CN214342532U

CN214342532U - Catheter sheath assembly for vein catheterization

Info

Publication number: CN214342532U
Application number: CN202023120349.9U
Authority: CN
Inventors: 林晓非; 孙文瑞; 林圆圆
Original assignee: First Affiliated Hospital of Wenzhou Medical University
Current assignee: First Affiliated Hospital of Wenzhou Medical University
Priority date: 2020-12-22
Filing date: 2020-12-22
Publication date: 2021-10-08
Anticipated expiration: 2030-12-22

Abstract

The utility model discloses a catheter sheath component for vein catheterization, which comprises an expander and a cannula sheath, wherein the expander comprises a puncture needle tube body and a needle tube tailstock arranged at the tail end of the puncture needle tube body, the cannula sheath comprises a tearable tube body and a tearable tailstock arranged at the tail end of the puncture needle tube body, the tearable tube body is axially provided with a through hole for the puncture needle tube body to be inserted, the inner side wall of the through hole is in sliding sealing contact with the outer side wall of the puncture needle tube body, the side wall of the tearable tube body is provided with a tearable structure along the axial direction, the puncture needle tube body is made of hard medical materials, and the length of the puncture needle tube body is 10-12cm, the tearable tube body is made of tearable medical materials, and the length dimension of the tearable tube body is 5-6cm, the end part of the tearable tube body far away from the tearable tailstock is arranged to be a bevel notch structure, and the front end of the puncture needle tube body can extend out of the tearable tube body in the process of inserting the puncture needle tube body into the puncture hole. Can effectively reduce the damage to the patient and is beneficial to improving the puncture success rate and the puncture efficiency.

Description

Catheter sheath assembly for vein catheterization

Technical Field

The utility model relates to the technical field of medical apparatus, more specifically say, it relates to a catheter sheath subassembly for vein catheterization.

Background

A Peripherally Inserted Central Venous catheter (PICC) is used for puncturing a vein of a peripheral arm by using a catheter, the catheter directly reaches a large vein close to the heart, so that the direct contact between a chemotherapy medicament and the arm vein is avoided, and the blood flow speed of the large vein is high, so that the chemotherapy medicament can be quickly diluted, the stimulation of the medicament to the blood vessel is prevented, the upper limb vein can be effectively protected, the occurrence of phlebitis is reduced, the pain of a patient is relieved, and the life quality of the patient is improved.

At present, the PICC is mostly placed by the seldinger technique (percutaneous insertion of a catheter, by a radiologist in sweden known as seldinger, utility model) with the main steps: firstly, performing venipuncture by using a puncture guide needle, and indicating that the puncture is successful when blood returns; then holding the guide wire and feeding the guide wire into the puncture guide needle so as to ensure that the guide wire extends into the blood vessel; then the puncture guide needle is removed, local anesthesia is given, and a scalpel is used for expanding the puncture point; then inserting the dilator/cannula sheath assembly along the guide wire and pushing the dilator/cannula sheath assembly into the vein along the guide wire; withdrawing the guide wire and the dilator, and sending the PICC catheter into the superior vena cava from the cannula sheath; finally, the sheath is torn off and the PICC catheter is fixed.

Because the scalpel is needed to enlarge the puncture point in the existing puncture technology so as to be inserted by the dilator/cannula sheath assembly, the scalpel is used to enlarge the puncture point, which not only increases the damage to the patient and the pain of the patient, but also causes local bleeding, and is easy to cause complications such as lymphatic leakage, and the medical staff is difficult to master the puncture technology training that the scalpel is needed to enlarge the puncture point (for example, how the puncture point is enlarged, how much the puncture point is enlarged, and how much the depth is enlarged all need a large amount of practice), and each set of intravenous cannula suit needs to be equipped with the scalpel, so that the treatment cost of the patient is increased.

SUMMERY OF THE UTILITY MODEL

The utility model aims to provide a catheter sheath subassembly for vein catheterization to the not enough that exists to prior art to solve the problem that provides in the above-mentioned background art.

