A New, Promising Experimental Ossicular Prosthesis: A Human Temporal Bone Study With Laser Doppler Vibrometry

Abstract

Objective: We compared the sound transmission using different types of total ossicular replacement prostheses (TORP); we then studied the performance of a new TORP that we designed inspired by the columella, the single ossicle found in birds. Methods: Stapedial vibrations were measured on nine freshly frozen human temporal bones with laser Doppler vibrometry. We then compared the performances of eight common TORP positions or designs as well as the new silver prototype of bird-type prosthesis, designed also according to our digital holography patterns of the human tympanic membrane (TM). Results: The TORPs placed in lateral contact with both the TM and the malleus handle outperformed, at most frequencies, those placed only in contact with the TM. The new bird-type prosthesis performed equally well or better than all other prostheses. Conclusion: If the malleus handle can be retained when placing a TORP, the best sound transmission can be achieved by placing the TORP in contact with both the distal part of the malleus handle and the TM. The good performance of our bird-type prosthesis suggests that there is still room for future improvement of prosthesis design to further optimize hearing outcomes after surgery.

A comparison of sound transmission of middle ear prostheses manufactured via SLM

“…The results show a similar trend between the ossicles, confirming the reliability of the simulated test measurement. It also shows that the effect of weight seems to be a non-factor to the sound response of the ossicle prostheses similar to the result in (8). The stapes velocity vibration as measured by laser doppler vibrometry at different frequencies is shown in figure 6.…”

“…A silver (Ag) additively manufactured prosthesis ossicle that was readily available was also tested. Silver prostheses have been used in literature to study middle ear sound transmission as in the study by Ronnblom et al [8]. Both prosthetics are shown in figure 1.…”

Design and optimization of auditory prostheses using the finite element method: a narrative review

“…For inner ear prostheses, many parameters need to be optimized, such as the electrode length, electrodeposition, and coding strategy of CI (18)(19)(20). Numerous designs and evaluation methods have been developed to optimize auditory prostheses, such as experiments on human temporal bones of cadavers (21)(22)(23), animals (24,25), and clinical volunteers (26). Animal and cadaveric experiments have determined parameters that influence hearing performance.…”

Handheld laser-fiber vibrometry probe for assessing auditory ossicles displacement

“…Laser-Doppler vibrometry (LDV) is widely used in the assessment of auditory ossicles displacement. The method has been used in fundamental research on middle ear mechanics, 1 – 6 optimization of surgical procedures 2 , 7 – 15 such as intraoperative qualification for implantable middle ear hearing devices, 2 , 16 , 17 and intraoperative evaluation of hearing improvement during ossiculoplasty. 18 – 26 Vibrometric studies have also been conducted for potential applications in the clinical diagnosis of hearing loss.…”

“…In cadaver studies, the approach is extended by removing the canal and opening the facial recess, 7 , 8 , 11 , 31 , 32 which cannot be done in vivo due to facial nerve palsy. In vivo measurement must be carried out on the posterior crus of the stapes 1 , 3 , 15 , 17 , 24 , 31 or prosthesis in the case of crus damage. 19 – 22 The transcanal approach consisting in elevation of the tympanic membrane is possible for vibrometry measurement using an alternative electromagnetic stimulation by means of a coil placed on the manubrium of the malleus.…”