CN113018645B

CN113018645B - Blood vessel wall injection catheter system based on electrified expansion medicine bag

Info

Publication number: CN113018645B
Application number: CN201911245820.6A
Authority: CN
Inventors: 黄智�; 周石; 张帅
Original assignee: Guizhou Medical University
Current assignee: Affiliated Hospital of Guizhou Medical University
Priority date: 2019-12-07
Filing date: 2019-12-07
Publication date: 2021-11-19
Anticipated expiration: 2039-12-07
Also published as: JP6719065B1; CN113018645A; JP2021090705A

Abstract

The invention discloses a blood vessel wall injection catheter system based on an electrified expansion medicine sac, which comprises a guide catheter, an injection catheter and a medicine sac made of an electroactive polymer material capable of being electrified, expanded and power-off recovered, wherein the medicine sac is provided with an injection needle, the medicine sac internally comprises a limiting mechanism for limiting the injection needle from penetrating into the blood vessel wall and a metal guide wire for assisting, and the system further comprises an external control assembly for controlling the metal guide wire. The medicine bag prepared by the electroactive polymer material realizes the control of the extension, the puncture angle and the recovery of the injection needle under the condition of a simple structure by utilizing the characteristic of power-on expansion and power-off recovery of the medicine bag, simplifies the structure of the catheter, and ensures that the medicine bag is more convenient to use and has stronger applicability.

Description

Blood vessel wall injection catheter system based on electrified expansion medicine bag

Technical Field

The invention belongs to the technical field of medical instruments, and particularly relates to an interventional catheter system for vascular wall microneedle targeted injection of drugs.

Background

With the progress of social development, more and more people suffer from chronic hypertension which is often an important cause of heart disease and death, while intractable hypertension is often related to the activity of renal sympathetic nerves which are divided into renal artery sympathetic afferent nerves and efferent nerves, both of which are densely distributed in the renal artery adventitia in a net shape. Most of treatment aiming at hypertension in the prior art depends on oral medicines, but the oral medicines enter blood to reach focuses after being metabolized, so that the treatment effect is poor.

In recent years, a new technology for treating refractory hypertension through percutaneous catheter renal sympathetic nerve radio frequency ablation (RDN) is internationally provided, and the method cuts off renal sympathetic nerves through the RDN, so that the aim of treating refractory hypertension is fulfilled. For example, the patent publication No. CN201310368577.3 discloses a renal sympathetic nerve electrical stimulation ablation apparatus, the patent publication No. CN201320003697.9 discloses a multipoint radio frequency ablation electrode for renal sympathetic nerve ablation, and the patent publication No. CN201310306004.8 discloses a renal sympathetic nerve radio frequency ablation electrode and a radio frequency ablation system, which all use the radio frequency ablation, but the RF ablation is firstly used to cause extreme pain to the "burn" inside the renal artery, and in addition, the renal artery is also damaged to cause late restenosis, thrombosis, renal artery spasm, debris embolism or other problems, so that the method is not the most suitable and effective method.

Based on the drawbacks of the conventional methods, there have been proposed in the prior art iontophoretic drug delivery systems and methods for denervation of renal sympathetic and iontophoretic drug delivery, such as that disclosed in publication No. CN201280017454.9, using drug-infiltration therapy in direct contact with the renal artery wall. However, this method increases the contact rate of the blood vessel wall with the drug, but the effect is slightly better than that of direct blood vessel administration, and the absorption and utilization rate of the drug by the blood vessel wall is still insufficient, so the therapeutic effect is not satisfactory.

Disclosure of Invention

Aiming at the technical problems, the invention provides a vessel wall injection catheter system based on an electrified expansion medicine sac, which has the advantages of simple structure, convenience in puncturing the vessel wall and good injection effect.

The technical scheme of the invention is as follows: an electrically-inflated balloon-based vessel wall injection catheter system, the system comprising:

the guiding catheter is provided with a proximal end, a distal end and an accommodating cavity longitudinally penetrating through the guiding catheter; the distal end of the guiding catheter is in a tip shape and can conveniently extend into a blood vessel so as to play a guiding role, and the proximal end of the guiding catheter is provided with two finger rings which are convenient to operate.

The injection catheter is positioned in the accommodating cavity and can freely stretch and retract along a central axis extending along the longitudinal direction, the injection catheter is provided with a near end, a far end and an injection cavity, and an injection port is arranged on a catheter body of the injection catheter close to the near end of the injection catheter;

the anther sac, the anther sac adopts the electroactive polymer material that can the circular telegram inflation outage resumes to make, the anther sac is stretching out and when waiting to pierce the operating condition of vascular wall, can be divided into the anther sac front portion, anther sac rear portion and anther sac front portion and anther sac rear portion juncture are used for two anther sac location portions with the vascular wall contact, anther sac rear portion links structure as an organic whole with the distal end of injection catheter, be equipped with a plurality of injection syringe needle on the anther sac front portion, the general case can select 2 of symmetry, 4 or 6 injection syringe needles, the anterior inboard end of anther sac is fixed with electrically conductive hemisphere, electrically conductive hemisphere's material is copper, electrically conductive hemisphere is connected with the metal seal wire, the metal seal wire can select to have medical seal wire, for example, the nickel titanium seal wire, the diameter size can be 0.5 mm. The metal guide wire extends along the longitudinal direction and penetrates out of the near end of the injection catheter, the shape of the front part of the medicine bag is changed by pulling the metal guide wire, so that the direction of the injection needle is changed, the medicine bag is conveniently contracted in the guide catheter, and the two ends of the front part of the medicine bag and the rear part of the medicine bag are both provided with developing mark points, so that the medicine bag can be conveniently positioned under the guidance of X-rays;