In order to achieve the above purpose, the utility model provides a following technical scheme: a catheter sheath assembly for intravenous catheterization comprises an expander and a cannula sheath, wherein the expander comprises a puncture needle tube body and a needle tube tailstock arranged at the tail end of the puncture needle tube body, the cannula sheath comprises a tearable tube body and a tearable tailstock arranged at the tail end of the tearable tube body, a through hole for the puncture needle tube body to be inserted is arranged in the tearable tube body in an axial penetrating manner, the inner side wall of the through hole is in sliding and sealing contact with the outer side wall of the puncture needle tube body, a tearing structure is arranged on the side wall of the tearable tube body along the axial direction, the puncture needle tube body is made of hard medical materials, the length of the puncture needle tube body is 10-12cm, the tearable tube body is made of tearable medical materials, the length of the tearable tube body is 5-6cm, and the end, far away from the tearable tailstock, of the tearable tube body is arranged to be of a bevel cut structure, the front end of the puncture needle tube body can extend out of the tearable tube body in the process of inserting the puncture needle tube body into the puncture hole.

The utility model discloses further set up to: tear the structure and tear the mouth including setting up the indent on can tearing the body inside wall, the indent tears the mouth and becomes the ditch column structure setting of bar to the length direction that the indent torn the mouth extends the setting along the axial direction that can tear the body, the indent tears the mouth and is provided with two to two indents tear the mouth and lie in can tear the body relative both sides.

The utility model discloses further set up to: the utility model discloses a pipe body, including the pipe body, can tear the inside wall of body, tear mouthful both sides in the indent and all protruding spacing sand grip that is equipped with in the indent on the inside wall of body, spacing sand grip growth strip structure sets up to the length direction of spacing sand grip tears the length direction extension setting of mouthful along the indent, spacing sand grip tears mouthful rounding off with the indent and connects.

The utility model discloses further set up to: be provided with the spacing structure of dodging that can contradict with spacing sand grip and indent tear mouthful and slide on the lateral wall of puncture needle body, the spacing structure of dodging extends the setting along the axial direction of puncture needle body, the spacing length dimension of dodging the structure and the length dimension looks adaptation that can tear the body.

The utility model discloses further set up to: the wall thickness size that can tear the body reduces the setting from tail end to head end gradually, can tear the body including cylindric inside wall and frustum of a cone form lateral wall, the pjncture needle body including the cylinder linkage segment that supplies to tear the body cover and establish and can follow the frustum of a cone direction section that can tear the body and stretch out, frustum of a cone direction section sets up with cylinder linkage segment is integrative, the length size of cylinder linkage segment and the length size looks adaptation that can tear the body.

The utility model discloses further set up to: the cone frustum guide section comprises a cone frustum transition section matched with the taper of the outer side wall of the tearable pipe body and a cone frustum insertion end positioned at the front end of the tearable pipe body, and the taper of the outer side wall of the cone frustum insertion end is larger than that of the outer side wall of the cone frustum transition section.

The utility model discloses further set up to: the tearable pipe body is provided with a setting support member for supporting the tearable pipe body to keep an open state in a natural state, the setting support member is embedded in the wall thickness of the tearable pipe body and is positioned between two inwards concave tear openings, the setting support member is of a long strip structure and is bent into a C-shaped structure, the setting support member is provided with a plurality of setting support members, and each setting support member is axially distributed along the tearable pipe body.

The utility model discloses further set up to: the design support piece is made into the slice by the elastic metal that can deform, design support piece becomes C font structure setting in its length direction's cross section in natural state, design support piece can cooperate and can tear the laminating of body lateral wall on pjncture needle body lateral wall when the puncture needle body inserts in can tearing the body.

The utility model discloses further set up to: the integrative elastic sealing piece that is used for preventing the blood outflow that is provided with on the opening inside wall of tearable body tail end, the elastic sealing piece is provided with a plurality ofly to each elastic sealing piece is around setting up on the inside wall of tearable body, the elastic sealing piece becomes the triangle-shaped structure and the slope sets up, the incline direction of elastic sealing piece is for extending the setting to the head end of tearable body, the elastic sealing piece both sides be can with the sealed limit of adjacent elastic sealing piece butt, each elastic sealing piece can realize the tail end opening of tearable body and seal through the butt of each sealed limit under natural state.

