Abstract:
The invention discloses a programmable implantable hearing aid including built-in electronics being in wireless communications with a hand-held programmer. The programmer transmits digital code signals of the type including RF, infrared and ultrasonic, based on selected parameter settings. A receiver accepts the signals for transmission to an input transducer in the middle ear. The input transducer collects the middle ear&#39;s response to the signals and transmits it to a circuit in the implanted hearing aid. The circuit searches for specific programming patterns and decodes the signals to effectuate the desired adjustment in the hearing aid. The conditioned signals are then transferred to an output transducer to operate the device at the adjusted signal level and condition. The invention enables both a patient and doctor to make unlimited number of adjustments in the implanted hearing aid without invasive surgery.

Description:
This application claims benefit of U.S. Provisional Application Ser. No. 60/118,857. 
    
    
     BACKGROUND OF THE INVENTION 
     1. Field of the Invention 
     The present invention relates generally to implantable hearing aid technology. Specifically, the invention pertains to a programmable hearing aid in which several parameters are adjustable by a patient and a physician after the hearing aid has been permanently implanted in the patient. 
     2. Description of Related Art 
     Several types of partially implantable hearing aids have been in use for sometime now. Although there are significant variations between these devices, the basic structural organization remains the same. Currently, very little adjustments could be made to these devices after implant. Generally, in hearing aids where the entire device is implanted there is only a one-time adjustment which is done during the time of installation. Subsequent adjustments would therefore require an invasive surgical procedure thus making continued fine tuning and real time adjustment very expensive and time consuming. 
     The imperatives for continued adjustment of hearing aids may primarily be driven by morphological changes in the auditory elements of the patient&#39;s ears. This may result in the hearing aid being occasionally out of tune thus needing adjustments to rectify the problem. Further, to be effective, a hearing aid must preferably be implemented to match a patient&#39;s specific needs. These needs may change over time and, as well, depend on the type of eminent auditory stimulus to which the patient is subjected. For example, a patient may at the very least be able to adjust the volume of an auditory stimulus. Moreover, the patient may elect to turn the device off, for example, and attempt to block out unwanted noise. Furthermore, the patient may elect to test the performance of the hearing aid and conduct a self-directed preliminary evaluation. 
     As indicated hereinabove, with the exception of invasive surgery, there are no systems known to the inventors which enable real time and non-invasive adjustments of hearing aids after implant. Accordingly, there is a need for a method and device to enable patients and physicians to adjust hearing aids, after implant, on an as needed basis. 
     SUMMARY OF THE INVENTION 
     It is one of the primary objectives of this invention to provide built-in adjustment tools and telemetry for hearing aids after permanent implant without any subsequent invasive surgery. 
     It is another object of this invention to provide a locally and remotely adjustable inner ear hearing aid to enable a high level of reliability and maintainability. In this regard, it is a further object of the invention to provide patient-adjustable features likely to reduce non-critical visits to the doctor while promoting patient freedom to travel and live in rural areas where a clinic or a hospital may not be readily available. 
     It is yet another object of the present invention to provide an external device configured to select parameters and settings, electronics for encoding the settings into, preferably, a digital pulse code modulated format, electronics for generating RF carrier for transmitting the encoded signals, and an antenna to receive the signals. The external device interfaces with an implanted hearing aid to thereby influence the functional parameters of the implanted hearing aid as needed. 
     It is yet another object of the invention to provide an infrared carrier to carry encoded information between the programmed and implanted hearing aid. In this configuration the transmitter/receiver (transceiver) is similar to a remote controller commonly used to program audiovisual equipment. The hearing aid is implanted subcutaneously with a window in the housing of the electronics package that is at least partially transparent to infrared signals. 
     Yet a further object of the present invention includes a method in which a programmer/transmitter emits ultrasonic signals which are received by ultrasonic transducer in or near the implanted electronics package. The transmitter may be touched to the skin of the patient near the receiver transducer in order to conduct the signals through the body from the transmitter to the receiver. 
     Yet another object of the invention includes a logic structure in which the programmer/transmitter sends encoded acoustic signals that are picked up by the ear drum and thus detected by the input transducer of the implanted hearing aid. The circuitry in the hearing aid continually checks for specific programming patterns (wake up code) in a specific frequency band of the programmer/transmitter and when detected decodes the information and makes the required changes. 
     Another object of the invention includes the provision of a telemetry structure including data streams. The telemetry structure uses, inter alia, pulse code telemetry and pulse interval telemetry. The data stream is formatted to instruct the receiver that data is being transmitted and that, subsequently, the data should be stored in memory upon reception. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 illustrates a section of an anatomically normal human ear in which the present invention is implemented. 
     FIG. 2A is a block diagram showing the major components of a remote control programmer including an RF transmitter. 
     FIG. 2B is a block diagram showing the major components of a remote control programmer including an infrared transmitter. 
     FIG. 2C is a block diagram showing the major components of a remote control programmer including an acoustic transmitter. 
