Power telemetry examples

The major satellite subsystems are described in, for example, Grifihn and French (1991). They are propulsion, power, antenna, communications repeater, structures, thermal, attitude determination and control, telemetry, tracking, and command. 

Neuromuscular prostheses and cochlear implants require higher data rate and power than artificial pacemakers. For neuromuscular prostheses, P. Troyk introduced frequency shift keying (FSK) [95], where two different frequencies of the carrier represent the binary data. The power signal serves as the data carrier, and an external Class-E amplifier sends the signal to increase the efficiency of power transfer. The data rate of this telemetry is 120 kbps modulated on 480 kHz that is power carrier frequency. For cochlear implants, several works have been discussing telemetry design [96-99], and amplitude shift keying (ASK) modulation, as an example, was used to transfer power and data to the implant in the ear [98]. The data rate is 400 kbps and it is modulated on 10-MHz power carrier frequency. 

Although there are several communication standards for biomedical applications, most of them eannot provide enough bandwidth for simultaneous recording from more than 100 ehannels. For example, MICS band, which is allocated for the unlicensed use of implantable devices, allows only 300 kHz for data transmission. Other wireless technologies such as Wi-Fi and Bluetooth cannot be used directly due to the power and area constraint of the implanted device. Therefore, there is a need for higher-bandwidth data transmission telemetry that consumes low power and occupies less physical area. 

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