IMPROVEMENT OF NEUROMUSCULAR STIMULATOR TECHNOLOGY

AS NEUROPROSTHESES BECOME SMALLER, THE NEED FOR SUPERIOR QUALITY CONTROL BECOMES VITAL. FOR SUCH DEVICES, VANDER LUGT OPTICAL CORRELATION (VLOC) TECHNIQUES OFFER THE POTENTIAL OF SUPERSEDING CONVENTIONAL LEAK TESTING METHODOLOGIES IN THAT WORKING WITH LIGHT IS CLEANER, FASTER, MORE SENSITIVE, AND ELIMINATES THE DISADVANTAGES OF TRACER GAS INTRODUCED THROUGH BACKFILLING OR "BOMBING". CURRENT LEAK TESTING METHODS OFTEN PROVE INADEQUATE FOR VERY SMALL AND DELICATE DEVICES, AS THEY SOMETIMES INVOLVE INORDINATE STRESS ON THE PACKAGE, OR INTRODUCE UNDESIRABLE RESULTS DUE TO CHEMICAL CONSIDERATIONS. IN THE CASE OF VERY SMALL PACKAGES, GROSS LEAKS ARE OFTEN MISSED BY CONVENTIONAL MEANS, SINCE MINUTE QUANTITIES OF TRACER GAS INTRODUCED INTO THE PACKAGE MAY HAVE DISAPPEARED BY THE TIME THE TEST IS RUN. PRELIMINARY STUDIES INDICATE THAT VLOC TECHNIQUES ARE CAPABLE OF DETECTING LEAKS IN THE 10E-6 ATM CC/SEC RANGE AND ABOVE IN LARGE ALUMINUM-ENCLOSED ELECTRONIC PACKAGES. THE PURPOSE OF THE PRESENT RESEARCH WILL BE TO DRIVE THIS LIMIT EVEN LOWER, DOWN TO THE REGIME OF 10E-10 ATM CC/SEC, WHERE NEUROPROSTHESES ARE CURRENTLY TESTED. ATTEMPTS WILL ALSO BE MADE TO LOCATE THE POSITION OF THE LEAK, WHICH IS IMPOSSIBLE TO DO WITH CURRENT LEAK TESTING METHODOLOGIES.