Heart-hugging robot does the twist (and squeeze)

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A new squishy robot could keep hearts from skipping a beat.

A silicone sleeve slipped over pigs’ hearts helped pump blood when the hearts failed, researchers report January 18 in Science Translational Medicine. If the sleeve works in humans, it could potentially keep weak hearts pumping, and buy time for patients waiting for a transplant.

To make the device contract, biomedical engineer Ellen Roche and colleagues lined it with two sets of narrow tubes. One set encircles the sleeve, like bracelets; the other runs from top to bottom. When air pumps through the tubes, the sleeve compresses (like a clenched fist) and twists (like wrung-out laundry). Those actions mimic how the layers of the heart contract.

Researchers programmed the sleeve to sync with the heart’s motion. And like a healthy heart, the robot sleeve’s double squeeze gets blood moving.

Roche’s team, which did the work while she was at Harvard University, triggered heart failure in six pigs and then measured the volume of blood pumped by the heart with and without the sleeve’s help. Heart failure cut the volume roughly in half, to about 1 liter of blood per minute. But the sleeve restored the pumped volume to about 2½ liters per minute — just about normal, Roche, now at National University of Ireland, Galway, and colleagues report.