Battery extends implantable's life

With the help of new silicon-based compounds, scientists - and patients - are getting a significant new charge out of the tiny lithium batteries used in implantable devices to help treat nervous system and other disorders.

The lithium battery is the workhorse of implantable devices, which are stimulators used to jump-start the heart and help the central nervous system make critical connections in, for example, Parkinson's and epilepsy patients.

Designed to be highly reliable and work for years, the batteries that power implantables are indispensable in everything from pacemakers to the electronic stimulators that help restore function in the brains of Parkinson's patients.

But lithium batteries don't last forever. New surgery is often required to maintain many devices seeded into the body or to replace batteries and devices at the end of their lives.

A new generation of tiny electrical devices to stimulate the nervous system, treat incontinence and overcome muscular impairment is coming on line as scientists and engineers continue to shrink the components that make up the devices.

Central to that ability, according to UW-Madison Prof Emeritus of chemistry Robert West, is new lithium battery technology, technology capable of making batteries smaller, last longer and, soon, accept a charge from outside the body without the need for surgery.

Using organosilicon compounds, West and his colleagues have developed a new generation of rechargeable lithium ion batteries whose lifetimes are more than twice as long as the batteries now used.

"It turns out the organosilicon compounds are really good for improving lithium battery technology," says West, whose new battery technology powers a 'microstimulater' not much larger than a pencil lead and that can be injected near target nerves to help overcome the faulty nervous system wiring at the heart of Parkinson's, epilepsy and incontinence.

"The idea is that whenever you have a broken nerve connection, you can supply the electrical impulse to complete the circuit," West explains.

West's group developed the electrolyte and the organosilicon compounds.

An advantage of the new battery is lifespan. It is projected to power the tiny implantable devices for more than 12 years.