| 摘要 |
The invention relates to wireless biotelemetry of low level bioelectric a nd biosensor signals by means of directly modulating the backscatter of a re sonant circuit. Low level electrical analog or digital signals are directly applied to a resonant circuit containing a voltage-variable capacitor such a s a varactor diode, that proportionally shifts the resonant frequency and so amplitude of radiofrequency backscatter in a way that represents analog bio electric or biosensor waveform data. By strongly driving the resonant circui t with a radiofrequency source, a voltage variable capacitance can be caused to amplify the bio-signal level by a parametric process and so provide suff icient sensitivity to telemeter for low millivolt and microvolt level signal s without additional amplification. A feature of the device is its simplicit y and that it accomplishes both modulation and preamplification of low level sensor signals by the same variable capacitance circuit which reduces the d evice size and power consumption. |
