Heart-powered pacemaker could one day eliminate battery-replacement surgery. This could also reduce the size of the pacemaker dramatically. Further information: http://bit.ly/1BmrBeL

1. No More Batteries
Heart-powered pacemaker could one day eliminate
battery-replacement surgery
Raunaq Singh | @rsingh__

2. The basics of how the human
heart and conventional
pacemakers work

8. traditional pacemaker

9. Pacemakers
• Power requirement of modern pacemakers has
now reduced to one microwatt.
• The size of the pacemaker is 42mm X 51mm X
6mm
• The batteries take up about 2/3rd of the size of
the pacemaker’s generator.
• A pacemaker’s batteries last for only 5 - 7 years.
[1]

10. Piezoelectric Pacemakers
• Piezoelectricity generated from mechanical
vibrations in our chest area could be used to
power the pacemaker.[1]
• M. Amin Karami and Daniel J. Inman, Phds from
the Aerospace Engineering Dept. of University of
Michigan have proposed have proposed this
concept.[6]

11. Piezoelectricity
• An electric charge accumulates in certain solid
materials in response to mechanical stress.
• Common piezoelectric materials :-
Natural crystals - quartz, rochelle salt, topaz
Synthetic crystals - Gallium orthophosphate, a
quartz analogic crystal
• The most common piezo electric material used is
Lead zirconate titanate.
[7]

12. Piezoelectric Pacemaker
• Vibrations produced by our beating heart our used
to generate electricity to power the pacemaker
• The piezoelectric energy harvester is placed in the
vicinity of the heart
• The vibrations in the vicinity of our heart are
estimated using ultrasonic velocity measurements
performed by Kanai H. in a paper published by
IEEE.
[1]

13. Piezoelectric energy
harvester
• A unimorph zigzag geometry piezoelectric structure is used so
that:
- its size remains small
- the natural frequency vibrations it responds to our within the
range of our heart’s frequency
- it is designed to have high strength
• The researchers target reducing the power source area by 50%.
[1]

14. Specifics
• the zigzag energy harvesters have 27mm long beams
• brass is chosen as the suitable substrate material
• the piezoelectric material used is Lead Zirconate
Titanate (PZT-5A)
• the piezoelectric layer is attached to the substrate
using poly-epoxide.
• the thickness of the PZT-5A used is 0.01 in (254um).
[1]

15. Specifics
• The maximum power harvested corresponds to
1800 um substrate thickness if excited at nominal
heart rate.
• The power output from such structure is 10 uW,
which is 10 times the power requirement of a
pacemaker
• This type of piezoelectric energy harvester is called
linear energy harvester and it harvests energy in
response to 39 Hz oscillations.
[1]

16. Limitations & Further
improvements
• Linear harvesters work well only at a specific heart rate, so
heart rate changes in patients with an irregular heart rate
could prevent them from harvesting enough power.[4]
• To overcome this limitation in patients who have a relatively
irregular heart rate, nonlinear broadband energy harvesters
are used.[4]
• A nonlinear harvester uses magnets to enhance power
production and make the harvester less sensitive to heart
rate changes. The nonlinear harvester generated enough
power from heartbeats ranging from 20 to 600 beats per
minute to continuously power a pacemaker.[5]

17. • Karami told the Daily Mail that, “What we have
proven is that under optimal conditions, this
concept is working.” I don’t know that that would
be enough to put my life on the line. But if the
device proves itself and manages to pass all the
regulatory lines of defense, it could be a real
boon to heart patients.And it’s a large market
opportunity for device-makers, too: some 700,000
people get a pacemaker or defibrillator each year,
reportedly.[2]

18. Citations
• [1] Powering pacemakers from heartbeat vibrations using linear and nonlinear energy
harvesters by M. Amin Karami and Daniel J. Inman, Applied Physics Letters, 23rd
January 2012
• [2] A Heartbeat-Powered Pacemaker - MIT Technology Review, Nov 7 2012
• [3] New device could allow your heartbeat to power pacemaker - American Heart
Association, Nov 04, 2012
• [4] UMich researchers closer to producing piezo-powered pacemaker - The American
Ceramic Society, March 05, 2012
• [5] No More Batteries: Piezoelectric Pacemaker Powered By The Heart - Science 2.0,
Nov 4, 2012
• [6] Heart-powered pacemaker could one day eliminate battery-replacement surgery -
University of Michigan News, March 02, 2012
• [7] Piezoelectricity - Wikipedia Article