JPH0370577A - Implantation type liquid medicine injection apparatus - Google Patents

Abstract

PURPOSE:To accurately inject a liquid medicine without receiving the effect of a midway route by arranging a piston part to the leading end part of an injection catheter. CONSTITUTION:When the rotary shaft 9 of a motor 5 is rotated, a disc 10 is rotated and the rotatory power thereof is transmitted to a flexible shaft 11 as linear reciprocating motion through a crank mechanism. When the flexible shaft 11 is subjected to linear reciprocating motion in an injection catheter 4, a piston part 22 is subjected to linear reciprocating motion in the injection catheter 4 on the leading end side thereof to discharge the liquid medicine in the injection catheter 4 from an injection orifice 4a. That is, the piston part has an almost saw-tooth-shape longitudinal section and the resistance received by the liquid medicine is large when the piston part moves in a feed-out direction but small when said piston part moves in the reverse direction and, therefore, the liquid medicine is discharged in one feed-out direction. By this constitution, the liquid medicine in the injection catheter 4 is forcibly discharged by the reciprocating motion of the piston part 22 and can be accurately injected in a region to be injected.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an implantable liquid drug injection device that is implanted in a living body and used for administering a drug or the like over a relatively long period of time.

[Prior art] This type of implantable drug infusion device is known, for example, from the
It is known from the publication No. 1-30719.

This has an injection liquid chamber for storing an injection liquid inside the housing and a drive chamber, and this compartment is partitioned by a bellows. The injection drug chamber is provided with a drug solution outlet, one end of a capillary tube is connected to this drug solution outlet, and the other end of this capillary tube is communicated with a drug solution injection part.

In this type of implantable drug infusion device, the bellows are contracted by the vaporization pressure caused by the body temperature of, for example, Freon gas filled in the drive chamber. It is designed to be sent to the target site within the body.

[Problems to be Solved by the Invention] However, in this injection method, the injected drug solution is delivered to the target site via a capillary tube, and due to the influence of flow path resistance in the capillary tube, the drug solution does not reach the target site. It is difficult to inject accurately, and the structure is complex and large, making it unsuitable for implantation in the body.

The present invention has been made in view of the above-mentioned problems, and its purpose is to provide an implantable liquid drug injection device that can accurately inject the liquid drug inside a catheter into a target site with a relatively simple configuration. It's about doing.

[Means and Effects for Solving the Problems] In order to solve the above-mentioned problems, the implantable liquid drug injector of the present invention houses a flexible shaft in a catheter so as to be able to move forward and backward, and at least the distal end of the flexible shaft has the above-mentioned structure. Provided with a piston portion having a substantially serrated longitudinal section for delivering the medicinal solution inside the catheter, and a piston drive portion for driving the piston portion forward and backward at the proximal end,
Furthermore, a reservoir is provided which communicates with the catheter and stores a medicinal solution.

When the piston drive unit moves the piston part back and forth inside the catheter via the flexible shaft, the medicinal liquid inside the catheter is delivered by the piston part, making it possible to inject the medicinal liquid accurately.

[Embodiment] FIGS. 1 to 5 show a first embodiment of the present invention. 1 and 2 show the entire body-implantable liquid medicine injection device 1, which is used by being implanted under the skin A as shown in FIG. 3.

The specific configuration of this implantable liquid drug injection device 1 will be described below. That is, the main body 1 includes a drive unit 2, a drug boat 3 and an injection catheter 4 connected to the drive unit 2.

The drug boat 3 communicates with a portion of the injection catheter 4 .

Housing 2 of drive unit 2 as piston drive
a is made of a non-extensible material, and inside this is a motor 5.
, a control section 7 connected to this motor 5 via a lead wire 6.
and a battery 8 are incorporated, resulting in an integral configuration as a whole.

