member supported by the main body of the delivery catheter, the handle member being selectively axially engageable with the inner core such that the handle member and the inner core move together in an axial direction when the handle member is engaged with the inner core; and an adjustment member supported by the main body, the adjustment member being configured such that rotation of the adjustment member causes the adjustment member to move axially along the main body by either axially sliding the handle member relative to the main body or by rotating the adjustment member.

The invention discloses a mini midline catheter, and relates to the technical field of medical instruments, the mini midline catheter comprises a catheter sheath, an expansion sheath and a protective sleeve, the catheter sheath comprises a catheter joint, a protective sleeve and an implantation catheter, the expansion sheath comprises an expansion joint, a locking ring and an expansion catheter, the catheter sheath wraps the expansion sheath, and the protective sleeve is connected with the expansion joint. The implantation catheter is wrapped outside the expansion catheter, the length of the expansion catheter is larger than that of the implantation catheter, the catheter connector is connected with the locking ring Luer, and the implantation catheter is made of a material with the biological risk assessment end point reaching the long-term or lasting contact level of circulating blood externally connected into a medical device. The dilation catheter and the dilation joint are connected through an injection molding and rubber coating process, and the implantation catheter and the catheter joint are connected through an injection molding and rubber coating process. The mini midline catheter is convenient, accurate and safe to operate, and the infusion time is prolonged compared with an indwelling needle scheme.

The sheathing canal with the adjustable pipe diameter comprises a catheter sheath, a connecting pipe and a blood vessel sheath which are sequentially connected to form a channel, the blood vessel sheath comprises a valve body and an adjusting device, the valve body comprises an annular pipe made of an elastic material and a circular truncated cone pipe made of a rigid material, the annular pipe is composed of a plurality of tubular units, and protruding sliding rails are arranged on the tubular units; the circular truncated cone pipe is provided with a sliding groove in the direction of the sliding rail, a connecting ring used for being connected with the sliding rail is arranged between the annular pipe and the circular truncated cone pipe, the connecting ring is an unclosed circular ring, the adjusting device is connected with the connecting ring and penetrates through the sliding groove, and the adjusting device can slide in the direction of the sliding groove. The valve body comprises the annular pipe and the circular truncated cone pipe, the unclosed connecting ring is arranged between the annular pipe and the circular truncated cone pipe, the sliding groove is formed in the circular truncated cone pipe, and the adjusting device is connected with the connecting ring and penetrates through the sliding groove, so that the adjusting device can slide in the direction of the sliding groove, the connecting ring is driven to slide, and finally the pipe diameter of the annular pipe is changed.

The present invention provides an expandable catheter and an expandable catheter sheath, wherein the expandable catheter includes a body, a connecting portion and a reinforcing portion; the expandable catheter switches between a contracted state and an expanded state along the circumferential direction; the body has an opening along the circumferential direction, the opening is continuously arranged along the axial direction, and the opening and closing of the opening corresponds to the state conversion of the expandable catheter; the connecting portion is connected to both sides of the opening; the reinforcing portion is continuously arranged in the body along at least a part of the circumference of the body, and the reinforcing portion does not overlap in the circumferential direction of the body. With such a configuration, the radial reinforcement of the body by the circumferentially non-closed reinforcing portion can effectively enhance the anti-bending and anti-compression capabilities of the expandable catheter without affecting the expansion performance of the body, achieving compliant bending in all directions, reducing the risk of bending due to excessive blood vessel curvature, and improving surgical safety.

A catheter assembly for performing a thrombectomy and methods of use, the catheter assembly including a catheter sheath and a dilation and capture assembly slidably positioned within the catheter sheath. The dilation and capture assembly includes a catheter having a balloon portion at a distal end of the catheter, and a retrieval basket. The balloon portion is selectively inflatable and deflatable between respectively a maceration orientation and a delivery orientation. The retrieval basket is deployable from a delivery configuration mounted to the balloon portion and a retrieving configuration axially displaced from the distal end of the catheter.