     FIG. 3 is a block diagram showing the major components of the implanted hearing device. 
     FIG. 4A illustrates pulse code telemetry. 
     FIG. 4B illustrates pulse interval telemetry. 
     FIG. 4C illustrates a typical data stream. 
    
    
     DESCRIPTION OF THE INVENTION 
     FIG. 1 illustrates, generally, the use of the invention in a human auditory system. Sound waves are directed into an external auditory canal  20  by an outer ear (pinna)  25 . The frequency characteristics of the sound waves are slightly modified by the resonant characteristics of the external auditory canal  20 . These sound waves impinge upon the tympanic membrane (eardrum)  30 , interposed at the terminus of the external auditory canal  20 , between it and the tympanic cavity (middle ear)  35 . Variations in the sound waves produce tympanic vibrations. The mechanical energy of the tympanic vibrations is communicated to the inner ear, comprising cochlea  60 , vestibule  61 , and semicircular canals  62 , by a sequence of articulating bones located in the middle ear  35 . This sequence of articulating bones is referred to generally as the ossicular chain  37 . Thus, the tympanic membrane  30  and ossicular chain  37  transform acoustic energy in the external auditory canal  20  to mechanical energy at the cochlea  60 . 
     The ossicular chain  37  includes three primary components: a malleus  40 , and incus  45 , and a stapes  50 . The malleus  40  includes manubrium and head portions. The manubrium of the malleus  40  attaches to the tympanic membrane  30 . The head of the malleus  40  articulates with one end of the incus  45 . The incus  45  normally couples mechanical energy from the vibrating malleus  40  to the stapes  50 . The stapes  50  includes a capitulum portion, comprising a head and a neck, connected to a footplate portion by means of a support crus comprising two crura. The stapes  50  is disposed in and against a membrane-covered opening on the cochlea  60 . This membrane-covered opening between the cochlea  60  and middle ear  35  is referred to as the oval window  55 . Oval window  55  is considered part of cochlea  60  in this patent application. The incus  45  articulates the capitulum of the stapes  50  to complete the mechanical transmission path. 
     Normally, prior to implementation of the invention, tympanic vibrations are mechanically conducted through the malleus  40 , incus  45 , and stapes  50 , to the oval window  55 . Vibrations at the oval window  55  are conducted into the fluid-filled cochlea  60 . These mechanical vibrations generate fluidic motion, thereby transmitting hydraulic energy within the cochlea  60 . Pressures generated in the cochlea  60  by fluidic motion are accommodated by a second membrane-covered opening on the cochlea  60 . This second membrane-covered opening between the cochlea  60  and middle ear  35  is referred to as the round window  65 . Round window  65  is considered part of cochlea  60  in this patent application. Receptor cells in the cochlea  60  translate the fluidic motion into neural impulses which are transmitted to the brain and perceived as sound. However, various disorders of the tympanic membrane  30 , ossicular chain  37 , and/or cochlea  60  can disrupt or impair normal hearing. 
     To provide an effective hearing aid, several parameters need to be made adjustable by the patient and the physician. At the very least the patient should be able to control volume and be able to turn the hearing aid off and on. Similarly, the physician should be able to check and or adjust gain range, filter responses, maximum power output and other parameters. FIG. 2A shows a remote controller  70  which includes data entry keyboard  72  being in data communications with microprocessor  74 , memory unit  76 , telemetry  78  and RF transmitter  80 A. Programmer  70  is preferably adapted to be hand held. The patient or the physician can enter data/instructions at keyboard  72 . Various types of signals may be used to induce a coded signal response in the hearing aid. Specifically, embodiments illustrated in FIGS. 2B and 2C use infrared and ultrasonic signals respectively. These features are provided herein as examples only and are not limiting as to the type of signals that could be used with the present invention. In FIG. 2B, infrared signal is transmitted by IR transmitter  80 B. Further, in FIG. 2C, ultrasonic signal is transmitted by transmitter  80 C. 
     Referring now to FIG. 3, implanted hearing aid  82  includes receiver  84 , telemetry  86 , controller  88 , programmable amplifiers and filters  92 , output driver circuit  94  and power source  96 . In this embodiment, hearing aid  82  is implanted subcutaneously at about the mastoid (not shown). Generally, a subcutaneous implant, as that is used in this embodiment, involves slight anterior pulling of outer ear  25 , to expose a region of the temporal bone (the mastoid). An incision is made in the skin covering the mastoid and an underlying access hole  85  is created through the mastoid allowing external access to the middle ear  35 . The access hole is located approximately posterior and superior to the external auditory canal  20 . By placing the access hole in this region, a transducer is disposed within the middle ear  35  cavity. 