The utility model discloses further set up to: the tearable tailstock comprises a tailstock connecting piece fixed at the tail end of the tearable pipe body and a tearable seat plate fixedly connected with the tailstock connecting piece, the tailstock connecting piece is bent into a C-shaped structure and is provided with two, the two tailstock connecting pieces are buckled with each other to form a tubular structure, two sides of the tearable seat plate are provided with tearable notches, the butt parts of the two tailstock connecting pieces correspond to the two tearable notches, and the middle of the tearable seat plate is provided with a through hole communicated with the through hole.

To sum up, the utility model discloses following beneficial effect has: the puncture needle tube body is slender in structure and hard in texture, the tearable tube body sleeved on the puncture needle tube body can be conveniently driven to be inserted in place, a scalpel is not required to be used for enlarging a puncture point in the puncture process, so that the damage to a patient can be effectively reduced, the pain of the patient can be reduced, the local bleeding can be reduced, the complications such as lymphatic leakage and the like can be reduced, medical staff does not need to master the puncture technology training of how to enlarge the puncture point by using the scalpel, the puncture step of the medical staff is effectively simplified, and the puncture success rate and the puncture efficiency are favorably improved; in addition, a scalpel does not need to be arranged in each set of intravenous tube set, so that the treatment cost of the patient can be reduced.

The puncture needle tube body is 10-12cm in length, has enough length for medical staff to puncture, is half of the length of the puncture needle tube body, and is provided with an oblique notch structure at the head end, so that the puncture needle tube body can be conveniently inserted in place along with the puncture operation of the puncture needle tube body.

Drawings

FIG. 1 is a schematic view of a catheter sheath assembly for intravenous tubing;

FIG. 2 is a cross-sectional view of the lancet body and the tearable body;

FIG. 3 is a schematic view of the structure of the puncture needle tube;

FIG. 4 is a schematic structural view of a cannula sheath;

FIG. 5 is a schematic perspective view of the shaping supporter;

fig. 6 is a schematic structural view of a tearable tailstock.

Reference numerals: 1. a dilator; 11. a puncture needle tube body; 12. a needle tube tailstock; 13. a limiting and avoiding structure; 14. a cylindrical connecting section; 15. a truncated cone guide section; 151. a truncated cone transition section; 152. a truncated cone insertion end; 2. a cannula sheath; 21. the pipe body can be torn; 211. perforating; 22. a tearable tailstock; 221. a tailstock connecting piece; 222. a tearable seat plate; 223. a tearable notch; 224. a through hole; 23. a tear-away feature; 231. an inward concave tearing opening; 232. limiting convex strips; 24. shaping the supporting piece; 25. an elastic sealing sheet.

Detailed Description

The present invention will be described in further detail with reference to the accompanying drawings and examples. In which like parts are designated by like reference numerals. It should be noted that the terms "front," "back," "left," "right," "upper" and "lower" used in the following description refer to directions in the drawings, and the terms "bottom" and "top," "inner" and "outer" refer to directions toward and away from, respectively, the geometric center of a particular component.

Referring to fig. 1-6, a catheter sheath assembly for intravenous catheterization comprises an expander 1 and an intubation sheath 2, wherein the expander 1 comprises a puncture needle tube 11 and a needle tube tailstock 12 arranged at the tail end of the puncture needle tube 11, the intubation sheath 2 comprises a tearable tube 21 and a tearable tailstock 22 arranged at the tail end of the tearable tube 21, a through hole 211 for the puncture needle tube 11 to be inserted is axially arranged in the tearable tube 21, the inner side wall of the through hole 211 is in sliding and sealing contact with the outer side wall of the puncture needle tube 11, a tearing structure 23 is arranged on the side wall of the tearable tube 21 along the axial direction, the puncture needle tube 11 is made of hard medical material, the puncture needle tube 11 has a length of 10-12cm, the tearable tube 21 is made of tearable medical material, the tearable tube 21 has a length of 5-6cm, the end of the tearable tube 21 far away from the tearable tailstock 22 is arranged in an oblique notch structure, the tip can protrude from the tearable tube body 21 during insertion of the puncture needle tube body 11 into the through hole 211.