A retainer system includes a catheter tube, a bifurcation, a drainage extension leg and an inflation extension leg. The system can also include an anchor pad and a retainer rotatably coupled to a top surface of the anchor pad. The retainer can include a base and a cap hingedly coupled to the base. Additionally, the retainer can feature one or more extension leg sleeves with a lumen, extending from the first side of the retainer, and a catheter tube sleeve with a lumen, extending from the second side of the retainer. The sleeve can define a serpentine shape to impart a predetermined amount of slack on the catheter and mitigate dislodgement of the catheter distal tip when the retainer system moves relative thereto. Further, the retainer system can mitigate kinking or collapse of the catheter by providing strain relief between the catheter and the retainer system.

An expandable sheath for inserting an interventional medical device, such as an intracardiac heart pump, into a blood vessel. The sheath has an elongate sheath body having a proximal end, a distal end, and a lumen (232) extending from the proximal end to the distal end. The sheath body has a first layer (240) that is a liner defining a lumen (232). The sheath has a second layer (250) disposed on the first layer (240) and being a patterned structure. The sheath has a third layer (260) disposed on a second layer (250). The sheath includes a slit through the second layer (250) and the third layer (260), the slit extending along at least a portion of the sheath. The first portion of the elongate sheath overlaps with the second portion of the sheath along the slit to form a fold (280).

The application relates to a rotary cutting type myocardial biopsy forceps, which comprises a sleeve assembly, a catheter and a handle assembly, the distal end of the handle assembly is connected with the proximal end of the catheter, and the distal end of the catheter is connected with the sleeve assembly; the sleeve assembly comprises a sleeve body, the proximal end of the sleeve body is connected with the catheter, the distal end of the sleeve body is provided with an open port, the inside of the sleeve body is slidably provided with a rotary cutting knife, the inside of the catheter is provided with a first driving member, the handle assembly is drivingly connected with the rotary cutting knife through the first driving member, so as to drive the rotary cutting knife to extend out of the sleeve body and cut myocardial tissue; the distal end of the sleeve body is movably provided with a closing assembly, the inside of the catheter is provided with a second driving member, the handle assembly is drivingly connected with the closing assembly through the second driving member, so as to control the closing assembly to selectively open or close the open port at the distal end of the sleeve body. The rotary cutting type myocardial biopsy forceps can accurately control the sampling depth, and the open port at the distal end of the sleeve body can be closed after sampling, so that myocardial cells are prevented from falling off.

The rotary cutting type myocardial biopsy forceps comprise a sleeve assembly, a catheter and a handle assembly, the far end of the handle assembly is connected with the near end of the catheter, and the far end of the catheter is connected with the sleeve assembly; the sleeve assembly comprises a sleeve body, the near end of the sleeve body is connected with the catheter, the far end of the sleeve body is provided with an opening, a rotary cutter is slidably arranged in the sleeve body, a first driving part is arranged in the catheter, and the handle assembly is in driving connection with the rotary cutter through the first driving part and used for driving the rotary cutter to stretch out of the sleeve body. The cardiac muscle tissue is subjected to rotary cutting; a closing assembly is movably arranged at the far end of the sleeve body, a second driving part is arranged in the catheter, and the handle assembly is in driving connection with the closing assembly through the second driving part and used for controlling the closing assembly to selectively open or close an opening in the far end of the sleeve body. The rotary cutting type myocardial biopsy forceps can accurately control the sampling depth, and the opening in the far end of the sleeve body can be closed after sampling, so that myocardial cells are prevented from falling off.

