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Pillong L, Stahn P, Hinsberger M, Sorg K, Schick B, Wenzel GI. Cytotoxicity studies of an optoacoustic stimulation strategy for the development of laser-based hearing aids. J Biomed Opt 2020; 25:1-15. [PMID: 32578405 PMCID: PMC7310877 DOI: 10.1117/1.jbo.25.6.068002] [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] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/14/2020] [Accepted: 06/05/2020] [Indexed: 06/11/2023]
Abstract
SIGNIFICANCE Worldwide, ∼460 million people suffer from disabling hearing impairment. Many of these patients are still not sufficiently supplied with currently available auditory technologies. Optical stimulation of the hearing organ offers a promising alternative for a new generation of auditory prostheses. AIM To assess the biocompatibility margins of our laser pulse amplitude strategy in vitro, we designed a protocol and present the effects on normal human dermal fibroblasts, human chondrocytes, and human osteoblasts. APPROACH Laser pulses of 532 nm were applied over 120 s using our laser pulse amplitude modulation strategy. We then assessed cell viability and cytotoxicity through fluorescence staining and quantitative polymerase chain reaction-analysis regarding 84 key player-genes for cytotoxicity and stress response. RESULTS The first in vitro biocompatibility margins for our stimulation parameters applied to cells of the peripheral hearing organ were between 200 and 223 mW (3348 J/cm2). After irradiation with a subphototoxic laser power of 199 mW (2988 J/cm2), only the fibroblasts showed a significant upregulation of GADD45G. CONCLUSION Further studies are underway to optimize parameters for the optoacoustic stimulation of the auditory system. Our protocol and results on laser-tissue interactions can be useful for translational laser applications in various other irradiated biological tissues.
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Affiliation(s)
- Lukas Pillong
- Saarland University, Department of Otorhinolaryngology, Faculty of Medicine, Homburg, Germany
| | - Patricia Stahn
- Saarland University, Department of Otorhinolaryngology, Faculty of Medicine, Homburg, Germany
| | - Marius Hinsberger
- Saarland University, Department of Otorhinolaryngology, Faculty of Medicine, Homburg, Germany
| | - Katharina Sorg
- Saarland University, Department of Otorhinolaryngology, Faculty of Medicine, Homburg, Germany
| | - Bernhard Schick
- Saarland University, Department of Otorhinolaryngology, Faculty of Medicine, Homburg, Germany
| | - Gentiana I. Wenzel
- Saarland University, Department of Otorhinolaryngology, Faculty of Medicine, Homburg, Germany
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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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Schacht SAL, Stahn P, Hinsberger M, Schick B, Wenzel GI. Laser-induced tissue remodeling within the tympanic membrane. J Biomed Opt 2018; 23:1-8. [PMID: 30499262 DOI: 10.1117/1.jbo.23.12.121614] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Accepted: 10/19/2018] [Indexed: 06/09/2023]
Abstract
The tympanic membrane (TM) separates the outer ear from the tympanic cavity. Repeated pathologies can permanently decrease its tension, inducing conductive hearing loss and adhesive processes up to cholesteatoma. The current main therapy is its surgical reconstruction. Even though lasers have been proposed to tighten atrophic TMs, details of this effect, specifically histological analyses, are missing. We therefore used laser pulses to induce TM collagen remodeling in an animal model to compare the histological and electrophysiological effects of different applied laser intensities before entering clinical studies. We irradiated Fuchsin-stained areas of the TM in anesthetized mice with 532-nm laser-pulses of 10 mW for 30 s (0.3 J), 25 mW for 30 s (0.75 J) or 50 mW for 30 s (1.5 J) monitoring hearing with auditory brainstem responses (ABRs). The mice were sacrificed after 2 to 8 weeks and histologically analyzed. An increase in the TM thickness within the defined, stained, and irradiated areas could be observed after 4 weeks. Polarized light microscopy and transmission electron microscopy demonstrated the tissue volume increase majorly due to new collagen-fibrils. Directly after irradiation, ABR thresholds did not increase. We herein demonstrate a controlled laser-induced collagen remodeling within defined areas of the TM. This method might be the prophylactic solution for chronic inflammatory ear pathologies related to decreased TM tension.
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Affiliation(s)
- Sophie A L Schacht
- University of Saarland, Department of Otorhinolaryngology, Homburg, Germany
| | - Patricia Stahn
- University of Saarland, Department of Otorhinolaryngology, Homburg, Germany
| | - Marius Hinsberger
- University of Saarland, Department of Otorhinolaryngology, Homburg, Germany
| | - Bernhard Schick
- University of Saarland, Department of Otorhinolaryngology, Homburg, Germany
| | - Gentiana I Wenzel
- University of Saarland, Department of Otorhinolaryngology, Homburg, Germany
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Adler HJ, Anbuhl KL, Atcherson SR, Barlow N, Brennan MA, Brigande JV, Buran BN, Fraenzer JT, Gale JE, Gallun FJ, Gluck SD, Goldsworthy RL, Heng J, Hight AE, Huyck JJ, Jacobson BD, Karasawa T, Kovačić D, Lim SR, Malone AK, Nolan LS, Pisano DV, Rao VRM, Raphael RM, Ratnanather JT, Reiss LAJ, Ruffin CV, Schwalje AT, Sinan M, Stahn P, Steyger PS, Tang SJ, Tejani VD, Wong V. Community network for deaf scientists. Science 2017; 356:386-387. [PMID: 28450605 DOI: 10.1126/science.aan2330] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Affiliation(s)
- Henry J Adler
- Center for Hearing and Deafness, University at Buffalo, Buffalo, NY 14214, USA.
