Monitoring after heart surgery. Surgeon using a MindDrive sensor (black) on a baby girl's finger to monitor her mental activity following heart surgery. MindDrive measures electrical signals in her skin, along with her heartbeat, temperature and blood pulse volume, using a skin sensor. These provide a guide to her overall mental state, which is shown on the monitor at upper right, allowing her health to be assessed more accurately. The surgery may have corrected a congenital heart abnormality. As well as showing the mental states of people who cannot describe them themselves, MindDrive allows computers to be operated using the mind alone. The surgeon is Carlo Marcelletti.