The system uses patient scan data to recreate a model of the heart, and then prints them out with soft polymer materials. The team then can add a pumping feature to accurately replicate the pressure and movement of that specific heart.

This allows doctors to physically try out different replacement valves on the printed heart in order to see which treatments will respond best to a specific patient, all before needing to do any surgery.

https://news.mit.edu/2023/custom-3d-printed-heart-replicas-patient-specific-0222
https://www.youtube.com/watch?v=52qNGqBbTQA