PUBLIC ALARM APPARATUS AND METHOD FOR COCHLEAR IMPLANTS

Abstract: A monitor for a therapeutic device such as a cochlear implant monitors the leakage RF signals between the external and the internal components. In one embodiment, absence of RF signals is interpreted by the monitor as being indicative of either an out-of-range condition or a flat battery condition and a sound and/or visual signal is generated to indicate this condition to an attendant. In a more complex embodiment, special indication signals either are superimposed on the standard signals and used to uniquely identify the cochlear implant or to provide an indication of certain preselected features of the external component. The monitor is especially useful where cochlear implants have been fitted to infants.

Description: PUBLIC ALARM APPARATUS AND METHOD FOR COCHLEAR IMPLANTS BACKGROUND OF THE INVENTION A. Field of the Invention This invention pertains to an apparatus for providing an alarm indicative of a condition of a wearable therapeutic device, such as, for example, a cochlear implant system, as well as to a method related to said apparatus. B. Description of the Prior Art Various devices, such as cochlear implants, are being used to assist persons having a chronic aural disability or impairment which cannot be alleviated by external hearing aids. These devices typically include two components: an external component and an internal component which is implanted into the patient. The external component typically includes a microphone for converting ambient sounds into electrical signals, signal processing means for converting the electrical signals into processed signals, and a signal transmitter for transmitting the processed signals to the internal component. In turn, the internal component includes receiver means for receiving signals from the transmitter, signal processor means for processing the received signals, and stimulating means for stimulating the inner ear of the person, such as the cochlea, in accordance with the received signals. The external component further includes various manual controls for the operation of the device, such as a volume control, battery checking, and so on. It has been found that for best results, cochlear implant devices should be provided to a patient at the earliest possible age. A problem however occurs if the patient is a small, immature infant. More specifically, with most patients, if the device stops functioning, for example due to a low battery, or a malfunction, the patient can indicate this to a nurse, spouse or other attendant. However, an infant who is essentially deaf and is unable to communicate cannot indicate to anyone that there is a problem, especially since he may be too young to even recognise that there was a problem in the first place. OBJECTIVES AND SUMMARY OF THE INVENTION In view of the above-mentioned disadvantages, it is an objective of the present invention to provide a system or apparatus which automatically monitors a cochlear device, and provides either an audible or visual indication to an attendant in case of a problem. A further objective is to provide a system which can be used easily by a person, without any special instructions or extensive learning period. Yet a further objective is to provide a device which can be made easily and inexpensively, preferably without the need for expensive additional parts or extensive changes in existing product lines. Preferably the indicating method and apparatus can be readily used with existing cochlear devices without any modifications. Other objectives and advantages of the invention shall become apparent from the following description. Briefly, a system for aiding a hearing impaired person constructed in accordance with this invention includes a first external component, located externally to the person, having a microphone for receiving ambient sounds and converting the same into electrical signals, signal processing means for converting the signals and a transmitter for sending the converted signals to an internal component, located internal to the person, through an inductive coupling. This coupling is normally associated with, or produces as a by-product, a radio frequency (RF) signal. Importantly, the present invention further contemplates a second external component, located extend to the patient, being a monitor for monitoring the operation of the first external component. The second external component is adapted to receive and sense an RF signal associated with the inductive coupling between the first external component and the internal component, and to generate an audible or visual indication via an appropriate annunciator as to whether said signal is sensed or not. This second external component is normally worn on a clothing article or pocket by an attendant including a parent, a nurse, or other attendant, so that the latter can determine easily whether the first external component, and preferably the internal component, is operating properly. Preferably the operation indicative signal is simply leaked RF associated with the transcutaneous RF coupling between the first external component and the internal component. Alternatively the invention envisages that the operation indicative signal may be provided by a second source of RF incorporated into the first external component. The present invention further provides a method of generating a signal indicative of the condition of a therapeutic device of the kind previously described by monitoring RF signals from the external component and generating an annunciator signal dependent on the RF signals. According to