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Sorg K, Stahn P, Pillong L, Hinsberger MP, Heimann L, Foth HJ, Schick B, Wenzel GI. First biocompatibility margins for optical stimulation at the eardrum via 532-nm laser pulses in a mouse model. J Biomed Opt 2019; 24:1-10. [PMID: 31436071 PMCID: PMC6983485 DOI: 10.1117/1.jbo.24.8.085003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/25/2019] [Accepted: 07/29/2019] [Indexed: 06/10/2023]
Abstract
Hearing impairment affects ∼460 million people worldwide. Conservative therapies, such as hearing aids, bone conduction systems, and middle ear implants, do not always sufficiently compensate for this deficit. The optical stimulation is currently under investigation as an alternative stimulation strategy for the activation of the hearing system. To assess the biocompatibility margins of this emerging technology, we established a method applicable in whole-mount preparations of murine tympanic membranes (TM). We irradiated the TM of anesthetized mice with 532-nm laser pulses at an average power of 50, 89, 99, and 125 mW at two different locations of the TM and monitored the hearing function with auditory brainstem responses. Laser-power-dependent negative side effects to the TM were observed at power levels exceeding 89 mW. Although we did not find any significant negative effects of optical stimulation on the hearing function in these mice, based on the histology results further studies are necessary for optimization of the used parameters.
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Affiliation(s)
- Katharina Sorg
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Patricia Stahn
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Lukas Pillong
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Marius P. Hinsberger
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Larissa Heimann
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Hans-Jochen Foth
- University of Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | - Bernhard Schick
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
| | - Gentiana I. Wenzel
- Saarland University, Department of Otolaryngology, Faculty of Medicine, Homburg, Germany
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Stahn P, Lim HH, Hinsberger MP, Sorg K, Pillong L, Kannengießer M, Schreiter C, Foth HJ, Langenbucher A, Schick B, Wenzel GI. Frequency-specific activation of the peripheral auditory system using optoacoustic laser stimulation. Sci Rep 2019; 9:4171. [PMID: 30862850 PMCID: PMC6414650 DOI: 10.1038/s41598-019-40860-8] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Accepted: 02/22/2019] [Indexed: 11/09/2022] Open
Abstract
Hearing impairment is one of the most common sensory deficits in humans. Hearing aids are helpful to patients but can have poor sound quality or transmission due to insufficient output or acoustic feedback, such as for high frequencies. Implantable devices partially overcome these issues but require surgery with limited locations for device attachment. Here, we investigate a new optoacoustic approach to vibrate the hearing organ with laser stimulation to improve frequency bandwidth, not requiring attachment to specific vibratory structures, and potentially reduce acoustic feedback. We developed a laser pulse modulation strategy and simulated its response at the umbo (1-10 kHz) based on a convolution-based model. We achieved frequency-specific activation in which non-contact laser stimulation of the umbo, as well as within the middle ear at the round window and otic capsule, induced precise shifts in the maximal vibratory response of the umbo and neural activation within the inferior colliculus of guinea pigs, corresponding to the targeted, modelled and then stimulated frequency. There was also no acoustic feedback detected from laser stimulation with our experimental setup. These findings open up the potential for using a convolution-based optoacoustic approach as a new type of laser hearing aid or middle ear implant.
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Affiliation(s)
- Patricia Stahn
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany.
| | - Hubert H Lim
- University of Minnesota, Department of Biomedical Engineering, Department of Otolaryngology, Minnesota, USA
| | - Marius P Hinsberger
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Katharina Sorg
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Lukas Pillong
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Marc Kannengießer
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
- Saarland University, Experimental Ophthalmology, Homburg, Germany
| | - Cathleen Schreiter
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Hans-Jochen Foth
- Technische Universität Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | | | - Bernhard Schick
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany
| | - Gentiana I Wenzel
- Saarland University, Faculty of Medicine, Department of Otolaryngology, Kirrbergerstr. 100, 66421, Homburg, Germany.
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