In an experiment, the technique was found to be as accurate as a 45-minute echocardiography scan, which currently requires a trained technician operating an expensive ultrasound machine. The smartphone technique measures how much the carotid artery displaces the skin of the neck as blood pumps through it.
To test the app, clinical trials were conducted with 72 volunteers between the ages of 20 and 92 at an outpatient magnetic resonance imaging (MRI) facility. MRI is the gold standard in measuring LVEF but is seldom used clinically due to its high cost and limited availability. The measurements made by smartphone had a margin of error of ±19.1 percent compared with those done in an MRI. By way of comparison, the margin of error for echocardiography is around ±20.0 percent.