Getting your blood pressure checked typically involves going to a clinic or pharmacy, and having an inflatable cuff applied to your arm. Thanks to technology being developed at Michigan State University, however, the process may soon be as simple as putting your finger on your smartphone case.
The prototype system consists of a 1-cm-thick case that's attached to the back of a standard smartphone, and an app that runs on that phone. Integrated into the case is a sensor unit, that consists of an optical sensor stacked on top of a force sensor.
To use it, the person holds the phone/case at heart level, and presses the tip of their index finger against the sensor unit – the case communicates with the app via Bluetooth, using an onscreen display to guide the user in maintaining the right amount of pressure.
In about the same amount of time that it currently takes to do a conventional arm cuff reading, the sensors proceed to measure the person's systolic and diastolic blood pressure via the transverse palmer arch artery in the fingertip. The figures are displayed in the app.
Although the readings are currently not quite as accurate as those obtained using an arm cuff, they're about as good as those from a finger cuff. Additionally, the app can calculate an average blood pressure based on multiple successive readings, boosting its accuracy.
That said, the scientists are now working on improving the accuracy of the system, along with streamlining the hardware – they believe that the electronics could ultimately be only about one millimeter thick, allowing them to be built into regular smartphones cases.
A paper on the research was recently published in the journal Science Translational Medicine.
Source: Michigan State University
