University research ushers in new rechargeable pacemaker technology
February 4, 2014
Out of 40 million heartbeats in a year, missing just a few can end a life.
Pacemakers are not always in use, but when a heart stops beating, they are everything. University researchers are developing a device — the first of its kind — with a battery that never needs to be replaced and is powered by the heart’s own motion — a simple beating.
John Rogers, professor of Materials Science and Engineering, explained the energy harvesting and storage device connected to the pacemaker as a piece of piezoelectric material — one-hundredth of the thickness of a human hair — that is placed on a piece of thin, orange plastic and then wrapped around the heart.
“When you apply stress or strain on the material, it creates voltage currents, like power,” said Canan Dagdeviren, lead researcher and graduate student in Materials Sciences and Engineering. “So by simply using this power you can operate any bio-implantable devices.”
The device generates a microwatt of power, the necessary amount to reinitiate a heart’s beating, Rogers said. The device provides minimal mechanical restraint on the heart so there are no adverse effects.
“Our work is in the context of that type of technology — trying to come up with strategies for harvesting at high efficiencies in devices that are biocompatible that have very long lifetimes,” Rogers said.
The research team chose to implement their research in pacemakers because using a rechargeable device would save patients from major surgery and surgical risk. Additionally, the device could save money by not having to pay for a replacement pacemaker.
Dr. Edwin Zishiri, cardiologist with a specialty in pacemakers at Carle Foundation Hospital, said the devices last anywhere from five to 10 years, depending on how often the patient’s heart beats on its own.
He explained that when the batteries run out on a traditional pacemaker, the whole device needs to be replaced because currently there is no way to recharge the device, and there is no way to replace the batteries. This surgery is not quite as involved as placing the pacemaker the first time, but is still a major procedure, he said.
“Anytime you go into a pacemaker pocket and open it up to put in a new one, there is some risk involved,” he said. “If you eliminated the need for replacing the pacemaker, then you would get rid of that risk.”
He said, for some people, pacemakers are the reason their hearts are beating, but for others it simply improves their quality of life.
Those who require a traditional pacemaker will need to have the batteries replaced every five to seven years. In White Heath, Ill., Tina Stephens Bennett’s 16-year-old son, Luke, may have to undergo pacemaker replacement surgery numerous times in his life.
“The doctor said after the surgery that she had no doubt in her mind that that surgery, him getting the pacemaker, absolutely saved his life,” Bennett said.
Bennett said her son’s pacemaker has been in for a little under a year and a half, and according to the most recent report, the batteries have five to seven years left. However, this is all dependent on how often the device has to work, she said.
Dagdeviren and Rogers said they will continue to work on and improve the device, making sure that it is suitable for the human heart. Rogers said the device will not be on the market for at least 10 years due to regulation procedures. Bennett said that if the rechargeable pacemaker were to become an option, they would consider it for Luke in the future.
She said her uncle, who had a similar condition to her son, had three pacemakers in his life before ultimately receiving a heart transplant.
“If they progress in (pacemaker) research, and that is able to happen, that would be wonderful,” Bennett said. “It would be putting everybody at less risk.”
Dagdeviren worked on piezoelectric materials because she said she knew they could create power. Before coming to the University from Istanbul, Turkey, her devices were bulky and boxy, which is not suitable for human organs. However, she learned a technique to make the devices thin and was able to successfully create the harvesting and storage device.
The piezoelectric device has been tested on pigs, sheep and cow — hearts that are comparable to human hearts, which gives an accurate reading of how much energy output there is and how much the heart can take before its natural beating is affected, Rogers said.
“I was thinking to work on the heart from my childhood because my granddad passed away because of heart failure,” Dagdeviren said.
She was the first person in her group to work with the piezoelectric materials three years ago and has been a part of every step of the process — even suturing the chest after surgeons implanted the device on the animal heart.
“If you ask me, nothing is impossible. So these things, at some point, will be inside your body,” she said. “I can see it is a baby step we just started, we need to work on it more, but it was a dream and it came true.”
Claire can be reached at [email protected]