the limiting mechanism is arranged in the medicine bag and used for limiting the depth of the injection needle penetrating into the vessel wall, and meanwhile, the success rate of injection can be greatly improved;

and the external control assembly comprises a handle which is connected to a proximal port of the injection catheter and can be penetrated and passed by the metal guide wire, a locking mechanism is arranged in the handle and used for limiting the movement of the metal guide wire, the metal guide wire is connected with a pulse generator through an external lead and electrified, and the metal guide wire is used for transmitting current to the medicine bag to enable the medicine bag to achieve the change of electrifying expansion power failure recovery.

Further, the medicine bag is of a diamond structure in the working state, the area of the front part of the medicine bag is smaller than that of the rear part of the medicine bag, and the lengths of the plurality of injection needles arranged on the same side of the front part of the medicine bag are sequentially increased along the advancing direction of the medicine bag. The purpose of the area of the front part of the capsule being smaller than the area of the back part of the capsule is to better inform the shape of the front part of the capsule and thus to control the direction of the injection needle, which otherwise could be confusing due to the fact that the injection needle is effectively supported by the too large area of the front part of the capsule.

Furthermore, the limiting mechanism comprises a support ring which is glued on the inner side of the distal end opening of the injection catheter and two elastic support rods which are connected to the support ring, wherein the elastic support rods are made of glass fiber materials, and the materials with certain supporting force and resilience force can be theoretically adopted. The elastic support rod is fixed on the inner side wall of the rear part of the medicine bag in a gluing mode, and the far end of the elastic support rod extends to the medicine bag positioning part and is used for positioning the medicine bag in a blood vessel.

Furthermore, the limiting mechanism also comprises a limiting wire rope connected between the far ends of the two elastic supporting rods which are opposite up and down and between the two injection needles which are opposite up and down.

Furthermore, the middle part of the limiting wire rope is provided with a limiting ring used for guiding the metal guide wire, and the length of the limiting wire rope connected between the two injection needles which are opposite up and down is reduced in sequence along the advancing direction of the medicine bag. The length of each pair of injection needles and the length of the limiting wire rope are equal, and the purpose of the limiting ring is to provide a certain guide for the metal guide wire and prevent the metal guide wire from being telescopically deviated.

Further, the inside of handle is equipped with the conduit that is used for supplying the metal seal wire freely to stretch out and draw back, perpendicular to conduit below and the screw hole that runs through the handle bottom, and perpendicular to conduit top and the plain noodles hole that runs through the handle top, the plain noodles hole, conduit and screw hole link up from top to bottom, be used for installing locking mechanism, the portion that the conduit extends the handle is used for connecting the near-end of injection catheter, and be equipped with the seal membrane that only supplies the metal seal wire to pass in the portion that the conduit extends the handle, the seal membrane is not shown in the figure, the main objective is in the liquid medicine refluence that is for the injection advances the handle. Through handle control, can conveniently be to the control of metal seal wire.

Further, locking mechanical system is including the bolt post of connection in the screwed hole, bolt post lower extreme links to each other with being connected impulse generator through the wiring mouth, locking mechanical system is still including the urceolus of connection in smooth surface hole top, the lower extreme is equipped with on the urceolus, lower limit ring, and be located the inside press the depression bar of urceolus, be equipped with on the press the depression bar, the lower flange, fixedly connected with reset spring between lower flange and the lower limit ring, be used for through pressing down the messenger press the depression bar lower extreme wear out down the limit ring with metal seal wire locking on the bolt post, the bolt post is the electric conductor, press the depression bar to be the insulator, the inside telescopic link that can stretch out and draw back along radially being provided with of lower flange, the telescopic link can stretch out the locating hole of seting up on the urceolus lateral wall and lock, can retract inside the lower flange after pressing. The locking mechanism facilitates precise control of the position of the metal guide wire.

Further, the preparation method of the electroactive polymer film layer comprises the following steps: the output current of the pulse generator is 0.5-1.0 mA. When the output current is less than 0.5mA, the medicine bag can not be effectively stimulated to achieve the expected effect, when the output current is more than 1.0mA, the stimulation effect is not greatly changed, in addition, the overlarge current is also unsafe for a human body, and the current is preferably 0.9mA through experiments.

Furthermore, the electroactive polymer material is prepared by taking a polyacrylate film as an electroactive polymer core layer, attaching carbon nanotube films as flexible electrode layers to the upper surface and the lower surface of the polyacrylate film, and finally compounding a crystalline colloid on one surface of the polyacrylate film as a protective supporting layer which is taken as the outermost layer in the manufactured medicine bag. The device not only can play a role in protecting the electroactive polymer core layer and the flexible electrode layer, but also can have certain hardness after being electrified, so that the device can provide support for the injection needle to penetrate into the vascular wall.

