1
|
Polspoel S, Moore DR, Swanepoel DW, Kramer SE, Smits C. Sensitivity of the antiphasic digits-in-noise test to simulated unilateral and bilateral conductive hearing loss. Int J Audiol 2023; 62:1022-1030. [PMID: 36121040 DOI: 10.1080/14992027.2022.2119611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2022] [Accepted: 08/28/2022] [Indexed: 11/05/2022]
Abstract
OBJECTIVES The objective of this study is (1) to assess whether the presentation level of the antiphasic digits-in-noise (DIN) test affects the speech recognition threshold (SRT), (2) to evaluate how accurately simulated unilateral and bilateral conductive hearing loss is detected (CHL) and (3) to determine whether increasing the presentation level normalises the antiphasic DIN SRT. DESIGN Participants performed antiphasic and diotic DINs at different presentation levels with unilateral, bilateral or no earplugs. STUDY SAMPLE Twenty-four and twelve normal hearing adults. RESULTS Without earplugs, antiphasic DIN SRTs did not differ between 60 and 80 dB SPL. At 60 dB SPL, the antiphasic DIN correctly classified 92% of the unilateral earplug cases; the diotic DIN 25%. The binaural intelligibility level difference did not differ between the no-earplug condition and the condition with bilateral earplugs when the presentation was increased with the attenuation level. CONCLUSIONS In normal hearing participants, diotic and antiphasic DIN SRTs are independent of presentation level above a minimum level of 60 dB SPL. The antiphasic DIN is more sensitive than the diotic DIN for detecting unilateral CHL; not for bilateral CHL. The effect of CHL on DIN SRTs can be largely compensated by increasing the presentation level. Audibility plays an important role in the antiphasic and diotic DIN.
Collapse
Affiliation(s)
- Sigrid Polspoel
- Otolaryngology-Head and Neck Surgery, Section Ear and Hearing, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, De Boelelaan, The Netherlands
- Amsterdam Public Health Research Institute, Quality of Care, Amsterdam, The Netherlands
| | - David R Moore
- Communication Sciences Research Center, Cincinnati Childrens' Hospital Medical Center and University of Cincinnati, Cincinnati, OH, USA
- Manchester Centre for Audiology and Deafness, University of Manchester, Manchester, UK
| | - De Wet Swanepoel
- Ear Sciences Centre, School of Surgery, University of Western Australia, Perth, WA, Australia
- Department of Speech-Language Pathology and Audiology, University of Pretoria, Pretoria, South Africa
| | - Sophia E Kramer
- Otolaryngology-Head and Neck Surgery, Section Ear and Hearing, Amsterdam UMC location Vrije Universiteit Amsterdam, Amsterdam, De Boelelaan, The Netherlands
- Amsterdam Public Health Research Institute, Quality of Care, Amsterdam, The Netherlands
| | - Cas Smits
- Amsterdam Public Health Research Institute, Quality of Care, Amsterdam, The Netherlands
- Amsterdam UMC location University of Amsterdam, Otolaryngology-Head and Neck Surgery, Ear and Hearing, Meibergdreef, Amsterdam, The Netherlands
| |
Collapse
|
2
|
Tollin DJ, Koka K, Peacock J. Using Stapes Velocity to Estimate the Efficacy of Mechanical Stimulation of the Round Window With an Active Middle Ear Implant. Otol Neurotol 2023; 44:e311-e318. [PMID: 36962010 PMCID: PMC10175173 DOI: 10.1097/mao.0000000000003859] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/26/2023]
Abstract
OBJECTIVE To test a method to measure the efficacy of active middle ear implants when coupled to the round window. METHODS Data previously published in Koka et al. ( Hear Res 2010;263:128-137) were used in this study. Simultaneous measurements of cochlear microphonics (CM) and stapes velocity in response to both acoustic stimulation (forward direction) and round window (RW) stimulation (reverse direction) with an active middle ear implant (AMEI) were made in seven ears in five chinchillas. For each stimulus frequency, the amplitude of the CM was measured separately as a function of intensity (dB SPL or dB mV). Equivalent vibrational input to the cochlea was determined by equating the acoustic and AMEI-generated CM amplitudes for a given intensity. In the condition of equivalent CM amplitude between acoustic and RW stimulation-generated output, we assume that the same vibrational input to the cochlea was present regardless of the route of stimulation. RESULTS The measured stapes velocities for equivalent CM output from the two types of input were not significantly different for low and medium frequencies (0.25-4 kHz); however, the velocities for AMEI-RW drive were significantly lower for higher frequencies (4-14 kHz). Thus, for RM stimulation with an AMEI, stapes velocities can underestimate the mechanical input to the cochlea by ~20 dB for frequencies greater than ~4 kHz. CONCLUSIONS This study confirms that stapes velocity (with the assumption of equivalent stapes velocity for forward and reverse stimulation) cannot be used as a proxy for effective input to the cochlea when it is stimulated in the reverse direction. Future research on application of intraoperative electrophysiological measurements during surgery (CM, compound action potential, or auditory brainstem response) for estimating efficacy and optimizing device coupling and performance is warranted.
