A wrist watch-like device developed by Cory Cornelius, a scientist at Dartmouth University, can determine a person’s “bioimpedance” that would enable medical devices to identify its wearer.

The device measures the wearer’s unique response to a weak electrical signal, and when used in conjunction with medical devices like blood pressure cuffs could send patient information directly to his or her electronic medical records.

Cornelius’ device works by determining an individual’s impedance – unique to each person because each individual’s wrist features a unique arrangement of bone, flesh and blood vessels. By sending current through the wrist between two electrodes the device is able to determine the wrist’s resistance and reactivity, which are key components of impedance.

With medical instruments becoming increasingly computerized security and authentication concerns are critical and while Cornelius’ device may not be the magic bullet, it is certainly a step in the right direction.

In a pilot test comprised of 46 volunteers- each of which provided 80 impedance measures- the device was able to correctly identify the person at a rate of 80-90%.

Bioimpedance is not without its skeptics- like Ari Juels, chief scientist at RSA Laboratories in Cambridge, Massachusetts- who believes that the false acceptance and rejection rates are too weak to justify its role in security and authentication.