Further, the preparation method of the electroactive polymer material comprises the following steps:

s1: taking a 5 x 5cm polyacrylate film, washing the polyacrylate film by using dewatering, soaking the washed polyacrylate film for 12-24 hours by using a hydrochloric acid solution with the mass fraction of 1-3% and a mixed liquid of water-soluble organic silicon oil with the mass fraction of 10-20%, taking out the polyacrylate film, washing the polyacrylate film by using deionized water, and blowing nitrogen to dry to obtain a pretreated polyacrylate film;

s2: then ultrasonically mixing the multi-walled carbon nanotube dispersion liquid with absolute ethyl alcohol according to the ratio of 1:1 to prepare an impregnation liquid, firstly uniformly spin-coating 1, 2-Aminopropyltriethoxysilane (APTS) adhesion promoter for 10-30s at 500r/min by using a spin coater on the surface of a pretreated polyacrylate film, then soaking the polyacrylate film coated with the adhesion promoter in the impregnation liquid for 5-30min, washing the surface by using a nitric acid solution with the mass fraction of 5-10% after pulling out, then washing the surface by using deionized water, and blowing nitrogen to be dry to obtain the polyacrylate film attached with the carbon nanotube film;

s3: mixing the nano cellulose whisker hydrosol with 500nm polypyrrole-coated magnetic nanoparticles with the particle size of 200-. The nano cellulose whisker hydrosol is prepared by a method for preparing the nano cellulose whisker hydrosol by utilizing kelp residues according to Chinese patent publication No. CN201310095395.3, has extremely high toughness and flexibility, can maintain certain ductility under the action of expansion force of an electroactive polymer film core layer, and can recover to the original shape and have good biocompatibility when the expansion force disappears due to good toughness. The polypyrrole coated magnetic nanoparticles (polypyrroe @ Fe3O4) are purchased from SiAnruix Biotechnology limited, the magnetic nanoparticles are changed from disorder to an ordered state when the polypyrrole coated magnetic nanoparticles are electrified, the supporting strength is increased, the polypyrrole coated magnetic nanoparticles are changed from disorder to disorder when the polypyrrole coated magnetic nanoparticles are electrified, and the polypyrrole coated magnetic nanoparticles are restored to flexibility after being sequentially switched off. When in use, the electroactive polymer material with proper size is cut for use, and is bonded and fixed with the front end of the injection catheter to form the medicine bag.

The invention has the beneficial effects that: the medicine bag prepared by the electroactive polymer material realizes the control of the extension, the penetration angle and the recovery of the injection needle under the condition of simple structure by utilizing the characteristic of power-on expansion and power-off recovery of the medicine bag, the medicine bag is internally provided with the limiting mechanism, the medicine bag is positioned by utilizing the elasticity of the elastic support rod which is easy to expand and recover, the deviation of the medicine bag can be effectively prevented, thereby causing the displacement of the injection needle, in addition, the invention is also provided with a limit wire rope between the tail end of the elastic supporting rod and the injection needle which is opposite up and down, the depth of the injection needle penetrating into the blood vessel can be controlled, and the length of the injection needle on the same side is increased along the advancing direction, but the lengths of the injection needles in each pair of the upper injection needle and the lower injection needle and the fiber silk rope connected between the injection needles are equal in sum, therefore, after the front part of the medicine bag is expanded, the injection needle can be ensured to effectively penetrate into the blood vessel wall, and the injury caused by excessive puncture can be prevented. The invention simplifies the structure of the catheter, and leads the use to be more convenient and the applicability to be stronger.

Drawings

FIG. 1 is a schematic view of the overall structure of the inventive capsule protruding into the vessel wall;

FIG. 2 is a schematic view of the overall structure of the inventive capsule as it is retracted through the catheter;

FIG. 3 is an enlarged view of a portion of the invention at A in FIG. 1;

FIG. 4 is an enlarged view of a portion of the invention at B in FIG. 2;

FIG. 5 is a schematic view showing the internal structure of the capsule of the present invention in an expanded state with a spacing wire and a spacing ring;

FIG. 6 is a schematic view showing the internal structure of the capsule with a position-limiting wire and a position-limiting ring in a contracted state;

FIG. 7 is a schematic view of the external structure of the sachet of the present invention in the expanded state;

FIG. 8 is a schematic view of the internal structure of the locking mechanism of the present invention in place;

FIG. 9 is a schematic view of the internal structure of the locking structure of the present invention when the locking metal wire is depressed;

fig. 10 is a schematic structural view of an electroactive polymer film material in example 9 of the present invention.

