A portable, battery-powered machine could free people with renal failure from the need to undergo regular dialysis sessions.

The Wearable Artificial Kidney, currently undergoing trials in the USA, enables patients to walk, work and sleep while undergoing a continuous dialysis more similar to normal kidney function than conventional dialysis.

The device has been tested successfully with two renal patients. It can be worn as a belt, weighs only 10 pounds and is powered by two 9V batteries.

"Our vision of a technological breakthrough has materialized in the form of a Wearable Artificial Kidney, which provides continuous dialysis 24 hours a day, seven days a week," said Victor Gura, MD, of the David Geffen School of Medicine, UCLA.

Dialysis patients have to endure regular sessions of forced immobility, and none the less face high rates of hospitalisation and death.

"We believe that the Wearable Artificial Kidney will not only reduce the mortality and misery of dialysis patients, but will also result in significant reduction in the cost of providing viable health care," said Gura.

"However, the long-term effect of this technology on the wellbeing of dialysis patients must be demonstrated in clinical trials. Although successful, this is but one additional step on a long road still ahead of us to bring about a much-needed change in the lives of this population."