A rookie police constable who disarmed a violent psychiatric patient wielding a meat cleaver is to receive a commendation for bravery.

Bradford-born Katie Bell, 24, was on her first nightshift with the Metropolitan Police when she and a fellow officer were called out to deal with the armed middle-aged woman threatening staff at a North London hospital.

"When we arrived she came at us with the knife shouting and screaming," said Katie, who was still a probationer during the dramatic incident in November 2002.

"She was intent on harming anyone near her. We had to act quickly but it seemed to take an age to disarm and handcuff her.

"It was my first night duty and it turned into a baptism of fire. It is certainly the most dangerous incident I've been involved in so far. It was only afterwards I realised how serious it was and how it could have gone horribly wrong."

Katie, who joined the Met after gaining a degree in criminology at London Middlesex University, is to receive a commendation at a special awards ceremony at Arsenal football club next month.

Educated in Baildon and at Ilkley Grammar School, Katie has wanted to be a police officer in the Met since she was a teenager. But she is clear the incident has not deterred her from police work.

"The cleaver was very close and she was aiming it straight at me. I've had to deal with other serious incidents but this was the worst so far," she said.

Katie's parents Richard and Joan Bell, of Highfield Crescent, Baildon, said they were extremely proud of their heroine daughter.

"I was alarmed when I heard about it," said Mrs Bell.

"No one wants to see their daughter attacked by someone with a cleaver. But she is a sensible person who would look after her own safety first."

Mrs Bell, a nursery nurse, will be travelling to London to see her daughter receive the bravery award from a senior police officer.