Analysis of Vibrant Soundbridge Placement Against the Round Window Membrane in a Human Cadaveric Temporal Bone Model

Abstract

Optimal placement of the VSB against the round window relies heavily on surgical precision in placement. There is improved transmission of vibrations with either interposed fascia, or with a covering material.

Comparison of Alternative Coupling Methods of the Vibrant Soundbridge Floating Mass Transducer

“…The coupling efficiency to the RW is determined by good contact between the FMT and the RW niche. However, variability in size and angle of the RW niche [Pennings et al, 2010] and the skewness of the RW [Atturo et al, 2014] may influence the coupling efficiency and vibration transmission into the cochlea. The spherical RW coupler has been invented to overcome the size mismatch between the RW niche and the FM.…”

Controlled round-window stimulation in human temporal bones yielding reproducible and functionally relevant stapedial responses

“…Using as reference, the displacement amplitude of the FMT for the standard-coupling situation (0.32 mm, with all measurements in response to 0.1-V rms drive voltage), the RW-induced stapes displacement relative to FMT displacement was 0.0175 (À35 dB) for direct coupling and 0.056 (À25 dB) for coupling underlaid with subcutaneous tissue, respectively. In Pennings et al (2010), velocity amplitude at the stapes for 1-V rms drive voltage and 1 kHz was À103 dB re. 1 m/s for direct coupling and À92 dB re.…”

“…However, using information published elsewhere, we estimate from the work of Arnold et al (2010), Pennings et al (2010), and that of Tringali et al (2010) a displacement ratio of stapes vibration relative to the vibration of the stimulating actuators at the RW of 0.0021e0.0125 (À38 dB to À54 dB). 1,2 In-vivo stimulation at the RW has presented a similarly confounding picture.…”

Vibrant Soundbridge Rehabilitation of Conductive and Mixed Hearing Loss

“…The RW coupler helps to overcome the diameter mismatch of the FMT (1.6 mm), unprepared RW niche (1.3-1.6 mm), and RW membrane (0.8-1.75 mm). 21,22 Besides optimizing the contact between FMT and RW, the RW coupler minimizes surgical risks, because the bony lip of the RW must not be maximally drilled away (bony rim flush to the membrane). To stabilize the position of FMT and titanium coupler assembly to the membrane, cartilage chips in conjunction with fibrin glue are placed around and below the FMT, resulting in a cylindrical encasement of the assembly, which vibrates like a piston toward the membrane.…”