Tuesday, November 11, 2008

Using the Heartbeat to Power Devices

An interesting concept was presented at the American Heart Association in New Orleans today: a device that uses atrial and ventricular contractions to power a pacemaker:
The SIMM microgenerator is a catheter-mounted device that would be placed on a conventional pacemaker or defibrillator lead. The device harvests energy by using differential pressure within the chambers of the heart to drive a linear generator. During testing, the device generated one-third of the power required to run a pacemaker (excluding pacing demand). Next-generation microgenerator devices are expected to fully power both the pacemaker and pacing requirements. Placement of the microgenerator is uncomplicated and is fully compatible with existing techniques for implanting cardiac devices.
From the SIMM project website, this is how it works:
Using pressure responsive balloons within the right atrium & ventricle, advantage is taken of the pressures generated in the heart during the cardiac cycle to drive a reciprocating linear generator. In normal function, the atrium contracts first, compressing the atrial balloon & driving the generator mechanism in one direction; then the ventricle contracts, compressing the ventricle balloon & driving the mechanism back to its ‘starting’ position. The reciprocating movement of the mechanism generates the electricity used to power implanted devices.
I can see visions of "green" hybrid pacemakers, can't you?

-Wes

References:

The Implantgen Project.

The Zarlink Semiconductor press release.

2 comments:

geena said...

Um...
I'm no cardiologist, and I did follow the link and read the page about how it works, but...

It seems that this thing gets it's juice from a *normal* cardiac cycle. What happens when the person flips into AFib? Vtach? Is there a backup battery I hope??

Am I missing something? If my heart isn't beating right, I wouldn't want the device that's helping it to beat correctly to be powered by my innately dysfunctional heart.

DrWes said...

geena-

I think the point is that, like hybrid cars, it will not replace the need for batteries, but rather prolong the existing battery's longevity - as you suggest, if there's no heart beat, there's no generator.