scholarly journals Comparative study of efficiency and characteristics of FMT and DRT installed in human cadavers for round-window stimulation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Dong Ho Shin ◽  
Jong Hoon Kim ◽  
Peter Gottlieb ◽  
Yona Vaisbuch ◽  
Sunil Puria ◽  
...  

AbstractAcoustic hearing aids generate amplified sound in the ear canal, and they are the standard of care for patients with mild to moderate sensorineural hearing loss. However, because of their limited frequency bandwidth, gain, and feedback, there is substantial room for improvement. Active middle ear implants, which directly vibrate the middle ear and cochlea, are an alternative approach to conventional acoustic hearing aids. They provide an opportunity to improve sound quality and speech understanding with amplification rehabilitation. For floating-mass type and direct-rod type (DRT) middle ear transducers, a differential floating-mass transducer (DFMT) and a tri-coil bellows transducer (TCBT), respectively, were fabricated to measure the output characteristics in four human temporal bones. Both were fabricated to have similar output forces per unit input and were placed in four human temporal bones to measure their output performances. The TCBT resulted in higher output than did the DFMT throughout the audible frequency range, and the output was more prominent at lower frequency ranges. In this study, we showed that DRT was a more effective method for round window stimulation. Because of its frequency characteristics and vibration efficiency, this implantation method can be utilized as a driving solution for middle ear implants.

Sensors ◽  
2021 ◽  
Vol 21 (3) ◽  
pp. 946
Author(s):  
Dong Ho Shin

This report describes the design of a new piezoelectric transducer for round window (RW)-driven middle ear implants. The transducer consists of a piezoelectric element, gold-coated copper bellows, silicone elastomer (polydimethylsiloxane, PDMS), metal cylinder (tungsten), and titanium housing. The piezoelectric element is fixed to the titanium housing and mechanical resonance is generated by the interaction of the bellows, PDMS, and tungsten cylinder. The dimensions of PDMS and the tungsten cylinder with output characteristics suitable for compensation of sensorineural hearing loss were derived by mechanical vibrational analysis (equivalent mechanical model and finite element analysis (FEA)). Based on the results of FEA, the RW piezoelectric transducer was implemented, and bench tests were performed under no-load conditions to confirm the output characteristics. The transducer generates an average displacement of 219.6 nm in the flat band (0.1–1 kHz); the resonance frequency is 2.3 kHz. To evaluate the output characteristics, the response was compared to that of an earlier transducer. When driven by the same voltage (6 Vp), the flat band displacement averaged 30 nm larger than that of the other transducer, and no anti-resonance was noted. Therefore, we expect that the new transducer can serve as an output device for hearing aids, and that it will improve speech recognition and treat high-frequency sensorineural hearing loss more effectively.


2010 ◽  
Vol 124 (12) ◽  
pp. 1263-1267 ◽  
Author(s):  
G Peters ◽  
J Lin ◽  
M A Arriaga ◽  
D W Nuss ◽  
B Schaitkin ◽  
...  

AbstractObjective:This study aimed to assess the feasibility of using a 1.3 mm, semi-rigid, interventional salivary endoscope for middle-ear endoscopy, and as a trans-tympanic route for delivery of medication, in human cadaveric temporal bones.Study design:Human cadaveric study.Methods:Five temporal bones harvested from human cadavers were examined. A 1.3 mm, interventional sialendoscope was used to make endoscopy-assisted myringotomy incisions in the postero-inferior quadrant (n = 5) and the antero-inferior quadrant (n = 3).Results:Middle-ear examination was successful in all specimens (n = 5). Access to the round window niche and adequate visualisation of the round window were achieved in all five temporal bones (100 per cent). A guide wire could be navigated to the round window niche without difficulty. Other structures identified in all specimens included the incudostapedial joint, stapedius tendon, pyramidal eminence and facial nerve via an extended myringotomy incision. The anterior middle-ear space was also successfully examined through an endoscope-guided anterior myringotomy. The opening to the eustachian tube was visualised and cannulated with a guide wire in all preparations in which this was attempted (n = 3).Conclusions:The 1.3 mm, interventional sialendoscope allowed adequate visualisation of the eustachian tube, middle-ear space and round window niche, with interventional capabilities, in a cadaveric model. Our result validates the feasibility of its use for trans-tympanic drug delivery.


2016 ◽  
Vol 16 (04) ◽  
pp. 1650040 ◽  
Author(s):  
HOUGUANG LIU ◽  
SHIRONG GE ◽  
GANG CHENG ◽  
JIANHUA YANG ◽  
ZHUSHI RAO ◽  
...  

Several types of middle ear implants (MEIs) have been invented as an alternative to conventional hearing aids for the rehabilitation of sensorineural hearing loss. Temporal bone and clinical studies have shown that the implantation of MEIs’ transducers influences middle ear transfer function. But there is little comparative data available about these influences. We conducted comparative studies on the influences of three principal types of MEI transducers in respect to their attachment points on the ossicular chain. To aid the investigation, a human middle ear finite element model was constructed. The model was built based on a complete set of micro-computerized tomography section images of a human ear by reverse engineering technology. The validity of the developed model was verified by comparing the motions obtained by this model with published experimental measurements on human temporal bones. The results show that the eardrum driving transducer (EDT) and the floating mass transducer (FMT) decrease stapes displacement prominently at high frequencies. The greater these transducers’ mass, the smaller is the displacement of the stapes footplate. In contrast, the incus body driving transducer (IBDT) decreases stapes displacement severely at low frequencies, and its adverse effect on residual hearing increases with increasing stiffness of the IBDT’s driving rod.


