Harvard University: Soft robot helps the heart beat

Harvard University and Boston Children’s Hospital researchers have developed a customizable soft robot that fits around the heart and helps it beat, potentially opening new treatment options for people suffering from heart failure.

The soft robotic sleeve twists and compresses in synch with a beating heart, augmenting cardiovascular functions weakened by heart failure. Unlike currently available devices that assist heart function, Harvard’s soft robotic sleeve does not directly contact blood. This reduces the risk of clotting and eliminates the need for a patient to take potentially dangerous blood thinner medications. The device may one day be able to bridge a patient to transplant or help in cardiac rehabilitation and recovery.

“This research demonstrates that the growing field of soft robotics can be applied to clinical needs and potentially reduce the burden of heart disease and improve the quality of life for patients,” said Ellen T. Roche, the paper’s first author and a former Ph.D. student at the Harvard John A. Paulson School of Engineering and Applied Sciences (SEAS) and Wyss Institute of Biologically Inspired Engineering. Roche is currently a postdoctoral fellow at the National University of Ireland.

The research, published in Science Translational Medicine, was a collaboration between SEAS, the Wyss Institute, and Boston Children’s Hospital.

“This work represents an exciting proof-of-concept result for this soft robot, demonstrating that it can safely interact with soft tissue and lead to improvements in cardiac function. We envision many other future applications where such devices can delivery mechanotherapy both inside and outside of the body,” said Conor Walsh, senior author of the paper, John L. Loeb Associate Professor of Engineering and Applied Sciences at SEAS, and core faculty member at the Wyss Institute.

Heart failure affects 41 million people worldwide. Today, some of the treatment options are mechanical pumps called ventricular assist devices (VADs), which pump blood from the ventricles into the aorta, and heart transplants. While VADs are continuously improving, patients are still at high risk for blood clots and stroke.

To create an entirely new device that doesn’t come into contact with blood, Harvard researchers took inspiration from the heart itself. The thin silicone sleeve uses soft pneumatic actuators placed around the heart to mimic the outer muscle layers of the mammalian heart. The actuators twist and compress the sleeve in a motion similar to the beating heart.

The device is tethered to an external pump, which uses air to power the soft actuators.

The sleeve can be customized for each patient, said Roche. If a patient has more weakness on the left side of the heart, for example, the actuators can be tuned to give more assistance there. The pressure of the actuators can also increase or decrease over time, as the patient’s condition evolves.

The sleeve is attached to the heart using a combination of a suction device, sutures, and a gel interface to help with friction between the device and the