Collapse
Affiliation(s)
- Daniel J. Tollin
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045
- Department of Otolaryngology, University of Colorado School of Medicine, Aurora, CO 80045
| | - Kanthaiah Koka
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045
| | - John Peacock
- Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO 80045
| |
Collapse
|
3
|
Jenkins HA, Greene N, Tollin DJ. Round Window Stimulation of the Cochlea. Front Neurol 2022; 12:777010. [PMID: 34970211 PMCID: PMC8712317 DOI: 10.3389/fneur.2021.777010] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2021] [Accepted: 11/11/2021] [Indexed: 11/14/2022] Open
Abstract
Mixed hearing loss associated with a sensorineural component and an impaired conductive mechanism for sound from the external ear canal to the cochlea represents a challenge for rehabilitation using either surgery or traditional hearing amplification. Direct stimulations of the ossicular chain and the round window (RW) membrane have allowed an improved hearing in this population. The authors review the developments in basic and clinical research that have allowed the exploration of new routes for inner ear stimulation. Similar changes occur in the electrophysiological measures in response to auditory stimulation through the traditional route and direct mechanical stimulation of the RW. The latter has proven to be very effective as a means of hearing rehabilitation in a group of patients with significant difficulties with hearing and communication.
Collapse
Affiliation(s)
- Herman A Jenkins
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine, Aurora, CO, United States
| | - Nathaniel Greene
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine, Aurora, CO, United States
| | - Daniel J Tollin
- Department of Otolaryngology-Head and Neck Surgery, University of Colorado School of Medicine, Aurora, CO, United States.,Department of Physiology and Biophysics, University of Colorado School of Medicine, Aurora, CO, United States
| |
Collapse
|
4
|
Trevino M, Lobarinas E, Maulden AC, Heinz MG. The chinchilla animal model for hearing science and noise-induced hearing loss. THE JOURNAL OF THE ACOUSTICAL SOCIETY OF AMERICA 2019; 146:3710. [PMID: 31795699 PMCID: PMC6881193 DOI: 10.1121/1.5132950] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2019] [Revised: 09/19/2019] [Accepted: 09/24/2019] [Indexed: 05/07/2023]
Abstract
The chinchilla animal model for noise-induced hearing loss has an extensive history spanning more than 50 years. Many behavioral, anatomical, and physiological characteristics of the chinchilla make it a valuable animal model for hearing science. These include similarities with human hearing frequency and intensity sensitivity, the ability to be trained behaviorally with acoustic stimuli relevant to human hearing, a docile nature that allows many physiological measures to be made in an awake state, physiological robustness that allows for data to be collected from all levels of the auditory system, and the ability to model various types of conductive and sensorineural hearing losses that mimic pathologies observed in humans. Given these attributes, chinchillas have been used repeatedly to study anatomical, physiological, and behavioral effects of continuous and impulse noise exposures that produce either temporary or permanent threshold shifts. Based on the mechanistic insights from noise-exposure studies, chinchillas have also been used in pre-clinical drug studies for the prevention and rescue of noise-induced hearing loss. This review paper highlights the role of the chinchilla model in hearing science, its important contributions, and its advantages and limitations.
