EAR-risistible Advancement in 3D Printing

Monday, December 2, 2019
How much does it cost to make an ear?

Max Feinstein, a fourth-year medical student, has been spearheading a project at UCSF to make prosthetic ears at a fraction of the typical cost.

Using his research year off, he aims to figure out a way to cheaply create molds that can then be used to cast a patient’s prosthetic ear.

He’s now optimistic about presenting his prototypes to surgeons and finding trial patients.

“It’s been really great to see kids and parents excited about the idea,” he said.

Feinstein has been interested in social entrepreneurship for a long time. Before entering medical school, he helped create a program to offer photography classes at a foster home.

Now he is finding that there is room for this kind of initiative in medicine as well.

The idea for the ears came out of a need from another UCSF-based social entrepreneurship project, Loving Eyes Foundation.

Loving Eyes Foundation is a nonprofit which works to 3D print glasses frames for children with craniofacial anomalies who would otherwise not be afford custom eyeglasses that fit.

As Feinstein began working with Dr. Alejandra de Alba Campomanes and Dr. Frank Brodie of Loving Eyes, they became aware of another challenge — some of the children who needed glasses also had a condition called microtia, where their outer ear is not fully developed.

This meant that the glasses frames would have difficulty staying on without special devices or a prosthetic ear.

Feinstein said these children and their parents have two options currently. One is grafting from places like the ribs to create an ear from the patient’s own tissue, but that requires multiple surgeries and comes with risks of infection or tissue rejection.

Another option is a state-of-the-art prosthetic, which Feinstein admits can be extremely lifelike but is beyond the reach of some patients.

“Unlike with an eye prosthetic, which prevents shrinking of the eye orbit, insurance companies don’t consider these ears medically necessary,” Feinstein said.

This can make a prosthetic ear unaffordable, especially in younger children who are prone to losing them or outgrowing them.

Feinstein said he thinks this overlooks the ways a prosthetic ear might be important for body image or for something as simple as wearing glasses.

“A week later, I was in the Maker’s Lab and saw someone had 3D printed an earring shaped like an ear,” Feinstein said. “They just did it for fun, as a joke. But it seemed like a sign from the universe.”

Feinstein began to figure out how to make ears.

At first, it didn’t seem possible due to cost when a surgeon in the field said it would cost around $3,000.

With the help of Dylan Romero and Scott Drapeau at the Maker’s Lab, along with first year medical student Rex Lee, Feinstein began by printing plastic molds of an ear and filling the molds with silicone.

“When we started,” he said, “it was a little intimidating.”

The first ears took 30 minutes to extract from the mold without breaking, and had a seam line along the front.

Now, almost three months later, they are still working with with Dr. Alejandra de Alba Campomanes and Dr. Frank Brodie on improving the design and fabrication process.

Medical student Alyssa Nip has helped paint some of the ears to give them more lifelike shadows and blood vessels.

New rubber molds will be reusable and easy to use. The ears are affordable, around $20 for material costs.

An app can be used to create 3D reconstructions of an ear using only a smartphone’s infrared sensor. Then the reconstruction can be flipped in a mirror image for the other side.

Alternatively, preexisting CT or MRI scans can be repurposed for creating the molds.

Just last month, Feinstein and his hackathon team won first place in their category at the MIT x UCSF Grand Hack, hosted at Mission Hall by MIT Hacking Medicine and UCSF’s Rosenman Institute.

Feinstein is encouraged by the feedback he’s received — and there’s been another twist to working on the project.

“You start hearing ear puns everywhere,” he said. “EAR-relevant. EAR-risistible.