28-03-2012, 12:54 PM
Eddy Current Based Flexible Sensor for Contactless Measurement of Breathing
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Eddy current monitoring
Apply RF energy to body
Energy induces Eddy currents in
conductive tissues at signal frequency
Eddy currents can be measured
With separate receive coil
With transmit coil, during of after signal
Challenges
Small signals from biological tissue
Higher frequencies used (10MHz) to
increase signal
Sensitive to interference
Sensitive to movement artefacts
Current work:
Sleep monitoring application
Flexible coils
Possible due to Single send/receive coil
Frequency counter to demodulate signal
Demodulation of DC component
Movement artefact is occasional, and can
be detected
Technology: Advantages
Lung volume measurement:
measurement of volume and breath timing
Safe:
Radio energy far below standards.
Non-contact operation and design
Inexpensive: Commodity Electronics
components and techniques.