1
|
Morse RP, Mitchell-Innes A, Prokopiou AN, Irving RM, Begg PA. Creation of an incus recess for a middle-ear microphone using a drill or laser ablation: a comparison of equivalent noise level and middle ear transfer function. Eur Arch Otorhinolaryngol 2023; 280:661-669. [PMID: 35834014 PMCID: PMC9849174 DOI: 10.1007/s00405-022-07532-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2022] [Accepted: 06/27/2022] [Indexed: 01/22/2023]
Abstract
PURPOSE Studies have assessed the trauma and change in hearing function from the use of otological drills on the ossicular chain, but not the effects of partial laser ablation of the incus. A study of the effectiveness of a novel middle-ear microphone for a cochlear implant, which required an incus recess for the microphone balltip, provided an opportunity to compare methods and inform a feasibility study of the microphone with patients. METHODS We used laser Doppler vibrometry with an insert earphone and probe microphone in 23 ears from 14 fresh-frozen cadavers to measure the equivalent noise level at the tympanic membrane that would have led to the same stapes velocity as the creation of the incus recess. RESULTS Drilling on the incus with a diamond burr created peak noise levels equivalent to 125.1-155.0 dB SPL at the tympanic membrane, whilst using the laser generated equivalent noise levels barely above the baseline level. The change in middle ear transfer function following drilling showed greater variability at high frequencies, but the change was not statistically significant in the three frequency bands tested. CONCLUSIONS Whilst drilling resulted in substantially higher equivalent noise, we considered that the recess created by laser ablation was more likely to lead to movement of the microphone balltip, and therefore decrease performance or result in malfunction over time. For patients with greatly reduced residual hearing, the greater consistency from drilling the incus recess may outweigh the potential benefits of hearing preservation with laser ablation.
Collapse
Affiliation(s)
- Robert P Morse
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK.
| | | | | | - Richard M Irving
- School of Engineering, University of Warwick, Coventry, CV4 7AL, UK.,Institute of Translational Medicine, Birmingham, B15 2TH, UK
| | - Philip A Begg
- Institute of Translational Medicine, Birmingham, B15 2TH, UK
| |
Collapse
|
2
|
Craddock LC, Hodson J, Gosling A, Cooper S, Morse RP, Begg P, Prokopiou A, Irving RM. Comparison of an Implantable Middle Ear Microphone and Conventional External Microphone for Cochlear Implants: A Clinical Feasibility Study. Otol Neurotol 2022; 43:1162-1169. [PMID: 36240742 PMCID: PMC7613807 DOI: 10.1097/mao.0000000000003713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES All commercially available cochlear implant (CI) systems use an external microphone and sound processor; however, external equipment carries lifestyle limitations. Although totally implantable devices using subcutaneous microphones have been developed, these are compromised by problems with soft tissue sound attenuation, feedback, and intrusive body noise. This in vivo pilot study evaluates a middle ear microphone (MEM) that aims to overcome these issues and compares hearing performance with that of an external CI microphone. DESIGN Six adult participants with an existing CI were implanted with a temporary MEM in the contralateral ear. Signals from the MEM were routed via a percutaneous plug and cable to the CI sound processor. Testing was performed in the CI microphone and MEM conditions using a range of audiometric assessments, which were repeated across four visits. RESULTS Performance of the MEM did not differ significantly from that of the CI on the assessments of Auditory Speech Sounds Evaluation loudness scaling at either 250 or 1000 Hz, or in the accuracy of repeating keywords presented at 70 dB. However, the MEM had significantly poorer aided sound-field thresholds, particularly at higher frequencies (≥4000 Hz), and significantly poorer performance on Arthur Boothroyd words presented at 55 dB, compared with the CI. CONCLUSION In this pilot study, the MEM showed comparable performance to that of an external CI microphone across some audiometric assessments. However, performance with the MEM was poorer than the CI in soft-level speech (55 dB) and at higher frequencies. As such, the benefits of MEM need to be considered against the compromises in hearing performance. However, with future development, MEM is a potentially promising technology.