Collapse
Affiliation(s)
- Monica Trevino
- School of Behavioral and Brain Sciences, Callier Center, The University of Texas at Dallas, 1966 Inwood Road, Dallas, Texas 75235, USA
| | - Edward Lobarinas
- School of Behavioral and Brain Sciences, Callier Center, The University of Texas at Dallas, 1966 Inwood Road, Dallas, Texas 75235, USA
| | - Amanda C Maulden
- Department of Speech, Language, and Hearing Sciences, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA
| | - Michael G Heinz
- Weldon School of Biomedical Engineering, Purdue University, 715 Clinic Drive, West Lafayette, Indiana 47907, USA
| |
Collapse
|
5
|
Müller C, Zahnert T, Ossmann S, Neudert M, Bornitz M. Vibroplasty combined with tympanic membrane reconstruction in middle ear ventilation disorders. Hear Res 2019; 378:166-175. [PMID: 30878272 DOI: 10.1016/j.heares.2019.02.012] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 02/19/2019] [Accepted: 02/22/2019] [Indexed: 10/27/2022]
Abstract
Although the Vibrant Soundbridge is one of the most frequently used active middle ear implants, data regarding how middle ear ventilation disorders may affect the transmission behavior of its floating mass transducer are still insufficient. Studies involving coupling the floating mass transducer to the stapes head are particularly lacking. This temporal bone study evaluated the influence of simulated middle ear ventilation disorders on the middle ear transfer function in the reconstructed middle ear. The middle ear transfer function was measured using Laser Doppler Vibrometry after vibroplasty onto the stapes head, with or without tympanic membrane reconstruction. Middle ear ventilation disorders were simulated through changes in static pressure via the external ear channel with a maximum pressure of +3 kPa. Slice thickness of tympanic membrane reconstruction material was measured using micro-CT. When the reconstructed ossicular chain and the reconstructed tympanic membrane were mechanically excited by the floating mass transducer under conditions of ambient static pressure, the transmission behavior was found to be independent of the type of tissue used. Increase in static pressure up to +3 kPa caused maximum low frequency transmission loss of 15 dB when elastic grafts were used and 5 dB when stiff tissue was inserted. At high frequencies, measured loss of up to 5 dB was relatively independent of the tissue stiffness. Increase in static pressure led to displacement of the tissues towards the vestibulum and caused stiffening, especially of the annular ligament. Stiffening-induced transmission losses were mainly found at low frequencies and could not be compensated by the floating mass transducer in this range. Above 1300 Hz, the continuous force spectrum of the actuator sufficiently protected against loss of amplitude. To minimize postoperative transmission loss due to persisting ventilation disorders, choosing a very stiff tympanic membrane reconstruction material seems to be appropriate.
Collapse
Affiliation(s)
- Christoph Müller
- Technische Universitaet Dresden, Faculty of Medicine Carl Gustav Carus, Department of Otorhinolaryngology, Ear Research Center, Dresden, Germany.
| | - Thomas Zahnert
- Technische Universitaet Dresden, Faculty of Medicine Carl Gustav Carus, Department of Otorhinolaryngology, Ear Research Center, Dresden, Germany
| | - Steffen Ossmann
- Technische Universitaet Dresden, Faculty of Medicine Carl Gustav Carus, Department of Otorhinolaryngology, Ear Research Center, Dresden, Germany
| | - Marcus Neudert
- Technische Universitaet Dresden, Faculty of Medicine Carl Gustav Carus, Department of Otorhinolaryngology, Ear Research Center, Dresden, Germany
| | - Matthias Bornitz
- Technische Universitaet Dresden, Faculty of Medicine Carl Gustav Carus, Department of Otorhinolaryngology, Ear Research Center, Dresden, Germany
| |
Collapse
|
6
|
Moncrieff D, Keith W, Abramson M, Swann A. Evidence of binaural integration benefits following ARIA training for children and adolescents diagnosed with amblyaudia. Int J Audiol 2017; 56:580-588. [DOI: 10.1080/14992027.2017.1303199] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Affiliation(s)
- Deborah Moncrieff
- Department of Communication Science and Disorders, School of Health and Rehabilitation Sciences, University of Pittsburgh, Pittsburgh, PA, USA,
| | | | - Maria Abramson
- Hear Now/Abramson Audiology, Laguna Niguel, CA, USA, and
| | - Alicia Swann
- Auditory Processing Center, LLC, Clinton, MS, USA
| |
Collapse
|
7
|
Evaluation of Round Window Stimulation Performance in Otosclerosis Using Finite Element Modeling. COMPUTATIONAL AND MATHEMATICAL METHODS IN MEDICINE 2016; 2016:3603207. [PMID: 27034709 PMCID: PMC4789402 DOI: 10.1155/2016/3603207] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/30/2015] [Revised: 01/17/2016] [Accepted: 01/27/2016] [Indexed: 11/17/2022]
Abstract
Round window (RW) stimulation is a new type of middle ear implant's application for treating patients with middle ear disease, such as otosclerosis. However, clinical outcomes show a substantial degree of variability. One source of variability is the variation in the material properties of the ear components caused by the disease. To investigate the influence of the otosclerosis on the performance of the RW stimulation, a human ear finite element model including middle ear and cochlea was established based on a set of microcomputerized tomography section images of a human temporal bone. Three characteristic changes of the otosclerosis in the auditory system were simulated in the FE model: stapedial annular ligament stiffness enlargement, stapedial abnormal bone growth, and partial fixation of the malleus. The FE model was verified by comparing the model-predicted results with published experimental measurements. The equivalent sound pressure (ESP) of RW stimulation was calculated via comparing the differential intracochlear pressure produced by the RW stimulation and the normal eardrum sound stimulation. The results show that the increase of stapedial annular ligament and partial fixation of the malleus decreases RW stimulation's ESP prominently at lower frequencies. In contrast, the stapedial abnormal bone growth deteriorates RW stimulation's ESP severely at higher frequencies.