Wherein, 1-guide catheter, 2-injection catheter, 21-injection port, 3-medicine bag, 31-front part of medicine bag, 32-back part of medicine bag, 33-medicine bag positioning part, 34-injection needle, 35-conductive hemisphere, 36-metal guide wire, 37-developing marking point, 4-limiting mechanism, 41-supporting ring, 42-elastic supporting rod, 43-limiting wire rope, 44-limiting ring, 5-external control component, 51-handle, 52-locking mechanism, 521-bolt column, 522-wiring port, 523-outer cylinder, 524-upper limiting ring, 525-lower limiting ring, 526-pressing rod, 527-upper flange, 528-lower flange, 529-telescopic rod, 510-positioning hole, 511-reset spring, 53-pulse generator, 54-conduit, 55-threaded hole, 56-smooth surface hole, 61-polymer core layer, 62-flexible electrode layer, 63-protective support layer, 7-vessel wall.

Detailed Description

Example 1

As shown in fig. 1, a blood vessel wall injection catheter system based on an electrically-inflated balloon, the system comprising: a guide catheter 1, wherein the guide catheter 1 is provided with a proximal end, a distal end and an accommodating cavity longitudinally penetrating through the inner part; the diameter of the guiding catheter 1 is about 3m, wherein the distal end of the guiding catheter 1 is tip-shaped and can be conveniently extended into a blood vessel to play a guiding role, and the proximal end of the guiding catheter 1 is provided with two finger rings which are convenient to operate. The injection catheter 2 is positioned in the accommodating cavity and can freely stretch and retract along a central axis extending along the longitudinal direction, the injection catheter 2 is provided with a proximal end, a distal end and an injection cavity, and an injection port 21 is arranged on the body of the injection catheter 2 close to the proximal end of the injection catheter 2;

the medical capsule is characterized by further comprising a medical capsule 3, as shown in fig. 3, the medical capsule 3 is made of an electroactive polymer material capable of being electrified, expanded and power-off recovered, wherein the electroactive polymer material is formed by silver plating on the surface of a polyacrylate film, when the medical capsule 3 extends out and is in a working state to be penetrated into a blood vessel wall, the medical capsule can be divided into a front portion 31 of the medical capsule, a rear portion 32 of the medical capsule and two medical capsule positioning portions 33 at the junction of the front portion 31 of the medical capsule and the rear portion 32 of the medical capsule and used for being in contact with the blood vessel wall 7, the rear portion 32 of the medical capsule and the far end of the injection catheter 2 are connected into a whole, 6 injection needles 34 are arranged on the front portion 31 of the medical capsule, a conductive hemisphere 35 is fixed at the inner side end of the front portion 31 of the medical capsule, the conductive hemisphere 35 is made of copper, the conductive hemisphere 35 is connected with a metal guide wire 36, the metal guide wire 36 can be selected to be provided with a medical guide wire, such as a nickel-titanium guide wire, and the diameter can be 0.5 mm. The metal guide wire 36 extends along the longitudinal direction and penetrates out of the proximal end of the injection catheter 2, the shape of the front part 31 of the medicine bag is changed by pulling the metal guide wire 36, so that the direction of the injection needle 34 is changed, the medicine bag is convenient to shrink in the guide catheter 1, as shown in fig. 7, developing mark points 37 are arranged at the two ends of the front part 31 of the medicine bag and the rear part 32 of the medicine bag, and the medicine bag is convenient to position under the guidance of X-rays; the medicine bag 3 is of a diamond structure in a working state, the area of the front part 31 of the medicine bag is smaller than the area of the rear part 32 of the medicine bag, and the lengths of a plurality of injection needles 34 arranged on the same side of the front part 31 of the medicine bag are sequentially increased along the advancing direction of the medicine bag 3. The purpose of the smaller area of the front part 31 of the capsule than the area of the rear part 32 of the capsule is to better inform the configuration of the front part 31 of the capsule and thus to control the orientation of the injection needle 34, which otherwise would be confused by the fact that the injection needle 34 is effectively supported by the large area of the front part 31 of the capsule.

As shown in fig. 3 and 4, the system further includes a limiting mechanism 4, as shown in fig. 1 or 2, the limiting mechanism 4 includes a support ring 41 glued on the inner side of the distal end opening of the injection catheter 2, and two elastic support rods 42 connected to the support ring 41, where the elastic support rods 42 are made of glass fiber, and the material with certain supporting force and resilience may be theoretically. The elastic support rod 42 is fixed on the inner side wall of the rear part 32 of the medicine bag in an adhesive joint mode, and the far end of the elastic support rod 42 extends to the medicine bag positioning part 33 and is used for positioning the medicine bag 3 in a blood vessel. The injection needle 34 is used for limiting the depth of the vessel wall 7 penetrated by the injection needle, and the injection success rate can be greatly improved.

As shown in fig. 1 and 2, the system further comprises an external control assembly 5 comprising a handle 51 connected to the proximal port of the injection catheter 2 and capable of passing the metal guide wire 36 therethrough, a locking mechanism 52 provided in the handle 51, the locking mechanism 52 being adapted to limit the movement of the metal guide wire 36, and a pulse generator 53 connected via an external lead for energizing the metal guide wire 36, and transmitting an electric current to the balloon 3 by means of the metal guide wire 36 to achieve a change in the return from the energizing to the de-energizing of the inflation.

