JPS6319060Y2 - - 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 is made up of four elements: (2) an amplifier, (3) a battery, and (4) a driving transducer. There are several types of methods that can be classified according to the type, from a semi-implantation type in which only the driving transducer is placed inside the body and the other elements are placed outside the body to send signals to the driving transducer by electromagnetic coupling, or a method in which a microphone, an amplifier, and a driving transducer are implanted inside the body and only the battery is placed outside the body to make battery replacement easy, to a fully implantation type in which all four elements are implanted inside the body. In any case, this implantable hearing aid transmits signals in place of those of patients who cannot efficiently receive acoustic signals from the inner ear due to defects in the outer or middle ear. In this case, the role of the transducer that ultimately drives the inner ear lymph is important, and this has a great impact 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 bone 4 It is desirable because it can be easily combined with 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 hinder the bending vibration of the element 3B itself. The coupling portion 3C transmits the bending vibration of the element 3B directly to the femoral head 4A of the stapes 4. This joint portion 3C is
It is made of biocompatible and elastic material, such as stainless steel. The configuration of the connecting portion 3C includes a root portion 3C1 that connects and fixes the connecting portion 3C to the element 3B, a substantially circular curved portion 3C2 into which the stapes 4 is fitted, and a tip portion 3C3 to which the wedge 3C4 is attached and detached. The root portion 3C1 may be formed of a pair of rod-shaped bodies as shown in this embodiment, or may be formed of a flat plate. In short, any material that can connect and fix the connecting portion 3C to the element 3B is sufficient. The approximately circular curved portion 3C2 is located approximately in the middle of the coupling portion 3C. The tip portion 3C3 has a narrow gap communicating with the substantially circular curved portion 3C2. In this embodiment, the tip portion 3C3 is integrally constructed, but the tips do not necessarily need to be connected.
There is no problem even if they are separated. The key is wedge 3, which will be discussed later.
It is sufficient to have a narrow gap in which C4 can intervene.

Next, the connection and fixation of the connection portion 3C and the stapes 4 will be explained. A wedge 3C4 is driven in advance into a narrow gap at the tip 3C3 of the joint 3C to enlarge the substantially circular curved portion 3C2. Then, the femoral head 4A of the stapes 4 is fitted into the approximately circular curved portion 3C2, and then the wedge 3C4 of the distal end portion 3C3 is pulled out. Therefore, since the connecting portion 3C is made of an elastic body,
The enlarged approximately circular curved portion 3C2 shrinks and returns to its original state, compressing the stapes head 4A, and achieving a connection and fixation between the connecting portion 3C and the stapes 4.

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 coupling portion having a narrow gap in which a wedge can be inserted and a substantially circular curved portion.
It is useful because it has a simple structure, can easily ensure vibration transmission to the stapes, and can prevent the connecting portion from falling off from the stapes.

[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 view showing an 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 portion, 3C2: Approximately circular curved portion, 3C3: Tip portion, 3
C4: Wedge.

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.
is composed of a bending vibrator such as a piezoelectric bimorph element, and the coupling part 3C is composed of an elastic body, and the substantially circular curved part 3C2 to be fitted into the head of the stapes bone and the wedge 3C4 can be attached and detached. A driving transducer for an implantable hearing aid, comprising a distal end portion 3C3 having the narrowest possible gap.