Collapse
|
8
|
Roh KJ, Lee EJ, Choi BI, Son EJ. A Case of Incus Vibroplasty: Postoperative Changes in Residual Hearing. J Audiol Otol 2015; 19:54-7. [PMID: 26185793 PMCID: PMC4491948 DOI: 10.7874/jao.2015.19.1.54] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2014] [Revised: 11/01/2014] [Accepted: 11/23/2014] [Indexed: 11/22/2022] Open
Abstract
In patients with mild to severe hearing loss, conventional hearing aids offer limited benefits and several problems with feedback and cosmesis. Middle ear implants are a feasible option for patients with moderate to severe hearing loss who are unable to achieve adequate benefit from or cannot tolerate hearing aids for various reasons. Here we present a case of middle ear implant surgery using Vibrant Soundbridge with incus vibroplasty technique, and describe the hearing changes during postoperative follow-up.
Collapse
Affiliation(s)
- Kyung Jin Roh
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Jung Lee
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Byung Il Choi
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| | - Eun Jin Son
- Department of Otorhinolaryngology, Yonsei University College of Medicine, Seoul, Korea
| |
Collapse
|
9
|
Grossöhmichen M, Salcher R, Kreipe HH, Lenarz T, Maier H. The Codacs™ direct acoustic cochlear implant actuator: exploring alternative stimulation sites and their stimulation efficiency. PLoS One 2015; 10:e0119601. [PMID: 25785860 PMCID: PMC4364953 DOI: 10.1371/journal.pone.0119601] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Accepted: 01/14/2015] [Indexed: 11/19/2022] Open
Abstract
This work assesses the efficiency of the Codacs system actuator (Cochlear Ltd., Sydney Australia) in different inner ear stimulation modalities. Originally the actuator was intended for direct perilymph stimulation after stapedotomy using a piston prosthesis. A possible alternative application is the stimulation of middle ear structures or the round window (RW). Here the perilymph stimulation with a K-piston through a stapes footplate (SFP) fenestration (N = 10) as well as stimulation of the stapes head (SH) with a Bell prosthesis (N = 9), SFP stimulation with an Omega/Aerial prosthesis (N = 8) and reverse RW stimulation (N = 10) were performed in cadaveric human temporal bones (TBs). Codacs actuator output is expressed as equivalent sound pressure level (eq. SPL) using RW and SFP displacement responses, measured by Laser Doppler velocimetry as reference. The axial actuator coupling force in stimulation of stapes and RW was adjusted to ~ 5 mN. The Bell prosthesis and Omega/Aerial prosthesis stimulation generated similar mean eq. SPLs (Bell: 127.5–141.8 eq. dB SPL; Omega/Aerial: 123.6–143.9 eq. dB SPL), being significantly more efficient than K-piston perilymph stimulation (108.6–131.6 eq. dB SPL) and RW stimulation (108.3–128.2 eq. dB SPL). Our results demonstrate that SH, SFP and RW are adequate alternative stimulation sites for the Codacs actuator using coupling prostheses and an axial coupling force of ~ 5 mN. Based on the eq. SPLs, all investigated methods were adequate for in vivo hearing aid applications, provided that experimental conditions including constant coupling force will be implemented.
