Scientists have developed a simple, low-cost clip that uses a smartphone's camera and flash to monitor blood pressure at the user's fingertip. The clip developed by researchers at the University of California (UC) San Diego, US, works with a custom smartphone app and currently costs about 80 cents (Rs. 5.6) to make.

source https://www.gadgets360.com/science/news/smartphone-camera-flash-attachment-monitor-blood-pressure-user-fingertip-4077882#rss-gadgets-all