Custom, 3D-printed heart replicas look and pump just like the real thing

No two hearts beat alike. The size and shape of the the heart can vary from one person to the next. These differences can be particularly pronounced for people living with heart disease, as their hearts and major vessels work harder to overcome any compromised function.

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.”

MIT engineers are hoping to help doctors tailor treatments to patients’ specific heart form and function, with a custom robotic heart. The team 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 that patient’s blood-pumping ability.

The procedure involves first converting medical images of a patient’s heart into a three-dimensional computer model, which the researchers can then 3D print using a polymer-based ink. The result is a soft, flexible shell in the exact shape of the patient’s own heart. The team can also use this approach to print a patient’s aorta — the major artery that carries blood out of the heart to the rest of the body.

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. The underside of each sleeve resembles precisely patterned bubble wrap. 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, mimicking 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 — a condition in which the aortic valve narrows, causing the heart to work harder to force blood through the body.

Source: https://news.mit.edu/

VR Gives 3D Depiction Inside Blood Vessels

UW Medicine interventional radiologist Wayne Monsky first saw virtual reality’s vivid, 3D depiction of the inside of a phantom patient’s blood vessels, his jaw dropped in childlike wonder.

A virtual-reality depiction of a catheter navigating blood vessel. With a VR headset, this would be 3D (click on the image to enjoy video)

When you put the (VR) headset on … you have a giddy laugh that you can’t control – just sheer happiness and enthusiasm. (I’m) moving up to the mesenteric artery and I can’t believe what I’m seeing,” he recalled.

The experience reminds him of “Fantastic Voyage,” the ’60s-era sci-fi film about a submarine and crew that are miniaturized and injected into a scientist’s body to repair a blood clot.

As a child, and today, I’ve been amazed at the premise that one day you can swim around inside someone’s body. And really, that’s the sensation: You’re in it,” he said. Interventional radiologists use catheters, thin flexible tubes that are inserted into arteries and veins and steered to any organ in the body, guided by X-ray visuals. With this approach, they (and cardiologists, vascular surgeons, and neuro-interventionalists) treat an array of conditions: liver tumors, narrowed and bleeding arteries, uterine fibroids, and more.

Monsky and two collaborators have pioneered VR technology that puts the operator inside 3D blood vessels. By following an anatomically correct, dynamic, 3D map of a phantom patient’s vessels, Monsky navigates the catheter through junctions and angles. The catheter‘s tip is equipped with sensors that visually represent its exact location to the VR headset. It’s a sizable leap forward from the 2D, black-and-white X-ray perspective that has guided Monsky’s catheters through vessels for most of his career.

He recently presented study findings that underscore VR’s value: In tests of a phantom patient, VR guidance got him to the destination faster – about 40 seconds faster, on average, over 18 simulations – than was the case with X-ray guidance.

Source: https://newsroom.uw.edu/