Polygraphic belt with force-sensing expander for physiological tests on cosmonauts

To study cardiorespiratory and neuromotor functions in cosmonauts a novel b elt with embedded polygraphic sensors and a force sensing expander were dev eloped. The sensors are: a three-electrode ECG/impedance plethysmographic s ystem to capture cardiac and respiratory activity, two triaxial acceleromet ers to record limb micromotions and an IR reflex-sensor to detect periphera l pulse waves. The expander consists of an elastic cable in series with a l oad cell to measure the extension force and to adjust the extensions by vis ual feedback. The cable stiffness was chosen rather high (150-200 N/m) in o rder to induce involuntary limb oscillations at higher extension levels. Th e equipment was tested in MIR spaceflights and is projected for physiologic al tests on the ISS.