New Smartphone Sensor Checks Your Blood Pressure

It’s more convenient than a cuff and could help patients monitor hypertension at home

For years, scores of engineers have been trying to develop a more unobtrusive, convenient device for blood pressure monitoring. Now, researchers at Michigan State University and University of Maryland appear to have succeeded.

In a paper published today in Science Translational Medicine, the researchers described a prototype blood pressure sensor that can be incorporated into a smartphone, and requires only the press of a fingertip.

The convenient device could encourage people to check their blood pressure more often, allowing them to catch hypertension—persistently high blood pressure—sooner, says Ramakrishna Mukkamala, a biomedical engineer at Michigan State, in East Lansing, who led the study.

Hypertension can lead to heart disease and stroke. But roughly half of people with the condition don’t know they have it, says Mukkamala.

In his team’s design, phones would be embedded with a sensor consisting of two main components: photoplethysmography (PPG), an inexpensive optical tool that measures blood volume changes, and a thin-filmed force transducer that measures applied pressure.

The user presses her finger on the sensor in a particular way, and an algorithm computes her blood pressure. The pressing of the fingertip generates external pressure on the underlying artery, much like that generated by a blood pressure cuff. [READ MORE]