JPS63272356A - Skin piercing terminal - Google Patents

Abstract

PURPOSE:To develop bending strength of 3,000kg/cm<2> or more and fracture toughness of 35MPa.m<1/2> or more, by containing a large amount of an apatite or whitlockite crystal. CONSTITUTION:A glass baked body contains a large amount of apatite or whitlockite excellent in the compatibility with a living body. As a reinforcing material, zirconia, alumina or SiC having heat resistance and high tensile strength is used. This skin piercing terminal is prepared by mixing the above- mentioned glass powder and the reinforcing material in a predetermined ratio and receiving the resulting mixture in a mold to heat-treat the same. The shape of the terminal is not especially limited. A large number of piercing holes 6 piercing from the bottom surface 2 of the terminal to the upper surface 4 thereof are provided. Head wires electrically connecting the body and the outside thereof are inserted in the piercing holes.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a skin-penetrating terminal for holding lead wires for extracting or supplying electrical signals within a living body.

(Prior Art) It is known that biological tissues, particularly nerves and muscles, are excited by electrical stimulation, resulting in generation and propagation of nerve impulses, muscle contraction, and the like.

In recent years, this development has been used to apply q-electrical stimulation to the human body to restore the motor functions of limbs lost due to accidents or diseases, i.e., functional electrical stimulation, which has been attracting attention as a treatment. .

Conventionally, in this method, one end of a lead wire for applying stimulation is implanted near the nerve, and the other end is taken out directly through the skin. For this reason, the lead wire and the skin do not come into close contact with each other at the portion where the lead wire is taken out of the body, and the interface between the lead wire and the skin is susceptible to bacterial infection and inflammation.

A skin-penetrating terminal leads multiple electrical stimulation lead wires from inside the body to outside the body through the through-hole of the terminal, and some are embedded outside the skin and some are embedded within the skin. It is necessary to have excellent bio-tissue compatibility and good adhesion to the skin, and to stimulate a large number of nerves and muscles, a large number of electrode wires are required. It is necessary to form a densely
It is desirable that the material itself has sufficient mechanical strength and fracture toughness.

Until now, skin-penetrating terminals have been used as electrical terminals for extracting various biological information such as blood pressure, blood flow rate, body temperature, and electrocardiographic signals, or for injecting various medicinal solutions through a single through-hole of the terminal. Progress has been made in the development of terminals for extracting and injecting blood flow during artificial kidney dialysis. As materials for these terminals, organic materials such as silicone rubber and fluororesin, as well as apatite ceramics and inorganic materials in which they are coated on metals have been proposed (Public Patent Publication No. 1986-027H).

However, when these materials are used as the skin-penetrating terminal, the former organic materials have poor adhesion to the skin and are susceptible to infection by bacteria from the interface between the material and the skin tissue, causing inflammation. It is necessary to frequently disinfect the affected area, and it cannot withstand long-term use in real life.

On the other hand, abatite ceramics and materials coated on metal have excellent compatibility with skin tissue, but the former has poor strength and toughness of the material itself (
200 MPa or less and ~I MPa, 1, respectively
/2) is low, making it difficult to form a large number of through holes at a high density, and the latter has problems such as peeling of the coating film and difficulty in coating the inner walls of the through holes.

(Problems to be solved) As mentioned above, conventional terminals made of organic materials have insufficient affinity with the skin, and apatite ceramics require wide holes in order to make a large number of through holes on the terminals. There is a problem that it requires area and becomes large.

The present invention has adhesiveness with the skin comparable to that of apatite ceramics, and also eliminates the drawbacks of low strength and toughness that apatite ceramics had, so that it has good adhesion with the skin. This project proposes a new skin-penetrating terminal that has excellent adhesion and can be miniaturized.

(Means for solving the problem) The present invention has been made to solve the above-mentioned problems,
At least one surface is exposed outside the body, and the device has a through hole that penetrates the surface exposed outside the body and the surface implanted inside the body, and the inside and outside of the body are electrically communicated by a lead wire inserted through the through hole. The purpose of the present invention is to provide a skin-penetrating terminal for the purpose of the present invention, which is composed of CaO-P2Os glass and an inorganic reinforcing material, and is provided with a plurality of through-holes.

