STEM II is the second half of our STEM I / Scientific and Technical Writing (STW) course here at Mass Academy. In this class, students are challenged to create a product, invention, or piece of technology which aims to fulfill the needs of someone in our communities. Through the assistive technology project, we are able to develop our technical engineering skills and learn how to work in structured teams which are composed of roles such as Chief Executive Officer (CEO), Chief Technical Officer (CTO), Chief Information Officer (CIO), and Chief Manufacturing Officer (CTO).

Problem Statement

The earmold manufacturing process is unnecessarily convoluted, lengthy, and expensive, which can be inconvenient for patients who use hearing aids. This issue is especially severe for pediatric patients, whose rapid development lead to frequent earmold refittings. A poorly-fit earmold can cause severe discomfort for the patient, hindering social and mental development in children.

Design Approach

To address the problem, our project proposes a process to enable fast and convenient fabrication of custom earmolds on the hospital site itself, allowing pediatric patients to receive new earmolds in a much more timely manner. This process involves taking a custom ear impression of the patient, scanning and processing this ear impression into a box cast designed for casting an earmold, 3D-printing the box cast, injecting the box cast with silicone, and finally fitting the patient with the produced earmold. To learn more about our design approach and process, take a look at our Design Study below.

Ariadne’s final product introduces a fabrication process for developing earmolds onsite within a hospital or medical facility. The process is as follows:

(1) Take an ear impression from the patient and let it cure.

(2) Scan the ear impression, post-process the scan with the digital scanner’s accompanying software, and export it as an STL.

(3) Import the ear impression scan and design the earmold box cast with Cyfex Secret Ear Designer and a mesh manipulation software such as Autodesk Fusion.

(3) Print the box cast with a 3D printer of any type.

(4) Put together the box cast, prepare the silicone for injection, and prepare the pressure pot.

(5) Inject the silicone into the box cast and let cure.

(6) Remove the earmold and test for patient comfort.

The Ariadne team pursued several design studies to evaluate the performance of each of our fabrication process designs. These design studies included an evaluation of the user-earmold compatibility as well as a space-time efficiency analysis for each proposed design. While our final design is less effective within the context of space-time efficiency, the earmolds generated using the silicone injection into a pressurized box mold were recorded as being most comfortable by the test patient. This final prototype can be easily implemented into hospitals and medical facilities. The process can be configured in a 90 sq. ft. space, the size of a typical treatment room, and takes about 5 hours and 40 minutes to fabricate each earmold. To implement the final prototype, it costs about $17,800, with remaining future costs being associating with license renewal and the cost of fabrication supplies. If you are interested in implementing this process or further learning about our design process, requirements, and more, visit this link.