News Column

Patent Issued for Information Processing and Storage in a Cochlear Stimulation System

September 10, 2014



By a News Reporter-Staff News Editor at Biotech Week -- A patent by the inventors Faltys, Michael A. (Northridge, CA); Starkweather, Timothy J. (Bellvue, CO); Arnold, Anthony K. (Valencia, CA), filed on May 5, 2006, was published online on August 26, 2014, according to news reporting originating from Alexandria, Virginia, by NewsRx correspondents (see also Nanotechnology Companies).

Patent number 8818517 is assigned to Advanced Bionics AG (Staefa, CH).

The following quote was obtained by the news editors from the background information supplied by the inventors: "The present disclosure relates to implantable neurostimulator devices and systems, for example, cochlear stimulation systems, and to strategies for storing parameters employed in conjunction with such systems.

"Prior to the past several decades, restoring hearing to the deaf was generally believed to be impossible. More recently, however, scientists have had increasing success in restoring normal hearing in subjects affected by substantial hearing loss. In some cases, hearing loss can be overcome through electrical stimulation. For example, electrical signals can be applied to the auditory nerve, bypassing damaged cochlear hair cells that may be disrupting hearing. Initial attempts to restore hearing using this type of technique were not very successful, because some patients were still unable to understand speech. Over time, however, the auditory sensations elicited by electrical stimulation gradually came closer to approximating normal speech. Electrical stimulation of the auditory nerve can be implemented through a prosthetic device, commonly referred to as a cochlear implant, which is surgically implanted into a subject affected by hearing loss.

"Cochlear stimulation systems, such as the systems described in U.S. Pat. Nos. 5,938,691 and 6,219,580, each of which is incorporated herein by reference, produce sensations of sound in patients affected by hearing loss through direct stimulation of the ganglia of the auditory nerve cells. Cochlear stimulation systems are generally comprised of several components, including an electrode array that incorporates one or more electrode pairs, an implantable cochlear stimulator, an externally wearable speech processor (or signal processor) with one or more microphones, and a communication path that couples the external speech processor and the implantable cochlear stimulator through the skin, such as a radio frequency link. The external portion of the communication pathway can be incorporated into a headpiece that can be affixed and aligned with the implantable cochlear stimulator, such as through the use of one or more magnets. Alternatively, the external portion of the communication pathway can be integrated into the speech processor, which can be affixed adjacent to the pinna in proximity to the implantable cochlear stimulator.

"The acoustic signals received by the one or more microphones included in the cochlear stimulation system are transformed into sound data by the speech processor. The sound data can then be transferred to the implantable cochlear stimulator, such as by transmission over the communication pathway. Once received in the implantable cochlear stimulator, the sound data can be used to selectively generate the electrical stimuli that are directed to one or more cochlea stimulating channels, each of which is associated with one or more electrodes or electrode pairs included within the electrode array.

"Within the cochlea, there are two main cues that convey 'pitch' (frequency) information to the listener. They are (1) the place or location of stimulation along the length of the cochlear duct and (2) the temporal structure of the stimulating waveform. Specific frequencies of sound are detected by specific portions of the cochlea, such that each frequency is mapped to a particular location along the cochlea. Generally, from low to high, sound frequencies are mapped from the apical to the basilar direction. Accordingly, the electrode array can be fitted to a patient to arrive at a mapping scheme such that electrodes near the base of the cochlea are stimulated with high frequency signals, while electrodes near the apex are stimulated with low frequency signals. Thus, the stimulation signals provided to the electrodes model the received acoustic signal associated with a particular frequency band.

"Several different strategies have been developed for processing detected acoustic signals and transforming them into electrical stimuli that can be applied to the cochlea. These strategies, often referred to as speech processing strategies, define a pattern of electrical waveforms that can be applied as controlled electrical currents to the one or more cochlea stimulating channels associated with the electrode array. Speech processing strategies can be broadly classified as: (1) sequential or non-sequential pulsitile stimulation, in which only one electrode receives an electrical pulse at a time; (2) simultaneous pulsitile stimulation, in which substantially all of the electrodes receive electrical pulses at the same time, approximating an analog signal; or (3) partially simultaneous pulsitile stimulation, in which only a select grouping of electrodes receive electrical pulses at the same time and the electrical pulses are received in accordance with a predefined pattern.

