Method Of Implanting A Hearing Aid

Abstract

A method is described of implanting a hearing improvement device within the human body, in which a postauricular incision is made in the skin of the anatomical area behind the auricular appendage of the external ear, to thereby expose the bony structure overlying the body of the mastoid, removing a predetermined area of bone down to the antrum cell of the mastoid, implanting the device in the cavity formed, and then closing the incision. The device has a portion which extends into the middle ear space.

Parent Case Text

This application is a division of my copending application, Ser. No. 333,858, filed Dec. 27, 1963, for MEANS FOR AIDING HEARING and since matured into Pat. No. 3,364,704.

Description

This invention relates generally to a method of implanting a hearing aid in the human body, but has reference more particularly to a method in which the hearing aid is so implanted as to be completely enclosed within the head of the individual utilizing the hearing aid.

Hearing aids which are presently available on the market are usually worn outside of the body, and are therefore objectionable from an esthetic, cosmetic or functional viewpoint.

Although attempts have been made to utilize such hearing aids in a manner to conceal them from view, as, for example, within the temples of spectacles, it is virtually impossible to conceal certain portions of the hearing aid, such as wires, etc., and fort for this reason, many persons whose hearing facilities can be improved do not avail themselves of such aids.

The present invention has as its primary object the provision of a method whereby an audio implant in the nature of a miniaturized system for amplifying sound, is placed directly in the structure of the ear and utilizes the impaired or damaged, but still functioning, normal channels for transmission of sound to the brain.

Another object of the invention is to provide a method wherein an implant of the character described, is disposed in its entirety within the head structure of the user, and is entirely concealed from view, thereby eliminating any and all objections to its use from an esthetic or cosmetic point of view.

A further object of the invention is to provide a method wherein the implant utilizes a battery which is enclosed within the head structure.

Other objects and advantages of the invention will become apparent in the course of the following description, taken in conjunction with the accompanying drawings wherein:

FIG. 1 is a vertical cross-sectional view of a portion of a human head taken through the right side of the head and passing through the mastoid antrum and middle ear in a plane parallel to a plane passing through the nose and the back of the head, and showing the components of the audio implant of the present invention in position;

FIG. 2 is a fragmentary elevational view showing a portion of the right side of the head, and with the external ear pulled forwardly to show or indicate where the implant and microphone tube are placed; and

FIG. 3 is a tabulation of the means utilizing the implant of the present invention, whereby sound is transmitted to the temporal lobe of the brain, where the sound is heard.

Referring more particularly to the drawings, an understanding of FIG. 1 can be gained if the observer can imagine he is inside the head of the person depicted in FIG. 1, and is looking outwardly and through the right ear.

The observer will see the auditory canal 1, the tympanic membrane 2, the malleus 3, the incus 4 and the mastoid antrum 5. The tip of the mastoid is indicated by reference numeral 6, the chorda tympani by reference numeral 7, a facial nerve by reference numeral 8, and the squama by reference numeral 9.

Normal hearing in an individual is accomplished by the help of the external ear, which concentrates the sonorous vibrations of the air upon the tympanic membrane, causing the latter to vibrate. The chain of bones in the middle ear, namely the malleus, incus and stapes, transmits these vibrations to the internal ear, where, wholly or chiefly through the hair cells in the organ of corti, they stimulate the fibers of the auditory nerve, which then carries the sound impulses to the temporal lobe of the brain.

In accordance with my invention, I provide a hearing improvement device which I term an "audio implant," and which consists of several components, including mainly a microphone, a battery, an amplifying system and a speaker, such as are found in a conventional hearing aid. These components are encased in a silicone rubber sponge with a hardened coat of silicone rubber to form a unit, designated by reference numeral 10 in FIGS. 1 and 2.

The unit 10 is rectangular in shape, measuring approximately 1 cm. .times. 1 cm., and a few millimeters in thickness, and is provided with a silicone rubber tube 11 extending centrally from one end of the unit 10, and a similar tube 12 extending centrally from one side of the unit 10. The tubes 11 and 12 are approximately 11/2 cm. in length, and approximately 2 mm. in diameter. The tube 11, which I term the microphone tube, is attached to the microphone within the unit 10, and both ends of the tube are sealed with a very thin membrane of silicone rubber. The tube 12, which I term the speaker tube, is attached to the speaker within the unit 10, and both ends of this tube are sealed with a very thin membrane of silicone rubber.

When the device is to be implanted, a postauricular incision is made adjacent the auricular appendage of the external ear, in the skin of the anatomical area of the ear. This incision is approximately three centimeters in length, and is carried out under local anesthesia. The bony structure overlying the body of the mastoid is exposed, and an area of bone, i.e., an area of approximately 2 square centimeters, is removed down to the antrum cell of the mastoid. A few of the air cells of the mastoid are then removed to enlarge the antrum cell to accommodate the unit 10.

The unit 10 is then placed directly into this space in the manner shown in FIG. 1, and the speaker tube 12 is then placed in a passageway which extends from the antrum cell of the mastoid into the middle ear space behind the ear drum. More specifically, the speaker tube is brought up through a small opening near the introitus of the ear canal, and to a point closely adjacent to what is commonly referred to as the "round window" The wave motion is transmitted to the cochlea, which starts the electrical impulses to the temporal lobe of the brain.

The microphone tube 11 is then extended externally from the antrum cell of the mastoid and is covered with skin and will be disposed just beneath the skin behind the ear. The incision is then closed, and the ear again completely sealed. Since the skin incision is made in a hidden area adjacent the ear, no noticeable scar will be produced, after healing.