Collapse
Affiliation(s)
| | - James Hodson
- University Hospitals Birmingham NHS Foundation Trust, UK
- Health Data Science Team, Research Development and Innovation, Institute for Translational Medicine, University Hospitals Birmingham NHS Foundation Trust
| | - Amy Gosling
- University Hospitals Birmingham NHS Foundation Trust, UK
| | - Stacey Cooper
- University Hospitals Birmingham NHS Foundation Trust, UK
| | | | - Philip Begg
- University Hospitals Birmingham NHS Foundation Trust, UK
- University of Kentucky, USA
| | | | | |
Collapse
|
3
|
Trudel M, Morris DP. The remaining obstacles for a totally implantable cochlear implant. Curr Opin Otolaryngol Head Neck Surg 2022; 30:298-302. [PMID: 36004785 DOI: 10.1097/MOO.0000000000000840] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
PURPOSE OF THE REVIEW For years, the development of a totally implantable cochlear implant (TICI) has faced several technical challenges hindering any prototypes from reaching full commercialization. This article aims to review the necessary specifications for a viable TICI. An overview of the remaining challenges when designing TICIs will be provided, focusing on energy supply and implantable microphones. RECENT FINDINGS The literature review highlights how research efforts to generate sufficient power to supply a fully implantable CI could take advantage of microelectromechanical systems (MEMS)-based energy harvesters incorporating piezoelectric materials. Using one of the various energy sources in the vicinity of the temporal bone would allow the development of a self-sufficient implant, overcoming the limitations of electrochemical batteries. Middle ear implantable microphones could also use similar fabrication techniques and transduction mechanisms to meet the sensor requirements for a TICI. SUMMARY Recent breakthroughs in power supply using MEMS-based energy harvesting technologies and piezoelectric implantable microphones may make TICIs become a more practical reality in the foreseeable future. Once available, TICIs will have major impact on our patients' quality of life and may help to make hearing rehabilitation a more appealing option to a greater proportion of those who fulfill our candidacy criteria.
Collapse
|
4
|
D'hondt C, Verhaert N, Wouters J. Directional Response of a subcutaneous hearing implant microphone. Hear Res 2021; 421:108412. [PMID: 34969577 DOI: 10.1016/j.heares.2021.108412] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/15/2021] [Revised: 10/26/2021] [Accepted: 12/06/2021] [Indexed: 11/04/2022]
Affiliation(s)
- Christiane D'hondt
- KU Leuven, University of Leuven, Department of Neurosciences, Research Group ExpORL, Onderwijs en Navorsing 2, Herestraat 49, bus 721, 3000, Leuven, Belgium; Cochlear Technology Centre Belgium, Schaliënhoevedreef 20i, 2800, Mechelen, Belgium.
| | - Nicolas Verhaert
- KU Leuven, University of Leuven, Department of Neurosciences, Research Group ExpORL, Onderwijs en Navorsing 2, Herestraat 49, bus 721, 3000, Leuven, Belgium; University Hospitals Leuven, Department of Otolaryngology, Head and Neck Surgery, Herestraat 49, 3000 Leuven, Belgium.
| | - Jan Wouters
- KU Leuven, University of Leuven, Department of Neurosciences, Research Group ExpORL, Onderwijs en Navorsing 2, Herestraat 49, bus 721, 3000, Leuven, Belgium.
