Featured Research

from universities, journals, and other organizations

Wireless power could cut cord for patients with implanted heart pumps

Date:
July 13, 2011
Source:
University of Washington
Summary:
A new system to send electricity over short distances has been shown to reliably power a mechanical heart pump. The system could free patients from being tethered to a battery or external power source, lowering their chance of infection and improving their quality of life.

Researchers envision a future where patients would install transmission coils in their homes and workplaces to create zones where the implant would receive uninterrupted power.
Credit: Pramod Bonde, University of Pittsburgh Medical Center

Mechanical pumps to give failing hearts a boost were originally developed as temporary measures for patients awaiting a heart transplant. But as the technology has improved, these ventricular assist devices commonly operate in patients for years, including in former vice-president Dick Cheney, whose implant this month celebrates its one-year anniversary.

Prolonged use, however, has its own problems. The power cord that protrudes through the patient's belly is cumbersome and prone to infection over time. Infections occur in close to 40 percent of patients, are the leading cause of rehospitalization, and can be fatal.

Researchers at the University of Washington and the University of Pittsburgh Medical Center have tested a wireless power system for ventricular assist devices. They recently presented the work in Washington, D.C. at the American Society for Artificial Internal Organs annual meeting, where it received the Willem Kolff/Donald B. Olsen Award for most promising research in the development of artificial hearts.

Joshua Smith, a UW associate professor of computer science and electrical engineering who recently moved to the UW from Intel Research Seattle, has for the past six years been working on wireless power. The concept is a variation on inductive power, in which a transmitting coil sends out electromagnetic waves at a certain frequency and a receiving coil absorbs the energy and uses it to charge a battery. Electric toothbrush charging stations and cell phone charging pads use a similar system, except that in both those cases the tool has to actually touch the charger and be held in a fixed position.

Smith and colleagues at UW and Intel devised an inductive system that adjusts the frequency and other parameters as the distance or orientation between the transmitter and receiver coils changes, allowing for flexible yet efficient wireless power over medium distances.

"Most people's intuition about wireless power is that as the receiver gets further away, you get less power," Smith said. "But with this technique there's a regime where the efficiency actually doesn't change with distance."

In what Smith calls the "magic regime," power stays constant over distances about the same as the diameter of the coil -- meaning a one-foot transmitter coil could deliver consistent power over a distance of a foot, or a four-inch coil could transmit power over a distance of four inches.

That's not far, but it's enough to bridge the skin and tissue to reach a medical implant.

Four years ago, Smith's system attracted the interest of a heart surgeon who had been experimenting with using traditional induction to transfer power, but was hampered by misalignment, unwanted heat generation, and ranges that were limited to a few millimeters.

"My primary interest is to help heart failure patients recover, and they can only recover if they are not tethered to a battery or external power supply so they can exercise and train their heart to recover," said Dr. Pramod Bonde, a heart surgeon at the University of Pittsburgh Medical Center. "With wireless technology patients can be free and they can have a chance to move around and exercise like normal human beings."

Using the wireless system means no power cord poking through the skin, dramatically reducing the risk of infection and improving the patient's quality of life. Researchers envision a vest that could hold an external transmitter coil connected to a power cord or battery. A small receiver coil implanted under the patient's skin would connect to a battery that holds enough power for about two hours, meaning the patient could be completely free for short periods of time to take a bath or go for a swim (current users of heart pumps cannot do either). Longer term, the researchers imagine additional power transmitters placed under a patient's bed or chair, allowing patients to sleep, work or exercise at home unencumbered.

Results presented at the meeting showed the system could power a commercial heart pump running underwater using a receiver coil as small as 4.3 cm (1.7 inches) across. The power transmitted reliably with an efficiency of about 80 percent. Next the researchers hope to test the system with a heart pump implanted in an animal.

"The potential for wireless power in medical fields goes far beyond powering artificial hearts," Dr. Bonde said. "It can be leveraged to simplify sensor systems, to power medical implants and reduce electrical wiring in day-to-day care of the patients."

Co-authors are UW doctoral students Alanson Sample and Benjamin Waters.

Collaborators at Intel Corp. are working on applications of the system to recharge consumer electronics. In addition to the heart pump, Smith is pursuing an application using wireless power to recharge ocean instruments underwater.


Story Source:

The above story is based on materials provided by University of Washington. The original article was written by Hannah Hickey. Note: Materials may be edited for content and length.


Cite This Page:

University of Washington. "Wireless power could cut cord for patients with implanted heart pumps." ScienceDaily. ScienceDaily, 13 July 2011. <www.sciencedaily.com/releases/2011/07/110712162826.htm>.
University of Washington. (2011, July 13). Wireless power could cut cord for patients with implanted heart pumps. ScienceDaily. Retrieved April 23, 2014 from www.sciencedaily.com/releases/2011/07/110712162826.htm
University of Washington. "Wireless power could cut cord for patients with implanted heart pumps." ScienceDaily. www.sciencedaily.com/releases/2011/07/110712162826.htm (accessed April 23, 2014).

Share This



More Matter & Energy News

Wednesday, April 23, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Is North Korea Planning Nuclear Test #4?

Is North Korea Planning Nuclear Test #4?

Newsy (Apr. 22, 2014) South Korean officials say North Korea is preparing to conduct another nuclear test, but is Pyongyang just bluffing this time? Video provided by Newsy
Powered by NewsLook.com
China Falls for 4x4s at Beijing Auto Show

China Falls for 4x4s at Beijing Auto Show

AFP (Apr. 22, 2014) The urban 4x4 is the latest must-have for Chinese drivers, whose conversion to the cult of the SUV is the talking point of this year's Beijing auto show. Duration: 00:40 Video provided by AFP
Powered by NewsLook.com
Lytro Introduces 'Illum,' A Professional Light-Field Camera

Lytro Introduces 'Illum,' A Professional Light-Field Camera

Newsy (Apr. 22, 2014) The light-field photography engineers at Lytro unveiled their next innovation: a professional DSLR-like camera called "Illum." Video provided by Newsy
Powered by NewsLook.com
3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

3 Reasons Why Harley Davidson Is Selling Tons of Epic Hogs

TheStreet (Apr. 22, 2014) Sales of motorcycles have continued to ride back from the depths of hell known as the Great Recession. Excluding scooters, sales of motorcycles increased 3% in 2013. In units, however, at 465,000 sold last year, the total remained about 50% below the peak hit in 2007. Industry leader Harley Davidson’s shareholders have benefited both by the industry recovery and positive headlines emanating from the company. Belus Capital Advisors CEO Brian Sozzi takes you beyond the headlines of the motorcycle maker. Video provided by TheStreet
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins