JPS6323077Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a drive transducer used in a micro-sized hearing aid having a function equivalent to a middle ear conductor, that is, a biologically implantable hearing aid which can also be called an artificial middle ear. The objective is to provide a drive transducer with a configuration that facilitates proper installation at a given site.

Currently, tympanoplasty is widely performed to improve hearing in cases of loss of the middle ear conductor due to otitis media or other diseases. He also suffers from problems with his sound system, and tympanoplasty surgery alone is not enough to improve his hearing, so he still requires hearing aids even after the surgery. Furthermore, there are cases where tympanoplasty surgery does not significantly improve hearing in the high-frequency range, and the wearing of hearing aids after surgery has become a reality.

On the other hand, although these hearing aids are useful enough to compensate for missing auditory functions, they may cause problems such as discomfort and depression for the earphone wearers themselves, or awareness of disability caused by the conspicuousness of the hearing aids. remains unresolved. Furthermore, since there are many types of hearing impairments and their degrees vary widely, problems with existing hearing aids have been pointed out, such as difficulty in selecting and fitting hearing aids.

Therefore, in recent years, in conjunction with advances in tympanoplasty surgery and rapid advances in the miniaturization of biocompatible materials and electronic circuits, progress has been made in the development of ultra-compact hearing aids that can be implanted into the body.

This ultra-compact implantable hearing aid basically consists of four elements: (1) microphone, (2) amplifier, (3) battery, and (4) drive transducer. Place only Yusa in the living body,
There are methods to place other elements outside the body and send signals to the drive transducer through electromagnetic coupling, and methods to implant the microphone, amplifier, and drive transducer inside the body, and to place only the battery outside the body for easy battery replacement. Several methods can be considered, ranging from so-called semi-implantable methods, such as a method in which all four elements are implanted, to a fully implantable method, in which all four elements are implanted in the living body. In any case, this implantable hearing aid performs signal transmission in place of a patient whose acoustic signals cannot efficiently reach the inner ear due to a defect in the outer or middle ear. In this case, the role of the transducer, which ultimately drives the inner ear lymph fluid, is important, and this has an extremely large effect on the characteristics of the implantable hearing aid. That is, one end of this driving transducer is connected and fixed to an appropriate body part such as the temporal bone or the wall of the tympanic cavity, and the other end is connected to the oval window and the remaining stapes head. This transmits the vibration stimulation generated by the transducer to the inner ear lymph fluid.

By the way, the distance between the temporal bone, etc. to which this drive transducer is connected and fixed, and the head of the stapes bone,
The positional relationship, such as the angle, cannot always be said to be constant due to individual differences in living organisms, the surgical site, angle, etc. Therefore, the transducer and the stapes should be quickly and appropriately connected and fixed. That was difficult.

On the other hand, this invention allows both ends of the drive transducer to be quickly and appropriately connected and fixed during hearing aid implantation surgery, regardless of the positional relationship between the body parts to which they are respectively connected and fixed. The present invention provides a drive transducer of the following configuration.

An embodiment of the present invention will be described below with reference to the drawings. FIG. 1 is a side sectional view showing the use of a drive transducer in a fully implantable hearing aid. The sound that enters microphone 1 is converted into an electrical signal,
The sound is transmitted to the drive transducer 3 via the sound processing device 2 including an amplifier and the like, and generates vibrations. The drive transducer 3 has one end fixedly connected to the temporal bone 4 and the other end fixedly connected to the stapes 5. Note that 6 is a battery, 7 is an external auditory canal, 8 is an eardrum, 9 is a middle ear cavity, and 10 is a cochlea. Reference numeral 11 denotes a lead wire for electrically connecting each part constituting the hearing aid, and in consideration of biocompatibility, a silver wire coated with Teflon or the like, a stainless steel wire, or the like is used.

Next, the drive transducer will be described in detail. As shown in FIG. 2, the drive transducer 3 includes a vibrating element 3A, a coupling portion 3B for reliably transmitting the vibration to the stapes 5, and a drive transducer 3 that connects the drive transducer 3 to a living body such as a temporal bone. It is composed of a support body 3C that is fixedly supported at an appropriate location. As the element 3A, a bending vibrator such as a piezoelectric bimorph element is used, for example. This piezoelectric bimorph element is made up of a pair of rectangular piezoelectric plates polarized in the thickness direction, pasted together so that the polarization is opposite to each other, and provided with electrodes, to which a voltage is applied via a lead wire 11. Vibrations are generated by electrical input. Further, the element 3A is coated with a flexible biocompatible material such as urethane resin or fluorine-based resin that does not hinder the bending vibration of the element 3A itself. Connection part 3B is element 3A
It is connected to one end of the femoral head 5A of the stapes 5 by an appropriate means such as adhesive, as shown in FIG.
It is fixed in combination with. Since the connecting portion 3B directly transmits the bending vibration of the element 3A to the femoral head 5A of the stapes 5, it is made of a material such as apatite that is biocompatible and rigid, and has an appropriate structure. can be adopted. In this embodiment, the connecting portion 3B is formed into a flat plate shape, and a through hole 3B1 into which the femoral head 5A of the stapes 5 fits is formed approximately in the center. The connection and fixation of the femoral head 5A and the connection portion 3B is performed, for example, with an adhesive such as dental cement.

