Concerns over the safety of traditional walking frames have led scientists to design a robotic version.

Elderly people with walking problems could soon benefit from the electronic frame which acts as a second pair of eyes and legs, audibly warning the user of impending collisions.

The Personal Adaptive Mobility (PAM) robot also tells people when they come to a junction or if they are about to encounter a door.

The prototype developed by computer scientists at Trinity College, Dublin, uses laser and sonar sensors to guide the robotically-steered wheels.

Powered by an electric battery, it could be the answer to the thousands of accidents which occur each year with standard walking frames.

Dr Gerard Lacey has been working on the machine for two years. He said: "I was visiting a relation in a nursing home and I saw an elderly fellow who needed help from two nurses to use a Zimmer frame.

"I thought I could use robot technology and put it in a Zimmer frame, making the elderly man's life easier and freeing up the nurses to do something else."

180 degree

The laser rangefinder has a 180 degree sweep and when it is unreliable, such as in front of glass doors, six sonar sensors take over.

It can be used in two modes - "manual" acts as a standard walking frame but issues audible warnings, while "aggressive" actually controls the steering and navigates safely around obstacles, reported New Scientist magazine.

Commercial sponsorship would be needed to develop a sufficiently reliable machine to make it marketable, but Dr Lacey claims it could be produced at a viable cost and that it only takes people 15 minutes to learn how to use it.

Charity Help the Aged gave a cautious welcome to the development. A spokeswoman said: "We think it is a helpful addition to the services available to elderly people, but it is not going to fit everybody's needs.

"There is also a cost issue. It is not going to be cheap to produce." Unlike standard frames, she suspected the robotic version would not be available from the NHS.