Electric heart sock: a new outfit for your heart

Instead of wearing your heart on your sleeve, why not try doing the reverse to find out what it’s telling you? A team led by Professor John Rogers at the University of Illinois at Urbana-Champaign in the US has designed an intelligent form-fitting electric heart sock that embraces the organ snugly and may one day replace pacemakers.

The team set out by embedding 68 sensors in a sheet of silicone that it placed around a 3D-printed replica of a rabbit’s heart. This customised membrane was then positioned on a real rabbit’s heart that was kept beating outside the animal’s body. That enabled them to test how much pressure might be placed on a living heart without hindering its heartbeat.

Wrapped around the heart, the sheath was able to detect physical properties, such as the temperature, electrical activity and pH levels, in different areas of the heart. It sensed changes in real-time as well when the researchers tweaked these properties. Overall, the information gathered by the sensors was comparable to data retrieved by other imaging methods.

New design boosts potential

Cardiac socks aren’t a new invention, but their crude design has hitherto limited their usefulness. In their paper published in Nature Communications journal in February this year, the researchers point out that traditional cardiac devices were “essentially 2D sheets” and thus unable to cover the organ’s surface area fully or “maintain reliable contact for chronic use without sutures or adhesives”.

The fact that the sock can now be contoured completely around beating, living tissue creates the potential for it to become an effective device that can be personalised to suit each patient’s heart problems. Electrodes can also be placed in specific areas of the sock to stimulate different parts of the heart as needed.

The team is also investigating how to dissolve both the sock and its electronics, in cases where the patient may no longer need the implant. But powering the electrodes independently is the first major hurdle to be overcome. One solution might be to place minute batteries in the device, or transmit power wirelessly from an external source.

The sock has also been tested on the heart of a deceased organ donor. Even if further development reveals little clinical use for the device, the sock could be a useful research tool, especially when vital data are needed. The team is already exploring ways to adapt its flexible system to other delicate organs, such as the brain.

Further links:
Rogers.matse.illinois.edu
Illinois.edu
Nature.com