"It also is possible to further divided these strategies based on the waveform of the electrical stimuli, i.e., whether the electrical stimuli is an analog waveform or a biphasic (or multiphasic) waveform. Generally, analog waveforms represent filtered versions of a continuous acoustic signal, such as the signal received by a microphone. Analog waveforms are typically reconstructed by the generation of continuous, short, monophasic pulses or samples. The rate at which the samples are taken from a continuous acoustic signal must be high enough to permit the accurate reconstruction of the temporal details of the continuous acoustic signal. If an analog signal is not sampled at a sufficiently high rate, artifacts may result. Biphasic (or multiphasic) pulses, commonly referred to as pulsitile waveforms, typically include a single cycle of a square wave in which current flows in one direction at a particular magnitude and for a particular time, followed by a current flow in the opposite direction at a similar magnitude and for a similar period of time.

"There are numerous other stimulation patterns known in the art that may be formulated. One simulation pattern may prove more effective for a particular patient than any other stimulation pattern, since each patient may respond differently to a particular speech processing strategy. The complex biophysical phenomenon associated with the electrical stimulation of neurons and psychophysical phenomena regarding the interpretation of neural activity by the auditory nervous system suggest that the quality and intelligibility of speech precepts evoked by a cochlear stimulation system may be improved in a given patient by more specific manipulations of the electrical stimuli tailored to that patient. Stimulation strategies are described in further detail in U.S. patent application Ser. No. 11/226,777, which is incorporated herein by reference. Identifying which of the available speech processing and stimulation strategies is most beneficial for a given patient is commonly performed at the fitting stage.

"A specialist, such as an audiologist, generally customizes or 'fits' a newly provided cochlear stimulation system to a patient. In fitting the cochlear stimulation system, the specialist selects the modes and methods of operation that will be used by the system to help the patient perceive sound. The modes and methods include information defining the general processing characteristics, such as parameters utilized by the speech processor. Additionally, the modes and methods include patient-specific information, such as stimulation parameters and settings. Although the specialist can exercise a substantial amount of control and discretion in selecting the modes and methods of operation, the specialist typically employs a fitting system to properly customize the cochlear stimulation system to meet the individual needs of a patient. Fitting systems are described in further detail in U.S. Pat. Nos. 5,626,629 and 6,289,247, both of which are incorporated herein by reference.

"Once they have been determined, the modes and methods of operation can be stored in the cochlear stimulation system for use in configuring the device each time it is initialized, which generally occurs whenever the external portion of the unit is powered off or disconnected from the patient. During initialization, one or more items of information can be transmitted between the speech processor portion and the implantable cochlear stimulator. In the implantable cochlear stimulator, information can be stored in a random access memory for use during operation. For example, a speech processor can be configured to detect the presence of an implantable cochlear stimulator and, upon such detection, communicate with the implantable cochlear stimulator to configure the cochlear stimulation system for operation. Further, the speech processor can include one or more user controls, which can be used to configure the implantable cochlear stimulator. Once configured, the implantable cochlear stimulator can use the patient specific parameters to generate the electrical stimuli that are applied to one or more cochlea stimulating channels. When configured to use one or more parameters stored in a volatile memory, an implantable cochlear stimulator can be periodically monitored during operation. Alternatively, the implantable cochlear stimulator can be configured to notify the speech processor of any change in configuration."

