Source: https://patents.google.com/patent/EP0974244A4/en
Timestamp: 2018-11-21 13:01:27
Document Index: 44563137

Matched Legal Cases: ['Application No. 08', 'Application No. 08', 'Application No. 08', 'Application No. 08', 'Application No. 08', 'Application No. 08']

EP0974244A4 - Improved dual coil floating mass transducers - Google Patents
Improved dual coil floating mass transducers
EP0974244A4
EP0974244A4 EP19980910266 EP98910266A EP0974244A4 EP 0974244 A4 EP0974244 A4 EP 0974244A4 EP 19980910266 EP19980910266 EP 19980910266 EP 98910266 A EP98910266 A EP 98910266A EP 0974244 A4 EP0974244 A4 EP 0974244A4
EP0974244B1 (en )
August C Pombo
Christopher A Julian
Eric M Jaeger
Bob H Katz
This application is a Continuation-In-Part of Application No. 08/582,301, filed January 3, 1996, which is a Continuation- In-Part of Application No. 08/568,006 filed December 6, 1995, which is a Continuation-In-Part of Application No. 08/368,219 filed January 3, 1995, which is a Continuation-In-Part of Application No. 08/225,153 filed on April 8, 1994, which is a Continuation-In-Part Application of Application No. 08/087,618 filed on July 1, 1993. The full disclosures of each of these applications is hereby incorporated by reference for all purposes.
The seemingly simple act of hearing is a task that can easily be taken for granted. The hearing mechanism is a complex system of levers, membranes, fluid reservoirs, neurons and hair cells which must all work together in order to deliver nervous stimuli to the brain where this information is compiled into the higher level perception we think of as sound .
Various types of hearing aids have been developed to restore or improve hearing for the hearing impaired. With conventional hearing aids, sound is detected by a microphone, amplified using amplification circuitry, and transmitted in the form of acoustical energy by a speaker or another type of transducer into the middle ear by way of the tympanic membrane. Often the acoustical energy delivered by the speaker is detected by the microphone, causing a high-pitched feedback whistle. Moreover, the amplified sound produced by conventional hearing aids normally includes a significant amount of distortion. Attempts have been made to eliminate the feedback and distortion problems associated with conventional hearing aid systems. These attempts have yielded devices which convert sound waves into electromagnetic fields having the same frequencies as the sound waves. A microphone detects the sound waves, which are both amplified and converted to an electrical current. A coil winding is held stationary by being attached to a nonvibrating structure within the middle ear. The current is delivered to the coil to generate an electromagnetic field. A separate magnet is attached to an ossicle within the middle ear so that the magnetic field of the magnet interacts with the magnetic field of the coil. The magnet vibrates in response to the interaction of the magnetic fields, causing vibration of the bones of the middle ear.
Existing electromagnetic transducers present several problems. Many are installed using complex surgical procedures which present the usual risks associated with major surgery and which also require disarticulating (disconnecting) one or more of the bones of the middle ear. Disarticulation deprives the patient of any residual hearing he or she may have had prior to surgery, placing the patient in a worsened position if the implanted device is later found to be ineffective in improving the patient's hearing. Although the Floating Mass Transducer (FMT) developed by the present assignee is a pioneering technology that has succeeded where prior art devices have failed, improved floating mass transducers would be desirable to provide hearing assistance.
With one aspect of the invention, an apparatus for improving hearing comprises: a housing; at least one coil coupled to an exterior of the housing; and a magnet positioned within the housing so that an electrical signal through the at least one coil causes the magnet to vibrate relative to the housing, wherein vibration of the magnet causes inertial vibration of the housing in order to improve hearing. Typically, a pair of oppositely wound coils are utilized. With another aspect of the invention, a system for improving hearing comprises : an audio processor that generates electrical signals in response to ambient sounds; and a transducer electrically coupled to the audio processor comprising a housing; at least one coil coupled to an exterior of the housing; and a magnet positioned within the housing so that an electrical signal through the at least one coil causes the magnet to vibrate relative to the housing, wherein vibration of the magnet causes inertial vibration of the housing in order to improve hearing. With another aspect of the invention, a method of manufacturing a hearing device comprises the steps of : providing a cylindrical housing; placing a magnet within the housing; biasing the magnet within the housing; sealing the housing; and wrapping at least one coil around an exterior of the housing.
