MIT
Engineers at the Massachusetts Institute of Technology (MIT) are hoping to help doctors tailor treatments to patients’ specific heart form and function with a custom robotic heart.
No two hearts beat alike. Size and shape of a heart can vary from one person to the next. The differences are particularly pronounced for those with heart disease.
The team at MIT has developed a procedure to 3D print a soft and flexible replica of a patient’s heart. They can then control the replica’s action to mimic the blood-pumping ability of the specific patient.
The process involves converting medical images of a patient’s heart into a 3D computer model, which the researchers then 3D print using a polymer-based ink. This results in a soft, flexible shell in the exact shape of the patient’s own heart. This approach can also be used to print a patient’s aorta, the major artery which carries blood out of the heart to the rest of the body.
In order to mimic the heart’s pumping action, the team has fabricated sleeves similar to blood pressure cuffs that wrap around a printed heart and aorta. When the sleeve is connected to a pneumatic system, researchers can tune the outflowing air to rhythmically inflate the sleeve’s bubbles and contract the heart to mimic its pumping action.
The researchers can also inflate a separate sleeve surrounding a printed aorta to constrict the vessel. This constriction, they say, can be tuned to mimic aortic stenosis, which is a condition in which the aortic valve narrows, causing the heart to work harder to force blood through the body.
Aortic stenosis is commonly treated by surgically implanting a synthetic valve designed to widen the aorta’s natural valve. The team says that in the future, doctors could potentially use the procedure to print a patient’s heart and aorta, then implant a variety of valves into the printed model to see which design results in the best function and fit for the patient.
MIT
Luca Rosalia, a student in the MIT-Harvard Program in Health Sciences and Technology, said: “All hearts are different. There are massive variations, especially when patients are sick. The advantage of our system is that we can recreate not just the form of a patient’s heart, but also its function in both physiology and disease.”
The researchers used medical scans of 15 patients diagnosed with aortic stenosis in their study. The team converted each patient’s images into a 3D computer model of the patient’s left ventricle (main pumping chamber of the heart) and aorta. The model was when fed into a 3D printer to generate a soft, anatomically accurate shell of both the ventricle and vessel.
The team says that each model heart could accurately recreate the same heart pumping pressures and flows that were previously measured in each patient. Mechanical Engineering Professor Ellen Roche said: “Being able to match the patient’s flows and pressures was very encouraging. We’re not only printing the heart’s anatomy, but also replicating its mechanics and physiology. That’s the part that we get excited about.”
Roche believes that the patient-specific replicas could help develop and identify ideal treatments for individuals with unique and challenging cardiac geometries.
The research as supported in part by the National Science Foundation, the National Institutes of Health, and the National Heart, Lung, and Blood Institute.
Read about other 3D printing developments at MIT here.