In addition to the background information obtained for this patent, NewsRx journalists also obtained the inventors' summary information for this patent: "The present inventor recognized the need to permanently store patient specific information, such as personalized configuration settings and individual stimulation parameters, within the internal portion of a cochlear stimulation system to reduce the amount of information transmitted to the internal portion, particularly during initialization. The present inventor also recognized the need to permanently store patient specific information within the internal portion of a cochlear stimulation system to permit recovery of the patient specific information without reference to an external storage device. Further, the need to permanently store non-patient specific information, such as one or more general parameters associated with a speech processing strategy, within the external portion of a cochlear stimulation system is recognized.

"The present inventor also recognized that, although patient specific information and non-patient specific information is permanently stored, at least a portion of the patient specific information and non-patient specific information should be stored in a manner that also will allow it to be purposely altered, such as through a reprogramming operation. Additionally, the need to perform non-patient specific speech processing operations within the external portion of a cochlear stimulation system and patient specific speech processing operations within the internal portion of a cochlear stimulation system is also recognized. Further, the present inventor recognized the need to permit reprogramming of non-patient specific information, such as speech processing parameters, without necessitating the reprogramming of patient specific information. Accordingly, the techniques and apparatus described here implement algorithms for permanently storing patient specific information in an internal portion of a cochlear stimulation system, permanently storing non-patient specific information within an external portion of a cochlear implant system, and/or for performing speech processing operations within a corresponding portion of a cochlear stimulation system.

"In general, in one aspect, the techniques can be implemented to include determining an item of patient specific information, transferring the item of patient specific information to an implantable portion of the cochlear stimulation system, and permanently storing the item of patient specific information in the implantable portion of the cochlear stimulation system.

"The techniques also can be implemented such that the item of patient specific information comprises a parameter for use in generating a stimulation current. The techniques further can be implemented such that the implantable portion of the cochlear stimulation system is configured to permanently store one or more items of patient specific information in an alterable fashion. Additionally, the techniques can be implemented to include initializing the implantable portion of the cochlear stimulation system using one or more of the permanently stored items of patient specific information.

"The techniques also can be implemented to include determining an item of non-patient specific information for use in processing a received acoustic signal and permanently storing the item of non-patient specific information in an external portion of the cochlear stimulation system, wherein the external portion comprises a speech processor. Further, the techniques can be implemented to include determining a substitute item of non-patient specific information, permanently storing the substitute item of non-patient specific information in the speech processor in place of the item of non-patient specific information, retaining the one or more items of patient specific information permanently stored in the implantable portion of the cochlear stimulation system, and generating a stimulation current using the substitute item of non-patient specific information and the one or more items of patient specific information.

"The techniques also can be implemented to include replacing the speech processor with a substitute speech processor, retaining the one or more items of patient specific information permanently stored in the implantable portion of the cochlear stimulation system, and operating the cochlear stimulation system using the substitute speech processor. The techniques further can be implemented to include retrieving the item of patient specific information from the implantable portion of the cochlear stimulation system. Additionally, the techniques can be implemented to include associating a write protection with the item of patient specific information permanently stored in the implantable portion of the cochlear stimulation system. Further, the techniques can be implemented such that the associated write protection is reversible.

"The techniques also can be implemented to include determining a substitute item of patient specific information, transferring the substitute item of patient specific information to the implantable portion of the cochlear stimulation system, and permanently storing the substitute item of patient specific information in the implantable portion of the cochlear stimulation system in place of the item of patient specific information.

"In general, in another aspect, the techniques can be implemented to include an implantable portion comprising circuitry configured to receive an item of patient specific information and an internal memory in the implantable portion configured to permanently store the received item of patient specific information, wherein the internal memory is capable of storing one or more items of patient specific information.

"The techniques also can be implemented such that the internal memory comprises one of an EEPROM, a flash EEPROM, an FRAM, and an embedded programmable non-volatile memory. Further, the techniques can be implemented to include processor electronics in the implantable portion configured to protect at least a portion of the internal memory from alteration. Additionally, the techniques can be implemented to include processor electronics in the implantable portion configured to initialize the implantable portion using one or more items of stored patient specific information.

