Wireless Communications and Powering of Implants
摘要
Communication and powering facilities augment the capabilities of the implants by providing remote monitoring of therapy and charging of implant batteries to avoid replacement by surgery. At short distances in the range of a few centimeters, inductive links are used. The transference of data and power pose conflicting requirements. These requirements are sometimes fulfilled by using separate coils. The cost is a larger footprint and increased electromagnetic interference. Load-shift keying (LSK) technique is applied for uplink data transmission. Downlink data transmission is implemented by one of the three techniques: binary amplitude-shift keying (BASK), binary frequency-shift keying (BFSK), or binary phase-shift keying (BPSK), with BASK representing the plainest approach. Long-distance telemetry > 2 m is restricted to the agreed 402–405 MHz band for therapeutic implants or the industrial, technical, and medicinal/curative radio bands: 902–928 MHz, 2.4–2.4835 GHz, and 5.725–5.875 GHz frequency bands with transmission range up to 10 m.