Acoustically functional 3D‑printed middle ear model for prosthesis development and otosurgical training.

Area of Science:

• Biomedical Engineering
• Otolaryngology
• Materials Science

Background:

• Cadaver temporal bones, traditionally used for otosurgical training, present significant limitations.
• Developing realistic artificial middle ear models is crucial for advancing individualized prostheses.
• The need exists for durable, anatomically, functionally, and acoustically accurate middle ear models.

Purpose of the Study:

• To create a 3D-printed middle ear model with acoustic and mechanical functionality.
• To overcome the limitations associated with cadaver temporal bones in otologic research.
• To facilitate the development and testing of novel middle ear prostheses.

Main Methods:

• Utilized micro-CT scans of cadaver temporal bones for model design.
• Employed Digital Light Processing (DLP) for printing rigid parts and silicone/glue for soft components.
• Assessed acoustic/mechanical performance via laser Doppler vibrometry (LDV) and tympanometry; evaluated surgical simulation with 16 otologists.

Main Results:

• 3D-printed models demonstrated statistically comparable middle ear transfer functions (METF) to cadaver bones.
• Model 1, using softer silicone, most closely replicated cadaver characteristics and produced normal tympanometry curves, though with limited reproducibility.
• Surgical simulation feedback indicated realistic anatomy but noted stapes motion as an area for improvement; the model and simulation were deemed promising for training.

Conclusions:

• 3D-printed middle ear models can achieve clinically acceptable accuracy in replicating anatomic and acoustic properties.
• Further material refinement for the tympanic membrane and ligaments is necessary to enhance tympanometry repeatability.
• The developed model is suitable for integrating into novel prosthesis design/testing and serves as a valuable otosurgical training tool.