Conducted electrical weapons (CEW), better known by the popular name brand Tasers, are most often used by police when trying to incapacitate criminals. The instruments might receive an upgrade that could save lives.

A study completed at Wake Forest Baptist Medical Center in Winston-Salem, North Carolina, tested a CEW that can record a subject’s heart rate and rhythm while still subduing them. The study, led by Jason Stopyra, MD, an assistant professor of emergency medicine at Wake Forest, was published in the Journal of Forensic and Legal Medicine.

Though CEWs are generally safe to use on people, medical complications can arise when the target of a Taser is using drugs or has a preexisting condition. Serious injury or death can occur because the electrical charges interfere with a subject’s heart rate.

"The basic components of a CEW—probes that penetrate the skin while attached to insulated wires connected to an electronic device—are functionally similar to what is used to obtain an electrocardiogram," Stopyra said in a statement. "We set out to see if we could combine a heart monitoring device with an existing CEW to detect and store cardiac rhythms without impeding the function of the weapon, and we succeeded."

To test their theory, the researchers modified a standard law enforcement model to transmit electrocardiogram (ECG) signals combined with a miniaturized ECG recorder. The modified devices were tested on human volunteers and successfully incapacitated participants while providing interpretable ECG signals.

The study was funded by grants from the National Institute of Justice, a government agency in Washington, D.C., and Medtronic, a medical technology company based in Minneapolis.