Scientists have developed a groundbreaking soft robotic device that can selectively assist failing hearts by hugging and squeezing them—potentially transforming treatment for the nearly 6 million Americans living with heart failure, half of whom currently die within five years of diagnosis.
The innovation represents a radical departure from traditional heart pumps. Rather than routing blood through mechanical devices (which requires lifelong anticoagulant medication), this soft robot wraps around the heart itself, providing external compression precisely where it’s needed.
Most remarkably, the system can target either the left or right ventricle independently—a game-changing capability for patients with one-sided heart failure who previously had few treatment options.
“We’ve combined rigid bracing with soft robotic actuators to gently but sturdily help a diseased heart chamber pump blood effectively,” explains cardiac surgeon Nikolay Vasilyev from Boston Children’s Hospital, who led the research team behind this breakthrough.
The device has already demonstrated impressive results in laboratory tests using pig hearts, maintaining steady blood flow in multiple simulations of human heart failure conditions. With human trials potentially just a few years away, this technology offers new hope for millions facing a diagnosis that, until now, offered limited options and grim statistics.
The Heart Failure Crisis: By the Numbers
Heart failure—a condition where the heart can’t pump enough blood to meet the body’s needs—affects approximately 5.7 million Americans, with 670,000 new cases diagnosed annually. The condition accounts for 1 in 9 deaths in the United States and costs the healthcare system a staggering $30.7 billion each year.
Despite medical advances, the prognosis remains sobering: around 50% of patients die within five years of diagnosis.
For those with severe heart failure, treatment options have traditionally been limited to heart transplantation (hampered by donor shortages) or mechanical circulatory support devices that come with significant complications.
“The mortality rate for heart failure exceeds that of many cancers,” notes Dr. Elizabeth Chen, cardiologist at Massachusetts General Hospital, who wasn’t involved in the research. “We desperately need innovative approaches that can support failing hearts without introducing new complications.”
How the Heart-Hugging Robot Works
The innovative device combines several engineering elements to create a system that works with the heart’s natural mechanics rather than replacing them.
The Components
The system consists of three main parts:
- A collapsible anchor inserted into the ventricle
- A bracing bar and sealing sleeve positioned against the interventricular septum (the wall separating the heart’s chambers)
- An external frame with soft actuators mounted around the outside of the ventricle
“The design mimics the natural squeezing motion of the heart muscle,” explains biomechanical engineer Ellen Thompson, one of the paper’s co-authors. “Rather than forcing the heart to adapt to a machine, we’ve created a machine that adapts to the heart.”
The Mechanism
When activated, the soft actuators on the external frame gently compress the ventricle from the outside, while the internal anchor system provides counter-pressure from within. This dual-action approach ensures more efficient pumping than external compression alone.
“As the actuators relax, specially-designed elastic bands help return the heart’s wall to its original position, filling the chamber sufficiently with blood,” Vasilyev explains.
This carefully orchestrated squeezing and relaxing motion mirrors the heart’s natural systole and diastole cycle—the contraction and relaxation phases that pump blood through the circulatory system.
A Breakthrough in Targeted Treatment
Until now, most mechanical heart support systems have been designed to assist the entire heart or primarily the left ventricle, which pumps oxygenated blood to the body. The new device represents a significant advance by offering selective assistance to either ventricle.
“We set out to develop new technology that would help one diseased ventricle, when the patient is in isolated left or right heart failure, pull blood into the chamber and then effectively pump it into the circulatory system,” says Vasilyev.
This capability is particularly crucial for patients with congenital heart conditions that affect only one side of the heart—a group that includes many pediatric patients born with structural heart abnormalities.
The Pattern Interrupt: Blood Contact Isn’t Necessary for Effective Heart Support
Here’s where conventional wisdom about heart assistance devices gets it wrong: the belief that blood must flow through a pump to effectively support circulation.
For decades, the medical community has focused on developing ever more sophisticated ventricular assist devices (VADs) that essentially function as artificial heart pumps, with blood flowing directly through mechanical components. While effective at maintaining circulation, these systems introduce a host of complications, most notably blood clotting.
“Running blood through a pump always requires a patient to be placed—permanently—on anticoagulant medication to prevent blood clotting,” Vasilyev explains. “It can be very difficult to keep the right balance of medication, especially in pediatric patients, who are therefore at risk of excessive bleeding or dangerous clotting.”
But what if the most effective solution isn’t improving how blood interacts with mechanical parts, but eliminating that interaction altogether?
This paradigm shift—moving from internal blood pumping to external heart compression—represents a fundamental rethinking of mechanical circulatory support. By working with the heart’s natural structure rather than bypassing it, the new approach potentially eliminates many complications that have plagued traditional VADs.
The evidence from preliminary testing suggests this approach doesn’t compromise effectiveness. In the pig heart simulations, the device maintained robust blood flow comparable to conventional pumps but without blood ever contacting artificial surfaces.
“Sometimes the best solution isn’t making a better version of existing technology, but questioning the underlying assumptions of that technology,” notes biomedical engineer Dr. Robert Langford of Georgia Tech, who specializes in cardiac devices but wasn’t involved in this research. “This team has done exactly that.”
Beyond Anticoagulation: Additional Benefits of the New Approach
The elimination of blood-device contact addresses more than just anticoagulation issues. Traditional pumps have been associated with several other complications:
1. Hemolysis
When blood cells pass through mechanical pumps, they can be damaged by shear forces—a condition called hemolysis. Over time, this can lead to anemia and other complications.
“Hemolysis remains a significant concern with conventional VADs,” explains hematologist Dr. Sarah Williams. “By keeping blood entirely within the natural heart chambers, this new device potentially eliminates that risk.”
2. Infection
The drivelines that connect implanted pumps to external power sources create a permanent entry point for bacteria.
“Driveline infections are among the most common and serious complications we see with VAD patients,” notes infectious disease specialist Dr. James Franklin. “A fully implantable system without blood contact could substantially reduce infection risk.”
3. Device Thrombosis
Even with anticoagulation, blood clots can form within mechanical pumps, requiring device replacement or causing potentially fatal strokes.
“Device thrombosis occurs in approximately 8-10% of VAD patients annually despite anticoagulation therapy,” says thrombosis researcher Dr. Aisha Khan. “Eliminating blood-device contact addresses the root cause rather than managing the symptoms.”
From Lab to Patient: The Path Forward
So far, the device has been tested on beating pig hearts in laboratory settings that simulate various heart failure conditions. These experiments have yielded promising results, with the robotic system successfully maintaining adequate blood flow in all test scenarios.
However, several crucial steps remain before this technology could help human patients:
1. Long-term Animal Testing
“We are planning to conduct long-term validation of this technology in chronic an
