Preliminary human tympanic membrane thickness data from optical coherence tomography
Faculty of Sciences. Physics
Faculty of Medicine and Health Sciences
OPTICAL MEASUREMENT TECHNIQUES FOR STRUCTURES & SYSTEMS2 (OPTIMESS2012)
5th International Conference on Optical Measurement Techniques for, Structures and Systems2 (OPTIMESS), APR 04-05, 2012, Antwerp, BELGIUM
, p. 75-84
University of Antwerp
At the moment, tympanic membranes (or eardrums) used in Finite-Element Modeling (FEM) possess either a uniform thickness or an interpolation of a few crudely measured points as thickness distribution. To obtain realistic outcome of FEM simulations, the real (strongly varying) thickness distribution is required as input. We hypothesize that Optical coherence tomography (OCT) is a suitable technique for obtaining the full-field thickness distribution of the human eardrum in high-resolution and in situ. OCT measures the magnitude and echo time delay of backscattered light, very much like ultrasound imaging measures the backreflection of acoustic waves, to receive information about the sample microstructure. The axial resolution is largely determined by the bandwidth of the light source and fluctuates between 1 and 15 microns. No other non-invasive, non-destructive, non-contact imaging modality achieves the same resolution as OCT for the first several millimeters into the sample. We measured B-scan and C-scan OCT images of human and rabbit tympanic membranes to assess this technique's performance and feasibility. After recording stacks of C-scans from each quadrant of the tympanic membrane, stitching the image data together with FIJI, performing filtering, and finally after image segmentation with AMIRA, we obtain a preliminary volume model of the 3D shape and thickness variation of the eardrum. Conclusions are drawn from this feasibility study and a plan is formulated to optimize the final measurements in the near future.