Joshua Smith, study leader and a University of Washington associate professor of computer science and electrical engineering, along with Dr. Pramod Bonde, a heart surgeon at the University of Pittsburgh Medical Center, and a team of researchers, have created a wireless mechanical pump that could improve a heart patient's quality of life. 

Traditional mechanical pumps, used to maintain failing hearts, were originally created as a temporary fix until the patient could receive a heart transplant. But these pumps have improved over time and can be a part of a patient's body for years. The problem with this is that a power cord is routed through the patient's stomach, and 40 percent of patients get infections in this area because of the cord. These infections lead to hospitalization and can even be fatal.

But Smith and his team have relieved this problem with the development of a wireless system that allows the patient to use mechanical pumps over a long period of time without worrying about infections in the stomach. 

"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 Bonde. "With wireless technology, patients can be free and they can have a chance to move around and exercise like normal human beings."

The wireless system works through a concept based on inductive power, where a transmitting coil sends electromagnetic waves out at a certain frequency and a receiving coil takes in the energy and uses it to charge a battery. This system is especially unique in that it doesn't require the tool to touch the charger like similar systems, such as cell phone charging pads. Also, distance from the charger doesn't affect the amount of power given to the patient's pump.

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

The power stays constant over distances the same diameter as the coil. So a one-foot transmitter coil could send consistent power over the distance of one foot. 

In tests, the researchers were able to power a mechanical heart pump using a small receiver coil that is 1.7 inches across. Power transmitted reliably with an efficiency of 80 percent.

The researchers are working to make the system apart of a vest, where an external transmitter coil would connect to a battery or power cord, and a small receiver coil would be implanted under the patient's skin. The receiver coil would connect to a battery that holds a two-hour charge, allowing infection-free freedom. 

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