a further aspect the present invention provides a system for monitoring the operation of a plurality of therapeutic hearing devices including : a) a plurality of transmitters each one tuned to a unique frequency and fitted to one of each of the plurality of therapeutic hearing devices and transmitting a signal indicative of the operating status of the therapeutic hearing device to which it is fitted; b) a monitor for monitoring the transmissions of said plurality of transmitters; wherein the monitor produces an alarm upon the cessation of standard operation of any one of the plurality of therapeutic hearing devices, said alarm identifying the particular one of said plurality of therapeutic hearing devices to have ceased standard operation. BRIEF DESCRIPTION OF THE FIGURES Figure 1 shows a standard prior art cochlear implant device; Figure 2 shows a monitoring component used to monitor a cochlear implant device such as the one shown in Figure 1 ; and Figure 3 shows an alternate embodiment of the invention. Figure 4 shows a further embodiment of the invention. DETAILED DESCRIPTION OF THE INVENTION Referring now to the drawings, and more particularly to Figure 1 , a typical cochlear implant device consists of an external component which is essentially a speech processor 1 and an internal component including an implanted receiver and stimulator unit 6. The external component 1 includes a microphone 2. The speech processor 1 is constructed and arranged so that it can fit behind the outer ear 11. Alternatively, it can be worn on the body. Attached to speech processor 1 is a transmitter coil 3 which transmits-the electrical signals to the internal component via an RF link 4. The internal or implanted component includes a receive coil 5 for receiving the electrical signals from the coil 3, i.e. RF signals 4. Attached to the receiver coil 5 is the implanted receiver-stimulator 6. A cable 7 extends from the receiver-stimulator 6 to the cochlea 12 and terminates in an electrode array 10. The signals thus received are applied by the array 10 to the nervous tissue of the basilar membrane 8 and thence to the auditory nerve 9. The operation of the device shown in Figure 1 is described for example in U.S. Patent No. 4,532,930. Under normal conditions, the microphone 2 picks up ambient sounds and converts them into corresponding electrical signals. The speech processor 1 senses these sounds and translates them into corresponding cochlear excitation signals. The excitation signals are then transmitted to the implanted component via channel 4. The receiver-stimulator 6 receives these signals and after suitable translation (if necessary) applies them by means of array 10 to the basilar membrane 8 and thence to auditory nerve 9. Preferably the RF signals are transmitted by an inductive coupling between the coils 3 and 5. Referring now to Figure 2, an arrangement of an embodiment according to the present invention is depicted, including a monitor 16. The device includes a speaker 17 and may also incorporate an indicator alarm light 19. The monitor is further provided with an on/off-volume controller 18 and an antenna 20. Importantly, not all the energy of the RF waves 4 (shown in Figure 1 ) are intercepted by coil 5. Instead some of the energy leaks away, as indicated in Figure 2 at 15. According to a first embodiment the monitor 16 is arranged and constructed so that it receives and senses this leakage and uses it as a confirmation signal that the cochlear device operates satisfactorily. The simplest method of implementing the invention is to make monitor 16 include a simple radio receiver for detecting the leakage signal 15. The monitor then decides whether the signal 15 is sensed or not. If no signal is sensed, then a sound is emitted by speaker 17 to indicate that either the cochlear implant device is out of range or it has ceased functioning properly. The volume of the sound is controlled by volume controller 18. Alternatively, or in addition, alarm lamp 19 is turned on for the same purpose. The monitor 16 is carried by a parent, guardian, nurse or other attendant associated with the patient. As an additional feature, the speech processor may use an encoder to provide a low battery indication. More particularly, as shown schematically in Figure 3, the speech processor (item 1 of Figure 1) may include a signal processor 21 which receives the electrical signals from microphone 2. The speech processor 1 further includes a battery 22 which provides power to both the speech processor and the internal component. The condition of the battery 22 is sensed by a sensor 23. The sensor 23 generates an appropriate signal to encoder 24 which generates an indication signal indicative of the battery's condition. This signal is combined with the signal from signal processor 21 by any appropriate means, herein represented by summer 25, for example mixing of the two signals followed by filtering. The resulting signal is transmitted by transmitter 26 to the internal component including coil 5, detected by receiver-stimulator 6 and processed to produce stimulation signals. The stimulation signals are delievered to the patient via cochlear electrode array 10. Leakage 15 is now detected by receiver 30 through the antenna 20. The received signal is decoded by decoder 32 and a signal dependent on the component of the received signal indicative of the battery condition is fed to an annunciator 34 which may consists of either the speaker 17 or lamp 19. The annunciator 34 is activated if the battery condition indicator signal indicates that the battery 22 is flat. In this case, the monitor 16 may