The puncture needle tube body 11 is slender in structure and hard in texture, the tearable tube body 21 sleeved on the puncture needle tube body 11 can be conveniently driven to be inserted in place, a scalpel is not required to be used for enlarging a puncture point in the puncture process, so that the damage to a patient can be effectively reduced, the pain of the patient is reduced, the local bleeding is reduced, complications such as lymphatic leakage and the like are reduced, medical staff does not need to master a puncture technology training for enlarging the puncture point by using the scalpel, the puncture steps of the medical staff are effectively simplified, and the puncture success rate and the puncture efficiency are favorably improved; in addition, a scalpel does not need to be arranged in each set of intravenous tube set, so that the treatment cost of the patient can be reduced.

The length of the puncture needle tube body 11 is 10-12cm, the length of the puncture needle tube body is enough for medical staff to puncture, the length of the tearable tube body 21 is half of the length of the puncture needle tube body 11, and the head end of the tearable tube body 21 is of an oblique notch structure, so that the puncture needle tube body 11 can be conveniently inserted in place along with puncture operation of the puncture needle tube body 11.

Tear structure 23 including setting up the indent tear mouth 231 on can tearing body 21 inside wall, indent tear mouth 231 becomes the ditch column structure setting of bar to the axial direction extension setting of tearable body 21 is followed to the length direction of indent tear mouth 231, and indent tear mouth 231 is provided with two, and two indent tear mouths 231 are located can tear body 21 interior relative both sides. The indent tears a mouthful 231 and becomes the groove structure setting, can effectively reduce the wall thickness size that can tear body 21 in the tank bottom department of indent tearing mouthful 231, is favorable to improving the convenient degree and the smooth degree of tearable body 21 when tearing to also can minimize when tearing body 21 when tearing the body and treat that fixed PICC pipe produces and draw even drag, and then be favorable to improving and prick the success rate and reduce patient's pain.

Can tear on the inside wall of body 21 the indent tears mouthful 231 both sides all protruding spacing sand grip 232 that is equipped with, spacing sand grip 232 length strip structure sets up to the length direction of spacing sand grip 232 is torn mouthful 231's length direction along the indent and is extended the setting, and spacing sand grip 232 tears mouthful 231 rounding off with the indent and be connected. The wall thickness that the body 21 can be torn in the indent in the both sides bodiness of tearing mouthful 231 in setting up of spacing sand grip 232, can be favorable to improving the body structure that can tear body 21 remain stable under the non-tear state, also can improve simultaneously that can tear body 21 and tear along the indent length direction who tears mouthful 231 when tearing the state down, be favorable to further improving the convenient degree and the smooth degree of can tearing body 21 when tearing, it draws even to drag to treat fixed PICC pipe production when also can effectively avoiding tearing body 21 to tear.

Be provided with the spacing structure 13 of dodging that can contradict with spacing sand grip 232 and indent tear mouth 231 and slide on the lateral wall of pjncture needle body 11, the axial direction extension setting along pjncture needle body 11 of spacing structure 13 of dodging, the length dimension of spacing structure 13 of dodging and the length dimension looks adaptation that can tear body 21. Spacing structure 13 of dodging can be including the indent that supplies spacing sand grip 232 embedding, and can imbed the indent and tear mouthful 231 protruding stupefied, the indent and protruding stupefied rounding off connection, can cooperate spacing sand grip 232 and indent to tear mouthful 231 and effectively realize contradicting and slide, and this design can also restrict to tear body 21 and rotate on pjncture needle body 11, make expander 1 and intubate sheath 2 can keep the uniformity when the puncture, be favorable to further improving puncture success rate and puncture efficiency.

