With over 200,000 medical devices being 3D Printed every day, the medical market is a strong driver in the 3D printing industry. But for implantable applications parts need to be very small and lightweight. Using a 3D Systems high resolution ProJet 3D Printer, Potomac Photonics in Baltimore, Maryland is able to create tiny parts which are especially beneficial in the medical device market. A new application is 3D Printing middle ear prosthesis for Otosclerosis disease.
We’ve all heard about the small bones of the inner ear, commonly called the anvil, stirrup, and hammer. Critical to hearing function is for these bones to vibrate when sound waves come in contact with their delicate mechanism. For people with Otosclerosis, the body’s normal lifelong regeneration of new bone is abnormally active in the area around the stapes or stirrup of the inner ear. With too much bone tissue, the stapes can no longer vibrate properly and hearing is lost.
According to the American Academy of Otolaryngology 10% of the world’s adult Caucasian population has Otosclerosis. In the US, NIH estimates there are over 3 million cases of the hearing disorder. No drugs are available, and hearing aids do not provide a solution. So, replacing the stapes is really the only option.
A researcher, Monika Kwacz, at the Institute of Micromechanics and Photonics at Warsaw Technical University in Poland whose own son has Otosclerosis, started to look at the possiblity of middle ear prosthesis with her team. Monika came to Potomac for prototyping the small device as she had read about their micro-fabrication work in medical devices. “Intuitively, it seemed to me that 3D Printing would be the best technology for first prototyping. We need the first prototypes to experimentally verify that the device geometry was well designed and we will be able to implant the device in a temporal bone. If the geometry is good, then we will check the mechanical operation of the device. However, if we find we do need to modify the device geometry, 3D Printing provides an easy way to modify in the CAD design step.”
Monika also elaborates that she had tried other 3D Printing processes, but the resolution was not sufficient to produce the intricate design of the stapes. The 3D Systems ProJet professional 3D Printer can put down layers as thin as 16 microns and so was an ideal machine for the job.
Once the design is finalized, Monika says they will need titanium parts for production. Mike Adelstein, Potomac President and CEO, explains that the 3D Systems printer portfolio includes metal 3D Printers but that they may need to integrate laser micromachining with the 3D Printing process. “There is a tiny hole in the stapes,” he says “that may be too small for any 3D Printer. With our UV laser micromachining processes we can make holes as small as 1 micron, so it is the perfect combination of technologies to get the best result for the customer’s project.”
Clearly 3D Printing may literally be music to the ears of hearing loss sufferers!