OpenCochlea generates a 3D scala tympani model by combining a parameterised centerline and publicly available cross-sectional data. The generated models can be 3D printed as test-ready phantoms or as negative moulds for subsequent casting. They are designed to be used for research purposes only.
Cohen's two-tier approach, which combines logarithmic and exponential spirals, is used as the main mathematical model. By numerically solving for the centerline coefficients that define the spiral trajectory, a patient-specific scala tympani is generated. The A, B, and H values are defined according to the consensus cochlear coordinate system (CCS).
The currently implemented obround cross-sections are described in detail by Leon et al. and Clark et al. The circular cross-section model uses ST height data originally published by Wysocki.
The prismatic phantom is based on the generated ST geometry, with different access channels (round window, cochleostomy, and open round-window access) for electrode insertion. The locations of these openings are described by Leon et al. An optional fluidic channel with a 1.2 mm diameter can be added to the apical end of the ST.