The wall thickness size that can tear body 21 reduces the setting from tail end to head end gradually, can tear body 21 including cylindric inside wall and the lateral wall of circular truncated cone form, and pjncture needle body 11 can tear the cylinder linkage segment 14 that body 21 cover was established and can follow the circular truncated cone direction section 15 that can tear body 21 and stretch out including supplying, circular truncated cone direction section 15 sets up with cylinder linkage segment 14 is integrative, the length size of cylinder linkage segment 14 and the length size looks adaptation that can tear body 21. The outer diameter size of the head end of the tearable tube body 21 is small, the outer diameter size of the tail end is large, the matching of the oblique notch structure can be favorable for improving the convenient degree of being put in along with the puncture needle tube body 11 during puncture, the puncture success rate can be further improved, the damage to the patient is reduced, the pain of the patient is reduced, and the local bleeding is reduced.

And the tearable tube body 21 is sleeved on the cylindrical connecting section 14, the head end of the tearable tube body 21 is connected with the tail end of the truncated cone guide section 15, the outer diameter of the head end of the truncated cone guide section 15 is small, and the outer diameter of the tail end is large, so that the design not only can be convenient for medical staff to puncture, improve the success rate of puncture, but also can effectively reduce the pain feeling brought to patients during puncture and reduce local bleeding.

The truncated cone guide section 15 includes a truncated cone transition section 151 adapted to the taper of the outer side wall of the tearable tube 21, and a truncated cone insertion end 152 located at the front end of the tearable tube 21, wherein the taper of the outer side wall of the truncated cone insertion end 152 is greater than the taper of the outer side wall of the truncated cone transition section 151. The design can further improve the convenient degree of the cone frustum guide section 15 during the puncture operation of medical staff, improve the success rate of puncture, and effectively reduce the pain feeling brought to patients during puncture and reduce local bleeding.

The tearable tube 21 is provided with a fixing support 24 for supporting the tearable tube 21 to maintain an open state in a natural state, the fixing support 24 is embedded in a wall thickness of the tearable tube 21 and located between the two inward concave tear openings 231, the fixing support 24 is in a long strip structure and is bent into a C-shaped structure, the fixing support 24 is provided in plurality, and each fixing support 24 is axially distributed along the tearable tube 21. Because the pipe body 21 that can tear needs to be made by the above-mentioned scheme, especially the head end, consequently be favorable to improving the structural strength that can tear pipe body 21 through setting up design support piece 24, make can tear pipe body 21 and take out the back at pjncture needle body 11 and can support the passageway that forms and supply PICC catheterization to be favorable to improving puncture success rate and puncture efficiency.

The design support members 24 can be alternatively arranged between the two concave tearing openings 231 at intervals, as shown in the attached drawing 4, so that the tearable tube 21 has certain structural strength and certain deformation capability, and is suitable for puncture.

The shaping support 24 is made of deformable elastic metal and is in a sheet shape, the shaping support 24 is arranged in a C-shaped structure along the cross section of the length direction of the shaping support 24 in a natural state, as shown in the attached drawing 5 in the specification, when the puncture needle tube body 11 is inserted into the tearable tube body 21, the shaping support 24 can be attached to the outer side wall of the puncture needle tube body 11 in a manner of matching with the side wall of the tearable tube body 21. The design support piece 24 structural strength of this structure is high, not only can be favorable to further improving to support can tear body 21 and form and supply PICC catheter insertion's passageway, can also insert when can tearing body 21 at pjncture needle body 11, thereby make design support piece 24 produce the flat deformation and make and can tear body 21 and closely laminate on pjncture needle body 11, make pjncture needle body 11 and can tear body 21 and can keep the uniformity when the puncture, and then make pjncture needle body 11 can tear body 21 and can be put into thereupon when the operation of puncturing, be favorable to improving puncture success rate and puncture efficiency.