Example 2

In the present embodiment, a specific structure of the handle 51 is further provided on the basis of embodiment 1, as shown in fig. 8 and 9, a conduit 54 for allowing the metal guide wire 36 to freely extend and contract is provided inside the handle 51, a threaded hole 55 is provided vertically below the conduit 54 and penetrates through the bottom of the handle 51, a smooth hole 56 is provided vertically above the conduit 54 and penetrates through the top of the handle 51, the smooth hole 56, the conduit 54 and the threaded hole 55 vertically penetrate through for installing the locking mechanism 52, a portion of the conduit 54 extending out of the handle 51 is used for connecting the proximal end of the injection catheter 2, and a sealing film is provided inside a portion of the conduit 54 extending out of the handle 51 for allowing the metal guide wire 36 to pass through, which is not shown, and is mainly used for pouring the injected medical liquid into the handle 51. Control of the metal guide wire 36 can be facilitated by the handle 51.

Example 3

In this embodiment, a specific structure of the locking mechanism 52 is further provided on the basis of embodiment 1, the locking mechanism 52 includes a bolt column 521 connected in the threaded hole 55, a lower end of the bolt column 521 is connected to the connection pulse generator 53 through a connection port 522, the locking mechanism 52 further includes an outer cylinder 523 connected above the smooth surface hole 56, upper and lower limiting rings 524, 525 are provided at upper and lower ends of the outer cylinder 523, and a pressing rod 526 located inside the outer cylinder 523, an upper flange 527, a lower flange 528 is provided on the pressing rod 526, a return spring 511 is fixedly connected between the lower flange 528 and the lower limiting ring 525 for locking the metal guide wire 36 on the bolt column 521 by pressing the lower end of the pressing rod 526 out of the lower limiting ring 525, the bolt column 521 is a conductive body, the pressing rod 526 is an insulating body, a telescopic rod 529 capable of extending and retracting is provided inside the lower flange 528 along a radial direction, the telescopic rod 529 can extend out of a positioning hole 510 provided on a side wall of the outer cylinder 523 to lock, which can retract into the interior of the lower flange 528 when depressed. Precise control of the position of the metal guidewire 36 is facilitated by the locking mechanism 52.

Example 4

The present embodiment is further extended from embodiment 3 by further comprising a limiting mechanism 4, as shown in fig. 5 and 6, further comprising a limiting wire 43 connected between the distal ends of two upper and lower opposite elastic support rods 42 and between the upper and lower opposite injection needles 34.

Example 5

In this embodiment, the limiting wire rope 43 is further optimized on the basis of embodiment 4, a limiting ring 44 for guiding the metal guide wire 36 is arranged in the middle of the limiting wire rope 43, and the length of the limiting wire rope 43 connected between the two injection needles 34 which are opposite up and down is reduced in sequence along the advancing direction of the medicine bag. The purpose of the retaining ring 44 is to provide some guidance to the wire 36 to prevent it from telescoping out of the way, as the combined length of each pair of needles 34 and retaining wire 43 is equal.

Example 6

This example modified the electroactive polymer film material of example 5 by using a carbon nanotube film as an electrode instead of a silver coating on the surface of the polyacrylate film. The preparation method comprises the following steps:

s1: taking a 5 x 5cm polyacrylate film, washing the polyacrylate film by using dewatering, soaking the washed polyacrylate film for 20 hours by using a mixed liquid of a hydrochloric acid solution with the mass fraction of 2% and water-soluble organic silicon oil with the mass fraction of 15%, taking out the polyacrylate film, washing the polyacrylate film by using deionized water, and blowing nitrogen to dry to obtain a pretreated polyacrylate film;

s2: and then ultrasonically mixing the multi-walled carbon nanotube dispersion liquid with absolute ethyl alcohol according to a ratio of 1:1 to prepare an impregnation liquid, firstly uniformly spin-coating 1, 2-Aminopropyltriethoxysilane (APTS) adhesion promoter for 20s at 400r/min on the surface of a pretreated polyacrylate film by using a spin coater, then soaking the polyacrylate film coated with the adhesion promoter in the impregnation liquid for 15min, washing the surface by using a nitric acid solution with a mass fraction of 8% after pulling out, then washing the surface by using deionized water, and blowing nitrogen to dry to obtain the polyacrylate film attached with the carbon nanotube film.

Example 7

In this embodiment, an electroactive polymer film material is improved based on embodiment 6, and a conductive support layer is sprayed on the surface of the polyacrylate film attached with the carbon nanotube film. The preparation method of the conductive supporting layer comprises the following steps: mixing a 15% chitosan solution and polypyrrole particles with the particle size of 350nm according to the mass ratio of 10:1, performing ultrasonic treatment for 30min, loading into a film spraying machine, spraying a protective supporting layer with the thickness of 15 microns on one surface of the polyacrylate film attached with the carbon nanotube film prepared in the embodiment 6, and performing vacuum drying at 50 ℃ to obtain the electroactive polymer material.

