Electrodermal activity can be used to measure excitement, stress, fear, engagement and relaxation. Affectiva says the measurements from its wristband are accurate enough to rival the established method of attaching wires to the fingertips.

The technology for the Q Sensor was developed at the Massachusetts Institute of Technology (MIT), and Affectiva has been using a pre-release version since November last year with clients including hospitals, universities and marketing group Interpublic.

The Q Sensor costs $2,000 per unit, with a 24-hour battery life and space for three months’ worth of data. The company also plans to release a smaller version for children, which can be inserted into a band that can be worn elsewhere on the body.

Affectiva was founded in 2009 by Rosalind Picard of MIT Media Lab and Rana el Kaliouby, who worked together at MIT developing technologies to help people with autism. The company also has technology for using webcams to read facial expressions.