Implant Sensor and Control

An implant includes a humidity sensor for generating a signal indicative of humidity within the implant. A controller within the implant receives the signal indicative of humidity, and controls the implant based on the signal indicative of humidity.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS

In illustrative embodiments, a sensor and/or self-test module is exploited by a controller within the implant for various control and switching functions. Thus, there is no need to rely on patient feedback, or interpretation of telemetry data, to monitor and react to changes in implant humidity. The sensor may be, for example, a humidity sensor, a temperature sensor, and/or a concentration of one or more gases. Details are discussed below.

FIG. 1shows an exemplary cochlear implant. It is to be understood that the present invention is not limited to a cochlear prosthesis, and that the present invention is applicable to other types of implants, as known in the art.

The cochlear implant typically includes two parts, an external component including a microphone27and a speech processor29, and an implanted component22that includes a stimulator element22. The speech processor29includes the power supply (batteries) of the overall system and is used to perform signal processing of the acoustic signal received by the microphone27to extract the stimulation parameters. Attached to the speech processor29is a transmitter coil24that transmits power and data signals to the implanted unit22transcutaneously via a radio frequency (RF) link. The implanted component22includes a receiver coil24that is capable of receiving the data and/or power from the transmitter coil24and a stimulator28. Based on the received data, the stimulator28sends stimulation signals via a cable21to an electrode array20positioned in the cochlea12, stimulating the auditory nerve9. It is to be understood that in various embodiments of the invention, various parts or all of the cochlear may be implanted. An exemplary fully implantable is described in U.S. Pat. No. 6,272,382 (Faltys et al.), incorporated herein by reference in its entirety. Furthermore, in various embodiments both the external component and the internal component may include a processor, with various functionality split between the two processors.

FIG. 2is a block diagram showing various elements of an implanted component122of a cochlear implant system, in accordance with one embodiment of the invention. The implanted component typically includes a hermetically sealed housing128, which may be made of, without limitation, titanium, nonmagnetic stainless steel, or a ceramic.

The implanted component122includes a sensor125, such as a humidity sensor125which generates a signal indicative of humidity within the implant. The humidity sensor125may be, without limitation, a capacitive or resistive humidity sensor, as known in the art. It is to be understood that instead of, or in addition to, a humidity sensor, other types of sensors known in the art, such as a temperature sensor, motion sensor, and/or gas sensor, may be used in accordance with the invention described herein, that provide a signal indicative of one or more conditions, such as an environmental condition, within the implant. In various embodiments, the implant may include a self-test module. The self-test module may initiate various tests within the implant, and/or receive input from one or more sensors, and provide a signal indicative of the performed self-test or a sensed condition. The self-test module may initiate, without limitation, self-test periodically or upon implant power-on.

A controller130is positioned within the implanted component122. The controller130is operationally coupled to, and receives the signal from the sensor125and/or self-test module. In various embodiments, the controller130may be, for example, electrically coupled to the sensor125and/or self-test module.

In illustrative embodiments of the invention, the controller130controls the implant based on the signal received from the sensor125and/or self-test module. Since both the controller130and the sensor125is positioned within the implanted component122, control of the implant based on sensed signal and/or self-test is advantageously performed without having to externally send or process telemetry data, and without patient interaction.

The controller130may include, without limitation, a processor (e.g., a microprocessor, microcontroller, digital signal processor, or general purpose computer), programmable logic for use with a programmable logic device (e.g., a Field Programmable Gate Array (FPGA) or other PLD), discrete components, integrated circuitry (e.g., an Application Specific Integrated Circuit (ASIC)), memory, or any other means including any combination thereof. Memory may include, for example, a diskette, a fixed disk, a Compact Disk (CD), Read Only Memory (ROM), Erasable Programmable Read-Only Memory (EPROM), and/or Random Access Memory (RAM). Computer program logic implementing all or part of the functionality previously described herein may be embodied in various forms, including, but in no way limited to, a source code form, a computer executable form, and various intermediate forms (e.g., forms generated by an assembler, compiler, linker, or locator.) Source code may include a series of computer program instructions implemented in any of various programming languages (e.g., an object code, an assembly language, or a high-level language such as Fortran, C, C++, JAVA, or HTML) for use with various operating systems or operating environments. The source code may define and use various data structures and communication messages. The source code may be in a computer executable form (e.g., via an interpreter), or the source code may be converted (e.g., via a translator, assembler, or compiler) into a computer executable form.

The controller130may command various functionality based on the signal received from the sensor125and/or self-test module. Deviations from a desired environmental condition may trigger the command and control. For example, in receiving signals from a humidity sensor, at the beginning ingress of humidity the controller130may cause stimulator150to stimulate electrode array160to produce a perceived alert to the person wearing the cochlear implant. Note that such an alert is perceived only by the person wearing the cochlear implant, who can then proceed, for example, to see an audiologist for a telemetry check (which may include reading out relative humidity). In other embodiments, the controller130may cause an externally audible alert when, for example, the speech processor is attached. Instead of an audible alert, other types of alerts may be provided, such as a visual alert.

The alert provided may last for a predetermined duration upon turning on the implant. For example, when turning on the implant, three short beeps may be provided. Of course, other alerts may be provided upon further ingress, or at various levels, of humidity or other condition within the implant.

Upon further ingress of humidity (or other condition within the implant), or at, for example, a predetermined humidity level, the controller130may inhibit stimulation at the electrode array160, thus avoiding any current flow at the electrodes. In various embodiments, the controller130may switch power off in the implant and/or discharge an implanted battery165in a controlled fashion. In still further embodiments, the resonance frequency and/or the quality factor of the RF circuit on the implant side may be changed.

In various embodiments, a hydrophilic agent170, such as silica gel, may be positioned in the internal component122to concentrate moisture at a desired location. For example, the hydrophilic agent170may be positioned in close proximity to the humidity sensor125. Water vapor is thus concentrated at the hydrophilic agent170, and consequently at the humidity sensor125, increasing the implant's sensitivity to humidity.