Example 8

In this embodiment, an electroactive polymer film material is improved based on embodiment 6, and a conductive support layer is sprayed on the surface of the polyacrylate film attached with the carbon nanotube film. The preparation method of the conductive supporting layer comprises the following steps: mixing a 15% chitosan solution and polypyrrole-coated magnetic nanoparticles with the particle size of 350nm according to a mass ratio of 10:1, performing ultrasonic treatment for 30min, loading into a film spraying machine, spraying a protective supporting layer with the thickness of 15 microns on one surface of the polyacrylate film attached with the carbon nanotube film prepared in example 6, and performing vacuum drying at 50 ℃ to obtain the electroactive polymer material.

Example 9

This example is an improvement of the electroactive polymer film material based on example 6, as shown in fig. 10, a polyacrylate film is used as an electroactive polymer core layer 61, carbon nanotube films are attached to the upper and lower surfaces of the polyacrylate film to be flexible electrode layers 62, and finally a crystalline colloid is compounded on one surface of the polyacrylate film to be a protective support layer 63, which is used as the outermost layer in the manufactured medicine bag 3. Not only can play the effect of protection electroactive polymer core layer 61 and flexible electrode layer 62, and above all can have certain hardness after the circular telegram to can provide the support for injection needle 34 pierces the vascular wall.

The preparation method of the electroactive polymer membrane material of the embodiment comprises the following steps: taking nano cellulose whisker hydrosol (prepared by a method for preparing the nano cellulose whisker hydrosol by utilizing kelp residues according to the Chinese patent publication No. CN201310095395.3, having extremely high toughness and flexibility, being capable of maintaining certain ductility under the action of expansion force of an electroactive polymer film core layer, simultaneously being capable of recovering the original shape and having good biocompatibility due to good toughness when the expansion force disappears) and polypyrrole-coated magnetic nanoparticles (polypyrre @ Fe3O4, purchased from the Xian Ruixi Biotech Limited company, wherein the magnetic nanoparticles are changed from disorder to order state when being electrified, the supporting strength is increased, the magnetic nanoparticles are changed back to disorder when being electrified and are recovered to flexibility when being electrified, the magnetic nanoparticles are mixed according to the mass ratio of 8-12:1, the mixture is placed into a film spraying machine after being subjected to ultrasonic treatment for 30min, a protective supporting layer with the thickness of 10-20 mu m is sprayed on one surface of the polyacrylate film with the carbon nanotube film prepared in the embodiment 6, vacuum drying at 30-60 deg.C to obtain electroactive polymer material.

Example 10

This example was used to investigate the effect of the energising current on the materials of examples 1-9, the test output current of the pulse generator (53) being 1 mA. The expansion rate of the material in 5 seconds after electrification, the shrinkage recovery rate in 5 seconds after outage and the hardness increase rate in the expansion state compared with the shrinkage state under different currents respectively.

Wherein, the polyacrylate films with silver-plated surfaces are adopted in the examples 1 to 5 and are marked as an experimental group 1;

example 6 a polyacrylate film coated with a carbon nanotube film on the surface thereof was used and recorded as experimental group 2;

in example 7, chitosan-polypyrrole was used as a conductive support layer as an outer layer of the carbon nanotube film-polyacrylate film, and the layer was designated as experimental group 3;

in the embodiment 8, chitosan-polypyrrole coated magnetic nanoparticles are used as a conductive supporting layer and used as an outer layer of a carbon nanotube film-polyacrylate film, and the conductive supporting layer is marked as an experimental group 4;

in example 9, the nanocellulose whisker hydrosol-polypyrrole coated magnetic nanoparticles are used as a conductive support layer and used as an outer layer of a carbon nanotube film-polyacrylate film, and the conductive support layer is marked as an experimental group 5.

The results of the experimental tests are shown in table 1:

TABLE 1 test results of expansion rate, contraction recovery rate and hardness increase rate of experimental groups 1-5 at 1mA current

	The swelling ratio%	Shrinkage recovery%	The hardness increase rate%
				Experimental group 1	85％	42％	0％
Experimental group 2	141％	82％	0％
				Experimental group 3	134％	85％	0％
Experimental group 4	231％	87％	176％
				Experimental group 5	280％	100％	243％

As can be seen from Table 1, the results of the expansion ratio, the shrinkage recovery ratio and the hardness increase ratio of the test group 5 are more consistent with the requirements of the present invention than those of the other test groups.

Example 11

This example uses different current levels for experimental group 5 of example 10 to test the expansion rate within 5 seconds of power-on, the contraction recovery rate within 5 seconds of power-off, and the hardness increase rate in the expanded state compared to the contracted state for optimizing the current parameters. The test range of the current magnitude is 0.1-1.5mA, and the test results are shown in Table 2:

TABLE 2 test results of the expansion rate, shrinkage recovery rate and hardness increase rate of the material of Experimental group 5 in the range of 0.1-1.5mA

As shown in table 2, the expansion rate of the material of experimental group 5 (example 9) increases with the increase of the current, but the expansion rate remains almost the same after 0.9mA, that is, the expansion rate reaches the limit, while the hardness increase rate decreases after 0.9mA, because the heat generated by the gradually increasing current increases gradually, the material is softened by heat and the hardness increase rate decreases, thereby the supporting force of the injection needle is reduced, and the success rate of the injection needle puncture is also reduced. This gives an optimum value of 0.9mA for the current.

