A smartphone with a clip for 80 cents measures blood pressure

7 July 2023

The Problem

Blood pressure is one of the basic parameters for assessing the health of the cardiovascular system, including diagnosing hypertension – a disease that kills 9.4 million people every year, according to WHO data. The challenge is that only a fraction of patients see a doctor for preventive research, and professional devices for taking measurements at home are relatively expensive. Now that more than 86% of the world's population owns a smartphone, it has become one of the most accessible devices that can be used to measure health parameters. One problem is that a smartphone does not have such capabilities for the time being. However, all it takes is a simple trick to turn a smartphone into a diagnostic device.

The technology

The solution is a 3D-printed plastic clip that is applied to the place where the flash is located. When a finger is applied, the system evaluates the amount of blood flowing through and the amount of pressure exerted on the clip by the finger. When the user's fingers are pressed against the clip, a red dot is displayed on the screen. Its size is proportional to the pressure exerted on the clip, and its brightness is proportional to the amount of blood flowing into the fingertip. The results go to a mobile application that uses artificial intelligence algorithms to interpret the data and estimate blood pressure. The production of one clip costs 80 cents, but the researchers say that mass production could reduce the price to 10 cents. Because of the low cost, the clips could be handed out by doctors or even pharmacists, just as a dentist hands out toothpaste samples during a check-up visit. This would be a milestone in cardiovascular disease prevention. The technology has another advantage – it does not need to be calibrated with a blood pressure cuff device, as many smartwatches do. All you have to do is fit the clip, and immediately, you can perform a blood pressure test to get a reliable blood pressure measurement. The research results were published in the scientific article "Ultra-low-cost mechanical smartphone attachment for no-calibration blood pressure measurement."