CN119327008A

CN119327008A - Adjustable angiography catheter

Info

Publication number: CN119327008A
Application number: CN202411267116.1A
Authority: CN
Inventors: 彭涛
Original assignee: Individual
Current assignee: Individual
Priority date: 2024-09-11
Filing date: 2024-09-11
Publication date: 2025-01-21
Anticipated expiration: 2044-09-11
Also published as: CN119327008B

Abstract

The invention relates to medical equipment, and discloses a debugged radiography catheter which comprises an inner tube (100) and a middle tube (200), wherein round through holes (221), an outer tube (300), a first stay rope (400) and a driving part (500) are formed at two ends of each compression groove (220), and a rope wheel (510) is driven by a motor (530) to rotate so as to tighten or loosen the first stay rope (400). The bending section (210) of the invention bends and swings along the notch of the compression groove (220) so as to drive the inner tube (100) and the outer tube (300) to swing to the angle which is required to be controlled by a user, so that the end part of the catheter can swing to the angle which has the least influence on a patient when the catheter is inserted into intestines and stomach, or the angle which is most convenient to insert.

Description

Adjustable radiography catheter

Technical Field

The invention relates to medical equipment, in particular to a catheter for cholangiography.

Background

The contrast catheter is a percutaneous angiography device, and is an elongated rubber tube which is mainly used for providing a tube guide so that a contrast agent can be smoothly introduced into a blood vessel to generate a contrast effect.

At present, the catheter for pancreatic duct radiography is only a simple plastic tube, and the adjusting direction is mainly by hand breaking or forceps lifting.

U.S. patent No. US20230285721A1, discloses an apparatus, system, and method for a catheter having an actuation portion, which provides for bending the actuation portion of the catheter may include reducing the axial width of each slot of a plurality of slots. Fluid may be supplied into the body lumen through the second lumen of the catheter. The proximally translating wire may include pulling the wire along the actuation portion toward the handle of the catheter outside the plurality of slots. A portion of the body lumen may be cut by an electrically activated wire. The above patent is the initial idea of the present invention by pulling the cord to cause the catheter to bend at both ends, but after practice it has been found that the pulling of the cord greatly increases the width of the catheter, i.e. the pulling of the bow-like string causes discomfort to the patient when the catheter is bent. Although the catheter is curved, it is not easy to pass through complex curved sites such as the stomach, intestines, etc.

U.S. patent application publication No. US10814100B2, which is incorporated herein by reference, provides a deflectable device, such as a catheter, that includes a hinge that enhances the ability of the device to deflect or bend in a predetermined plane. The catheter includes an elongate tubular catheter body having proximal and distal ends and at least one lumen extending therethrough. The distal section is disposed distally of the distal end of the catheter body. A tubular hinge is disposed between the distal end of the catheter body and the proximal end of the distal section. Longitudinal movement 76 of the pull wire relative to the catheter shaft 12 in the proximal region 20, which results in deflection 22 of the distal region, is accomplished 18 by appropriate manipulation of the control handle. The above patent uses a catheter with a lumen with a special hinge to achieve a curved configuration. The hinge cavity structure has certain deflectable property. It is assumed that the stay is disposed at the inner circumference of the cavity in the hinge as described above, i.e., the stay is disposed at the circular arc where the radius of the cavity in the hinge is smallest when the hinge is bent. The advantage of this is that the structure is simple and the cost is low, but the disadvantage is that the stay wire will here further increase the maximum width of the catheter when bending, even possibly when the stay wire of patent US20230285721A1 becomes the string of the bow when exerting too much force, reducing the comfort for the user.

U.S. Pat. nos. 5,488,31, 5,798,24, re34,502, 5,897,529, and U.S. Pat. nos. 6,171,277, 6,123,699, 6,183,463 and 6,198,974 cited therein are also intended as prior art to the present invention.

Based on this, how to provide an adjustable contrast catheter which can drive the active bending of the catheter for cholangiography as much as possible and reduce the width of the catheter as much as possible.

Disclosure of Invention

The invention aims to provide an adjustable radiography catheter which can drive the active bending of a catheter for cholangiography as much as possible and reduce the width of the catheter as much as possible.

