Scientists have created a new application (app) and hardware for smartphones which, they say, can measure blood pressure (BP) with accuracy that rivals finger-cuff devices.
To use the device the user presses her/his finger against the smartphone. The external pressure of the underlying artery is steadily increased while the phone measures the applied pressure and resulting variable-amplitude blood volume oscillations. The smartphone app provides visual feedback to guide the amount of pressure applied over time via the finger pressing and computes systolic and diastolic BP.
Scientists tested the device for real-time BP monitoring among 30 people to evaluate usability and 32 people to measure accuracy against a standard automatic cuff-based device. They also tested a finger cuff device which uses the volume-clamp method of BP detection.
Presenting the findings in Science Translational Medicine, the authors said the smartphone-based device showed BP measurement accuracy similar to the finger cuff device with respect to the standard arm cuff device. Around nine out of 10 users learned the finger actuation after one or two trials.
Efforts are continuing to improve accuracy of the device.