Vital-sign monitoring reduced to the size of a postage stamp
16 November 2012
Engineers have developed new technology to monitor medical vital signs, with sensors so small and cheap they could fit on a bandage.
A patent is being processed for the monitoring system and it’s now ready for clinical trials, researchers say. When commercialized, it could be used as a disposable electronic sensor, with many potential applications due to its powerful performance, small size, and low cost.
Heart monitoring is one obvious candidate, since the system could gather data on some components of an ECG, such as pulse rate and atrial fibrillation. Its ability to measure EEG brain signals could find use in nursing care for patients with dementia, and recordings of physical activity could improve weight loss programmes. Measurements of perspiration and temperature could provide data on infection or disease onset.
“Current technology allows you to measure these body signals using bulky, power-consuming, costly instruments,” said Patrick Chiang, an associate professor in the Oregon State University (OSU) School of Electrical Engineering and Computer Science.
“What we’ve enabled is the integration of these large components onto a single microchip, achieving significant improvements in power consumption,” Chiang said. “We can now make important biomedical measurements more portable, routine, convenient and affordable than ever before.”
The much higher cost and larger size of conventional body data monitoring precludes many possible uses, Chiang said. Compared to other technologies, the new system-on-a-chip cuts the size, weight, power consumption and cost by about ten times.
The new electronics developed at OSU are about the size and thickness of a postage stamp, and could easily just be taped over the heart or at other body locations to measure vital signs. The system doesn’t have a battery; instead, it harvests the sparse radio-frequency energy from a nearby device – in this case, a mobile phone. Other energy-harvested power sources, such as body heat or physical movement, could also be exploited.