Collapse
Affiliation(s)
- Martin Grossöhmichen
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover, Germany
| | - Rolf Salcher
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover, Germany
| | | | - Thomas Lenarz
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover, Germany
| | - Hannes Maier
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover, Germany
- * E-mail:
| |
Collapse
|
10
|
Vibromechanical assessment of active middle ear implant stimulation in simulated middle ear effusion: a temporal bone study. Otol Neurotol 2014; 35:470-5. [PMID: 23988990 DOI: 10.1097/mao.0b013e318299aa37] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
HYPOTHESIS Active middle ear implant (AMEI) generated vibromechanical stimulation of the ossicular chain (ossicular chain vibroplasty [OCV]) or the round window (round window vibroplasty [RWV]) is not significantly affected by simulated middle ear effusion in a human temporal bone model. BACKGROUND OCV and RWV may be employed for sensorineural, mixed, and conductive hearing losses. Although middle ear effusions may be encountered across patient populations, little is known about how effusions may affect AMEI vibromechanical efficiency. METHODS Laser Doppler vibrometry of stapes velocities (SVs) were performed in a human temporal bone model of simulated effusion (N = 5). Baseline measurements to acoustic sinusoidal stimuli, OCV, and RWV (0.25-8 kHz) were made without effusion. The measurements were repeated with simulated middle ear effusion and compared with baseline measurements. Data were analyzed across 3 frequency bands: low (0.25-1 kHz), medium (1-3 kHz), and high (3-8 kHz). RESULTS Acoustic stimulation with simulated middle ear effusion resulted in a significant (p < 0.001) frequency-dependent attenuation of SVs of 4, 10, and 7 dB (low, medium, and high ranges, respectively). OCV in simulated effusion resulted in attenuated SVs of 1, 5, and 14 dB (low, medium, and high) compared to without effusion; however, this attenuation was not significant (p = 0.07). Interestingly, in the setting of RWV, simulated effusion resulted in significantly (p = 0.001) increased SVs of 16, 11, and 8 dB (low, medium, and high). A 3-dB variance in AMEI efficiency was observed in repeated measurements in a single temporal bone. CONCLUSION The efficiency of OCV was not significantly affected by the presence of a middle ear effusion. Improved efficiency, however, was observed with RWV.
Collapse
|
11
|
Abstract
This article describes outcomes for the Otologics active middle ear implant for the semi-implantable and fully implantable (Carina, Otologics LLC, Boulder, CO) devices. Inclusion and exclusion criteria are reported in detail for surgical and audiologic management. Results from the clinical trial demonstrated no change for unaided air and bone conduction thresholds and no significant change in monosyllabic word scores or sentences in noise. Experiments are reported for conductive and mixed types of hearing losses in animal and human cadaveric models. These devices are in their infancy, and further study is needed to better identify candidates and develop appropriate expectations.
Collapse
|
12
|
Salcher R, Schwab B, Lenarz T, Maier H. Round window stimulation with the floating mass transducer at constant pretension. Hear Res 2014; 314:1-9. [DOI: 10.1016/j.heares.2014.04.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2013] [Revised: 03/24/2014] [Accepted: 04/01/2014] [Indexed: 10/25/2022]
|
13
|
Kaltenbacher D, Schächtele J, Goll E, Burkhardt C, Arnold H, Dalhoff E, Zenner HP. Design study of a miniaturized displacement transducer (MDT) for an active middle ear implant system. Biomed Microdevices 2014; 16:805-14. [PMID: 25034230 DOI: 10.1007/s10544-014-9884-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
People suffering from moderate to severe hearing loss can be treated with active middle ear implants. A new approach in this field is to implant an electromechanical transducer onto the round window membrane in order to improve coupling and be able to treat patients with middle-ear problems. In this paper the design study for a miniaturized displacement transducer (MDT) for the round window is presented. Based on a requirement analysis, the basic principle and analytical modeling of the actuator is shown. A parameter variation study results in an optimized actuator configuration that is able to generate an amplification of 110 dB SPL theoretically. As a next step this actuator has to be manufactured and tested.