Referring to FIG. 3 of the drawing, it is seen that through the use of the hearing aid of this invention, sound vibrations are transmitted through the skin, posterior to the auricle, hence to the microphone tube 11, amplifier unit 10, speaker tube 12, middle ear cavity, round window, and duct to choclea, thence in the normal manner to the temporal lobe of the brain.

The battery within the unit 10 is preferably a silver-cadmium battery and can be charged by a magnetic induction coil which is attached to a head band, which can be worn on the head while sleeping, or at any other time which is convenient. The induction coil is connected to a wire which leads to a transistorized charging unit which is energized from a conventional electrical outlet. In charging the battery, the induction coil on the head band is placed directly over the main structure of the mastoid.

The implant will function for approximately eight days before it becomes necessary to recharge such a battery with the magnetic induction coil. Recharging of the battery requires approximately 6 hours.

One of the advantages of the use of such an implant is that it is embedded solidly in the bone of the skull, and is so situated that it can drive the sound directly into the inner ear, without the necessity of driving the sound through the tympanic membrane, which offers considerable resistance to transmission of sound in cases of conductive deafness where the oval window and stapes are fused by abnormal bone closure called otosclerosis.

Another advantage is that there are no parts which are disposed externally of the head or are visible, so that objections to use of the device, based on psychological factors, and cosmetic viewpoints, are eliminated.

A further advantage lies in the fact that the replacement batteries, and its attendant costs, are eliminated.

A still further advantage resides in the elimination of the rushing and clothing noise which is a constant source of annoyance to individuals from movement across the microphones of hearing aids which are carried about the body.

The device is also of particular advantage for children who require the use of a hearing aid to hear sufficiently to carry on their school work, while finding it necessary to remove these aids during play and physical activity since external hearing aids and devices are easily dislodged or broken during such play or physical activity.

It is thus seen that I have provided a means of aiding hearing of individuals whose hearing is not remediable medically or surgically, but who require amplification of sound for hearing.

It is also seen that I have provided an audio implant in the nature of a miniaturized system for amplifying sound, which is placed directly in the structure of the ear and utilizes the impaired or damaged, but still functional, normal channels for transmission of sound to the brain.

It is further seen that I have provided an implant which is disposed in its entirety within the head structure of the user, and is entirely concealed from view, thereby eliminating any and all objections to its use from an esthetic or cosmetic point of view.

It will be understood that various changes may be made in the details of the invention, as described, without departing from the spirit of the invention, or the scope of the appended claims.

Claims

I claim:

1. The method of implanting a self-contained hearing improvement device within the human body, in which said device contains a microphone, a battery, an amplifying system, which is neutral to the adjacent portions of the body, a microphone tube extending from the microphone in said unit; a speaker and a speaker tube extending therefrom including the steps of making an incision adjacent the auricular appendage of the external ear, in the skin of the anotomical area of the ear, exposing the bony structure overlying the body of the mastoid, removing a predetermined area of bone down to the antrum cell of the mastoid, implanting the self-contained hearing improvement device in said antrum cell, situating an outer end of the microphone tube into position and adjacent the skin behind the auricular appendage and situating an outer end of said speaker tube into the middle ear space behind the ear drum through the antrum-inner ear passage; and thereafter closing the incision.

2. The method of implanting in the human body a hearing improvement device including signal-receiving means for receiving an incoming signal representative of a sound wave existing outside of the human body, intermediate means for converting said incoming signal to an audiofrequency electrical signal, output means including electrical-mechanical transducer means to generate mechanical motion from said electrical signal, an operative connection between said signal-receiving means, said intermediate means and between said intermediate means and said output means, said method comprising the steps of making an incision in the skin in the auricular area of the ear adjacent the auricular appendage of the external ear; exposing the bony structure overlying the body of the mastoid; removing an area of bony structure to expose the antrum cell cavity; positioning said hearing improvement device within said cavity and with at least part of said output means in the middle ear space to deliver said generated mechanical motion directly thereinto; and then closing the incision.

3. The method specified in claim 2 and the step of removing sufficient air cells of the mastoid to enlarge the antrum cell cavity to accommodate the implanting of said hearing improvement device, said step being performed before the step of positioning said output means.

4. The method of implanting a hearing improvement device in a human body, said device including signal-receiving means for receiving an incoming signal representative of a sound wave existing outside of said human body, intermediate means for converting said incoming signal to an audiofrequency electrical signal, output means including electrical-mechanical transducer means adapted to generate mechanical motion from the electrical signal, and operative connections from said signal-receiving means to said intermediate means and from the intermediate means to the output means; said method comprising the steps of surgically positioning at least a portion of said output means within the human body in the middle ear space at the round window to permit said generated mechanical motion to pass from said output means directly to the middle ear space behind the area of the tympanic membrane; concurrently positioning said signal-receiving means within the human body in position to receive said incoming signal; and further, surgically positioning said intermediate means within the human body at a locus removed from the middle ear space but adjacent the area of the auricular appendage of the ear and in operative relationship to said signal-receiving means and said output means.

5. The method of implanting a hearing improvement device within the human body, said method comprising the steps of: making an incision adjacent the auricular appendage of the external ear in the skin of the anatomical area of the ear; exposing the bony structure overlying the body of the mastoid; removing a predetermined area of bone down to the antrum cell of the mastoid; implanting a hearing improvement device in the cavity formed by the bone removal and mastoid antrum cell with at least a portion of the device extending into the middle ear space; and closing the incision.