The CaO-P2O5-based glass fired body in the present invention is apatite (Ca+o (PO4
)60), 4-/trochite (3(CaO.

MgO)・P2Os).

Such a fired glass body can be manufactured by heat-treating glass having the following composition.

Essentially in weight % Ga0 14-82 P2O5 7-37 MgO 0~30 Si0212~50 Al2O2O, 1-10 A glass with a structure consisting of is manufactured by a melting method.

The reason for the limited composition of this glass will be explained.

If CaO is less than 14%, it is not preferable because less apatite and whitlockite crystals will be precipitated from the glass.

Moreover, if it is 61% or more, the tendency of glass to devitrify is significant and it is difficult to form glass.

If Sioz is 50% or more, the melting temperature of the glass becomes too high, making it difficult to manufacture the glass.

When the MgO content exceeds 30%, the tendency of glass to devitrify increases, making it difficult to mold the glass.

If P2O5 is less than 7%, the amount of witrockite and apatite crystals precipitated from the glass will be small, which is undesirable.If it is more than 37%, Ca or Mg will be relatively small, and the main crystals of witlockite and apatite will be small. I don't like it.

Introducing Al2O3 into glass makes it easier to obtain glass, but if it is more than 10%, the amount of whitlockite crystals and apatite crystals precipitated from the glass will decrease, which is not preferable.

In addition to the above components, B2O is added to facilitate crystal precipitation.
3, Z ro2, TiO2, Ta2Os, CaF2
, one or more of Li2O, Na2O and Ni2O,
They may be added in an amount of 10% or less, but if the total amount of these components exceeds 10%, it is not preferable because it reduces the amount of apatite crystals and witlockite crystals produced.

Among the above additives, GaF2, Li2O, Na2O, K2
If O is added in an amount of 5% or more, the tendency of the glass to devitrify becomes significant, so the amount of these oxides or fluorides added is preferably 5% or less.

These glasses are made by heating the prepared raw materials at 1400 to 1600℃.
, by heating for 1 to 5 hours.

As the reinforcing material in the present invention, a material having heat resistance and high tensile strength is used. Specifically, zirconia, alumina, SiC, and 5i3Ns are used.

Carbon is exemplified. These reinforcements are used as particles, fibers and whiskers.

The content of such reinforcing materials is preferably 1 to 70% by volume, and may be used alone or in combination.゛Reinforcement material is 1%
If it is less than 70%, it will not be possible to sufficiently improve the mechanical strength, and if it exceeds 70%, it will be difficult to obtain a material with a dense structure, resulting in a decrease in mechanical strength. Reinforcement material is 10 to 60 in the above range
% range is more preferred.

The skin TJ penetration terminal in the present invention can be manufactured, for example, as follows. The glass produced as described above is formed into flakes and crushed to obtain glass powder. Next, this glass powder and reinforcing material are mixed in a predetermined ratio and press-molded.Next, this is heated to a temperature slightly higher than the softening point of glass and held for more than 1 hour to sinter and form apatite, Whitlockite crystals are deposited in glass.

The thus manufactured material is subjected to post-processing such as machining into the desired shape. Instead of post-processing, a mold with a predetermined shape is used,
It can also be manufactured by putting a mixture of glass powder and reinforcing material into a mold and heat-treating it.

The shape of such a terminal is not particularly limited, but there are, for example, shapes as shown in FIGS. 1 and 2. That is, the cylindrical circumferential surface has four parts 1 at the center, and the circumferential surface 3 of the portion close to the bottom surface 2 and the circumferential surface 5 of the portion close to the top surface 4 each protrude, forming a flange shape. The through holes 6 penetrating from the bottom surface 2 to the top surface 4 are arranged in multiple stages.

This through hole is for inserting a lead wire that electrically communicates between the inside and outside of the body, and its diameter is 0.1 to 31111 mm.
It is preferable to have a diameter in the range of .If the diameter is too small, it will be difficult to insert the lead wire, and if it is too large, the seal between the subcutaneous tissue and the outside of the body will be insufficient, so both are not preferable.

The through holes can be processed by ultrasonic processing, laser processing, etc.

