SensNews June 2020

Sensor100 2020 20 Softsonics: a device to take blood-pressure readings continuously UC San Diego spin-off company Softsonics has been named by Nature as a company to watch, Softsonics is developing a soft, flexible patch that can be worn on the skin over the carotid artery or jugular vein, and which uses pulses of ultrasound to meas- ure blood pressure. Softsonics’s approach relies on bendable electronics developed by co-founder Sheng Xu, a nano-engineer- ing researcher at the University of Califor- nia, San Diego. The electronics include piezoelectric devices, which change shape in response to elec- tricity and produce an electrical output in response to mechanical pressure.A voltage applied to the actuators causes them to emit an ultrasonic pulse, which penetrates several centimeters into the body (see ‘A soft touch’).When the ultrasonic waves bounce off an artery and return to the patch, the waves squeeze the piezoelectrics and produce a voltage. Measuring the time difference between when waves return from the near wall of the artery and from the far wall provides the diameter of the artery, and watching how that diameter changes as the blood pulses through gives the blood pressure. Read more Sibel Health: designing vital-sign sensors for delicate skin A spin-off from Northwestern University that makes flexible devices to monitor heart rate and blood pressure in premature babies is on the shortlist for Nature's Spin-off Prize. The sensors, which monitor vital signs such as heart rate, blood oxygenation and blood pressure, are small, flex- ible and light enough to stick to the fragile skin of a baby. Co-founder Xu says that the most important innovation in Sibel’s monitoring device is that it can attach to a pre- mature infant without the adhesive normally used to stick leads to skin. Read more