A spinal cord stimulation (SCS) system includes multiple electrodes, multiple, independently programmable, stimulation channels within an implantable pulse generator (IPG) which channels can provide concurrent, but unique stimulation fields, permitting virtual electrodes to be realized. The SCS system includes a replenishable power source (e.g., rechargeable battery), that may be recharged using transcutaneous power transmissions between antenna coil pairs. An external charger unit, having its own rechargeable battery can be used to charge the IPG replenishable power source. A real-time clock can provide an auto-run schedule for daily stimulation. An included bi-directional telemetry link in the system informs the patient or clinician the status of the system, including the state of charge of the IPG battery. Other processing circuitry in the IPG allows electrode impedance measurements to be made. Further circuitry in the external battery charger can provide alignment detection for the coil pairs.

Rechargeable spinal cord stimulator system

As the most successful neural prosthesis, cochlear implants have provided partial hearing to more than 120000 persons worldwide; half of which being pediatric users who are able to develop nearly normal language. Biomedical engineers have played a central role in the design, integration and evaluation of the cochlear implant system, but the overall success is a result of collaborative work with physiologists, psychologists, physicians, educators, and entrepreneurs. This review presents broad yet in-depth academic and industrial perspectives on the underlying research and ongoing development of cochlear implants. The introduction accounts for major events and advances in cochlear implants, including dynamic interplays among engineers, scientists, physicians, and policy makers. The review takes a system approach to address critical issues in cochlear implant research and development. First, the cochlear implant system design and specifications are laid out. Second, the design goals, principles, and methods of the subsystem components are identified from the external speech processor and radio frequency transmission link to the internal receiver, stimulator and electrode arrays. Third, system integration and functional evaluation are presented with respect to safety, reliability, and challenges facing the present and future cochlear implant designers and users. Finally, issues beyond cochlear implants are discussed to address treatment options for the entire spectrum of hearing impairment as well as to use the cochlear implant as a model to design and evaluate other similar neural prostheses such as vestibular and retinal implants.

Cochlear Implants: System Design, Integration, and Evaluation

Methods of using unidirectionally propagating action potentials (UPAPs) for cavernous nerve stimulation and for certain disorders are provided. Stimulators capable of creating such UPAPs include, but are not limited to, miniature implantable stimulators (i.e., microstimulators), possibly with programmably configurable electrodes.

Cavernous nerve stimulation via unidirectional propagation of action potentials

A method and system for providing electrical stimulation to tissue includes implanting one or more battery-free microtransponders having spiral antennas into tissue. Energy is provided wirelessly to the plurality of microtransponders. Tissue is stimulated using the energy.

Implantable Transponder Systems and Methods

Provided is a fully automated web service with location based services generally involved in transmission of situational location dependent information to automatically located mobile receiving data processing systems. The web service communicates with a receiving data processing system in a manner by delivering information to the device when appropriate without the device requesting it at the time of delivery. There are varieties of configurations made by different user types of the web service for configuring information to be delivered, and for receiving the information. The web service maximizes anonymity of users, provides granular privacy control with a default of complete privacy, and supports user configurable privileges and features for desired web service behavior and interoperability. The web service is fully automated to eliminate human resources required to operate services. Integrated with the web service are enhanced location based services providing map solutions, alerts, sharing of novel services between users, and complete user control for managing heterogeneous device interoperability through the web service.