Can tear body 21 tail end on the opening inside wall an organic whole be provided with be used for preventing the elastic sealing piece 25 that blood flows, elastic sealing piece 25 is provided with a plurality ofly, and each elastic sealing piece 25 is around setting up on can tearing body 21's inside wall, elastic sealing piece 25 becomes the triangle-shaped structure and the slope sets up, elastic sealing piece 25's incline direction is for extending the setting to can tear body 21's head end, elastic sealing piece 25 both sides be can with the sealed limit of adjacent elastic sealing piece 25 butt, each elastic sealing piece 25 can realize under natural state that can tear body 21's tail end opening seals through the butt of each sealed limit. Each elastic sealing piece 25 can be clamped between the puncture needle tube body 11 and the tearable tube body 21 when the puncture needle tube body 11 is inserted into the tearable tube body 21, so that other medical appliances cannot be blocked to conveniently pass through, and each elastic sealing piece 25 is closed when the puncture needle tube body 11 is pulled away, so that blood is placed to reversely flow and leak.

Tearable tailstock 22 is including fixing the tailstock connecting piece 221 at tearable body 21 tail end, and with tailstock connecting piece 221 fixed connection's tearable bedplate 222, tailstock connecting piece 221 bends and makes the setting of C font structure and be provided with two, two tailstock connecting pieces 221 become the tubular structure setting when each other lock, tearable bedplate 222 width both sides all are provided with tearable breach 223, the butt department of two tailstock connecting pieces 221 corresponds the setting with two tearable breach 223, the middle part that can tear bedplate 222 is provided with the through-hole 224 that switches on with perforation 211. The tailstock connecting piece 221 is connected with the tail end of the tearable pipe body 21 through hot melting or bonding, the tearable seat plate 222 can be torn through the tearable notches 223 on the two sides after being broken off, the tearable pipe body 21 is driven to be torn along the tear structure 23 through the two tailstock connecting pieces 221, the structure increases the contact area with the tearable pipe body 21 through the tailstock connecting piece 221, and the improvement of the smoothness of the tearable pipe body 21 which can be torn along the tear structure 23 is facilitated.

In addition, still can be equipped with solid fixed ring at the tail end cover that can tear body 21, gu fixed ring corresponds the setting with tailstock connecting piece 221, can improve the firm in connection degree that can tear body 21 and tailstock connecting piece 221, also can effectively avoid can tearing body 21 and torn by the maloperation.

Above only the utility model discloses an it is preferred embodiment, the utility model discloses a scope of protection not only limits in above-mentioned embodiment, and the all belongs to the utility model discloses a technical scheme under the thinking all belongs to the utility model discloses a scope of protection. It should be noted that, for those skilled in the art, various modifications and decorations can be made without departing from the principle of the present invention, and these modifications and decorations should also be regarded as the protection scope of the present invention.

Claims

1. The utility model provides a catheter sheath subassembly for vein catheterization, is including expander (1) and intubate sheath (2), expander (1) is including puncture needle body (11) and needle tubing tailstock (12) of setting at puncture needle body (11) tail end, intubate sheath (2) including can tearing body (21) and setting can tear tailstock (22) at can tearing body (21) tail end, can tear body (21) axial and run through and be provided with and supply puncture needle body (11) male perforation (211), the inside wall of perforation (211) slides with the lateral wall of puncture needle body (11) and seals the contact, be provided with along axial direction on the lateral wall of can tearing body (21) and tear structure (23), characterized by: the puncture needle tube body (11) is made of hard medical materials, the length of the puncture needle tube body (11) is 10-12cm, the tearable tube body (21) is made of tearable medical materials, the length of the tearable tube body (21) is 5-6cm, the end, far away from the tearable tailstock (22), of the tearable tube body (21) is of a bevel notch structure, and the front end of the puncture needle tube body (11) can extend out of the tearable tube body (21) in the process of being inserted into the through hole (211).

2. The catheter sheath assembly of claim 1, wherein: tear structure (23) including setting up indent tear mouth (231) on can tearing body (21) inside wall, indent tear mouth (231) one-tenth bar ditch form structure setting to the length direction of indent tear mouth (231) extends the setting along the axial direction that can tear body (21), indent tear mouth (231) are provided with two to two indent tear mouth (231) are located can tear body (21) interior relative both sides.

