evidence: A newly developed Android phone app is able to remotely estimate pressure in a person's arteries as their heart squeezes, providing potentially life-saving details on individual health without the need for specialized equipment. [...] Smartphones can't apply pressure to stop and restart blood flow as a traditional blood pressure cuff does. As an alternative approach, the app uses the force of gravity and the force of finger pressure on the phone touchscreen to figure out pulse pressure. [...] "Development of a cuffless blood pressure measurement device that does not require any external calibration is the holy grail – such a device currently does not exist," says biomedical engineer Sanjeev Shroff, from the University of Pittsburgh.