The invention relates to a debugged radiography catheter, comprising

An inner tube for delivering a contrast agent;

The middle tube is sleeved outside the inner tube and connected with the inner tube, the middle tube comprises at least two bending sections which are fixed end to end, at least two compression grooves are formed in two sides of each bending section along the length direction, and round through holes are formed in two ends of each compression groove;

The outer tube is sleeved outside the middle tube and connected with the middle tube;

The middle part of the first stay rope sequentially surrounds the circular through hole of the bending section, and one end of the first stay rope is fixed with the bending section;

and a driving part for tightening or loosening the first rope by driving the rope wheel to rotate by the motor.

The invention relates to a debugged radiography catheter, wherein the driving part comprises at least two driving units, each driving unit comprises a rope wheel, a first gear and a motor, two first stay ropes in two circular through holes of the same compression groove are fixed with the outer circumferential surface of the rope wheel of the same driving unit near to the second end, the outer circumferential surface of the rope wheel is a gear, the rope wheel is meshed with the first gear, the first gear is coaxially fixed with an output shaft of the motor, the motor is fixed with a head section of a bending section, and the head section of the bending section is connected with an inner circumferential surface bearing of the rope wheel.

The invention relates to a debugged radiography catheter, wherein the driving part comprises at least two driving units, each driving unit comprises a rope wheel, a first gear and a motor, two first stay ropes in two circular through holes of the same compression groove are fixed with the outer circumferential surface of the rope wheel of the same driving unit near to the second end, the outer circumferential surface of the rope wheel is a gear, the rope wheel is meshed with the first gear, the first gear is coaxially fixed with an output shaft of the motor, the motor is fixed with a head section of a bending section, and the head section of the bending section is in threaded connection with the inner circumferential surface of the rope wheel.

The invention relates to a debugged radiography catheter, wherein the driving part further comprises guide pieces, the guide pieces are arranged on two sides of the round through hole, which are close to the head section and the tail section, a first pull rope is sleeved in the guide pieces, the guide pieces are fixed with the outer surface of the bending section, and the guide piece, closest to the head section and the tail section, of each bending section is fixed with an outer tube.

The invention relates to a debugged radiography catheter, wherein a head section of a fixed motor is fixed with a fixed end of a rope collector, and a movable end of the rope collector is fixed with a second end of a first pull rope.

The invention discloses a debugged radiography catheter, wherein the middle part of a first stay rope sequentially surrounds a circular through hole of a bending section, and the debugged radiography catheter comprises the following steps:

s1, encircling the middle part of a first stay rope by one and a half times with a gap between a circular through hole of the nearest tail section and a circular through hole of a second near tail section;

s2, sequentially encircling the first rope from a gap between the second circular through hole close to the tail part and the third circular through hole close to the tail part to a gap between the circular through hole closest to the head part and the circular through hole close to the head part;

S3, sleeving a first stay rope at the gap by using the guide piece, and fixing the guide piece and the gap of the bending section;

and S4, fixing the first end of the first stay rope with a guide piece closest to the head section, and connecting the second end of the first stay rope with the rope wheel.

The invention discloses a debugged radiography catheter, wherein the middle part of the first stay cord is orderly surrounded in a circular through hole of a bending section, and the debugged radiography catheter further comprises the following steps:

S5, fixing the first end of the first pull rope closest to the bending section of the tail part of the middle pipe with the guide piece of the bending section, and connecting the second end of the first pull rope to the driving part through the guide pieces of other bending sections.

The invention relates to a debugged radiography catheter, wherein motors of at least two driving units are all in communication connection with a control module, and the control module controls the rotation angle and the rotation direction of each motor according to the needs.

The invention relates to an adjustable radiography catheter, wherein the opening directions of compression grooves of adjacent bending sections are different.

The invention relates to an adjustable contrast catheter, wherein the inner tube can be single-cavity, double-cavity or multi-cavity.

The adjustable contrast catheter is different from the prior art in that the adjustable contrast catheter provided by the invention has the advantages that the driving part is matched with the first pull rope to pull the circular through hole of each bending section, so that the first pull rope closes the compression groove corresponding to the adjacent circular through hole, and the bending section is caused to bend and swing along the notch of the compression groove, so that the inner tube and the outer tube are driven to swing to an angle which needs to be controlled by a user, and the end part of the catheter can be swung to an angle which has the least influence on a patient or the angle which is most convenient to insert when the adjustable contrast catheter is inserted into intestines and stomach.

An adjustable contrast catheter of the present invention is further described below with reference to the accompanying drawings.

