A small, hermetic, wirelessly-controlled retinal prosthesis was developed for pre-clinical studies in Yucatan mini-pigs. The device was implanted on the outside of the eye in the orbit, and it received both power and data wirelessly from external sources. The prosthesis drove a sub-retinal thin-film array of sputtered iridium oxide stimulating electrodes. The implanted device included a hermetic titanium case containing the 16-channel stimulator chip and discrete circuit components. Feedthroughs in the hermetic case connected the chip to secondary power- and data-receiving coils, which coupled to corresponding external power and data coils driven by a power amplifier. Power was delivered by a 500 KHz carrier, and data were delivered by frequency shift keying. Stimulation pulse strength, duration and frequency were programmed wirelessly from an external computer system. Through an 'outbound' telemetry channel, electrode impedances were monitored by an on-board analog to digital converter that sampled the output voltage waveforms. The final assembly was tested in vitro in physiological saline and in vivo in two mini-pigs for up to three months by measuring stimulus artifacts generated by the implant's current drivers.

We report on the design and testing of a custom application-specific integrated circuit (ASIC) that has been developed as a key component of the Boston retinal prosthesis. This device has been designed for patients who are blind due to age-related macular degeneration or retinitis pigmentosa. Key safety and communication features of the low-power ASIC are described, as are the highly configurable neural stimulation current waveforms that are delivered to its greater than 256 output electrodes. The ASIC was created using an 0.18 micron Si fabrication process utilizing standard 1.8 volt CMOS transistors as well as 20 volt lightly doped drain FETs. The communication system receives frequency-shift keyed inputs at 6.78 MHz from an implanted secondary coil, and transmits data back to the control unit through a lower-bandwidth channel that employs load-shift keying. The design’s safety is ensured by on-board electrode voltage monitoring, stimulus charge limits, error checking of data transmitted to the implant, and comprehensive self-test and performance monitoring features. Each stimulus cycle is initiated by a transmitted word with a full 32-bit error check code. Taken together, these features allow researchers to safely and wirelessly tailor retinal stimulation and vision recovery for each patient.

A small, hermetic, wirelessly-controlled retinal prosthesis was developed for pre-clinical studies in Yucatan mini-pigs. The device was implanted on the outside of the eye in the orbit, and it received both power and data wirelessly from external sources. The prosthesis drove a sub-retinal thin-film array of sputtered iridium oxide stimulating electrodes. The implanted device included a hermetic titanium case containing the 16-channel stimulator chip and discrete circuit components. Feedthroughs in the hermetic case connected the chip to secondary power- and data-receiving coils, which coupled to corresponding external power and data coils driven by a power amplifier. Power was delivered by a 500 KHz carrier, and data were delivered by frequency shift keying. Stimulation pulse strength, duration and frequency were programmed wirelessly from an external computer system. Through an 'outbound' telemetry channel, electrode impedances were monitored by an on-board analog to digital converter that sampled the output voltage waveforms. The final assembly was tested in vitro in physiological saline and in vivo in two mini-pigs for up to three months by measuring stimulus artifacts generated by the implant's current drivers.

This paper presents an articulatory biofeedback system and discusses new research methods made possible by this technology. The real-time electromagnetic articulography biofeedback system (RT-EMA) enables speakers to observe a visual representation of the movements of their speech articulators while they are speaking. Investigators can dynamically control the visual display of virtual targets or other objects in vocal tract space, track events involving interactions between virtual objects and articulators, and define custom actions in response to such events. Preliminary findings from experimental studies and games employing biofeedback are reported, with emphasis on the potential applications of articulatory biofeedback for investigating questions of linguistic interest.

Fatigue cracking and plastic deformation occur in both new and aging aircraft engines, requiring periodic manual inspections with ultrasonic and eddy current probes. Often cracking occurs in inaccessible areas that require engine disassembly just to perform the inspection. In many cases, the cost of assembling and reassembling the engine far exceeds the cost of inspection and can also induce new damage. This paper addresses "Smart Coatings" -under 10 micron thick coatings that contain planar sensors sandwiched between layers of tough protective insulators. The resulting sensing film is much lighter than adhesively attached sensors, and forms a life-extending protective coating that also performs structural sensing.Prototype sensors were deposited onto Inconel 7 1 8 coupons, using standard microelectronic lithography and deposition techniques. The demonstrated sensors include a crackwire sensor for detecting surface cracks and plastic deformation, and a capacitive sensor for detecting surface contamination. The paper will describe destructive tensile testing of Inconel coupons containing the crack and these sensors