A team of cardiologists, materials scientists, and bioengineers has created and tested an implantable device to measure the heart’s electrical output that they say represents the first use of flexible silicon technology for a medical application. “This technology may herald a new generation of active, flexible, implantable devices for applications in many areas of the body,” says Brian Litt, MD, associate professor of neurology in the School of Medicine and associate professor of bioengineering in the School of Engineering and Applied Science at the University of Pennsylvania. Initially, the researchers plan to apply their findings to the design of devices for localizing and treating abnormal heart rhythms. “We believe these new devices will allow doctors to more quickly, safely, and accurately target and destroy abnormal areas of the heart that are responsible for life-threatening cardiac arrhythmias,” Litt says.
The new devices bring electronic circuits right to the tissue, rather than having them located remotely inside a sealed can placed elsewhere in the body, Litt explains. “This enables the devices to process signals right at the tissues, which allows them to have a much higher number of electrodes for sensing or stimulation than is currently possible in medical devices,” he says. The implantable silicon-based devices also have the potential to serve as tools for mapping and treating epileptic seizures as well as providing more precise control over deep brain stimulation and other neurological applications, says Story Landis, PhD, director of the National Institute of Neurological Disorders and Stroke, which provided support for the study.
The team tested the new devices — made of nanoscale, flexible ribbons of silicon embedded with electrodes that form a lattice-like array of connections — on the heart of a porcine animal model. In their experiment, the researchers built a device using 288 contacts and more than 2,000 transistors spaced closely together. Standard clinical systems usually use five to 10 contacts and no active transistors. “We demonstrated high-density maps of electrical activity on the heart recorded from the device, during both natural and paced beats,” says team member David Callans, MD, professor of medicine at U-Penn. The team described its proof-of-principle findings in Science Translational Medicine. “The next big step in this new generation of implantable devices will be to find a way to move the power source onto them,” says John Rogers, PhD, Lee J. Flory founding chair in engineering innovation at the University of Illinois. “We’re still working on a solution to that problem.”
Source: ScienceBlog.com