3. The catheter sheath assembly of claim 2, wherein: can tear on the inside wall of body (21) and tear mouth (231) both sides in the indent and all protruding spacing sand grip (232) that are equipped with, spacing sand grip (232) growth strip structure sets up to the length direction of spacing sand grip (232) is torn the length direction extension setting of mouth (231) along the indent, spacing sand grip (232) is torn mouth (231) rounding off with the indent and is connected.

4. A catheter sheath assembly for an intravenous catheter in accordance with claim 3, wherein: be provided with on the lateral wall of pjncture needle body (11) and can contradict the spacing structure (13) of dodging that slides with spacing sand grip (232) and indent tear mouth (231), the axial direction extension setting along pjncture needle body (11) is dodged in spacing structure (13), the length dimension of spacing structure (13) of dodging and the length dimension looks adaptation that can tear body (21).

5. The catheter sheath assembly of claim 1, wherein: the wall thickness size that can tear body (21) reduces the setting from tail end to head end gradually, can tear body (21) including cylindric inside wall and the lateral wall of circular truncated cone form, puncture needle body (11) including supply can tear cylinder linkage segment (14) that body (21) cover was established and can follow circular truncated cone direction section (15) that can tear body (21) and stretch out, circular truncated cone direction section (15) and cylinder linkage segment (14) an organic whole set up, the length size of cylinder linkage segment (14) and the length size looks adaptation that can tear body (21).

6. The catheter sheath assembly of claim 5, wherein: the cone frustum guide section (15) comprises a cone frustum transition section (151) matched with the outer side wall taper of the tearable tube body (21) and a cone frustum insertion end (152) located at the front end of the tearable tube body (21), and the outer side wall taper of the cone frustum insertion end (152) is larger than that of the cone frustum transition section (151).

7. The catheter sheath assembly of claim 1, wherein: the tearable pipe body (21) is provided with a shaping support member (24) for supporting the tearable pipe body (21) to keep an open state in a natural state, the shaping support member (24) is embedded in the wall thickness of the tearable pipe body (21) and is located between two inward concave tearing openings (231), the shaping support member (24) is of a long strip structure and is bent into a C-shaped structure, the shaping support member (24) is provided with a plurality of pieces, and the shaping support members (24) are axially distributed along the tearable pipe body (21).

8. The catheter sheath assembly of claim 7, wherein: design support piece (24) are made the slice by the elastic metal that can deform, design support piece (24) become the setting of C font structure along its length direction's cross section in natural state, design support piece (24) can cooperate when puncture needle body (11) insert can tear body (21) in can tear the laminating of body (21) lateral wall on puncture needle body (11) lateral wall.

9. The catheter sheath assembly of claim 1, wherein: the integrative elastic sealing piece (25) that is used for preventing the outflow of blood that is provided with on the opening inside wall of tearable body (21) tail end, elastic sealing piece (25) are provided with a plurality ofly to each elastic sealing piece (25) is around setting up on the inside wall of tearable body (21), elastic sealing piece (25) become the triangle-shaped structure and the slope sets up, the incline direction of elastic sealing piece (25) is for extending the setting to the head end of tearable body (21), elastic sealing piece (25) both sides be can with the sealed limit of adjacent elastic sealing piece (25) butt, and each elastic sealing piece (25) can realize the tail end opening that can tear body (21) and seal under natural state through the butt of each sealed limit.

10. The catheter sheath assembly of claim 1, wherein: the tearable tailstock (22) comprises a tailstock connecting piece (221) fixed at the tail end of the tearable pipe body (21) and a tearable seat plate (222) fixedly connected with the tailstock connecting piece (221), the tailstock connecting piece (221) is bent into a C-shaped structure and is provided with two, the two tailstock connecting pieces (221) are buckled with each other to form a tubular structure, tearable gaps (223) are formed in two width sides of the tearable seat plate (222), the butt joint parts of the two tailstock connecting pieces (221) correspond to the two tearable gaps (223), and a through hole (224) communicated with the through hole (211) is formed in the middle of the tearable seat plate (222).