Minimally Invasive Intraoperative Laser Vibrometry (MIVIB)—A Peroperative Method to Measure Fixation of the Ossicular Chain

Abstract

Background

Conductive hearing loss requires the surgeon to evaluate ossicular movement to plan and execute surgery. An objective assessment of the ossicular chain with laser vibrometry would likely improve the results of ossiculoplasty.

Methods

Minimally invasive intraoperative laser vibrometry (MIVIB), a fast and accurate technique, using a continuous time-domain signal that stimulates the Med-El FMT transducer attached to the malleus in a temporal bone model, was used to evaluate artificial fixation of the ossicular chain.

Results

Through this analysis method, differing incus velocity responses were seen between simulated single and multiple ossicle fixations in frequencies above 1000 Hz (</> −25 dB respectively). The incus–umbo velocity ratio was shown to detect stapes fixation in both multiple and single ossicle fixations (> −20 and > −10 dB, respectively) highlighting the importance of determining between single and multiple ossicle fixations first.

Conclusion

MIVIB provides an objective assessment of the ossicular chain to identify specific fixations and therefore assist the surgeon in improving surgical outcomes.