# Dynamic X-ray Microtomography vs. Laser-Doppler Vibrometry: A Comparative Study

## TL;DR

This study compares two techniques for analyzing the biomechanics of the human middle ear and finds that a new X-ray method is promising but needs refinement.

## Contribution

The study introduces dynamic synchrotron-based X-ray microtomography as a novel method for middle ear biomechanics.

## Key findings

- Displacement values from X-ray microtomography and LDV are consistent or within 5–10 dB differences.
- Both techniques show similar overall behavior in middle ear measurements.
- Standardization of acoustic stimulation and measurement points is needed for better comparison.

## Abstract

There are challenges in understanding the biomechanics of the human middle ear, and established methods for studying this system show significant limitations. In this study, we evaluate a novel dynamic imaging technique based on synchrotron X-ray microtomography designed to assess the biomechanical properties of the human middle ear by comparing it to laser-Doppler vibrometry (LDV).

We examined three fresh-frozen temporal bones (TB) using dynamic synchrotron-based X-ray microtomography for 256 Hz and 512 Hz, stimulated at 110 dB and 120 dB SPL. In addition, we performed measurements on these TBs using 1D LDV, a well-established method.

The normalized displacement values (μm/Pa) at the umbo and the posterior crus of the stapes are consistent or within 5–10 dB differences between all LDV and dynamic microtomography measurements and previously reported literature references. In general, the overall behavior is similar between the two measurement techniques.

In conclusion, our results demonstrate the suitability of dynamic synchrotron-based X-ray microtomography in studying the middle ear’s biomechanics. However, this study shows that better standardization regarding acoustic stimulation and measurement points is needed to better compare the two measurement techniques.