Fig. 2 is a cross-sectional view of an embodiment of a floating mass transducer. Fig. 3 is a cross-sectional view of another embodiment of a floating mass transducer.
Fig. 4A shows views of a magnet and biasing mechanisms .
Fig. 4D shows a cross-sectional view of a magnet biased within the sealed cylindrical housing. Fig. 4E illustrates beginning the process of wrapping a wire around a groove in the cylindrical housing.
Fig. 41 shows a cross-sectional view of thicker leads connected to the ends of the wire wrapped around the cylindrical housing that form a pair of coils of the floating mass transducer.
Fig. J shows a cross-section view of the thicker leads wrapped around the cylindrical housing. Fig. 4K shows a clip for connecting the floating mass transducer to an ossicle within the inner ear.
Fig. 4L shows the clip secured to the floating mass transducer. Fig. 4M shows views of a floating mass transducer that is ready to be implanted in a patient.
The present invention provides innovative floating mass transducers for assisting hearing. The following description describes preferred embodiments of the invention; however, the description is for purposes of illustration and not limitation. For example, although specific steps are described for making a floating mass transducer, the order that the steps are described should not be taken as an implication that the steps must be performed in any particular order .
Fig. 1 is a schematic representation of a portion of the auditory system showing a floating mass transducer positioned for receiving electrical signals from a subcutaneous coil inductively coupled to an external audio processor positioned outside a patient's head. An audio processor 100 receives ambient sounds and typically processes the sounds to suit the needs of the user before transmitting signals to an implanted receiver 102. The audio processor typically includes a microphone, circuitry performing both signal processing and signal modulation, a battery, and a coil to transmit signals via varying magnetic fields to the receiver. An audio processor that may be utilized with the present invention is described in U.S. Application No. 08/526,129, filed September 7, 1995, which is hereby incorporated by reference for all purposes. Additionally, an implanted audio processor may be utilized with the invention. Receiver 102 includes a coil that transcutaneously receives signals from the audio processor in the form of varying magnetic fields in order to generate electrical signals. The receiver typically includes a demodulator to demodulate the electrical signals which are then transmitted to a floating mass transducer 104 via leads 106. The leads reach the middle ear through a surgically created channel in the temporal bone .
The above description of the operation of a floating mass transducer with reference to Fig. 1 illustrates one embodiment of the floating mass transducer. Other techniques for implantation, attachment and utilization of floating mass transducers are described in the U.S. Patents and Applications previously incorporated by reference. The following will now focus on improved floating mass transducer design. Fig. 2 is a cross-sectional view of an embodiment of a floating mass transducer. A floating mass transducer 200 includes a cylindrical housing 202 which is sealed by two end plates 204. In preferred embodiments, the housing is composed of titanium and the end plates are laser welded to hermetically seal the housing.
Silicone springs 214 are secured to magnet 212 by, e.g., an adhesive. End plates 204 have indentations within o which an end of the silicone springs are retained. In this manner, the magnet biased within the center of the housing but not in contact with the interior surface of the housing. Figs. 4A-4M will illustrate a process of making the floating mass transducer shown in Fig. 3.
Fig. 4A shows views of a magnet and biasing mechanisms. The left side of the figure shows a cross- sectional view including magnet 212 and silicone springs 214. The silicone springs are secured to the magnet by an adhesive 302. The right side of the figure shows the magnet and biasing mechanisms along the line indicated by A.
