Printing the Perfect Fit: Key to Hearing
A team of Maryland researchers have pioneered a technique using 3D printing to substitute damaged parts of the middle ear with artificial equivalents. It proved to have huge potential for treating hearing loss and other related hearing issues.
They are just the size of rice grains, three little bones (called ossicles) in the middle ear that conduct sounds from the ear drums. They enables one to hear outside sounds. When damaged, from physical trauma or bacterial infection, surgeons can replaced them with ceramic or metal. But they have to fit right for they can shift and cause further hearing damage. The shifting can happen during or after surgery or they can no longer conduct sound once scar tissue grows over them. Success rates are between 55 to 75%. Hence, failure rates are considerable.
From the University of Maryland School of Medicine in Baltimore, researchers were inspired to use 3D printing technology to replace damaged ossicles. If 3D printing can manufacture prostheses for different body parts, it might just do the same for parts as tiny as these middle ear bones.
So the team tested out the concept by working on cadavers. They removed the middle link of the ossicles which connect to one another like a chain. They CT scanned the cadavers, used a desktop 3D printer to create a simple strut out of resin to fit into the gap. They used four cadavers and managed to correctly fit each with its corresponding 3D printed ossicle. They turn out to be snaply fitted. This should be able to address one failure rate cause – incorrect sizing. The replacement must be custom-designed to fit.
One problem that can’t be addressed now is that during surgery, the bone’s anatomy and relationships change. If the hearing loss is caused by infection, surgeons have to clean out first, changing the anatomy between a preoperative CT scan and the operating room. To solve this, a scan and printer must be available in the operating room to create custom-fitted ear bones in the middle of surgery.
The printed material must also be biocompatible – must not be too elastic, spongy or heavy or it will affect sound transmission. The possibilities are promising though there are limitations now. With more research and improvements, higher rates of success can be achieved for surgical interventions in hearing loss treatment.
Imaging the Perfect Fit in Seattle
It all starts with the imaging data. Anything you want 3D-printed as a small part of a whole, putting accurate measurements into the data make that perfect fit. Done right at the start saves time here at Pro 3D Composites in Seattle.
