Napa State Hospital in California, US, will launch a new and controversial alarm system on 14 August 2012.

The move follows the death of a psychiatric technician who was strangled by a patient nearly two years ago in the hospital, which treats patients accused or convicted of crimes.

The alarms, which are worn on lanyards around the necks, will send signals on the whereabouts of every employee and receive data so that they can reach one another in emergencies.

California State Hospitals Department chief deputy director Kathy Gaither was quoted by the Los Angeles Times as saying that the department doesn’t often get to give people good news, adding: "The fact that we’re going live with a big project that’s going to have such a huge positive impact for our staff and our patients, we’re very proud."

Many staff members have criticised the launch of the new technology, saying that there is still a risk of strangulation.

Many staff members have, however, criticised the launch of the new technology, saying that there is still a risk of strangulation as they are asked to wear the alarms on lanyards around their necks.

"We need to move forward to improve the safety of our employees and our patients, and not having the alarm at all is a less safe situation than moving forward with the alarm," said Gaither.

If the new alarm technology achieves results at Napa State Hospital there are plans to deploy it at Norwalk’s Metropolitan State Hospital and San Bernardino’s Patton State Hospital followed by Coalinga State Hospital and Atascadero State Hospital next year.

The state has awarded a contract to Virginia-based manufacturer Ekahau to supply the safety systems.