Drawings

FIG. 1 is a schematic cross-sectional view of an adjustable contrast catheter;

FIG. 2 is a schematic illustration of a single bend segment of a middle tube of an adjustable contrast catheter in a first position;

FIG. 3 is a schematic illustration of a single bend segment of a middle tube of an adjustable contrast catheter in a second position;

FIG. 4 is a schematic illustration of a second dual bend section of a middle tube of a debugged contrast catheter;

FIG. 5 is an enlarged partial view of FIG. 2;

FIG. 6 is an enlarged partial view of the first position of FIG. 4;

FIG. 7 is an enlarged partial view of the second position of FIG. 4;

fig. 8 is a partial enlarged view of the third position of fig. 4.

Detailed Description

Referring to fig. 1-8, referring to fig. 1,2 and 3, a tunable contrast catheter according to the present invention includes an inner tube 100 for delivering a contrast agent;

The middle pipe 200 is sleeved outside the inner pipe 100 and connected with the inner pipe 100, the middle pipe 200 comprises at least two bending sections 210 fixed end to end, at least two compression grooves 220 are formed in two sides of the bending sections 210 along the length direction, and circular through holes 221 are formed in two ends of each compression groove 220;

An outer tube 300 which is sleeved outside the middle tube 200 and connected with the middle tube 200;

the middle part of the first pull rope 400 sequentially surrounds the circular through hole 221 of the bending section 210, and one end of the first pull rope 400 is fixed with the bending section 210;

And a driving part 500 for rotating the rope wheel 510 by a motor 530 to tighten or loosen the first rope 400.

The driving part 500 is matched with the first pull rope 400 to pull the circular through hole 221 of each bending section 210, so that the first pull rope 400 closes the compression groove 220 corresponding to the adjacent circular through hole 221, and the bending section 210 swings along the notch of the compression groove 220, so that the inner tube 100 and the outer tube 300 are driven to swing to an angle which is required to be controlled by a user, and the end part of the catheter can swing to an angle which has least influence on a patient when the catheter is inserted into intestines and stomach, or the angle which is most convenient to insert.

It should be noted that, the compression groove 220 may be formed on both the upper and lower sides of each bending section 210, and the compression groove 220 may be understood as a crescent through hole, that is, when the bending section 210 is bent to the maximum degree along the compression groove 220, both sides of the compression groove 220 may be completely attached to the degree of almost sealing, so that the thicker bending section 210 is convenient to have sufficient bending degree. The two ends of the bending section 210 are respectively provided with a circular through hole 221, that is, the cross section of the same bending section 210 can be provided with 4 circular through holes 221, correspondingly, the 4 circular through holes 221 of the same bending section 210 should pass through the 4 first pull ropes 400, that is, each circular through hole 221 is the middle part of one first pull rope 400 and surrounds the same. Taking fig. 2 and 3 as an example, fig. 2 is a straight line state, and when the right end is required to be lifted upwards, the driving part 500 should tighten the two first pull ropes 400 at the upper side, but not tighten, or even loosen, the two first pull ropes 400 at the lower side.

For another example, as shown in fig. 2, if the bending section 210 needs to be bent forward, the driving portion 500 should tighten the two first pull ropes 400 on the front side of the bending section 210, and not tighten, or even loosen, the two first pull ropes 400 on the rear side.

In this manner, by adjusting the degree of tension of the four first pull cords 400, the bending section 210 can theoretically be bent in any direction at will. However, to ensure that the width of the bent segment 210 or conduit is minimized, it is preferable to bend only the two first pull cords 400 within the two circular through holes 221 of the same compression groove 220 so as to minimize the width of the bent segment 210 or conduit. Because the two active, stretched first pull cords 400 are farther from the arc at the smallest radius of the bent segment 210, the maximum diameter of the bent segment 210 is not increased, and thus the user is not uncomfortable.

The materials of the outer tube 300, the middle tube 200 and the inner tube 100 can be soft rubber or soft resin or pvc or soft plastic tube. The flexible material characteristics can be used for bending when clamping the flexible material.

Wherein the head section 211 of the bending section 210 closest to the head may be made of iron or stainless steel or aluminum alloy or hard resin, thereby providing a supporting force to the driving part 500.

In some embodiments, referring to fig. 4 and 8, the driving part 500 includes at least two driving units, each driving unit includes a sheave 510, a first gear 520, and a motor 530, two first pull ropes 400 in two circular through holes 221 of the same compression groove 220 are fixed to an outer circumferential surface of the sheave 510 of the same driving unit near the second end, the outer circumferential surface of the sheave 510 is a gear, the sheave 510 is meshed with the first gear 520, the first gear 520 is coaxially fixed to an output shaft of the motor 530, the motor 530 is fixed to a head section 211 of the bending section 210, and the head section 211 of the bending section 210 is in bearing connection with an inner circumferential surface of the sheave 510.