The invention relates to a flexible lockable rope-driven mechanical arm system for cardiac resection, which belongs to the technical field of minimally invasive interventional surgical instruments and comprises a flexible mechanical arm component, an end effector component, a near-end connecting seat and a locking component. The flexible mechanical arm assembly is formed by connecting a plurality of guiding discs and a plurality of locking pieces in series, the guiding discs are arranged at intervals, one locking piece is arranged every multiple guiding discs, and the guiding discs are connected with a driving rope in series through a length restraining rod. The near-end connecting base is used for being connected with a catheter sheathing canal or a mechanical arm driving base and providing an inlet for the length restraining rod and the multiple driving ropes. The end effector assembly is used for cardiac muscle resection; according to the flexible mechanical arm assembly, complex three-dimensional path planning in a narrow cardiac cavity and posture locking under a target posture can be achieved, and the positioning precision and posture stability in the myocardial resection process are improved. The end effector assembly includes a telescopic knife and a protective depth limiting structure that reduces the risk of penetrating the ventricular wall and damaging adjacent valves and conduction bundles.

The invention discloses an artificial implant conveying system and a recovery control method.The artificial implant conveying system comprises a catheter sheath, a bending adjusting assembly, an inner shaft assembly and a control handle, the catheter sheath is used for constructing an intervention channel, and a fixing base is arranged at the near end of the catheter sheath; the far end of the bending adjusting assembly can be controlled to change the direction, and the bending adjusting assembly penetrates through the fixing base in a sliding mode and further extends towards the near end. The far end of the inner shaft assembly is provided with a loading section used for being connected with an artificial implant, and the loading section is exposed to the far end of the bending adjusting assembly all the time. The control handle is connected with the bending adjusting assembly and the near end of the inner shaft assembly. The control handle is located on the near end side of the fixing base, and the distance between the control handle and the fixing base is adjustable. When the artificial implant is recycled and the far end of the catheter sheath is close to or in contact with the artificial implant, the far end of the control handle abuts against the near end of the catheter sheath, so that supporting force during recycling is provided, and recycling is facilitated.

The disposable tearable catheter sheath comprises a sheath tube and an expansion tube penetrating through the interior of the sheath tube, a sheath tube connector is arranged at the insertion rear end of the sheath tube, tearing marks are arranged on the two sides of the surface of the sheath tube in the axis direction, and an expansion tube connector is arranged at the insertion rear end of the expansion tube. And a sealing assembly is arranged between the sheath tube joint and the expansion tube joint. The hemostasis valve is simple in structure and reasonable in design, it is guaranteed that a doctor can tear the sheath conveniently and rapidly, a torn opening is smooth, damage to blood vessels and nerves of a patient is reduced, and the firmness of the hemostasis valve is guaranteed.

Urinary catheter kits can include a working tray, a storage tray, a protective paperboard, and a urinary catheter assembly, including a urinary catheter and a drainage system. The working tray can be nested on top of the storage tray. The working tray can include preformed sections configured to accommodate a plurality of components of the urinary catheter kit.

The utility model relates to the technical field of medical instruments, in particular to a catheter sheath base structure convenient to operate, which comprises a main body, and a fixing component is arranged on the side surface of the main body; a larger contact area can be provided through the widened rubber positions growing on the two sides of the sheath tube seat, medical staff can easily hold the sheath tube in the operation process, looseness or displacement caused by external force in the use process is effectively prevented, stress can be better dispersed through the widened rubber positions, and the safety performance of the sheath tube is improved. Shaking caused by movement or improper operation of a patient is reduced, so that the safety and the reliability of an operation are improved, the widened rubber position can provide a larger operation space for medical staff, the operation difficulty can be reduced, the working efficiency can be improved, and especially in an emergency, the clamping ring can move in the axial direction of the sheath tube base, so that the operation is more convenient. And the elastic fixing band is used for adjusting the insertion depth of the sheathing canal body and surrounds the outer side of the sheathing canal body, and the sheathing canal body is fixed and released through tensioning and loosening.

The dilatation balloon comprises a catheter, a balloon body arranged on the catheter in a sleeving mode and a support arranged on the balloon body in a sleeving mode, and the support comprises a support body arranged outside the balloon body in a sleeving mode and a plurality of anchoring components arranged on the outer surface of the support body. The anchoring components are configured to penetrate into calcification lesion of the inner wall of a blood vessel when the stent body is in an expansion state, the capsule forms an outline with the middle portion obviously protruding relative to the two end portions in a full state, the catheter is provided with a first limiting structure, and the stent body is correspondingly provided with a second limiting structure. The first limiting structure and the second limiting structure can be matched with each other so as to allow the catheter and the stent body to generate certain relative movement in the axial direction, and local pressurization and expansion are conducted on a specific area of the stent body through the middle portion of the bag body. Therefore, not only are the fitness and anchoring effect of the stent in irregular calcification lesions improved, but also the pertinence and safety of treatment are enhanced.

