Utilising pneumatically powered ‘air muscles’, different parts of the device bend and flex via remotely-controlled actuators that initiate the movement, mimicking the orientation of a heart's contracting muscle fibres. One part of the device takes care of the twist, and another, the squeeze. The device is tethered to an external pump, which uses air to power the soft actuators.
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.
“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 Roche, postdoctoral fellow at the National University of Ireland Galway, formerly of the School of Engineering and Applied Sciences (SEAS) at Harvard.
Heart failure affects 41million people worldwide. Currently, some of the options to treat it are mechanical pumps called ventricular assist devices (VADs), which pump blood from the ventricles into the aorta, and heart transplant. While VADs are continuously improving, patients are still at high risk for blood clots and stroke.
The researchers said the sleeve can be customised for each patient. For example, if a patient has more weakness on the left side of the heart the actuators can be tuned to give more assistance on that side. The pressure of the actuators can also increase or decrease over time, as the patient’s condition evolves.
The SEAS and Wyss engineers worked with surgeons at Boston Children’s Hospital to develop the device and determine the best ways to implant the device and test it on animal models.
More research needs to be done before the sleeve can be implanted in humans but the research is an important first step towards an implantable soft robot that can augment organ function.
“This research is really significant at the moment because more and more people are surviving heart attacks and ending up with heart failure,” said Roche. “Soft robotic devices are ideally suited to interact with soft tissue and give assistance that can help with augmentation of function, and potentially even healing and recovery.”