Donate to Science & Enterprise

S&E on Mastodon

S&E on LinkedIn

S&E on Flipboard

Please share Science & Enterprise

Reading Vital Signs with Radio Waves Designed

Edwin Kan

Edwin Kan holds a radio-frequency tag for detecting vital signs (Daryl Lovell, Cornell University)

15 December 2017. Engineers at Cornell University developed techniques for reading a person’s key health indicators with plastic tags and radio waves instead of the specialized devices used today. The team of computer engineering professor Edwin Kan and graduate student Xiaonan Hui describe their system in the 27 November issue of the journal Nature Electronics.

Kan and Hui are seeking better ways of measuring a patient’s vital signs, basic indicators of a person’s health, including heart rate, blood pressure, respiration rate, and breath effort. Monitoring these vital signs today usually requires separate and sometimes intrusive equipment, such as a blood pressure cuff or sensors attached to the skin, making it uncomfortable for patients and disturbing their sleep. With current methods, some of these measures can also be taken only periodically or with expensive monitoring equipment.

The Cornell team devised a different approach using plastic tags like those attached to garments in department stores to deter theft. Like anti-theft tags, these sensors emit radio-frequency signals, but in this case the signals are sent into the body, where they capture human functions with a backscatter technique similar to airport X-ray machines. This technique detects movements of heart or lung muscles, or blood flow, which can then be measured, captured, displayed, and assessed.

Captured signals from the tags are then attached to a unique identifier assigned to the tag, where they can be integrated into a data stream read by a nearby base system. The unique identifiers make it possible to measure vital signs for up to 200 individuals with one central reader system, according to the authors.

Kan and Hui built radio-frequency tags to attach to wrist cuffs and insert into breast pockets of garments. “If this is an emergency room,” says Kan in a university statement, “everybody that comes in can wear these tags or can simply put tags in their front pockets, and everybody’s vital signs can be monitored at the same time.” He adds that the unique identifiers in the signals sent by the tags let the system know to whom the vital signs belong.

The authors tested the concept of a prototype system with volunteers and matched the results to commercial blood pressure monitors and electrocardiograms, and found their system as accurate as the current technologies. Kan’s lab in Ithaca, New York plans to develop the system further, working with Cornell’s Center for Sleep Medicine at the university’s medical school in New York City. In addition, the team plans to work with the university’s Fiber Science and Apparel Design department to come up with a method for embroidering the tags directly into garments, with nanoparticle-coated fibers.

The following brief (22 second) video shows heart beat and pulse signals captured with tags and radio waves.

More from Science & Enterprise:

*     *     *

1 comment to Reading Vital Signs with Radio Waves Designed