distinguish between a flat battery condition and the infant being out of range since in the first instance the battery condition signal is present, while in the second instance no signal is sensed at all. Apart from encoding the battery status the signal from encoder 24 may also include a serial number or other data uniquely identifying the speech processor 1. In this manner, several infants may be located in a common area, for example a class room, each infant wearing a special speech processor as described in Figure 3 and the attendant having either a monitor for each infant or a combined monitor adapted to monitor several infants. Of course a disadvantage of this embodiment is that it requires more parts, and in addition the speech processor has to be redesigned to include the battery sensor 23, encoder 24 and summer 25. According to this embodiment monitor 16 may perform more complicated functions as well, such as determining if the signals from the speech processor 1 are appropriate for the implant, or whether other functions are performed properly by the speech processor. According to another implementation of the invention, depicted in Figure 4, the condition of the battery 22 is sensed as before by a sensor 23. The sensor 23 generates an appropriate signal to encoder 24 which in turn produces a battery condition signal. The battery condition signal is transmitted by second transmitter 41 and transmit antenna 39. The transmitted condition signal 37 is distinct from the transcutaneous coupling RF signal 4. Signal 37 is detected by receiver 30 through antenna 20. The received signal is decoded by decoder 32 and a signal dependent on the component of the received signal indicative of the battery condition is fed to an annunciator 34 which may consist of either the speaker 17 or lamp 19. The operation of the annunciator 34 is exactly the same as that of the annunciator in the embodiment depicted in Figure 3. The operation of the microphone 2, processor 21 , first transmitter 26, which generates a transcutaneous coupling signal 4, coils 3 and 5 and the implanted component, including receiver-stimulator 6 and cochlear electrode array 10, is exactly the same as described in the previous embodiment. It will be readily apparent to those skilled in the art that it is preferable that the condition signal 37 be of a frequency and/or modulation type that does not interfere with transcutaneous coupling signal 4. Whilst the above described embodiment of Figure 4 is more complex to implement than the earlier embodiment of the invention it has the advantage that the transmitter 31 and antenna 33 can be specifically designed to maximise the operating range between the patient and the monitor. Furthermore in some situations it may be that two or more patients will be situated in close proximity e.g. in a classroom situation. In that case a convenient way of discriminating between alarm signals is to have the transmitter 31 of each each patient's prosthesis operating on a different frequency. The monitor 16 may be accordingly modified to scan through the relevant frequencies and upon detecting either a loss of signal or a signal indicative of non-standard operation of a particular cochlear implant device the monitor will issue an alarm identifying the cochlear implant device which is either out of service or operating in a non- standard manner. Alternatively a plurality of monitors, each tuned to monitor a particular patient, may be used, each operating as described previously. Although the invention has been described with reference to preferred embodiments, it is to be understood that these are merely illustrative of the application of the principles of the invention. Accordingly, the embodiments described in particular should be considered exemplary, not limiting, with respect to the following claims.

Claims: CLAIMS: 1. A system for aiding a person having a hearing impairment, said system including: an external component including a microphone for converting ambient sounds to electrical signals, a signal processor for processing said electrical signals into stimulation signals and a transmitter for transmitting RF signals dependent on said stimulation signals; an internal component for receiving said RF signals, said internal component applying electrical stimulations to said person's auditory nerve dependent on said stimulation signals; and a monitor located external to the person and receiving said RF signals, said monitor generating an output signal dependent on said RF signals. 2. The system of claim 1 wherein said monitor includes an annunciator. 3. The system of claim 2 wherein said annunciator is activated in the absence of said RF signal. 4. The system of claim 2 wherein said annunciator is a speaker. 5. The system of claim 2 wherein said annunciator is a lamp. 6. The system of claim 1 wherein said external component includes a battery having a normal and a flat condition, and wherein said output signal is generated to indicate said flat condition. 7. The system of claim 6 wherein said external component includes an encoder for generating an indication signal indicative of a preselected condition and a means for combining said stimulation signals and said indication signal. 8. The system of claim 7 wherein said monitor includes a decoder for decoding said condition signals from said external component. 9. The system of claim 8 wherein said encoder generates a signal including an identifier uniquely identifying said external component and wherein said monitor includes a decoder for recognising said identifier. 