Derriford is the only hospital in Britain to use the table concerned

Two patients requiring cardiac surgery and five patients needing thoracic surgery are being operated on.

Three new theatre tables have been installed at Derriford.

A female patient died after the top of the table became detached during a procedure at Derriford Hospital in Plymouth on 20 February.

The woman died the following Sunday, although the hospital has said there is no evidence to link the death to the table incident.

It was top-of-the-range equipment, properly maintained and properly serviced Terrence Lewis, Derriford Hospital

A post-mortem examination has been carried out on the woman, but the results have not been released. An inquest is expected to open next week.

The hospital's medical director, Terrence Lewis, said the problem was completely unexpected.

He said: "It was top-of-the-range equipment, properly maintained and properly serviced.

"We don't know what caused it. The Medical Devices Agency (MDA) and our own investigations will have to show that.

"But it seemed inappropriate to have to ask our surgeons to operate on systems which, although we might have been able to amend them, we didn't know what was wrong."

HAVE YOUR SAY NHS message board I am grateful for the NHS and am proud to live near one of the best hospitals in the country Wendy, Barnstaple Join the debate

It is believed Derriford is the only hospital in Britain to use the type of table concerned.

Mike Storey from the Plymouth Community Health Council watchdog said he had never come across anything like it.

He said: "I'm sure every patient on the waiting list would want to know they weren't going to have to go in until the question of this problem is resolved."

The new operating tables are being supplied by company that made the malfunctioning table, ALM, owned by Swedish company Getinge.

Getinge spokesman John Jones said they will co-operate with any investigations.