In the research by Swartzendruber et al, they noted some specific problems we intended to overcome. They placed RFID tags on a patient’s limb and prosthetic device in different locations, and noted the signal collision problems related to the RFID high-frequency tags, where signals coming from multiple tags would cause interference between themselves.They also noted that there were specific problems related to relative orientation of the transmitting antenna and the RFID tags in question. Their solution was to switch to an ultrahigh-frequency RFID system [2]. Our system uses NFC which operates at 13.56 MHz, and as such, signal blocking issues were not prevalent unless the devices were located within about 3 cm of each other.