Wireless powered heart pumps to save lives by preventing infection

A new wireless system to power heart pumps could save lives by reducing deadly infections caused by current forms of the device. The current system used to power a heart pump, which is attached directly to the heart to assist weakened muscle to keep working, requires a cable running from the heart pump through the skin to a battery.

Image: Lead researchers, Professor Mahinda Vilathgamuwa and Prasad Jayathurathnage

Life saving Ventricular Assist Devices (VADs) are mechanical heart-support devices that help patients’ hearts to keep pumping while they wait for a transplant or recover from cardiac surgery or to augment the action of weakened heart muscles.

Many deaths occur from infection because the problem with VADs is that they are powered via a cable that goes through the skin from an external battery, worn in a holster, to the VAD which is implanted in the heart.

Diagram: Schematic representation of a person with current wired VAD equipment. Courtesy of Thoratec Corporation.

Infection often begins at the point where the cable enters the body and is one of the most significant complications of VAD use. While the one-year survival rate for people with VADs was 1–2 per cent better than that of heart transplant patients, the risk associated with these devices means comparatively few VADs are implanted. Sadly, as a result, many people have succumbed to heart disease.

Professor Mahinda Vilathgamuwa and Prasad Jayathurathnage, from the power engineering group in Queensland University of Technology’s (QUT) Science and Engineering Faculty led the groundbreaking project to solve this problem with a power engineering solution.

The system they are developing includes a lightweight copper coil that will be worn outside the body to power the heart pump, or VAD. The VAD is embedded in the body, no longer requiring a wire that breaks the skin.

Diagram illustrating the electronic components of the alternative, wireless VAD newly designed by Professor Mahinda Vilathgamuwa and Prasad Jayathurathnage.

The wireless power transfer system they had developed uses a small copper coil receiver which would be implanted inside the body, with a transmitter and battery worn in a holster or a jacket.

Diagram illustrating the placement of the wireless VAD and the separate garment holding the transmitter and battery designed by Professor Mahinda Vilathgamuwa and Prasad Jayathurathnage.

“The system we are developing will replace the cable completely. In tests it has achieved 94 per cent efficiency in powering a commercial heart pump, without the need to break the skin for a cable,” Dr Jayathurathnage said.

“Although some patients have now survived more than 10 years with VAD support, VADs cannot continue to improve without wireless power to reduce the risk of life-threatening infection.”

The US National Institute of Health estimates up to 100,000 people could benefit immediately from VADs if they could be safely implemented with this new technology. While in Australia, cardiovascular diseases are a leading cause of mortality, affecting 1 in 6 Australians. Nearly 45000 deaths were reported in Australia from cardiovascular diseases in 2015. Heart failure affects nearly 300,000 Australians, and cost over one billion dollars.

This research is funded by the Prince Charles Hospital Foundation.

Research on the technology has been published in IEEE Transactions on Industrial Electronics.

Contact Professor Mahinda Vilathgamuwa and Prasad Jayathurathnage, from the power engineering group at QUT’s Science and Engineering faculty for more information.

Find out more about research at QUT.