Passive and Battery-Free RFID-Based Wireless Healthcare and Medical Devices: A Review

Passive radio-frequency identification (RFID) technology has recently been applied to many battery-free wireless medical and healthcare (WMH) applications including wearable and implantable medical devices. The presence of the human body near RFID devices creates, however, several challenges in terms of design, fabrication, and testing of such WMH devices. The use of comparatively unsecured wireless links enabled by RFID communication may also jeopardize patients privacy as well as raise ethical concerns. With these factors in mind, this article provides a systematic review spanning two decades of the wide range of passive RFID applications in medical and healthcare devices based on the classification of RFID frequency bands. The strengths and limitations of these techniques are benchmarked against each other using performance metrics such as communication distance, tissue safety, size of the devices, as well as patients privacy and ethical implications. The article concludes by discussing the future opportunities and challenges raised by passive RFID for battery-free WMH devices. This comprehensive literature review aims to become a point of reference for experts and non-experts in the field.