System and method for anonymous location based services

A cochlear implant system includes an electrode array (1) comprising multiple platinum ring electrodes in a silastic carrier to be implanted in the cochlea of the ear. A receiver-stimulator (3) containing a semiconductor integrated circuit and other components is implanted in the patient adjacent the ear to receive data information and power through tuned coil (5) using an inductive link (6) from a patient-wearable external speech processor (7) including an integrated circuit and various components which is configured or mapped to emit data signals from an EPROM programmed to suit each patient electrical stimulation perceptions through testing of the patient and his implanted stimulator/electrode using a diagnostic and programming unit (12) connected to the processor by an interface unit (10). The system allows use of various speech processing strategies including dominant spectral peak and amplitude and compression of voice pitch so as to include voiced sounds, unvoiced glottal sounds and prosodic information. Biphastic pulses are supplied to various combinations of electrodes by a switch controlled current sink in various modes of operation. In-place testing of the implant is also provided. Various safety features are incorporated to insure that harmful impulses are not imposed on the patient. Transmission of data is by a series of discrete data bursts which represent the chosen electrode(s), the electrode mode configuration, the stimulating current, and amplitude determined by the duration of the amplitude burst.

Cochlear implant system for an auditory prosthesis

A data link and protocol for a subcutaneous, tissue stimulating device. While stimulation is taking place, under control of pulses whose durations in a data frame determine the stimulation pulse widths, data is actually transmitted and processed for determining the parameters of the next stimulation. Thus transmission of data occurs simultaneously with stimulation. Data is represented by sequences which have more 1s than 0s, with each 1 being represented by a number of successive RF cycles and a single 0 by the absence of a number of RF cycles. In this way a duty cycle of 75 % can be achieved so that required power is transferred to the implant. Variations in link condition, e.g., degree of ringing, are accommodated by means of offset tuning the transcutaneous transmit and receive coils. This ensures that the oscillating signal in the receive circuit that persists during the transmission of a 0 becomes out-of-phase with the RF transmission that is received for the next 1. The signal induced in the receive coil with the transmission of a new 1 cancels the out-of-phase ringing in the receive coil due to the earlier transmission, thereby causing the oscillation's amplitude to fall below a detection level to ensure the detection of an earlier transmitted 0 during the time that the next 1 is transmitted. A bit decoder is implemented that unambiguously recovers the number of 1s over a prescribed range of link transmission conditions. Also disclosed is a transmission system using variable-length frames representing both digital data and time-interval information, and a transmission system in which each frame has both analog and digital command information for selected utilisation circuits.

Embedded data link and protocol

A system is disclosed for enabling telemetry from an audio prosthesis, preferably a cochlear prosthesis. An electrode array (10) is used for both delivering stimuli and for seeking evoked potentials. Preferably a delay is provided between stimulus and measurement. The sensing electrodes (14, 31) are distinct from the stimulus electrodes (12, 13).

Telemetry system and apparatus

There is disclosed an implantable tissue-stimulating prosthesis, such as a cochlear prosthesis, which can not only be implemented in single-chip form, but which also permits great flexibility in stimulation strategy and data transmission format. Only sixteen electrodes are required for stimulating fifteen different sites. Each site is stimulated by a biphasic pulse under control of two adjacent electrodes whose polarities are reversed in the middle of the site stimulation cycle. Although the transmission scheme requires a pulse-width modulation format, the precise form of the format can be varied in order to accommodate widely different stimulation strategies. For example, only a single site may be stimulated during each transmission frame or multiple sites may be stimulated during the same frame. Although only one site can be stimulated at any instant of time, the system cycling is so fast that "simultaneous" site stimulations are perceived. The system is designed for minimum power usage, and its operation is fail-safe in that no site may be stimulated for longer than a pre-set time interval.

Implantable tissue-stimulating prosthesis

The invention provides a method of electrical artefact compensation in measurement of a neural response. The neural response is evoked by a first stimulus, after which a compensatory stimulus is applied in order to counteract a stimulus artefact caused by the first stimulus. The invention also provides for short circuiting the stimulating electrode subsequent to the first stimulus. A system for implementing such steps is also provided. The invention may be of application in measurement of physiological responses, including neural responses and in particular a neural response of the auditory nerve.

Christopher N Daly

Papers

Cochlear implant system for an auditory prosthesis

Embedded data link and protocol

Telemetry system and apparatus

Implantable tissue-stimulating prosthesis

Method and apparatus for measurement of evoked neural response