STEM Two
This course, taught by Dr. Crowthers, is centered around scientific research and engineering principles. In STEM II, students form teams to create new products, focusing on assistive technology. They collaborate with clients, research patents, and develop prototypes. Their innovations are evaluated by experts, and the final products are provided to the clients. The course emphasizes effective communication in science and technology, covering purpose, clarity, organization, and audience engagement. Assignments include research papers, essays, reports, and presentations. Active participation is encouraged, with students refining their work for potential publication in digital and print media.
Problem Statement
Major problems arise when considering a fundamental part of the hearing aid: the earmold. The earmold is the part of a hearing aid that sits precisely within the ear canal and the surrounding outer structure, the concha. It channels amplified sound from the electronics via a tube into the eardrum (Clason, 2023). For this reason, it is crucial for earmolds to perfectly fit their users to permit the stable flow of sound and maximize comfort. Poor-fitting earmolds result from many factors, mainly growth and development. When a child outgrows the earmold, the amplified sound leaks out via a gap around it. When received by the hearing aid microphone, it is further amplified and sent back to the earmold, escaping from the gap again and causing feedback. This feedback generates a high-pitched and high-intensity noise (known as whistling, screeching, or howling), irritating the user (Bustamante et al., 1989). A poorly fitted earmold could also press against parts of the ear, causing sores. As a result, children are less likely to wear the hearing aid if the earmold does not fit. When children outgrow their earmolds, they need to get a replacement. This process, however, can be lengthy or unpredictable, leading to delays in procuring the necessary device for the child's optimal hearing (Anderson & Madell, 2014). This waiting time, along with the manufacturing expense, makes it challenging for families to promptly address the evolving needs of their child with hearing loss. The existing process for earmold manufacturing is unnecessarily convoluted and inadequate. The patient first visits the hospital, and an audiologist has to take an impression of the outer ear. Then, the impression must be shipped to an offshore manufacturing company, which uses it to create the correct earmold. The patient must wait weeks before revisiting the hospital to collect the newly manufactured earmold. In case of a misfit, the whole process must again be repeated, leading to another waiting period filled with discomfort and hindrance.
Design Approach
Our design approach focuses on developing an efficient, cost-effective, and space-saving earmold fabrication process that can be implemented onsite at hospitals. The process involves taking a patient's ear impression, scanning it, and using software to design and 3D print a box cast for silicone injection. This method ensures that the earmold is well-fitting, comfortable, and made from biocompatible materials. While the initial setup cost exceeds the target budget, the process eliminates the need for middlemen, reducing overall costs and lead times significantly compared to traditional methods. Future work will explore optimizing materials and printing strategies to further reduce costs and fabrication time, ensuring the system remains accessible and effective for hospital use.