Further, as shown in FIG. 4, a disk 10 is fixed to the rotating shaft 9 of the motor 8, and a base end portion of a flexible shaft 11 is fixed to a part of the periphery of the disk 10. . That is, the rotational motion of the rotary shaft 9 is converted into linear reciprocating motion by the crank mechanism, and the flexible shaft 11
It is transmitted to

Further, an injection catheter 4 is fluid-tightly connected to this drive unit 2. The injection catheter 4 is formed from a non-extensible tube such as polyurethane, and the flexible shaft 11 is inserted into the injection catheter 4 so as to be freely movable back and forth in the axial direction. Furthermore, a 7-shaped connecting tube 12 is interposed in the middle of the injection tube 4, and this 7-shaped connecting tube 12 is connected to the medicinal solution boat 3 via a medicinal solution tube 13.
It is connected to the. Therefore, the drug boat 3 is connected to the injection catheter 4 via the drug tube 13.

The chemical liquid boat 3 is constructed as shown in FIG. 3. That is, the main body 3a of the drug boat 3 is provided with a puncture hole 15 that opens toward the surface on the skin A side. Inside the puncture hole 15 is a puncture wall 1 through which an injection needle (to be described later) is penetrated.
6, and this puncture wall 16 is made of silicone rubber having self-sealing properties. A needle retaining wall 17 is provided below the puncture hole 15, and a reservoir 18 for storing a medicinal solution is provided through a communication hole 19. Further, the reservoir 18 is composed of an elastic membrane 20 made of stretchable silicone rubber. The reservoir 18 is provided with a liquid feeding port 21, and the chemical liquid tube 13 is connected to this liquid feeding port 21.

Further, as shown in FIG. 5, the flexible shaft 11 is provided with a piston portion 22 having a shape in which a plurality of truncated cones are connected in the axial direction and whose longitudinal section is approximately serrated, as shown in FIG. The surface is close to the inner surface of the injection catheter 4, and the tip of the piston portion 22 is close to the inner surface of the injection catheter 4.
It extends to the vicinity of the injection port 4a.

Next, the operation of the implantable liquid drug injection device 1 configured as described above will be explained. The drive unit 2, drug boat 3, and injection catheter 4 of this drug injector 1 are connected to the skin A.
At the same time, the injection port 4a at the tip of the injection catheter 4 is placed and fixed in the target site for injection of the drug solution, for example, in the hepatic artery in the case of injection of an anticancer drug for liver cancer.

Injecting a chemical into the reservoir 18 of the chemical boat 3 is performed as follows. First, an injection needle of a medicinal liquid syringe (not shown) is percutaneously penetrated into the puncture wall 16 of the medicinal liquid boat 3 . Then, the chemical solution is injected into the reservoir 18. As a result, the elastic membrane 20 forming the reservoir 18 is expanded, and the drug solution is stored in the reservoir 18.

Furthermore, when injecting the drug into a target site within a living body, the motor 5 is driven by a signal from the control unit 7 . When the rotating shaft 9 of the motor 5 rotates, the disc 10 rotates, and this rotational force is transferred to the flexible shaft 11 via the crank mechanism.
is transmitted as a linear reciprocating motion. When the flexible shaft 11 linearly reciprocates inside the injection catheter 4, the piston portion 22 moves linearly and reciprocates inside the distal end side of the injection catheter 4, and the drug solution inside the injection catheter 4 is delivered from the injection port 4a. That is, the piston portion 22 has a substantially serrated longitudinal section, and the resistance to the chemical solution is large when moving in the delivery direction and small when moving in the opposite direction, so that the drug solution is released in one direction in the delivery direction. It turns out. Therefore, the reciprocating movement of the piston portion 22 forces the liquid medicine inside the injection catheter 4 to be released, allowing the liquid medicine to be accurately injected into the injection target site. In addition, since the injection catheter 4 communicates with the reservoir 18 via the drug tube 13, the drug is gradually delivered from the reservoir 18 toward the injection port 4a.
Administer to the target site from a.

The amount of medicine injected at this time can be controlled by controlling the rotation speed of the motor 5.

According to this first embodiment, by arranging the piston portion 22 at the distal end of the injection catheter 4, accurate injection can be performed without being affected by the intermediate route.

6 and 7 show a second embodiment of the present invention. This embodiment differs from the first embodiment in the following points.