"The techniques also can be implemented to include processor electronics in the implantable portion configured to communicate one or more items of stored patient specific information to an external device. Further, the techniques can be implemented to include an external portion comprising circuitry configured to receive an item of non-patient specific information and an external memory in the external portion configured to permanently store the received item of non-patient specific information, wherein the external memory is capable of storing one or more items of non-patient specific information. Additionally, the techniques can be implemented to include processor electronics in the external portion configured to communicate sound data to the implantable portion, circuitry in the implantable portion configured to receive the sound data; and processor electronics in the implantable portion configured to generate a stimulation current using the sound data and one or more items of patient specific information.

"In general, in another aspect, the techniques can be implemented to include initializing an implantable portion of the cochlear stimulation system using one or more items of patient specific information, wherein the patient specific information is permanently stored in the implantable portion and initializing an external portion of the cochlear stimulation system using one or more items of non-patient specific information, wherein the non-patient specific information is permanently stored in the external portion. The techniques also can be implemented to include communicating control data from the external portion to the implantable portion, wherein the control data defines a status of one or more user controls.

"The techniques described in this document may be implemented to realize one or more of the following advantages. For example, the techniques can be implemented to permit storing patient specific information in an internal portion of a cochlear stimulation system. Further, the techniques can be implemented to include recovering patient specific information from the internal portion of a cochlear stimulation system. The techniques also can be implemented to permit storing non-patient specific information in an external portion of a cochlear stimulation system. The techniques further can be implemented such that only sound data is transmitted from the speech processor to the implantable cochlear stimulator, thereby reducing the amount of information that is transmitted from the external portion to the internal portion of the cochlear stimulation system. Additionally, the techniques can be implemented to reduce the frequency of or to eliminate altogether the periodic validation of patient specific information stored in an internal portion, thereby reducing the complexity of the communication link between the external portion and the internal portion of a cochlear stimulation system.

"The techniques also can be implemented such that the cochlear stimulation portion can be configured as soon as the cochlear stimulation system is initialized, without having to first receive information, such as parameters, from the speech processor portion. Further, the techniques can be implemented to permit replacing the external portion of the cochlear stimulation system, including the speech processor, without replacing the internal portion of the cochlear stimulation system or requiring the patient to undergo a new fitting procedure. Additionally, the techniques can be implemented to include reprogramming the speech processor, such as with a new speech processing strategy, without requiring the patient to undergo a new fitting procedure. Also, the techniques can be implemented to permit the substitution of an existing external speech processor with an alternate external speech processor without first programming the alternate external speech processor with patient specific information and without requiring the patient to undergo a new fitting procedure.

"These general and specific techniques can be implemented using an apparatus, a method, a system, or any combination of an apparatus, methods, and systems. The details of one or more implementations are set forth in the accompanying drawings and the description below. Further features, aspects, and advantages will become apparent from the description, the drawings, and the claims."

URL and more information on this patent, see: Faltys, Michael A.; Starkweather, Timothy J.; Arnold, Anthony K.. Information Processing and Storage in a Cochlear Stimulation System. U.S. Patent Number 8818517, filed May 5, 2006, and published online on August 26, 2014. Patent URL: http://patft.uspto.gov/netacgi/nph-Parser?Sect1=PTO1&Sect2=HITOFF&d=PALL&p=1&u=%2Fnetahtml%2FPTO%2Fsrchnum.htm&r=1&f=G&l=50&s1=8818517.PN.&OS=PN/8818517RS=PN/8818517

Keywords for this news article include: Advanced Bionics AG, Advanced Bionics Corp., Audiology, Bioengineering, Biotechnology, Ear Diseases, Electronics, Emerging Technologies, Hearing Disorders, Hearing Loss, Machine Learning, Nanotechnology, Nanotechnology Companies, Nervous System Diseases, Neurologic Manifestations, Otolaryngology, Sensation Disorders.

Our reports deliver fact-based news of research and discoveries from around the world. Copyright 2014, NewsRx LLC


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Source: Biotech Week


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