Constrained Safety-Integrity Performance of Through-the-Arms UHF-RFID Transcutaneous Wireless Communication for the Control of Prostheses

Advanced prostheses for recovery of arm amputation can be nowadays controlled by the electromyographic (EMG) signals. Implanted myoelectric sensors, suitable to transcutaneous wireless reading, permit to improve the signal-to-noise ratio. This paper explores the feasibility of a through-the-arm telemetry link based on the radiofrequency identification in the UHF band (860-960 MHz). The proposed model accounts for the power sensitivity of the commercial devices, the constraints enforced by the exposure regulations (SAR) and by the communication integrity (BER). The reliability of the link is evaluated against possible misalignments between sensors and the reading unit. Results demonstrate that the transcutaneous link can be in some case limited by integrity constraints but can be nevertheless correctly established by means of less than 23 dBm input power (full compatible with embedded readers). The link is moreover robust against angular displacement up to at least Δφ = ±35° and linear displacement up to 2.5 cm.