JPS6319057Y2 - - Google Patents

Description

[Detailed Description of the Invention] This invention relates to a drive transducer used in a hearing aid intended to be implanted in a living body.

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 use of hearing aids after surgery has become a reality.

On the other hand, although these hearing aids are useful enough to compensate for the lack of auditory function, they may cause the wearer to feel uncomfortable or depressed when wearing earphones.
Furthermore, issues such as awareness of disabled people due to their visibility remain 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 implantable hearing aid basically consists of (1) a microphone;
It consists of four elements: (2) an amplifier, (3) a battery, and (4) a drive transducer. Classified by method, only the drive transducer is placed inside the body, and the other elements are placed outside the body and electromagnetically coupled. There are four methods ranging from so-called semi-implantable methods, such as methods that send signals to the drive transducer using a method that transmits signals to the drive transducer, and methods that embed the microphone, amplifier, and drive transducer in the living body and place only the battery outside the living body to facilitate battery replacement. Several methods are possible, including a fully implantable hearing aid in which all elements are implanted in the body, but in any case, this implantable hearing aid is suitable for patients whose acoustic signals cannot efficiently reach the inner ear due to defects in the outer or middle ear. Instead, it performs signal transmission. 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.

The present invention relates to this drive transducer. By the way, the oval window, which is the original inner ear stimulation opening, is suitable as the site for driving the inner ear lymph fluid, and the present invention utilizes the stapes bone remaining in the oval window. That is, by fixing one end of the driving transducer of the present invention to the wall of the tympanic cavity near the oval window and connecting the other end to the head of the stapes bone, the vibration stimulation generated by the transducer can be applied to the inner ear lymph fluid. It is something that can be conveyed to people.

The present invention relates to a drive transducer having an optimal structure for coupling with the above-mentioned stapes head, and one embodiment of the present invention will be described below with reference to the drawings.

FIG. 1 is a side sectional view showing the drive transducer in use in a fully implantable hearing aid. Sound entering the microphone 1 is converted into an electrical signal through a sound processing device 2 including an amplifier, and is transmitted to a drive transducer 3 to generate vibrations. The drive transducer 3 is fixed at one end and connected to the stapes 4 at the other end. Note that 5 is a battery, 6 is an external auditory canal, 7 is an eardrum, 8 is a middle ear cavity, and 9 is a cochlea.

FIGS. 2A and 2B are a side view and a top view of the drive transducer. The drive transducer 3 includes a pedestal 3A, an element 3B, and a coupling portion 3C. Pedestal 3A is element 3
This is for fixing the drive transducer to one end of the tympanic cavity wall near the oval window, and is made of a material such as apatite that is biohazardous or securely bonded to the tympanic cavity wall. The bottom surface of the pedestal 3A is fixed to the tympanic cavity wall with an appropriate means such as adhesive. At this time, if the wall surface of the tympanic cavity is shaved into a hemispherical shape and the pedestal 3A is formed into a hemispherical shape to fit this hemispherical part, the pedestal 3A can be set at any angle, and the connecting part 3C and the stapes 4 This is desirable because it allows for easy connection. It is fixed to the tympanic cavity wall using an appropriate means such as adhesive. Element 3B is a bending vibrator such as a piezoelectric bimorph element. A piezoelectric bimorph element is constructed by attaching a pair of rectangular piezoelectric plates polarized in the thickness direction so that they are polarized in opposite directions, and provided with electrodes. Note that this element 3B is coated with a flexible biocompatible material such as urethane resin that does not interfere with the bending vibration of the element 3B itself. The connecting portion 3C is connected to the other end of the element 3B, and transmits the bending vibration of the element 3B directly to the femoral head 4A of the stapes 4, as shown in FIG. This joint portion 3C is made of biocompatible material,
Moreover, it is made of a rigid material, such as stainless steel, and has a U-shape with both ends fixedly connected to the element 3B. The connection and fixation between the connection part 3C and the stapes 4 is first performed by the connection part 3C.
This is done by fixing C to the femoral head 4A and then narrowing the root of the joint 3C. Note that the fixation between the pedestal 3A and the element 3B, and the fixation between the coupling portion 3C and the element 3B are performed by appropriate means such as adhesive that is safe for the living body, taking biocompatibility into consideration. Further, the lead wire 10 is also made of a silver wire coated with Teflon or the like, a stainless steel wire, etc. in consideration of biocompatibility.

As described above, the present invention provides a drive transducer having a U-shaped joint, which has a simple structure, can easily ensure vibration transmission to the stapes, and has a U-shaped joint. It is useful because it ensures prevention of falling off from the 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. 2A is a side sectional view showing one embodiment of the drive transducer of the present invention. FIG. 2B is also a plan view. FIG. 3 is a perspective view showing a state in which the drive transducer of the present invention is connected to the stapes. 3A: Pedestal, 3B: Element, 3C: Joint.

Claims (1)

[Scope of utility model registration request] Pedestal 3 to be fixed to the tympanic cavity wall near the oval window at one end
Element 3B that connects and fixes A, and connects and fixes the connecting part 3C to be connected to the head of the stapes at the other end.
A drive transducer for an implantable hearing aid, comprising a bending vibrator such as a piezoelectric bimorph element, and the coupling portion 3C having a U-shape with both ends fixedly coupled to the element 3B.