The working method of the system comprises the following steps:

1. taking the catheter part out of the sterile bag, and filling and flushing the injection cavity and the accommodating cavity by using normal saline;

2. in the non-working state, the medicine bag 3 is contracted in the guiding catheter 1 as shown in fig. 2 and 4, and the injection needle 34 is gathered due to the contraction of the medicine bag 3 and is also hidden in the guiding catheter 1;

3. before working, the wiring port 522 and the pulse generator 53 are connected, the tip-shaped distal end of the guide catheter 1 is inserted into a blood vessel and is continuously pushed forward, positioning is carried out by using the developing mark point 37, after the position is appointed, an operator fixes the guide catheter 1 by one hand and pushes the handle 51 by the other hand forward until the medicine bag 3 is pushed out of the guide catheter 1 and is exposed in the blood vessel, the elastic support rod 42 loses the binding force and recovers the expanded state, the medicine bag 3 is propped open and positioned in the blood vessel, and a medicine bag rear part 32 and a medicine bag positioning part 33 are formed, and the state is shown in fig. 1 and 4;

4. opening a switch of the pulse generator 53, setting a current of 0.9mA, conducting by utilizing a bolt column 521 electrically contacted with the metal guide wire 36, transmitting the current to the front part 31 of the medicine bag through the metal guide wire 36, wherein the electroactive polymer material of the front part 31 of the medicine bag begins to expand and expand to 2-3 times of the original area after being electrified, and meanwhile, slowly pushing the metal guide wire 36 forwards to push the front part 31 of the medicine bag with the expanded area to gradually extend towards the far end, so that the metal guide wire 36 with the expanded area can easily push the medicine bag to the far end without worrying about the pushing blockage caused by the small tension of the medicine bag 3, and the back part 32 of the medicine bag is fixed in a blood vessel by the elastic support rod 42, thereby having little influence on the area change; the outer layer of the electroactive polymer material is the protective supporting layer 63 which can become harder than the original layer after being electrified, so that good supporting force can be effectively provided for the injection needle 34, the included angle between the insertion angle and the blood vessel wall 7 is ensured to be between 60 and 80 degrees, the advancing length of the metal guide wire 36 is generally controlled to be between 3 and 10mm, the pressing rod 526 of the locking mechanism 52 is pressed in time after the pushing is finished, the metal guide wire 36 is fixed between the pressing rod 526 and the bolt column 521, and the metal guide wire 36 is prevented from automatically retreating to cause needle withdrawal;

5. the liquid medicine is injected into the medicine bag 3 from the injection port 21, and the injection of the liquid medicine can further ensure that the injection needle 34 is more tightly attached to the vessel wall 7, so that the injection is convenient;

6. after the injection finishes, close impulse generator 53, press telescopic link 529 simultaneously and make pressing rod 526 rebound upwards, for the unblock of metal seal wire 36, the anterior 31 of anther sac resumes original area gradually after the outage, in addition slowly withdraw metal seal wire 36 then can make injection needle 34 lose the holding power and extract from vascular wall 7, the completion moves back the needle, pull handle 51 backward, elastic support rod 42 can retract guide catheter 1 owing to elasticity, and then also drive anther sac 3 and retract guide catheter 1, the state is shown in fig. 2 or fig. 4, withdraw guide catheter 1 from the human body.

Multiple experimental studies show that the operation success rate of the system is up to more than 99%, the curative effect of the drug injection on the blood vessel wall is improved by 49% compared with the direct injection of the drug into the blood vessel by adopting the catheter system combining the catheter structure of the embodiment 5 and the medicinal sac material of the embodiment 9, the curative effect is improved by 18% compared with the method disclosed by CN201310306004.8, and the problems of infection and accidents are avoided.

Claims

1. An electrically expandable balloon-based vessel wall injection catheter system, the system comprising:

a guide catheter (1), wherein the guide catheter (1) is provided with a proximal end, a distal end and a containing cavity which longitudinally penetrates through the interior;

the injection catheter (2) is positioned in the accommodating cavity and can freely stretch and retract along a central axis extending along the longitudinal direction, the injection catheter (2) is provided with a proximal end, a distal end and an injection cavity, and an injection port (21) is formed in the body of the injection catheter (2) close to the proximal end of the injection catheter (2);

anther sac (3), anther sac (3) adopt the electroactive polymer material that can the circular telegram inflation outage resumes to make, and anther sac (3) can be divided into anther sac front portion (31), anther sac rear portion (32) and anther sac front portion (31) and anther sac rear portion (32) juncture are used for two anther sac location portions (33) with vascular wall (7) contact when stretching out and waiting to pierce the operating condition of vascular wall, anther sac rear portion (32) with the distal end of injection catheter (2) is structure as an organic whole even, is equipped with a plurality of injection needle (34) on anther sac front portion (31), and anther sac front portion (31) inboard end is fixed with electrically conductive hemisphere (35), electrically conductive hemisphere (35) are connected with metal guide wire (36), metal guide wire (36) extend and wear out from the near-end of injection catheter (2) along longitudinal direction, change anther sac front portion (31) shape through pulling metal guide wire (36), thereby changing the direction of the injection needle (34) and facilitating the shrinkage of the medicine bag in the guide catheter (1), and developing mark points (37) are arranged at the front part (31) and the rear part (32) of the medicine bag;