According to the invention, the rope wheel 510 driven by the motor 530 and the first gear 520 rotates, so that the two first pull ropes 400 of the same compression groove 220 are driven to shrink, and the bending section 210 can be bent along with the rotation of the rope wheel 510, so that the bending section 210 can be controlled to be bent when the motor 530 rotates.

In addition, it should be noted that when the plurality of bending sections 210 are connected in series, the number of driving units of the driving portion 500 should be equal to two times the number of bending sections. And, the plurality of driving units should be fixed to the head section 211 of the same bending section 210 and should be fixed to the head section 211 of the bending section 210 of the head so that only the head section 211 does not extend into the user's body, while the head sections 211 and the tail sections 212 of the other bending sections 210 can extend into the user's body to ensure that the motor 530 does not leak electricity, and the head section 211 can be conveniently controlled and observed by the user.

Since the sheave 510 is directly bearing-connected to the head 211, the motor 530 should be kept from being rotated at will when not energized or rotated. That is, when the motor 530 is not rotated, the external force cannot drive the motor 530 to rotate, so that the first rope 400 is ensured to maintain the contracted state of the first rope 400 after the rope sheave 510 is contracted. Preferably, the motor 530 is a single-speed reduction motor or a three-phase asynchronous motor.

Wherein the head section 211 of one bending section 210 may be fixed or sealed to the tail section 212 of the other bending section 210.

It should be noted that, the first rope 400 may pass through a through hole formed in the outer axial direction of the rope sheave 510 and be fixed with the through hole, so as to achieve the effect of fixing the outer circumferential surface of the rope sheave 510 with the first rope 400, and of course, the outer circumferential surface of the rope sheave 510 is a gear, a tooth valley between two teeth of the gear may be fixed with the first rope, and the tooth height of the gear is high enough that the thickness of the first rope 400 does not affect the engagement between the rope sheave 510 and the first gear 520.

It should be noted that, because the head section 211 is connected to the sheave 510, when the first pull ropes 400 of the plurality of bending sections 210 require the plurality of sheaves 510 arranged in sequence of the head section 211 to control, in order to avoid interference between the sheave 510 and the first pull ropes 400 not belonging to the control, a plurality of through holes or pipes guiding the first pull ropes 400 may be provided in the head section 211, so that the first pull ropes 400 not belonging to the sheave 510 may bypass the sheave 510 and be connected to the corresponding sheaves 510.

As a variant of the present invention, referring to fig. 4 and 8, the driving part 500 includes at least two driving units, each driving unit includes a sheave 510, a first gear 520, and a motor 530, two first pull ropes 400 in two circular through holes 221 of the same compression groove 221 are fixed to an outer circumferential surface of the sheave 510 of the same driving unit near the second end, the outer circumferential surface of the sheave 510 is a gear, the sheave 510 is meshed with the first gear 520, the first gear 520 is coaxially fixed to an output shaft of the motor 530, the motor 530 is fixed to a head 211 of the bending section 210, and the head 211 of the bending section 210 is in threaded connection with an inner circumferential surface of the sheave 510.

According to the invention, the rope wheel 510 driven by the motor 530 and the first gear 520 rotates, so that the two first pull ropes 400 of the same compression groove 220 are driven to shrink, so that the bending section 210 can be bent along with the rotation of the rope wheel 510, and the bending section 210 can be controlled to be bent when the motor 530 rotates, and it is noted that the head section 211 is in threaded connection with the rope wheel 510. That is, the outer circumferential surface of the head section 211 and the inner circumferential surface of the sheave 510 are provided with threads that mesh with each other. The present invention can freely power off or not control the motor 530 after rotating the rotation angle of the rope wheel 510 by means of self-locking of the screw thread, and the rope wheel 510 can not freely rotate, thereby being suitable for any kind of motor.

In some embodiments, referring to fig. 4, 5, 6,7, and 8, the driving part 500 further includes guide members 550, the guide members 550 are disposed at two sides of the circular through hole 221 near the head section 211 and the tail section 212, the guide members 550 are sleeved with the first pull ropes 400, the guide members 550 are fixed to the outer surface of the bending sections 210, and the guide members 550 closest to the head section 211 and closest to the tail section of each bending section 210 are fixed to the outer tube 300.

