Orthopedists currently use electrical bone-growth stimulators, also known as waveform generators, to promote faster healing in injured bone, but the devices must be planted into the body after delayed healing has already been discovered through, for example, an X-ray. However, Berger says, once a stimulator is surgically attached to a bone, there is no way for the doctor to ensure that it is working properly. In the case of Berger's patented system, the device would already be embedded in the implant, and doctors could turn it on or off remotely. A sensor built into the circuitry would monitor the stimulator.
Although Berger's prototype uses generic passive
EPC Gen 2 UHF RFID tags and sensors attached to an orthopedic bolt, he says the tags and sensors could fit on any of the orthopedic implants he typically uses. In the future, he notes, the system could be implemented with tags of a variety of frequencies, to suit the implant's intended purpose. Each device's RFID chip would have a unique ID number, he says, which would be linked to data such as when the device was implanted, the type of implant it was and who conducted the surgery.
Because only the ID number would be stored on the RFID chip, and since any associated data would be password-protected in a back-end system, Berger says the chip would not be a privacy concern for implant wearers. "Confidentiality is very important to me," he states. He estimates the cost would be low for the added RFID chip, sensors and bone-growth stimulator, though he adds that it's too early to know for sure.
"I think RFID tags could be very inexpensive, and the waveform generators could also be very inexpensive," Berger says. "I've been working on this for about 10 years, and it will still require more development, but it shouldn't be hard to do. The technology is out there—it's just a matter of combining it all together."