The soft robotic sleeve twists and compresses in sync with a beating heart, augmenting cardiovascular functions weakened by heart failure.
Unlike currently available devices that assist heart function, the soft robotic sleeve developed at Harvard University in the US 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 to aid 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, former PhD student at Harvard University.
“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,” said Roche, currently a postdoctoral fellow at the National University of Ireland.
“We envision many other future applications where such devices can delivery mechanotherapy both inside and outside of the body,” said Conor Walsh, professor at Harvard.
Heart failure affects 41 million people worldwide. Today, 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.
To create a device that does not come into contact with blood, 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 similar motion to the beating heart.
The device is tethered to an external pump, which uses air to power the soft actuators.
The sleeve can be customised 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 on that side.
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 heart.