Collapse
Affiliation(s)
- D Kaltenbacher
- Fraunhofer Institute for Manufacturing Engineering and Automation IPA, Nobelstr. 12, 70569, Stuttgart, Germany,
| | | | | | | | | | | | | |
Collapse
|
14
|
Lee J, Seong K, Lee SH, Lee KY, Cho JH. Comparison of auditory responses determined by acoustic stimulation and by mechanical round window stimulation at equivalent stapes velocities. Hear Res 2014; 314:65-71. [PMID: 24768763 DOI: 10.1016/j.heares.2014.04.003] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 04/10/2014] [Accepted: 04/15/2014] [Indexed: 10/25/2022]
Abstract
Active middle ear implants (AMEIs) have been studied to overcome the limitations of conventional hearing aids such as howling, occlusion, and social discrimination. AMEIs usually drive the oval window (OW) by means of transmitting vibrational force through the ossicles and the vibrational force corresponding to sound is generated from a mechanical actuator. Recently, round window (RW) stimulation using an AMEI such as a floating mass transducer (FMT) to deliver sound to the cochlea has been introduced and hearing improvement in clinical use has been reported. Although previous studies demonstrated that the auditory response to RW stimulation was comparable to a sound-evoked auditory response, few studies have investigated the quantification of the physiologic performance of an AMEI through RW stimulation on the inner ear in vivo. There is no established relationship between the cochlear responses and mechanical stimulation to RW. The aim of this study is to assess the physiologic response in RW stimulation by an AMEI. The transferred energy through the RW to the inner ear could estimate the response corresponding to acoustic stimulation in order to quantify the AMEI output in the ossicular chain or OW stimulation. The parameters of the auditory brainstem responses (ABRs) were measured and compared based on stapes velocities similar enough to be regarded as the same for acoustic stimulation to the external auditory canal (EAC) and mechanical stimulation to the RW in an in vivo system. In conclusion, this study showed that the amplitudes and latencies of the ABRs of acoustic and RW stimulation showed significant differences at comparable stapes velocities in an in vivo system. These differences in the ABR amplitudes and latencies reflect different output functions of the cochlea in response to different stimulation pathways. Therefore, it is necessary to develop a new method for quantifying the output of the cochlea in the case of RW stimulation.
Collapse
Affiliation(s)
- JangWoo Lee
- Graduate School of Electrical Engineering and Computer Science, Kyungpook National University, Daegu, South Korea
| | - KiWoong Seong
- Department of Biomedical Engineering, Kyungpook National University Hospital, Daegu, South Korea
| | - Sang-Heun Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, Daegu, South Korea
| | - Kyu-Yup Lee
- Department of Otorhinolaryngology-Head and Neck Surgery, School of Medicine, Kyungpook National University, Daegu, South Korea.
| | - Jin-Ho Cho
- School of Electronics Engineering, College of IT Engineering, Kyungpook National University, Daegu, South Korea.
| |
Collapse
|
15
|
Microanatomic Analysis of the Round Window Membrane by White Light Interferometry and Microcomputed Tomography for Mechanical Amplification. Otol Neurotol 2014; 35:672-8. [DOI: 10.1097/mao.0000000000000193] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
|
16
|
Bergin M, Vlajkovic S, Bird P, Thorne P. Systematic review of animal models of middle ear surgery. World J Otorhinolaryngol 2013; 3:71-88. [DOI: 10.5319/wjo.v3.i3.71] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2013] [Revised: 08/09/2013] [Accepted: 08/20/2013] [Indexed: 02/06/2023] Open
Abstract
Animal models of middle ear surgery help us to explore disease processes and intervention outcomes in a manner not possible in patients. This review begins with an overview of animal models of middle ear surgery which outlines the advantages and limitations of such models. Procedures of interest include myringoplasty/tympanoplasty, mastoidectomy, ossiculoplasty, stapedectomy, and active middle ear implants. The most important issue is how well the model reflects the human response to surgery. Primates are most similar to humans with respect to anatomy; however, such studies are uncommon now due to expense and ethical issues. Conversely, small animals are easily obtained and housed, but experimental findings may not accurately represent what happens in humans. We then present a systematic review of animal models of middle ear surgery. Particular attention is paid to any distinctive anatomical features of the middle ear, the method of accessing the middle ear and the chosen outcomes. These outcomes are classified as either physiological in live animals, (e.g., behavioural or electrophysiological responses), or anatomical in cadaveric animals, (e.g., light or electron microscopy). Evoked physiological measures are limited by the disruption of the evoking air-conducted sound across the manipulated middle ear. The eleven identified species suitable as animal models are mouse, rat, gerbil, chinchilla, guinea pig, rabbit, cat, dog, sheep, pig and primate. Advantages and disadvantages of each species as a middle ear surgical model are outlined, and a suggested framework to aid in choosing a particular model is presented.
