Researchers at Harvard University and Boston Children's Hospital have developed a robotic sleeve that fits around a heart and helps it beat with a twisting embrace. The device could one day keep people with heart failure alive while they're waiting for a transplant or aid in recovery.The silicone sleeve, which they're calling a "customizable soft robot," twists and compresses from the bottom up, just like a beating heart does, assisting the normal functions that are weakened during heart failure. It's pretty soothing to watch.The current option for augmented beating is a ventricular assist device (VAD), a mechanical pump that's implanted in the heart. VADs come with a risk of clotting so patients usually need to take blood thinners as long as they have the device to reduce their risk of stroke. And VADs also don't mimic the twisting squeeze of our hearts.This robot sleeve simply envelops the heart without coming into contact with blood, so there's no increased clot risk and no need for blood thinners (which can be dangerous). It can be customized for each patient by giving more assistance on one side of the heart, for instance, and the pressure can be increased or decreased over time depending on their needs.Researchers tested the sleeve in pigs but they need to do more studies before they can try it out in humans. Harvard's Office of Technology Development has already filed a patent application.