| |
Collapse
|
5
|
Chung J, Jung Y, Hur S, Kim JH, Kim SJ, Kim WD, Choung YH, Oh SH. Development and Characterization of a Biomimetic Totally Implantable Artificial Basilar Membrane System. Front Bioeng Biotechnol 2021; 9:693849. [PMID: 34336805 PMCID: PMC8324085 DOI: 10.3389/fbioe.2021.693849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2021] [Accepted: 06/23/2021] [Indexed: 11/13/2022] Open
Abstract
Cochlear implants (CIs) have become the standard treatment for severe-to-profound sensorineural hearing loss. Conventional CIs have some challenges, such as the use of extracorporeal devices, and high power consumption for frequency analysis. To overcome these, artificial basilar membranes (ABMs) made of piezoelectric materials have been studied. This study aimed to verify the conceptual idea of a totally implantable ABM system. A prototype of the totally implantable system composed of the ABM developed in previous research, an electronic module (EM) for the amplification of electrical output from the ABM, and electrode was developed. We investigated the feasibility of the ABM system and obtained meaningful auditory brainstem responses of deafened guinea pigs by implanting the electrode of the ABM system. Also, an optimal method of coupling the ABM system to the human ossicle for transducing sound waves into electrical signals using the middle ear vibration was studied and the electrical signal output according to the sound stimuli was measured successfully. Although the overall power output from the ABM system is still less than the conventional CIs and further improvements to the ABM system are needed, we found a possibility of the developed ABM system as a totally implantable CIs in the future.
Collapse
Affiliation(s)
- Juyong Chung
- Department of Otolaryngology, Wonkwang University School of Medicine, Iksan, South Korea
| | - Youngdo Jung
- Department of Nature-Inspired System and Application, Korea Institute of Machinery and Materials, Daejeon, South Korea
| | - Shin Hur
- Department of Nature-Inspired System and Application, Korea Institute of Machinery and Materials, Daejeon, South Korea
| | - Jin Ho Kim
- Nano-Bioelectronics & Systems Laboratory, Department of Electrical and Computer Engineering, Seoul National University, Seoul, South Korea
| | - Sung June Kim
- Nano-Bioelectronics & Systems Laboratory, Department of Electrical and Computer Engineering, Seoul National University, Seoul, South Korea
| | - Wan Doo Kim
- Department of Nature-Inspired System and Application, Korea Institute of Machinery and Materials, Daejeon, South Korea
| | - Yun-Hoon Choung
- Department of Otolaryngology, Ajou University School of Medicine, Suwon, South Korea
| | - Seung-Ha Oh
- Department of Otorhinolaryngology, Sensory Organ Research Institute, Seoul National University Medical Research Center, Seoul National University College of Medicine, Seoul, South Korea
| |
Collapse
|
6
|
Calero D, Paul S, Gesing A, Alves F, Cordioli JA. A technical review and evaluation of implantable sensors for hearing devices. Biomed Eng Online 2018; 17:23. [PMID: 29433516 PMCID: PMC5810055 DOI: 10.1186/s12938-018-0454-z] [Citation(s) in RCA: 30] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 02/07/2018] [Indexed: 11/10/2022] Open
Abstract
Most commercially available cochlear implants and hearing aids use microphones as sensors for capturing the external sound field. These microphones are in general located in an external element, which is also responsible for processing the sound signal. However, the presence of the external element is the cause of several problems such as discomfort, impossibility of being used during physical activities and sleeping, and social stigma. These limitations have driven studies with the goal of developing totally implantable hearing devices, and the design of an implantable sensor has been one of the main challenges to be overcome. Different designs of implantable sensors can be found in the literature and in some commercial implantable hearing aids, including different transduction mechanisms (capacitive, piezoelectric, electromagnetic, etc), configurations microphones, accelerometers, force sensor, etc) and locations (subcutaneous or middle ear). In this work, a detailed technical review of such designs is presented and a general classification is proposed. The technical characteristics of each sensors are presented and discussed in view of the main requirements for an implantable sensor for hearing devices, including sensitivity, internal noise, frequency bandwidth and energy consumption. The feasibility of implantation of each sensor is also evaluated and compared.
Collapse
Affiliation(s)
- Diego Calero
- Laboratory of Vibration and Acoustics, Florianópolis, Brazil
| | - Stephan Paul
- Laboratory of Vibration and Acoustics, Florianópolis, Brazil
| | - André Gesing
- Laboratory of Vibration and Acoustics, Florianópolis, Brazil
| | | | | |
Collapse
|