Collapse
|
17
|
Maier H, Salcher R, Schwab B, Lenarz T. The effect of static force on round window stimulation with the direct acoustic cochlea stimulator. Hear Res 2012; 301:115-24. [PMID: 23276731 DOI: 10.1016/j.heares.2012.12.010] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/11/2012] [Revised: 11/29/2012] [Accepted: 12/16/2012] [Indexed: 11/30/2022]
Abstract
The Direct Acoustic Cochlea Stimulator Partial Implant (DACS PI, Phonak Acoustic Implants SA, Switzerland) is intended to stimulate the cochlea by a conventional stapedotomy piston that is crimped onto the DACS PI artificial incus. An alternative approach to the round window (RW) is successfully done with other devices, having the advantage of being also independent of the existence of middle ear structure (e.g. ossicles). Here the possibility of stimulating the RW with the DACS actuator is investigated including the impact of static force on sound transmission to the cochlea. The maximum equivalent sound pressure output with RW stimulation was determined experimentally in fresh human temporal bones. Experiments were performed in analogy to the ASTM standard (F2504.24930-1) method for the output determination of implantable middle ear hearing devices (IMEHDs) in human cadaveric temporal bones (TBs). ASTM compliant temporal bones were stimulated with a prosthesis having a spherical tip (∅0.5 mm) attached to the actuator. The stimulation was performed perpendicular to the round window membrane (RWM) at varying position relative to the RW and the resulting static force on the RW membrane was determined. At each position the displacement output of the DACS PI actuator and the stapes footplate (SFP) vibration in response to actuator stimulation was measured with a Laser Doppler Velocimeter (LDV). By comparison of the achieved output at the stapes footplate in response to sound and transducer stimulation the equivalent sound pressure level at the tympanic membrane at 1Vrms input voltage was calculated assuming that the SFP displacement in both conditions is a measure of perceived loudness, as it is done in the ASTM standard. Ten TB preparations within the acceptance range of the ASTM standard were used for analysis. The actuator driven stapes footplate displacement amplitude as well as the resulting equivalent sound pressure level was highly dependent on the static force applied to the RW. The sound transfer efficiency from the RW to the stapes footplate increased monotonically with increasing static load. At a moderate static force load (approx. 3.9 mN) the obtained average sound equivalent sound pressure level was 102-120 eq. dB SPL @ nominally 1Vrms input for frequencies ≤4 kHz. At higher frequencies (6-10 kHz) the achieved output dropped to ∼90 dB SPL. This output was obtained at loading conditions compatible with the actuator safe operating range, although it was possible to increase the output further by increasing the static force load. Our results demonstrate for a first time that static force applied to the RW is crucial for sound transmission efficiency. Further we could show that RW stimulation with the DACS PI actuator is possible having a maximum output that is sufficient to treat moderate and pronounced sensorineural hearing losses (SNHL). This article is part of a Special Issue entitled "MEMRO 2012".
Collapse
Affiliation(s)
- Hannes Maier
- Institute of Audioneurotechnology (VIANNA), Department of Experimental Otology, ENT-Clinics, Medical University Hannover, Hannover, Germany.
| | | | | | | |
Collapse
|
18
|
Concept and evaluation of an endaurally insertable middle-ear implant. Med Eng Phys 2012; 35:532-6. [PMID: 22998896 DOI: 10.1016/j.medengphy.2012.08.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2011] [Revised: 07/27/2012] [Accepted: 08/09/2012] [Indexed: 11/21/2022]
Abstract
A concept for a partially implantable hearing device, for which the power supply and signal transmission are provided by an optical transmission path, is evaluated. The actuator is designed to fit into the round-window niche and to couple directly to the round-window membrane. Implantable hearing aids can be a suitable solution in the case of severe hearing loss, where conventional hearing aids often fail. However, the surgical effort for an implantation is comparatively high. Therefore, the objective of our work was to provide a hearing system which combines reliable coupling to the auditory system with an easy implantation technique. The actuator was designed as a piezoelectric thin-film cantilever. The optical transmission path was realised using an infrared light-emitting diode combined with an active receiver circuit. For a voltage of 1V, the unloaded actuator presents displacement amplitudes of 1μm up to a stimulus frequency of 25kHz and forces up to 0.2mN. Proportionally larger forces can be achieved by stacking single actuators. The overall transmission loss from the electrical input of the light-emitting diode driver to the mechanical output of the unloaded actuator was less than 25dB at 1kHz and maximum output.
Collapse
|