With the emergence of new tools that can measure a person’s mental and physiological states, computer interfaces are starting to attention to how users feel to help computers cater to their needs, say experts.

Design Interactive is prototyping Next Generation Interactive Systems, or NexIS, a system that will place biological sensors on soldiers. If a sensor detects that a soldier’s pulse is weakening, or determines another problem with her physical state, the system might call for help or administer adrenaline. The company is also developing a system using electroencephalography, eye tracking, and heart-rate monitoring to assess the performance of baggage screeners.

Sensors can already detect when a driver is drowsy, distracted, overloaded, or engaged, and could determine other states, such as frustration in computer users.