A dual band wireless power and FSK data telemetry for biomedical implants.

A dual-link coil arrangement and a novel digital frequency-shift keying (FSK) demodulator are presented. The primary application of this system is for inductively powered biomedical implants. The implant is provided with data and power via two separate links. Two sets of coils are used in an arrangement such that the magnetic interference between the two pairs is minimized. The demodulator circuitry presented relies solely on delaying elements, utilizing a delayed digital FSK signal to sample the original digital FSK signal. A synchronized clock can be derived from the FSK signals alone, however, by utilizing the power signal to obtain a synchronized clock, a higher data rate and a decrease in complexity of the receiver circuitry can be achieved. The system was implemented on the bench and experimentally tested at a data rate of 2.083 Mbps with zero bit error rate while receiving a 4.17/6.25 MHz FSK carrier signal synchronized with 2.083 MHz clock derived from the power carrier. The power link was set to provide 58mW.

A wideband frequency-shift keying demodulation technique for inductively powered biomedical implants.

A digital wideband frequency-shift keying (FSK) demodulator is presented. The primary application of this system is for inductively powered biomedical implants. By providing both the data and the power to the implant via an inductive link, the need for a battery and the interconnect wires are eliminated. This reduces revision surgeries that may take place for maintenance purposes, provides extra safety measures in the case of failures and reduces the risk of infection. However these devices are challenged by power requirements and size availability at the receiving site and often require a high data rate. These challenges lead to the need for an efficient demodulation technique, as traditional methods often do not overcome the restrictions that prevail. The demodulator circuitry presented relies solely on delaying elements, utilising a delayed FSK carrier to sample the incoming FSK waveform. The system architecture is based on a digital environment and both the data and a synchronised clock are derived concurrently. This can be achieved with the coherent-FSK modulated raw binary data stream without the need of any additional baseband coding schemes. The demodulator circuitry was simulated up to a data rate of 5 Mbps while receiving a 5/10 MHz FSK carrier. The system was also implemented on the bench and experimentally tested at a data rate of 1.042 Mbps with no detectable bit error rate while receiving a 4.16/6.25 MHz FSK carrier signal.