A quadriplegic English man has been left brain damaged after a nurse accidentally switched off his ventilator _ an act caught on a camera the patient had reportedly installed because he was concerned about the quality of his care.

Footage released Monday by the BBC shows nurse Violetta Aylward turning off Jamie Merrett's ventilator in January 2009, then struggling to revive him. The broadcaster said it took 21 minutes for the machine to be restarted.

Merrett was left paralyzed from the neck down in a 2002 road accident, but was able to talk, use a wheelchair and operate a computer.

His sister Karen Reynolds told the BBC that since his brain damage, his level of understanding had dropped to that of a young child.

"He has an existence but it's nowhere near what it was before," she said. "He is very brain-damaged compared to what he was before."

The health authority responsible for Merrett's care has apologized for "the incident in January 2009 when the patient's ventilator care was compromised." In a statement, NHS Wiltshire Primary Care Trust said it had "put in place a series of actions to ensure that such an event will not occur again either for this patient or others."

Aylward worked for an agency contracted by the health care trust. The Nursing and Midwifery Council said she has been suspended pending an investigation.