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Twelve, versatile wrist worn pulse monitors were developed and delivered. A light, non-constricting band worn around the wrist is pneumatically coupled to a small electro-optical unit worn on the forearm. The forearm unit contains a fiber optic sensor, pulsed laser, photodiode, PIC processor, DSP, transceiver, antenna, memory, battery, and other parts. Physiological data is radioed to an RS-232 port on a standard IBM compatible computer. The computer switches the unit between two selectable modes; one streaming the 16-bit raw data at 512 Hertz and the other transmitting only the DSP processed heart and breathing rates. Algorithms are stored on the DSP via a standard computer cable. The DSP contains a wavelet algorithm, which aids in extracting data where there is excessive wrist motion present. It is likely that systolic and diasystolic blood pressure and inspiratory effort could be extracted with a different algorithm. Subsystem components are activated only when needed, saving energy. Current drain is six milliamps if all subsystems are simultaneously activated. Re-chargeable coin cells allow about eight hours of continuous monitoring.

The Phase I effort has established the feasibility of a heartbeat and respiration sensor with high sensitivity based on a fiber optic coupler that will fit within the dimensions of a wrist watch. Radio frequency transmission tests have demonstrated the feasibility of using a custom designed IC with on-board antenna and driver circuitry to transmit the sensor's low frequency signal to a receiver unit over a distance of one meter or more frequencies of 220 - 420 MHz. Electronic interface units were constructed that contain the circuitry necessary for opto-electronic conversion as well as to perform the sum and difference calculations to isolate the heartbeat-related changes in the sensor's output signal. A laptop-based A/D) data acquisition system was implemented.