14 DAY TRIAL // A collaboration of investigators in the United States announces the development of a prototype wireless heart pump that does not require a power cord. If their new device turns out to be as efficient as early tests predict, then they could improve the quality of life for patients with medical implants.
At this point, wearing medical implants is still very uncomfortable and inconvenient, and also very likely to cause infection. When it comes to implanted heart pumps, the situation is especially dire. These instruments are installed in patients whose hearts are unable to circulate blood through the body on their own. The pumps take over the task, but require so much energy that a simple battery does not suffice. A power cord is usually required.
The cord extends from the implanted device to the abdominal wall, where it passes through the skin and goes into a power source worn outside the body. But having a cable going out of the body is very uncomfortable, and carries a large risk of infection.
The new prototype created by experts at the University of Washington (UW) and the University of Pittsburgh Medical Center (UPMC) eliminates the need for a cord altogether. The instrument was presented at the annual meeting of the American Society for Artificial Internal Organs, in June.
It was developed by UW associate professor of computer science and electrical engineering Josh Smith and UPMC heart surgeon Pramod Bonde, Technology Review reports. This is not the first time such a system is proposed.
However, it is the first time a wireless system works from a range of distances, between several centimeters and more than a meter. This ability was enabled by innovations the team applied to the way in which electricity is sent and received.
The external transmitter is made up of a power coil capable of transmitting oscillating magnetic fields at 6.78 megahertz and 13.56 megahertz. The coil on the artificial pump resonates with these frequencies at around 80 percent efficiency.
Smith also included a feedback system into the device, which enables it to automatically adjust the frequency of the power transmitter whenever the latter is moved farther away form the body.
By switching to using magnetic fields instead of electric fields, the team eliminated most of the heating problems associated with other wireless devices. Still, some residual heat does form. The team is convinced that tinkering with the technology will ultimately reduce the heating to extremely low levels.