By the way, the support body 3C, which is the gist of the present invention, is composed of three members: a large diameter pipe member 3C1, a small diameter pipe member 3C2, and a rod-shaped member 3C3. The large-diameter pipe member 3C1 and the small-diameter pipe member 3C2, and the small-diameter pipe member 3C2 and the rod-shaped member 3C3 are configured to fit into each other and to be slidable and rotatable. It is made of biocompatible metal such as stainless steel. Large diameter pipe member 3
Both ends of C1 are open, and a flat coupling portion 3C4 is provided approximately in the center to couple the element 3A. This joint portion 3C4 and the large diameter pipe member 3C
1, it was most appropriate to form them both from the same metal material and weld them. Further, the element 3A and the connecting portion 3C4 are connected and fixed by appropriate means such as an insulating adhesive that is safe for living organisms. It is convenient to use an adhesive because it can also ensure insulation between the element 3A and the support 3C. On the other hand, small diameter pipe member 3
One end of C2 is open, into which one end of a rod-shaped member 3C3 is inserted, and a hemispherical pedestal 3C5 is provided at the other end in contact with the middle ear bone wall to serve as a fulcrum for the drive transducer 3. . Small diameter pipe member 3C
2 and the pedestal 3C5 are bonded using an epoxy adhesive with excellent biocompatibility. Also, pedestal 3C
A rigid apatite is used for the drive transducer 3 because it firmly contacts the middle ear bone wall as a fulcrum for the drive transducer 3 to prevent it from vibrating. The shape of the semicircle is also essential in order to ensure reliable contact without damaging the middle ear bone wall. Another member, the rod-shaped member 3C3, has a support fixing part 3C fixed to an appropriate part of the living body such as the temporal bone at one end.
6 is provided. Various structures may be adopted for the support fixing portion 3C6, but in this embodiment, the support fixing portion 3C6 has a flat plate shape and is provided with a through hole 3C7 for fixing with screws. It is desirable that there be a plurality of through holes 3C7 so that the support body fixing part 3C6 does not rotate due to the screw tightening torque during fixation. Further, the rod-shaped member 3C3 has a support fixing portion 3C6.
It can be attached to the biological fixation site by arbitrarily bending the part close to the body, but if that part is to be made into a thin neck shape, it may be made into a thin tube shape instead of a rod shape. Therefore, the term "rod shape" here includes the concept of tubular shape. Note that if the support body fixing part 3C6 cannot be formed into an integral structure, joining by welding is appropriate.

Next, the process of installing the drive transducer will be explained. First, the rod-shaped member 3C3 is pulled out by an appropriate amount from the small-diameter tube member 3C2 fitted in advance, and the support fixing portion 3C6 is held with surgical forceps. On the other hand, pull up the lead wire 11 and insert the element 3 near the relatively upper part of the small diameter pipe member 3C2.
Let A slide. While maintaining this state, as shown in FIG.
The drive transducer 3 is brought into the middle ear until it hits the nearby middle ear bone wall. Subsequently, the femoral head 5A of the stapes 5 is inserted into the through hole 3B1 of the joint portion 3B.
pedestal 3C5 until it fits snugly.
move. Once the position of the pedestal 3C5 has been determined, the surgical forceps are moved downward and the rod member 3C3 is slid along the inside of the small diameter tube member 3C2 until the support fixing portion 3C6 hits the temporal bone 4. This completes the approximate positioning of the drive transducer 3. Next, a pilot hole is drilled in the part of the temporal bone 4 where the through hole 3C7 of the support fixing part 3C6 is located, and the support fixing part 3C6 is screwed and fixed with a screw. Thereafter, the large diameter tube member 3C1 is slid downward along the outside of the small diameter tube member 3C2 so that the femoral head 5A of the stapes 5 fits into the through hole 3B1 of the joint portion 3B. At this time, even if a slight deviation occurs in the position of the connecting portion 3B due to tightening of screws, etc., it cannot be restored to its original position by rotating the small diameter tube member 3C2 left and right or bending the rod member 3C3. It is quite possible. After completing the adjustment in this way, each fitting portion of the support 3C is fixed with dental cement, completing the fixed installation of the support 3C.

As described above, in the present invention, the support of the drive transducer, which is composed of a coupling part, an element, and a support, is composed of a large-diameter pipe member, a small-diameter pipe member, and a rod-shaped member, and each of them is slidable. It is fitted so that it can move and rotate freely. Therefore, since adjustment is possible, it is possible to quickly adapt to each individual case, and it is advantageous that the connecting portion of the drive transducer can be easily and appropriately connected to the head of the stapes bone.

[Brief explanation of the drawing]

FIG. 1 is a side sectional view showing the driving transducer of the present invention in use in a fully implantable hearing aid. FIG. 2 is a side sectional view showing an embodiment of the present invention.
FIG. 3 is a schematic diagram showing how the drive transducer of the present invention is used. 3A...Element, 3B...Joining part, 3C...
... Support body, 3C1 ... Large diameter pipe member, 3C2 ... Small diameter pipe member, 3C3 ... Rod-shaped member, 3C5 ... Pedestal, 3C6 ... Support fixing part.

Claims (1)

[Claims for Utility Model Registration] The femoral head 5 of the stapes 5 is attached to one end of the element 3A composed of a vibrating body such as a piezoelectric bimorph element.
A connecting part 3B that connects with A and directly transmits vibration,
At the other end, a support 3 is connected and fixed to an appropriate part of the living body, such as the temporal bone 4, and supports the element 3A.
C, the support body 3C is composed of a large-diameter pipe member 3C1, a small-diameter pipe member 3C2, and a rod-shaped member 3C3, each of which is slidably and rotatably fitted to each other; The diameter tube member 3C1 is provided with a coupling portion 3C4 that couples with the element 3A, and holds the small diameter tube member 3C2 inside, and the small diameter tube member 3C2 has a pedestal 3C5 at one end.
However, one end of the rod-shaped member 3C3 is inserted into the other end opening, and the other end of the rod-shaped member 3C3 is provided with a support fixing portion 3C6 for coupling and fixing to the temporal bone 4, etc. Drive transducer for implantable hearing aids.