a limiting mechanism (4), wherein the limiting mechanism (4) is arranged inside the medicine bag (3) and is used for limiting the depth of the injection needle (34) penetrating into the vessel wall (7);

and the external control assembly (5) comprises a handle (51) which is connected to the proximal port of the injection catheter (2) and can be penetrated by the metal guide wire (36), a locking mechanism (52) is arranged in the handle (51), the locking mechanism (52) is used for limiting the movement of the metal guide wire (36), the metal guide wire (36) is electrified through an external lead connecting pulse generator (53), and current is transmitted to the medicine sac (3) through the metal guide wire (36) to achieve the change of electrifying expansion power-off recovery.

2. A system according to claim 1, wherein the capsule (3) is of a rhomboidal configuration in the active position, the area of the front part (31) of the capsule being smaller than the area of the rear part (32) of the capsule, and the length of the plurality of injection needles (34) arranged on the same side of the front part (31) of the capsule increasing in succession in the direction of advancement of the capsule (3).

3. The system according to claim 1, characterized in that said limiting means (4) comprise a support ring (41) glued inside the distal mouth of said injection catheter (2), and two elastic support bars (42) connected to said support ring (41), said elastic support bars (42) being glued fixed to the inner side walls of said capsule rear portion (32), the distal ends of said elastic support bars (42) extending to a capsule positioning portion (33) for positioning the capsule (3) in the blood vessel.

4. A system according to claim 3, wherein the restraining means (4) further comprises a restraining wire (43) connected between the distal ends of two upper and lower opposing resilient support rods (42) and between two upper and lower opposing injection needles (34).

5. The system according to claim 4, characterized in that the middle of the limiting wire rope (43) is provided with a limiting ring (44) for guiding the metal guide wire (36), and the length of the limiting wire rope (43) connected between the two opposite injection needles (34) is reduced along the advancing direction of the medicine bag.

6. The system as claimed in claim 1, wherein the handle (51) is provided inside with a conduit (54) for allowing the metal guide wire (36) to freely extend and retract, a threaded hole (55) perpendicular to the lower portion of the conduit (54) and penetrating the bottom of the handle (51), and a smooth surface hole (56) perpendicular to the upper portion of the conduit (54) and penetrating the top of the handle (51), wherein the smooth surface hole (56), the conduit (54) and the threaded hole (55) are vertically penetrated for installing the locking mechanism (52), the portion of the conduit (54) extending out of the handle (51) is used for connecting the proximal end of the injection catheter (2), and a sealing film for allowing the metal guide wire (36) to pass through is arranged in the portion of the conduit (54) extending out of the handle (51).

7. The system of claim 6, wherein the locking mechanism (52) comprises a bolt column (521) connected in the threaded hole (55), the lower end of the bolt column (521) is connected with the connection pulse generator (53) through a wire connection port (522), the locking mechanism (52) further comprises an outer cylinder (523) connected above the smooth surface hole (56), the upper end and the lower end of the outer cylinder (523) are provided with upper and lower limiting rings (524, 525), and a pressing rod (526) positioned in the outer cylinder (523), the pressing rod (526) is provided with upper and lower flanges (527, 528), a return spring (511) is fixedly connected between the lower flange (528) and the lower limiting ring (525) and used for locking the metal guide wire (36) on the bolt column (521) by pressing the lower end of the pressing rod (526) to penetrate out of the lower limiting ring (525), and the bolt column (521) is an electric conductor, the pressing rod (526) is an insulator, a telescopic rod (529) capable of stretching and retracting is arranged in the lower flange (528) along the radial direction, the telescopic rod (529) can extend out of a positioning hole (510) formed in the side wall of the outer cylinder (523) to be locked, and the telescopic rod can retract into the lower flange (528) after being pressed.

8. The system of claim 1, the electroactive polymer film layer being prepared by a process comprising the steps of: the output current of the pulse generator (53) is 0.5-1.0 mA.

9. A system according to claim 1, wherein the electroactive polymer material is a polyacrylate film as an electroactive polymer core layer (61), carbon nanotube films as flexible electrode layers (62) attached to the upper and lower surfaces of the polyacrylate film, and finally a crystalline colloid as a protective support layer (63) attached to one of the surfaces, wherein the protective support layer is the outermost layer in the manufactured sachet (3).

10. The system of claim 9, the method of making the electroactive polymer material comprising the steps of:

s3: mixing the nano cellulose whisker hydrosol and the polypyrrole-coated magnetic nanoparticles with the particle size of 200-500nm according to the mass ratio of 8-12:1, carrying out ultrasonic treatment for 30min, then loading into a film spraying machine, spraying a protective supporting layer with the thickness of 10-20 mu m on one surface of the polyacrylate film attached with the carbon nanotube film, and carrying out vacuum drying at 30-60 ℃ to obtain the electroactive polymer material.