Panic button alarms are being issued to 30,000 NHS employees who work on their own and face the possibility of being threatened or assaulted.
The Reliance i750 identicom device uses location-based service (LBS) technology to locate the user and link them to a call centre that can summon help.
It is intended for nurses and other healthcare staff, and provides legally-admissible evidence that can be used in the event of a prosecution being brought.
Says health secretary Alan Johnson: "No NHS staff should have to put up with violence in the workplace, but sadly it happens. Lone workers are particularly vulnerable and I am determined to provide them with as much protection as we can to enable them to carry out their valuable work knowing that they have the support they need should their personal safety be threatened."
Ann Duffy, Community and District Nurses Association, said: "This is the best news for district nurses. We have campaigned for the safety of nurses for some time, Alan Johnson has delivered his pledge to us and we thank him. We have a duty of care for the nurses who care for all of us."
"Of course it is. When individual patients who threaten a member of staff are automatically visited by the police, if the incident was witnessed by other staff, it is extremely important that lone members of staff can attract attention and witnesses. This also applies in hospitals which are understaffed on individual wards." - Elizabeth Kennedy, Groomsport
"As a community nurse we are very vulnerable and at risk, and I would welcome an alarm system. I feel that it would be beneficial for each individual nurse to have one" - Pat Smith