First, the piston part 23 is provided over the entire length of the injection catheter 4, and the plurality of members 24 constituting the piston part 23 are streamlined, and the large diameter end faces 25 and 24 of the piston part 23 are streamlined.
... is an arcuate recess.

By providing the piston portion 23 having such a configuration, the medicinal liquid inside the injection catheter 4 can be reliably delivered.

FIG. 8 shows a third embodiment of the present invention. This embodiment uses a stacked piezoelectric element 26 as a driving source. One end of the piezoelectric element 26 is fixed to the housing 2a of the drive unit 2, and is configured to expand and contract in the stacking direction. The expansion and contraction movement of the piezoelectric element 26 is transmitted to one end of a rotating arm 28 that rotates about a pivot 27, and the other end of this rotating arm 28 is connected to the base end of the flexible shaft 11.

Therefore, the expansion and contraction movement of the piezoelectric element 26 is caused by the rotation arm 28
This rotational movement of the rotational arm 28 causes the flexible shaft 11 to reciprocate linearly within the injection catheter 4. In addition, the control of the injection amount of the chemical solution is as follows.
It can be controlled by the amount of electrostriction of the piezoelectric element 26 and its period.

According to this embodiment, the drive unit 2 can be made smaller than the embodiment using a motor as the drive source.

FIG. 9 shows a fourth embodiment of the present invention, in which a plurality of members 30 constituting the piston portion 29...
・ is shaped like an abacus bead, and the front side 31 of each member 30 is steeper than the back side 32. FIG. The front side 31 of the front side 31 is roughened.

By providing the piston portion 29 having such a configuration, the medicinal liquid inside the injection catheter 4 can be reliably delivered.

FIG. 11 shows a sixth embodiment of the present invention, in which the flexible shaft 11 is provided with a large diameter portion 33, and this large diameter portion 33 is provided with a screw-shaped piston portion 34. be.

12 and 13 show a seventh embodiment of the present invention. In this embodiment, annular protrusions 35 are provided at equal intervals on the outer periphery of the tip of the flexible shaft 11. A triangular channel 36 is formed on the surface of the protrusion 35.
・It has been established.

14 and 15 show an eighth embodiment of the present invention, in which the inner lumen of the injection catheter 37 is square and flexible. The present invention is not limited to the above, and various modifications can be made without changing the gist thereof.

[Effects of the Invention] As explained above, according to the present invention, the flexible shaft is provided with a piston portion, and the piston portion is moved linearly and reciprocally inside the catheter to deliver the medicinal solution inside the catheter. It has the advantage of being able to accurately inject a drug solution into a target site, and also having a simple structure and miniaturization.

[Brief explanation of drawings]

1 to 5 show a first embodiment of the present invention, FIG. 1 is a plan sectional view of the entirety, FIG. 2 is a plan view of the entirety, and FIG. 3 is a side sectional view near the reservoir. , FIG. 4 is a side sectional view of the drive unit, FIG. 5 is a perspective view of the piston section, FIG. 6 is a plan sectional view of the entire second embodiment of the present invention, and FIG. 7 is the same embodiment. FIG. 8 is a plan sectional view of the drive unit showing the third embodiment of the present invention, FIG. 9 is a side view of the piston part showing the fourth embodiment, and FIG. FIG. 11 is a side view of the piston portion showing the fifth embodiment; 1... In-body implantable drug infusion device; 2... Drive unit (piston 3. Chemical solution boat, 4. Infusion catheter, 11. Flexible shaft, 18. Reservoir, 22. Piston section. Figure 3 Figure 11 Figure 4 Figure 2 Figure 5 Figure 6 Figure 5 Figure 8 Figure 0 Figure 1

Claims (1)

[Claims] a catheter, a flexible shaft housed in the catheter so as to be able to move forward and backward; a piston section provided at least at the distal end of the flexible shaft and having a substantially serrated longitudinal section for delivering a medicinal solution inside the catheter; and the flexible shaft. An implantable drug solution injector comprising: a piston drive section provided at a proximal end portion of the catheter for driving the piston section forward and backward; and a reservoir provided in communication with the catheter for storing a drug solution.