The present invention can guide the movement of the first pulling rope 400 by the guide 550, thereby preventing the first pulling rope 400 from sagging in a manner similar to the string of a bow, and increasing the maximum diameter of the bent bending section 210. In addition, the guiding element at the head and tail positions can be used as a connecting fixing element for fixing the bending section 210 of the middle pipe 200 and the outer pipe 300, so that each bending section 210 and the outer pipe 300 can travel a free cavity, the outer pipe 300 is prevented from blocking the bending section 210 to bend, and meanwhile, a user is prevented from being scratched by the bending section 210.

The guide 550 may be a sleeve or a through hole formed on the bending section 210.

The same guide 550 may guide different first pull cords 400 of the plurality of bending segments 210.

In some embodiments, referring to fig. 4, 5, 6, 7, 8, the head section 211 of the stationary motor 530 is fixed to the stationary end of the rope retractor 540, and the movable end of the rope retractor 540 is fixed to the second end of the first pull rope 400.

The second end of the first pull rope 400 can be always converged by the rope retractor 540.

The retractor 540 may be, for example, a spring tape.

As a variation of the present invention, the second end of the first pull cord 400 may also be directly secured to the sheave 510.

In some embodiments, referring to fig. 4,5, 6, 7, 8, the first pull cord 400, the middle of which sequentially surrounds the circular through hole 221 of the bending section 210, comprises the following steps:

s1, encircling the middle part of the first pull rope 400 by one and a half times around the gap between the circular through hole 221 of the nearest tail section 212 and the circular through hole 221 of the second near tail section 212;

s2, sequentially encircling the first stay rope 400 from a gap between the second circular through hole 221 close to the tail part and the third circular through hole close to the tail section 212 to a gap between the circular through hole 221 closest to the head part and the circular through hole 221 close to the head section 211;

s3, sleeving the first stay rope 400 at the gap by using the guide piece 550, and fixing the guide piece 550 and the gap of the bending section 210;

S4, fixing the first end of the first pull rope 400 with the guide 550 closest to the head section 211, and connecting the second end of the first pull rope 400 with the rope sheave 510.

The invention can adjust the size of the gap by rotating the rope wheel 510 in the above way, thereby adjusting whether the bending section is bent. In addition, when the bending section 210 is bent, the first pull rope 400 can be prevented from being in a posture similar to the string of an arrow so as to increase the maximum diameter, and the possibility of discomfort of a user is reduced.

S5, fixing the first end of the first pull rope 400 closest to the bending section 210 at the tail part of the middle pipe 200 with the guide piece 550 of the bending section 210, and connecting the second end of the first pull rope 400 to the driving part 500 through the guide piece 550 of the other bending section 210.

According to the invention, the bending of the bending section can be driven by driving only one side of the first pull ropes 400 in the mode, so that the problem of increase of the maximum diameter caused by stacking of two ends of a plurality of first pull ropes 400 is solved.

In order to facilitate the arrangement of the first pull ropes 400 of the plurality of bending sections 210, the first pull rope 400 closest to the tail of the middle tube 200 is located at the maximum opening of the other first pull ropes 400 near the compression groove 220, so that the first pull ropes 400 are stacked like a cone, and the maximum diameter is reduced.

In some embodiments, referring to fig. 4, 5, 6, 7, 8, the motors 530 of the at least two drive units are each communicatively coupled to a control module that controls the angle and direction of rotation of each motor 530 as desired.

The present invention controls the plurality of motors 530 through the control module of the unified control, which can facilitate controlling the motors as needed.

In some embodiments, referring to fig. 4, 5, 6, 7,8, the compression grooves 220 of adjacent bending sections 210 are oriented differently.

For example, the opening direction of the compression groove 220 of two adjacent bending sections 210 is one in the up-down direction and one in the front-back direction. The control module can control only one bending section 210 to work when bending up and down is required, and can control the other bending section to work when bending back and forth is required.

In some embodiments, referring to fig. 4, 5, 6, 7, 8, the inner tube 100 may be single-lumen or dual-lumen or multi-lumen.

The above examples are only illustrative of the preferred embodiments of the present invention and are not intended to limit the scope of the present invention, and various modifications and improvements made by those skilled in the art to the technical solution of the present invention should fall within the scope of protection defined by the claims of the present invention without departing from the spirit of the present invention.

