Low-power transceivers get patients mobile

Abstract

The growing use of radio communications to monitor medical conditions is making life easier for patients and their carers. Wireless systems enabled by low-power radio technology are delivering mobility, higher levels of patient care and relative comfort inside and outside the medical facility environment. Both 'on-the-skin' and implantable medical electronic devices are benefiting from transceivers that use the latest mixed-signal ASIC technology to provide desired rates of data transfer over short ranges. Electronics used in medical environments - especially implanted devices - need to have a low-power consumption and high reliability design. Low-power radio devices that use ASICs are already starting to be specified in applications such as cardiac pacemakers, blood glucose monitoring and body temperature sensing. There are two protocols that relate to devices of this type. The first is known as medical implant communications services (MICS). It applies to implantable technologies that need to communicate with the outside world periodically, or when there is a deviation from specified parameters. The second is wireless medical telemetry service (WMTS), which deals with non-implanted (on-the-skin) patient monitoring systems that communicate on a far more regular, timed basis with a suitably equipped remote location, such as a nursing station. Present designs and the future of such systems are discussed.