In such a terminal, a lead wire is usually inserted into a through hole, and the bottom surface 2 and the protruding portion 3 on the circumferential surface are embedded and fixed in the living body. The lead wire is fixed by injecting adhesive into the gap between the lead wire and the through hole.

(Example) Glasses corresponding to the compositions shown in Table 1 were mixed with oxides, carbonates,
It was prepared using raw materials such as phosphate fluoride and melted in a platinum crucible at 1400 to 1600°C for 3 hours.

The molten glass was formed into a thin glass plate using a roll forming machine, and then placed in a bot mill and pulverized to a particle size of 350 mesh.Next, a reinforcing material was added to the glass powder.
Mixed in a pot mill. The mixed glass powder was heated at 5°Q/
The sample was heated at a temperature increase rate of sin from room temperature to a constant temperature in the range of 850 to 1050° C. while applying a pressure of 350 kg/cm 2 and held at this temperature for 1 hour to perform sintering and crystallization.

As a result of pulverizing this sample and identifying the precipitated crystals by X-ray diffraction, apatite or wittrochite crystals were observed in all samples, and in addition to these crystals, wollastonite, diopside, enstatite, and forsterite were found. It was observed that crystals such as , Felpospur, and anorthite were precipitated.

Regarding some samples of the above sintered bodies, #2O00 S
Bending strength was measured using a 3 x 3 x 25 mm square column whose surface was polished with iC abrasive grains, and fracture toughness was measured using a chevron notch method using a sample of the same size. The results are shown in Table 2. The table shows the types of reinforcing materials, their shapes,
The amount added is also listed.

As is clear from the table, the composite sintered body according to the present invention has extremely superior bending strength and fracture toughness compared to apatite ceramics.

The above composite sintered body was lathe-processed into the shape shown in Figs.
．． A porous transcutaneous electrode skin-penetrating terminal was prepared by opening 24 through-holes of 7 mm in diameter. When this terminal was implanted into the skin of dogs and rabbits for one month, no inflammation or other tissue reactions were observed, and the terminal adhered firmly to the skin.

Table 1 CaO 50.4 48.7 42.9 31.5
43.4MgO - 7.4 14.9 8
．． 3P2O5 1B, 0 1B, 3 27.5 9.2
31.8Si0?33.8 31.0 22.2 4
4.4 12.0 Others -Na2O--Al2O3 2.0 5.0 Table 2 Glass No. 1 1
3 3 5 (Effects of the Invention) As described above, the skin-penetrating terminal according to the present invention contains a large amount of apatite or witrockite crystals, and 3
000kg/cm2 or more bending strength and 3.5MPa, m
Therefore, it exhibits a fracture toughness of 172 or higher.

The skin-penetrating terminal according to the present invention is extremely compatible with the skin, and can have fine through-holes concentrated at high density.
It is extremely effective as a skin-penetrating terminal for fixing a plurality of lead wires for stimulating nerves and muscles, and at the same time guiding the lead wires from inside the living body to outside the body.

[Brief explanation of the drawing]

FIG. 1 shows a terminal according to the present invention, and is a sectional view taken along the line AA in FIG. FIG. 2 is a bottom view of a terminal according to the invention. 6... Through-hole procedure formal letter (method) August 1, 1986

Claims (4)

[Claims] (1) At least one surface is exposed outside the body, and has a through hole that penetrates the surface exposed outside the body and the surface implanted inside the body, and a lead wire inserted through the through hole electrically connects inside and outside the body. A skin-penetrating terminal for communicating with CaO-P_2
A skin-penetrating terminal made of O_5 glass and an inorganic reinforcing material and provided with a plurality of through holes. (2) The CaO-P_2O_5 glass is in the range of CaO 14-81 P_2O_5 57-37 MgO 0-30 SiO_2 12-50 Al_2O_3 0.1-10 in weight percent, and the total amount of these oxides is 90%. The terminal according to claim 1, which is the above. (3) The reinforcing material is SiC, Al_2O_3, Si_
The terminal according to claim 1, which is a fiber, whisker or particle of 3N_4, C or ZrO_2. (4) The terminal according to claim 1, wherein the diameter of the through hole is in the range of 0.1 to 3 mm.