     Still referring to FIG. 3, programmable amplifiers and filters  92  are connected to input signal transducer  98  which is, for example, attached to malleus  40 . Further, output driver circuit  94  is connected to output signal transducer  100 , attached at incus  45 . Thus, when a signal is received at receiver  84 , it is directed to telemetry receiver  86  and subsequently relayed to programmable amplifiers and filters  92  where the signal is filtered and adequately amplified and transmitted to input signal transducer  98  at, for example, malleus bone  140 . Transducer  98  converts the signal to a vibration for perception as audible sound in the ear. An alternate output signal transducer  100  at incus bone  145  transduces the vibratory signal as feedback into output driver circuit  94 . An alternate embodiment, which may be preferred according to patient need, includes an implant in the cochlear region of the patient. In such an embodiment, the functional aspects of the invention are essentially as described for the middle ear type of application also described and also claimed herein. 
     Referring now to FIG. 2A in more detail, RF transmitter  80 A is used to send signals to hearing aid  82 . The signals are representative of desired settings at which hearing aid  82  needs to be set. Receiver  84  in hearing aid  82  responsively directs the signal to programmable amplifiers and filters  92 . Subsequently, the signal is directed to input signal transducer  98  attached to, for example, malleus  40  in middle ear cavity  35 . Microprocessor  74 , memory  76  and telemetry  78  co-operate to enable the setting, selection and encoding of the signals to transmit to hearing aid  82 . The encoded signal is received at receiver  84 , decoded in telemetry receiver  86  and directed to programmable amplifiers and filters  92  from where it is directed to the middle ear  35 . Input transducer  98  collects the middle ear&#39;s response to the signals and provides the information to programmable amplifiers and filters  92 . Thereafter, the signal is conditioned to effectuate the desired adjustment in hearing aid  82 . The conditioned signal is directed to output driver circuit  94  for transfer to output transducer  100 . Specifically, output driver circuit  94  searches for specific programming patterns in the signals and decodes the signals for transmission to output transducer  100  to thereby implement the desired adjustment. 
     Sound loudness generally depends on the intensity and frequency of the sensitivity of the patient&#39;s ear. Thus the selected parameters and settings include frequency adjustments suited to the patient&#39;s needs. The present invention provides RF, infrared, ultrasonic and equivalent encoded signals to induce a response in middle ear  35  of the patient. In the alternate embodiment shown in FIG. 2B, an infrared carrier is used to carry encoded information between programmer  70  and implanted device  82 . In this embodiment, transceiver  80 B is equivalent to a remote controller/programmer used in audio visual equipment. Implanted device  82  is subcutaneously implanted with a window in the housing of the electronics package. The window is at least partially transparent to infrared signals. 
     Another embodiment includes a structure in which programmer  70  transmits ultrasonic signals at transmitter  80 C. The ultrasonic transmission is preferably received by telemetry receiver  86 . Receiver  86  is adapted to receive ultrasonic signals. Subsequently, the signal is received by transducer  98  which is preferably piezoelectric. The ultrasonic signal may be transmitted at a distance. In the alternate, the patient or doctor may bring the programmer close to the skin of the patient in order to conduct the signals through the body from transmitter  80 C to receiver  84 . 
     FIGS. 4A and 4B represent encoded signals which, in the alternate embodiment, are transmitted by programmer  70 . Specifically, telemetry  78  is designed to include digital data streams structured in at least one of the manners of pulse code telemetry of FIG.  4 A and pulse interval telemetry of FIG.  4 B. The transmitted data stream may include short bursts of carrier at fixed intervals where the width of the burst indicates the presence of a “one” or “zero”. Pulse code modulation (PCM) is implemented to divide the peak-to-peak amplitude range of the signal to be transmitted. Further, the transmitted data stream may include pulse interval telemetry which includes short bursts of carrier of equal length whose interval indicates a “one” or a “zero”. FIG. 4C illustrates an exemplary embodiment wherein identification (or wake up) and address components of a signal precede a data component. 
     Accordingly, the present invention enables adjustment of critical operational parameters after implant. In the preferred embodiment, RF receiver  84  is installed as part of the implanted hearing aid electronics. Programmer  70  sends RF signals representative of desired settings in implanted RF receiver  84 . Programmer  70  includes means for selecting parameters and settings, electronics for encoding the settings into a preferably encoded digital pulse code modulated format or equivalent format such as FM, electronics for generating the encoded signals and an antenna. The system further comprises the implanted electronics which, inter alia, includes means for receiving the encoded programming signals, decoding the signals and making changes, as desired, in the functional parameters of the implanted hearing aid. 
     In an alternate embodiment, an infrared carrier is used to carry the encoded information between the programmer and implanted device. As discussed hereinabove, another alternate embodiment includes an infrared carrier used to carry encoded information between the programmer and implanted device. In yet another embodiment the programmer unit emits ultrasonic signals for reception by a transducer near the implanted electronics package. 
     Although the description of the preferred embodiment has been presented, it is contemplated that various changes could be made without deviating from the spirit of the present invention. Accordingly, it is intended that the scope of the present invention be dictated by the appended claims, rather than by the description of the preferred embodiment.