Fixing a person's broken heart thanks to a 3D-printed replica of their real one

Sometimes you can't mend a broken heart and just need to replace parts of it. However, the size and shape of peoples' hearts can vary quite a bit, making it difficult to use off-the-shelf artificial valves and other implants. Now though, MIT researchers can use a medical scan of a patient's heart to create a digital model that's then 3D printed out of soft plastic that "can squeeze and stretch, similarly to a real beating heart." Physicians could then use the 3D model to test various repairs before doing any surgery. From MIT News:

"All hearts are different," says Luca Rosalia, a graduate student in the MIT-Harvard Program in Health Sciences and Technology. "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 team used an actuated printed heart to compare implants of different sizes, to see which would result in the best fit and flow — something they envision clinicians could potentially do for their patients in the future.

"Patients would get their imaging done, which they do anyway, and we would use that to make this system, ideally within the day," says co-author [Christopher] Nguyen. "Once it's up and running, clinicians could test different valve types and sizes and see which works best, then use that to implant."

Ultimately, [mechanical engineering professor Ellen] Roche says the patient-specific replicas could help develop and identify ideal treatments for individuals with unique and challenging cardiac geometries.