Claims

1. An adjustable radiography catheter is characterized by comprising

An inner tube (100) for delivering a contrast agent;

The middle tube (200) is sleeved outside the inner tube (100) and connected with the inner tube (100), the middle tube (200) comprises at least two bending sections (210) fixed end to end, at least two compression grooves (220) are formed in the two sides of the bending sections (210) along the length direction, and round through holes (221) are formed in the two ends of each compression groove (220);

an outer tube (300) which is sleeved outside the middle tube (200) and is connected with the middle tube (200);

The middle of the first stay cord (400) sequentially surrounds the circular through hole (221) of the bending section (210), and one end of the first stay cord (400) is fixed with the bending section (210);

and a driving unit (500) that tightens or loosens the first rope (400) by rotating the sheave (510) with a motor (530).

2. The adjustable contrast catheter as set forth in claim 1, wherein the driving unit (500) comprises at least two driving units, each driving unit comprises a sheave (510), a first gear (520) and a motor (530), two first pull ropes (400) in two circular through holes (221) of the same compression groove (220) are fixed with the outer circumferential surface of the sheave (510) of the same driving unit near the second end, the outer circumferential surface of the sheave (510) is a gear, the sheave (510) is meshed with the first gear (520), the first gear (520) is coaxially fixed with an output shaft of the motor (530), the motor (530) is fixed with a head section (211) of the bending section (210), and the head section (211) of the bending section (210) is in bearing connection with the inner circumferential surface of the sheave (510).

3. The adjustable contrast catheter as set forth in claim 1, wherein the driving unit (500) comprises at least two driving units, each driving unit comprises a sheave (510), a first gear (520) and a motor (530), two first pull ropes (400) in two circular through holes (221) of the same compression groove (221) are fixed with the outer circumferential surface of the sheave (510) of the same driving unit near the second end, the outer circumferential surface of the sheave (510) is a gear, the sheave (510) is meshed with the first gear (520), the first gear (520) is coaxially fixed with an output shaft of the motor (530), the motor (530) is fixed with a head section (211) of the bending section (210), and the head section (211) of the bending section (210) is in threaded connection with the inner circumferential surface of the sheave (510).

4. An adjustable contrast catheter according to any of claims 2 or 3, wherein the drive section (500) further comprises guide members (550), the guide members (550) being arranged on both sides of the circular through hole (221) near the head section (211) and the tail section (212), the guide members (550) being sleeved with the first pull cord (400), the guide members (550) being fixed to the outer surface of the bending section (210), the guide members (550) closest to the head section (211) and closest to the tail section of each bending section (210) being fixed to the outer tube (300).

5. An adjustable contrast catheter as defined in any one of claims 2 or 3, wherein the head section (211) of the fixed motor (530) is fixed to the fixed end of the rope retractor (540), and the movable end of the rope retractor (540) is fixed to the second end of the first pull rope (400).

6. The adjustable contrast catheter as set forth in claim 1, wherein the first pull cord (400) has a central portion that sequentially surrounds the circular through hole (221) of the bending section (210), and the method comprises the steps of:

S1, encircling the middle part of a first stay rope (400) around a gap between a circular through hole (221) of the nearest tail section (212) and a circular through hole (221) of a second near tail section (212) by one and a half turns;

S2, sequentially winding the first stay rope (400) from a gap between the second circular through hole (221) close to the tail part and the third circular through hole close to the tail section (212) to a gap between the circular through hole (221) closest to the head part and the circular through hole (221) close to the head section (211);

S3, sleeving the first stay rope (400) at the gap by using the guide piece (550) and fixing the guide piece (550) and the gap of the bending section (210);

S4, fixing the first end of the first stay rope (400) with a guide piece (550) closest to the head section (211), and connecting the second end of the first stay rope (400) with the rope wheel (510).

7. The adjustable contrast catheter as set forth in claim 6, wherein the first pull cord (400) has a central portion that sequentially surrounds the circular through hole (221) of the bending section (210), further comprising the steps of:

s5, fixing the first end of a first pull rope (400) closest to the bending section (210) at the tail part of the middle pipe (200) with a guide piece (550) of the bending section (210), and connecting the second end of the first pull rope (400) to the driving part (500) through the guide piece (550) of the other bending sections (210).

8. An adjustable contrast catheter as set forth in claim 2 wherein the motors (530) of the at least two drive units are each communicatively coupled to a control module that controls the rotational angle and direction of each motor (530) as desired.

9. An adjustable contrast catheter as set forth in claim 2, wherein the compression slots (220) of adjacent bending segments (210) are oriented in different directions.

10. An adjustable contrast catheter as defined in claim 1, wherein the inner tube (100) is single lumen, double lumen or multi-lumen.