10. The system of claim 7 where said indication signal is indicative of a battery condition. 11. A monitor for monitoring a therapeutic device, said therapeutic device including an external component generating RF signals, and an internal component receiving said RF signals and applying therapy in response to said major portion of said RF signals, said monitor comprising: a detector for detecting said RF signals from said external component; and an annunciator for generating an annunciator signal dependent on said RF signal. 12. The monitor of claim 11 wherein said annunciator signal is generated in the absence of said RF signals. 13. The monitor of claim 11 wherein said annunciator signal is an audio signal. 14. The monitor of claim 11 wherein said annunciator signal is a visual signal. 15. A method of generating a signal indicative of the condition of a therapeutic device of the kind having an external component and an internal component, said external and internal components communicating _by exchanging RF signals, said method comprising: monitoring said RF signals; and generating an annunciator signal dependent on said RF signals. 16. The method of claim 15 wherein said annunciator signal is generated in the absence of said RF signals. 17. The method of claim 15 wherein said annunciator signal is an audio signal. 18. The method of claim 15 wherein said annunciator signal is a visual signal. 19. A system for aiding a person having a hearing impairment, said system including: an external component including a microphone for converting ambient sounds to electrical signals; a signal processor for processing said electrical signals into stimulation signals; a first transmitter for transmitting a first RF signal dependent on said stimulation signals; a second transmitter for operatively transmitting a second RF signal; an internal component for receiving said first RF signal, said internal component applying electrical stimulation to said persons auditory nerve dependent on said stimulation signals; and a monitor separate from said internal component and receiving said second RF signal, said monitor generating an output dependent on said second RF signal. 20. The system of claim 19 wherein said monitor includes an annunciator. 21. The system of claim 20 wherein said annunciator is activated in the absence of said second RF signal. 22. The system of claim 20 wherein said annunciator is a speaker. 23. The system of claim 20 wherein said annunciator is a lamp. 24. The system of claim 19 wherein said external component includes a battery having a normal and a flat condition, and wherein said output signal is generated to indicate said flat condition. 25. The system of claim 24 wherein said first external component includes an encoder for generating an indication signal indicative of a preselected condition said indication signal being transmitted by said second transmitter. 26. The system of claim 25 wherein said monitor includes a decoder for decoding said indication signal from said external component. 27. The system of claim 26 wherein said encoder generates a signal including an identifier uniquely identifying said external component and wherein said monitor includes a decoder for recognising said identifier. 28. The system of claim 25 where said indication signal is indicative of a battery condition. 29. A monitor for monitoring a therapeutic device, said therapeutic device including an external component generating first and second RF signals and an internal component receiving said first RF signal and applying therapy in response to said major portion of said first RF signal, said monitor comprising; a detector for detecting said second RF signal from said external component; and an annunciator for generating an annunciator signal dependent on said RF signal. 30. The monitor of claim 29 wherein said annunciator signal is generated in the absence of said RF signal. 31. The monitor of claim 29 wherein said annunciator signal is an audio signal. 32. The monitor of claim 30 wherein said annunciator signal is a visual signal. 33. A method of generating a signal indicative of the condition of a therapeutic device of the kind having an external component and an internal component, said external and internal components communicating by exchanging a first RF signal, said method comprising: operatively transmitting from said external component a second RF signal; monitoring said second RF signal; and generating an annunciator signal dependent on said second RF signal. 34. The method of claim 33 wherein said annunciator signal is generated in the absence of said second RF signal. 35. The method of claim 33 wherein said annunciator signal is an audio signal. 36. The method of claim 33 wherein said annunciator signal is a visual signal. 37. A system for monitoring the operation of a plurality of therapeutic hearing devices including : a) a plurality of transmitters each one tuned to a unique frequency and fitted to one of each of the plurality of therapeutic hearing devices and transmitting a signal indicative of the operating status of the therapeutic hearing device to which it is fitted; b) a monitor for monitoring the transmissions of said plurality of transrτιitteχs; wherein said monitor produces an alarm upon the cessation of standard operation of any one of said plurality of therapeutic hearing devices, said alarm identifying the particular one of said plurality of therapeutic hearing devices to have ceased standard operation.

Inventors: SINGLE PETER, SINGLE, PETER
Applicants: COCHLEAR LTD, COCHLEAR LIMITED
Application year: 1997
Main classification: H04R25
IPC codes: A61F2, A61F11, A61N1, H04R25, H04R27