Body cameras are being used to record attacks and abuse towards hospital staff at five of Wales' health boards in a bid to deter violent behaviour.
Aneurin Bevan is the latest to give security staff the cameras after 15,113 incidents in the last five years.
One A&E nurse said he was threatened on a weekly basis and once had a patient grab him by the throat.
He said the cameras meant "it's no longer just our word against theirs".
First introduced at the University Hospital of Wales in Cardiff in 2013, body cameras are now being worn by all security staff at sites managed by Cardiff and Vale University Health Board.
Head of security, Damian Winstone, said the cameras were more effective than traditional CCTV and had led to successful convictions for a range of offences.
"The use of body cameras is improving how patients, staff and visitors conduct themselves," he said.
Aneurin Bevan, Cwm Taf, Betsi Cadwaladr, and Abertawe Bro Morgannwg (ABMU) health boards also use the equipment at some sites.
No staff at Hywel Dda or at Velindre Cancer Centre in Cardiff, wear body cameras, while there are no district hospitals in Powys.
The cameras, which are the size of a smart phone, are worn by security staff, and some car park and smoking enforcement officers.
People are warned they are being switched on before recording begins.
On Friday, legislation introduced by Rhondda MP Chris Bryant to impose harsher prison sentences on those who attack 999 workers, passed a major hurdle in the bid to become UK law.
An A&E nurse, who did not want to be identified, said he received threats and verbal abuse on an "almost weekly basis".
"Physically it is not that bad but it is always a threat," he said.
"The people using abusive language are often under the influence of a substance, or have behavioural issues.
"We try to talk to them and treat them as someone who is distressed. We try to calm the situation. It doesn't always work."
The nurse said he had once been grabbed around the throat by a patient who was cautioned by the police – he was later was diagnosed with mental health issues.
"The security guys do wear body cams," he said.
"It helps because it means it's no longer just our word. They can allege we were rough, but this goes some way to backing up what we said."
From April security, car park and smoking enforcement officers at the Royal Gwent Hospital, Newport, and Nevill Hall Hospital in Abergavenny, will be wearing the cameras.
Aneurin Bevan health board said the measure had been brought in to reduce "the likelihood of violent assaults against staff".
New figures show in 2017-18 alone, almost 1,400 violent incidents were reported at Cwm Taf premises.
The board said cameras, worn by security staff at the Royal Glamorgan Hospital, in Llantrisant, and Prince Charles Hospital, in Merthyr Tydfil, had "been used to capture evidence for prosecutions and convictions".
They are worn by security staff at Glan Clwyd Hospital, in Denbighshire, with staff at all north Wales' district hospitals given violence and aggression training to "teach techniques designed to de-escalate situations".
In 2017, 1,136 staff working for ABMU were physically assaulted while at work.
While no staff wear body cameras, Hywel Dda said it encouraged staff to report incidents of violence and aggression and worked closely with the police.
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