Wearable RF Sensors for Vital Signs and More
ECE 595 Department Seminar Series
October 8, 2021
11:00 AM - 12:15 PM
Wearable RF Sensors for Vital Signs and More
Presenter:Edwin C. Kan, Cornell University
Abstract: The fundamental principle of sensing is to couple sufficient energy into the area of interest and make observation on the channel. To probe inside human body, ultrasound, X-rays and radio-frequency (RF) waves in certain frequency ranges have acceptable dispersion and loss for accurate external measurements. A new design of wearable RF sensors, based on near-field coupling in the band of 300 MHz – 6GHz, will be introduced. The operational principle, named as near-field coherent sensing (NCS), can accurately read large and small dielectric boundary motion inside the body in a broad spectrum over clothing and animal surface coverings, as well as from furniture or habitats. The sensing signal can ride on established multiplexed RF channels with digital isolation to achieve multiplexed implementation. For biomedical applications, we have demonstrated sensing of heartbeats, respiration, pulses, vocal cords and tissue vibration to derive the heart rate, seismocardiogram, blood pressures in the systemic and pulmonary circulation, heart sound, breath rate, lung volume, breath sound, glottal sound, and vital-sign based biometrics. The sensor is comfortable, convenient and covert, and can thus be used for continuous long-term monitoring with minimal bias. For animal applications, we have read vital signs from animals with various sizes and surface coverings, including mice, rats, hamsters, birds, fish, tortoises, dogs, cows and even sea elephants! Most animals under study were not aware of the existence of the sensor!
Due to the high sensitivity and broad bandwidth in RF sensing, these sensors can also be “worn” on or embedded in robots and smart buildings for precision location sensing. We can use a passive RF marker like an RFID (RF identification) tag for reading of specific location, taking advantages of the low cost of passive tags that can be abundantly and redundantly deployed. This approach can provide a spatial resolution of less than 50 microns in air and less than 5 microns in water with a sampling rate of greater than 1 kHz for the passive RF marker. When sufficient tags are deployed around a capture volume to provide the necessary spatial diversity of 3D observation of arbitrary layout, tagless objects can be counted, imaged and positioned as well.
Speaker Bio: Edwin C. Kan received his B.S. from National Taiwan University in 1984, and his M.S. and Ph.D. degrees from the University of Illinois at Urbana-Champaign in 1988 and 1992, all in electrical engineering. From 1997, he served as an assistant professor with the school of electrical and computer engineering at Cornell University, where he is now a professor in the fields of ECE and applied math. His main research areas include biosensors, RF indoor locating and tracking, RFID, CMOS technologies, semiconductor devices, flash memory, and numerical methods for PDE and ODE. Kan received the Presidential Early Career Award for Scientists and Engineer (PECASE) from President Bill Clinton in October 2000. He has published over 270 journal and referred conference papers and has graduated 30 Ph.D. students. He also received several inventor and teaching awards from Cornell Universities.
Faculty Host: Pai-Yen Chen, pychen@uic.edu
Date posted
Oct 4, 2021
Date updated
Oct 4, 2021