2018 ◽  
Vol 97 ◽  
pp. 171-177 ◽  
Author(s):  
Kiwoong Seong ◽  
Kyuyup Lee ◽  
Sunil Puria ◽  
Jin-Ho Cho

2004 ◽  
Vol 15 (03) ◽  
pp. 249-257 ◽  
Author(s):  
Ad Snik ◽  
John Noten ◽  
Cor Cremers

We compared the output of two electronic middle ear implants: the Otologics MET™ device and the Vibrant Soundbridge™ device. Both devices were programmed in the linear amplification mode. Aided minus unaided sound pressure levels recorded in the ear canal (objective gain) were compared to unaided minus aided soundfield thresholds (functional gain) in 13 patients with severe sensorineural hearing loss. In addition, input/output characteristics were studied with the help of ear canal measurements. Objective gain was consistently lower than functional gain, with wide variation between patients and frequencies. Using input/output data measured in the ear canal in combination with functional gain data, the mean maximum output of the two devices was estimated, expressed in dB SPL. In comparison to NAL-R target values, (functional) gain was adequate; however, the maximum output was low, especially for the Vibrant Soundbridge device.


2020 ◽  
Vol 25 (3) ◽  
pp. 125-132
Author(s):  
Nina Wardenga ◽  
Victoria Diedrich ◽  
Bernd Waldmann ◽  
Thomas Lenarz ◽  
Hannes Maier

Objective: The purpose of the present study was to determine the fraction of patients with mixed hearing loss who can or cannot expect benefit from power hearing aids (HAs) after stapes surgery. Design: The audiological outcome of 374 stapes surgeries was used to calculate the patients’ individual postoperative requirements in terms of gain and output of HAs. These requirements were compared to the available gain and output provided by state-of-the-art power HAs at 0.5, 1.0, 2.0, and 4.0 kHz. According to these comparisons, ears were divided into three groups. For G0, required gain and output lay within the corresponding technical limits of the HAs at all frequencies. In G1, one or both requirements could not be fulfilled at 1 frequency. G2 combined all ears where the requirements lay beyond the HA’s technical limitations at 2 or more frequencies. Results: Stapes surgery resulted in an improvement of air-bone gap (ABG) in 84.5% of the cases by 15.7 dB on average. Based on pure-tone average (0.5, 1.0, 2.0, 4.0 kHz), 40.6% of all cases showed an ABG ≤10 dB. 44.9% of all cases did no longer need a HA after stapes surgery. A power HA would fulfill both audiological criteria at all 4 frequencies in 81.6% of cases that needed a HA postoperatively. However, 18.4% would not be sufficiently treatable at 1 or more frequencies (15.0% in G1, 3.4% in G2). Conclusions: The present study identified a subset of patients with mixed hearing loss after stapes surgery that cannot be treated sufficiently with available power HAs. As the residual ABG is an important reason for this lack of treatment success, the advancement of alternative hearing devices that circumvent the middle ear, such as powerful active middle ear implants, is indicated.


1983 ◽  
Vol 92 (2) ◽  
pp. 134-136 ◽  
Author(s):  
George Kelemen

The otologic literature contains no description of the histopathological features of temporal bones of persons who perished in drowning accidents. Three temporal bones from two fatal cases of drowning were studied in serial sections. Two temporal bones were from a man aged 31 years who collapsed after scuba diving and died three days later. One temporal bone was from a 32-year-old man, serving in the navy, who drove his car, probably accidentally, into the sea and drowned in it. Histopathological findings appeared to be similar in the two cases. Diffuse hemorrhage was evident throughout the middle ear and inner ear. The tympanic and round window membranes appeared to be intact although hemorrhage had occurred within the tissue layers of the membranes. This finding contrasts with observations of ruptured membranes by other investigators.


2014 ◽  
Vol 24 (6) ◽  
pp. 2503-2510
Author(s):  
Dong Ho Shin ◽  
Hyung-Gyu Lim ◽  
Eui Sung Jung ◽  
Qun Wei ◽  
Ki Woong Seong ◽  
...  

Author(s):  
Chan Il Song ◽  
Hyong-Ho Cho ◽  
Byung Yoon Choi ◽  
Jae Young Choi ◽  
Jin Woong Choi ◽  
...  

Objectives. To evaluate the user satisfaction, efficacy, and safety of round window (RW) vibroplasty using the Vibrant Soundbridge (VSB) in patients with persistent mixed hearing loss after mastoidectomy.Methods. The study included twenty-seven patients (mean age, 58.7 years; age range, 28–76 years; 11 men and 16 women) with mixed hearing loss after mastoidectomy surgery from 15 tertiary referral centers in Korea. The VSB was implanted at the RW. The Korean translation of the Abbreviated Profile of Hearing Aid Benefit (APHAB) questionnaire and the Korean version of the International Outcome Inventory for Hearing Aids (K-IOI-HA) questionnaire were used to evaluate user satisfaction as the primary outcome. Secondary outcome measures were audiological test results and complication rates.Results. The mean scores on the Ease of Communication (61.3%


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