Monday, February 19, 2007

'Smart Bladder' Pacemaker Could Help Paralyzed

Duke University researchers say they've moved a step closer in their efforts to develop a 'smart bladder pacemaker' that could restore bladder control in people with spinal cord injury or neurological diseases.

The latest finding of the project, which started in 2004, shows that electrical stimulation of the pelvic nerve in the spinal cord can control the contraction and relaxation of muscles involved in bladder control.

In tests on cats, the researchers found that high frequency electrical pulses directed at the pelvic nerve helped empty the bladder, while low frequency pulses increased bladder capacity and improved continence.

This method of manipulating the nervous system is a more flexible way of controlling urinary function than direct bladder stimulation, said Warren Grill of Duke's Pratt School of Engineering.

"Stimulating the bladder directly can cause it only to contract, not to keep it from contracting. We stimulate the sensory inputs in the spinal cord to orchestrate either the inhibition or activation of urination," Grill said in a prepared statement.

"This illustrates an important principle: We can use the 'smarts' of the nervous system to orchestrate control of complex functions," he said.

It may be possible to use a similar approach to stimulate spinal reflexes that control movement to help people who are paralyzed, Grill said.

The research is expected to be presented Friday at the American Association for the Advancement of Science annual meeting in San Francisco.