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An implantable joint-angle transducer (IJAT) was implemented to provide command-control information from the wrist for functional neuromuscular stimulation (FNS) neuroprostheses. The IJAT uses the Hall effect to sense joint angle. The objectives of this study were to evaluate (1) chronic functionality, (2) safety and biocompatibility, (3) repeatability of(More)
An advanced neuroprosthesis that provides control of grasp-release, forearm pronation, and elbow extension to persons with cervical level spinal cord injury is described. The neuroprosthesis includes implanted and external components. The implanted components are a 10-channel stimulator-telemeter, leads and electrodes, and a joint angle transducer; the(More)
We show here that a protein tyrosine phosphatase inhibitor, sodium orthovanadate, induces rat pheochromocytoma cells to express neurites, a prominent morphological marker of neuronal phenotype. Vanadate-induced differentiation and neurite outgrowth in pheochromocytoma cells was not as extensive as that induced by the positive control employed, nerve growth(More)
In order to test the hypothesis that overproduction of cerebrospinal fluid can cause the hydrocephalus seen in choroid plexus papillomas, adult mongrel dogs with and without hydrocephalus were subjected to high pressure intraventricular infusions of artificial cerebrospinal fluid (CSF). Pre- and postinfusion volumes were calculated, using a new method for(More)
The present experiments examine the suprathreshold response of the motion or direction-selective portion of the human visual system by means of the motion aftereffect (MAE). The MAE was measured as a function of the contrast and spatial frequency of moving sinusoidal gratings. For spatial frequencies less than 1 cy/deg, the MAE speed was found to increase(More)
Implanted neuroprosthetic systems have been successfully used to provide upper-limb function for over 16 years. A critical aspect of these implanted systems is the safety, stability, and-reliability of the stimulating electrodes and leads. These components are (1) the stimulating electrode itself, (2) the electrode lead, and (3) the lead-to-device(More)
Water vapour partial pressure (PH2O) and temperature (T) were measured together, continuously, at the airway opening (either lips or nares) and at the oropharynx of human subjects with normal lungs or with cystic fibrosis (CF). No apparent differences in PH2O or T were found between normal and CF groups breathing ambient air (22 +/- 2 degrees C). During(More)
An implantable stimulator-telemeter (IST-12) was developed for applications in neuroprosthetic restoration of limb function in paralyzed individuals. The IST-12 provides 12 stimulation channels and two myoelectric signal (MES) channels. The MES circuitry includes a two-channel multiplexer, preamplifier, variable gain amplifier/bandpass filter, full-wave(More)
A second generation implantable neuroprosthesis has been developed which provides improved control of grasp-release, forearm pronation, and elbow extension for individuals with cervical level spinal cord injury. In addition to the capacity to stimulate twelve muscles, the key technological feature of the advanced system is the capability to transmit data(More)
A modular external control unit (ECU) for Functional Electrical Stimulation (FES) is expected to provide flexibility and capability beyond current ECUs. The earlier units require duplication of effort in design and maintenance, are specialized for a single FES application, and lack sufficient flexibility to serve both laboratory and clinical research needs.(More)
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