Chris Somps and John Hines
Sensors 2000! Program
NASA-Ames Research Center, Mail Stop 213-2
Moffett Field, CA 94035-1000

    The space life sciences research community needs physical, chemical, and biological sensors and associated instrumentation to monitor physiologic adaptation to the space flight environment. Cardiovascular deconditioning, bone demineralization, skeletal muscle atrophy, and vestibular disturbances are just a few of the physiologic changes which occur during space flight and which are the focus of current scientific inquiry. Because crew time is limited, automated data acquisition, processing, and storage are required, and since animal models are group-housed to conserve volume and mass, wireless data systems are clearly preferred. In response to these needs, NASA’s Sensors 2000! (S2K!) program is developing radio frequency biotelemetry systems for automated physiologic monitoring of animal models in space.

    The S2K! program collaborates with academia, industry, and other government agencies in the development of a variety of wireless telemetry systems, subsystems, and components. Collaborations take the form of codevelopment partnerships, grants, cooperative ventures, and contracted vendor efforts. Development phases include definition of need and constraints, preliminary design and prototyping of novel or advanced concepts, further development and testing of promising technologies, and finally integration and flight. Technologies are also evaluated for application to ground-based biomedical research and clinical monitoring needs.

    Areas of current focus include the development of miniaturized, implantable chemical sensors, development and evaluation of pulse-encoded biotelemeters including pulse interval and pulse code modulation systems, evaluation of commercial off-the-shelf low-power microcontrollers and DSP processors for use in encoding and decoding circuits, and the establishment of standardized, miniaturized biotelemetry building blocks, e.g., signal conditioning blocks, controller blocks, data buses, and transmitter circuits. We are also working on a novel slot antenna design for use in metal wire-mesh animal enclosures. As an example of a project in its final phases, a biotelemetry system for monitoring circadian rhythms in rodent heart rate and body temperature is currently undergoing final test and evaluation in preparation for an upcoming Space Shuttle mission.