3-D heart sock could replace pacemaker

Scientists have designed a 3-D silicone 'heart sock' that could eventually replace the pacemaker.
Hyun-Joong Chung, professor of chemical and mechanical engineering at the University of Alberta and John Rogers, professor of engineering and chemistry at the University of Illinois, said the stretchable silicone device can monitor vital signs and could help doctors pinpoint heart problems.
"My role specifically involved developing the first stretchable multiplexing chemical sensor, namely a pH sensor with multichannel mapping ability," said Chung.
"The pH sensor array was embedded in the heart sock format, enabling real-time observation of the heart's chemical activities," Chung said.
The researchers embedded 68 tiny sensors into a sheet of silicone that they fit around a 3-D printed replica of a rabbit heart. The circuits were laid out in a curved, S-shaped design that allows them to stretch and bend without breaking.

The heart sock physically resembles the shape of the pericardium, the naturally occurring membrane surrounding the heart.

The sensors in the soft, flexible membrane track vital signs such as temperature, mechanical strain and pH.
The device is designed to maintain a stable fit to the heart tissue, while exerting minimal force on the contracting and relaxing heart muscle.
The heart sock could be used to identify critical regions that indicate the origin of conditions such as arrhythmias, ischemia or heart failure-information that could guide therapeutic interventions.
The finished design will feature electrodes capable of regulating heartbeat, like a pacemaker, and it could counteract heart attacks.

The team is now looking at ways to dissolve the implant in the body once it is no longer needed and finding the optimal way to power the electrodes embedded in the device.
Chung noted that many of the key technologies from this research could also be adapted to industrial uses, such as wear-resistant coatings for drills.
"The next step will be to develop a novel processing pathway to fabricate non-conventional electronic devices," he said.
The research was detailed in two articles in Nature Communications and in Advanced Healthcare Materials.