The invention discloses a tracheal catheter special for upper gastrointestinal endoscopic surgery, which comprises an inner tube, an outer tube capable of sliding up and down with the inner tube is sleeved outside the inner tube, the top end of the outer tube is fixedly connected with the inner tube through a fixing knob, a respirator joint is arranged at the top end of the inner tube, an inner tube water bag is arranged at the bottom of the inner tube, and an outer tube water bag is arranged at the bottom of the inner tube. An inner tube suction hole is formed in one side of the inner tube water bag, and a Murphy hole is formed in the position, located below the inner tube water bag, of the bottom of the inner tube. The problems that in an upper gastrointestinal endoscopic surgery in the prior art, the exposed part of the tracheal catheter affects surgical operation, the cuff of the tracheal catheter compresses a surgical site or affects taking out of a specimen, the tracheal catheter rubs with an endoscope and is prone to disengagement to damage tracheal mucosa, and blood and secretions in the trachea are not sucked thoroughly are solved.

The utility model relates to the technical field of catheter sheath regulation and control, especially a sheath type regulation and control device applied to disposable catheter sheaths, which comprises an external assembly frame, a turnover closing cover plate is installed on the assembly surface of the external assembly frame, an internal assembly groove for installing the disposable catheter sheath is arranged on the assembly surface of the external assembly frame and the turnover closing cover plate, and an external adjustment frame is installed on the side wall of the external assembly frame through a flexible connecting belt. The sheath type regulation and control device applied to the disposable catheter sheath adopts a sheath type structure design, can be directly sleeved on the existing catheter sheath, and is very simple and convenient to assemble and disassemble. The external adjustment frame is installed on the side wall of the external assembly frame through the flexible connecting belt, the external adjustment frame is sleeved on the external catheter, and then the flow or temperature of the catheter is adjusted by the hand control adjustment module inside the external control port, so that the operation is very simple and convenient.

The present invention discloses a ventricular volume reduction puncture device, which includes a puncture structure and a control structure; the puncture structure includes a puncture catheter and a mapping catheter. A first limiting member is provided at the proximal end of the puncture catheter, and a puncture needle is provided at the distal end of the puncture catheter. The mapping catheter is sleeved outside the puncture catheter; the control structure includes a fixed sleeve. The proximal end of the mapping catheter is fixed in the fixed sleeve, and a guide groove adapted to the first limiting member is provided on the fixed sleeve so that the first limiting member moves axially along the guide groove, thereby driving the puncture catheter to move axially.

The invention discloses a catheter sheath for cardiac surgery and a using method thereof.The catheter sheath for cardiac surgery is used for feeding in a cardiac surgery electrode wire and is provided with a catheter sheath assembly, the catheter sheath assembly is formed by combining two symmetrically-arranged catheter bases, and the catheter sheath is connected to the lower portion of the spliced catheter base assembly. The catheter sheath assembly, the fixing assembly and the expansion tube are installed, sealing is achieved when the catheter sheath assembly is inserted into a patient body through cooperation of the catheter sheath assembly and the expansion tube, blood is prevented from flowing out, and meanwhile the two separated catheter sheaths abut against the lower closing valves on the outer sides respectively when the catheter sheaths are stripped through the fixing assembly; the position of the opening is limited, the abutting position is the connecting position of the two lower closing flaps, the lower closing flaps cannot be expanded, in this way, the catheter sheath can be withdrawn conveniently, the situation that the expansion tube rebounds is avoided, it is guaranteed that insertion of the catheter sheath cannot be affected when the connecting rod is installed through the damping mechanism, and operation is convenient and fast.