Implantable Temperature Measurement System Using the Parametron Phenomenon

Yoshiaki SAITOH  Akira KANKE  Isamu SHINOZAKI  Tohru KIRYU  Jun'ichi HORI  

IEICE TRANSACTIONS on Communications   Vol.E79-B    No.8    pp.1129-1134
Publication Date: 1996/08/25
Online ISSN: 
Print ISSN: 0916-8516
Type of Manuscript: PAPER
Category: Measurement and Metrology
parametron phenomenon,  temperature sensor,  quartz resonator,  oscillation-center frequency,  excitation power,  

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Adapting the principle of parametron oscillation, a small implantable temperature sensor requiring no internal power supply is described. Since this sensor's oscillation frequency is half that of the excitation frequency, the oscillated signal can be measured from the reception side, free of any signal, interference, simply by positioning the sensor and the excitation antenna so that; 1) they are separated up to 95 cm in the air; 2) a 41 cm gap, the phantom equivalent of the thickness of the human abdomen maintain between them. In the temperature-dependent quartz resonator sensor, oscillation occurs only when frequency and temperature correspond. The excitation power is then adjusted so that the frequency bandwidth narrows. As a result, the margin of error in measuring the temperature is minimized; (0.07).