Affiliations: [a] Institute of Electrodynamics, Microwave and Circuit
Engineering (EMCE), Vienna University of Technology, Gusshausstr. 27, A-1040
Vienna, Austria
Abstract: The paper concerns a detector for biomedical screening of sleep
apnea which may yield severe reduction of life expectation. The detector is
mounted on the thorax including several sensors for respiratory and cardiac
activities. An additional magneto-elastic sensor, which is described in this
paper, should register both the body position and body movements, both being
relevant for diagnostics. The sensor is based on a magneto-elastic bilayer of
high bending sensitivity operated in acceleration mode. The sensor is being
optimized with respect to material matching, loading (mass optimization) and
length, as well as (limited) excursion, resonance frequency and thermal
behavior. Application is reported for lab tests on short time events of three
kinds: (a) body positions, with focus on back position which favors
positive findings, (b) body movements, ranging from arm/leg movements up to
upper body rolls, and (c) physiological activities such as respiration,
indicating additional potentials of the sensor. The magnetic concept promises a
component which is compact, robust, free of wear and cheap. It will be used in
combination with sensors for respiration effort and cardiac activity, aiming
for a robust single-spot home monitoring device for the assessment of sleep
apnea syndrome.