Preferably, the wire includes a low resistance, biocompatible material. The housing is placed in a lathe 322 (although not a traditional lathe, the apparatus will be called that since both rotate objects) . Initially, wire 208 is wrapped around the housing within one of grooves 206 starting at a flange 353 between the two grooves. A medical grade adhesive like Loctite glue may be placed within the groove to help hold the wire in place within the groove. As indicated, the lathe is turned in a counter-clockwise direction. Although the actual direction of rotation is not critical, it is being specified here to more clearly demonstrate the process of making the floating mass transducer.
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opposing prongs that, when bent, allow for attachment to an ossicle. Although two pairs of prongs are shown, more may be utilized.
Fig. 4L shows the clip secured to the floating mass transducer. End 404 is wrapped and welded around one end of housing 202 of the floating mass transducer as shown. End 406 of the clip is then available for being clamped on an ossicle. As shown, the clip may be clamped onto the incus near where the incus contacts the stapes. Fig. 4M shows views of a floating mass transducer that is ready to be implanted in a patient. The left side of the figure shows a cross-sectional view of the floating mass transducer. The housing includes a coating 502 which is made of a biocompatible material such as acrylic epoxy, biocompatible hard epoxy, and the like. Leads 372 are threaded through a sheath 504 which is secured to the housing with an adhesive 506. The right side of the figure shows the floating mass transducer along the line indicated by A. Fig. 5A shows another clip for connecting the floating mass transducer to an ossicle within the inner ear. A clip 602 has an end 604 that for attachment to the housing of the floating mass transducer and an end 606 that is curved in the form of a "C" so that it may be easily clamped on an ossicle like the incus. At end 606, the clip has rectangular prongs with openings therethrough.
1. An apparatus for improving hearing, comprising: a housing; at least one coil coupled to an exterior of the housing; and a magnet positioned within the housing so that an electrical signal through the at least one coil causes the magnet to vibrate relative to the housing, wherein vibration of the magnet causes inertial vibration of the housing in order to improve hearing.
9. The apparatus of claim 1, further comprising a clip coupled to the housing for attachment to an ossicle.
10. The apparatus of claim 9, wherein the clip includes at least two pirs of opposing prongs.
12. An apparatus for improving hearing, comprising: a cylindrical housing having two ends; a pair of coils coupled to an exterior of the housing; and a cylindrical magnet positioned within the housing so that an electrical signal through the at least one coil causes the magnet to vibrate relative to the housing, wherein vibration of the magnet causes inertial vibration of the housing in order to improve hearing.
20. An apparatus for improving hearing, comprising: a cylindrical housing having two ends and a pair of grooves between the two ends; a pair of coils coupled to an exterior of the housing, each coil being wound around one of the pair of grooves; and a cylindrical magnet positioned within the housing so that an electrical signal through the at least one coil causes the magnet to vibrate relative to the housing, wherein vibration of the magnet causes inertial vibration of the housing in order to improve hearing.
27. A system for improving hearing, comprising: an audio processor that generates electrical signals in response to ambient sounds; and a transducer electrically coupled to the audio processor, the transducer comprising: a housing; at least one coil coupled to an exterior of the housing; and a magnet positioned within the housing so that an electrical signal through the at least one coil causes the magnet to vibrate relative to the housing, wherein vibration of the magnet causes inertial vibration of the housing in order to improve hearing.
28. A method of manufacturing a hearing device, comprising the steps of: providing a cylindrical housing; placing a magnet within the housing; biasing the magnet within the housing; sealing the housing; and wrapping at least one coil around an exterior of the housing.
EP0974244A4 true true EP0974244A4 (en) 2006-05-10
EP0974244B1 EP0974244B1 (en) 2008-12-03
DE60202678T2 (en) * 2001-05-25 2006-04-06 Gorm Danscher A process for the implantation of heavy metal, such as a precious metal, eg gold, and metal for use in the implantation
WO1996021335A1 (en) * 1995-01-03 1996-07-11 Symphonix Devices, Inc. Implantable and external hearing systems having a floating mass transducer
See also references of WO9841056A1 *