| | - Kelsey L Anbuhl
- University of Colorado School of Medicine, Aurora, CO 80045, USA
| | | | | | - Marc A Brennan
- Boys Town National Research Hospital, Boys Town, NE 68010, USA
| | | | - Brad N Buran
- Oregon Health & Science University, Portland, OR 97239, USA
| | | | - Jonathan E Gale
- University College London Ear Institute, London, WC1X 8EE, UK
| | - Frederick J Gallun
- Oregon Health & Science University, Portland, OR 97239, USA.,U.S. Department of Veterans Affairs, Portland, OR 97239, USA
| | | | | | - Joseph Heng
- Johns Hopkins Hospital, Baltimore, MD 21287, USA
| | | | | | | | | | | | - Stacey R Lim
- Central Michigan University, Mt. Pleasant, MI 48859, USA
| | | | - Lisa S Nolan
- University College London Ear Institute, London, WC1X 8EE, UK
| | - Dominic V Pisano
- University of Michigan School of Medicine, Ann Arbor, MI 48103, USA
| | | | | | | | - Lina A J Reiss
- Oregon Health & Science University, Portland, OR 97239, USA
| | - Chad V Ruffin
- Indiana University School of Medicine, Indianapolis, IN 46202, USA
| | - Adam T Schwalje
- University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA
| | - Moaz Sinan
- Wayne State University School of Medicine, Detroit, MI 48201, USA
| | - Patricia Stahn
- Saarland University Faculty of Medicine, D-66421 Homburg, Germany
| | | | - Stephen J Tang
- University of Wisconsin Hospital and Clinics, Madison, WI 53792, USA
| | - Viral D Tejani
- University of Iowa Hospitals and Clinics, Iowa City, IA 52242, USA
| | - Victor Wong
- Burke Medical Research Institute, White Plains, NY 10605, USA
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Oberfeld D, Stahn P, Kuta M. Why do forward maskers affect auditory intensity discrimination? Evidence from "molecular psychophysics". PLoS One 2014; 9:e99745. [PMID: 24937050 PMCID: PMC4061042 DOI: 10.1371/journal.pone.0099745] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2014] [Accepted: 05/18/2014] [Indexed: 11/25/2022] Open
Abstract
Nonsimultaneous maskers can strongly impair performance in an auditory intensity discrimination task. Using methods of molecular psychophysics, we quantified the extent to which (1) a masker-induced impairment of the representation of target intensity (i.e., increase in internal noise) and (2) a systematic influence of the masker intensities on the decision variable contribute to these effects. In a two-interval intensity discrimination procedure, targets were presented in quiet, and combined with forward maskers. The lateralization of the maskers relative to the targets was varied via the interaural time difference. Intensity difference limens (DLs) were strongly elevated under forward masking but less with contralateral than with ipsilateral maskers. For most listeners and conditions, perceptual weights measuring the relation between the target and masker levels and the response in the intensity discrimination task were positive and significant. Higher perceptual weights assigned to the maskers corresponded to stronger elevations of the intensity DL. The maskers caused only a weak increase in internal noise, unrelated to target level and masker lateralization. The results indicate that the effects of forward masking on intensity discrimination are determined by an inclusion of the masker intensities in the decision variable, compatible with the hypothesis that the impairment in performance is to a large part caused by difficulties in directing selective attention to the targets. The effects of masker lateralization are evidence for top-down influences, and the observed positive signs of the masker weights suggest that the relevant mechanisms are located at higher processing stages rather than in the auditory periphery.
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Affiliation(s)
- Daniel Oberfeld
- Section Experimental Psychology, Department of Psychology, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Patricia Stahn
- Section Experimental Psychology, Department of Psychology, Johannes Gutenberg-Universität Mainz, Mainz, Germany
| | - Martha Kuta
- Section Experimental Psychology, Department of Psychology, Johannes Gutenberg-Universität Mainz, Mainz, Germany
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Oberfeld D, Stahn P. Sequential grouping modulates the effect of non-simultaneous masking on auditory intensity resolution. PLoS One 2012; 7:e48054. [PMID: 23110174 PMCID: PMC3480468 DOI: 10.1371/journal.pone.0048054] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 09/26/2012] [Indexed: 11/22/2022] Open
Abstract
The presence of non-simultaneous maskers can result in strong impairment in auditory intensity resolution relative to a condition without maskers, and causes a complex pattern of effects that is difficult to explain on the basis of peripheral processing. We suggest that the failure of selective attention to the target tones is a useful framework for understanding these effects. Two experiments tested the hypothesis that the sequential grouping of the targets and the maskers into separate auditory objects facilitates selective attention and therefore reduces the masker-induced impairment in intensity resolution. In Experiment 1, a condition favoring the processing of the maskers and the targets as two separate auditory objects due to grouping by temporal proximity was contrasted with the usual forward masking setting where the masker and the target presented within each observation interval of the two-interval task can be expected to be grouped together. As expected, the former condition resulted in a significantly smaller masker-induced elevation of the intensity difference limens (DLs). In Experiment 2, embedding the targets in an isochronous sequence of maskers led to a significantly smaller DL-elevation than control conditions not favoring the perception of the maskers as a separate auditory stream. The observed effects of grouping are compatible with the assumption that a precise representation of target intensity is available at the decision stage, but that this information is used only in a suboptimal fashion due to limitations of selective attention. The data can be explained within a framework of object-based attention. The results impose constraints on physiological models of intensity discrimination. We discuss candidate structures for physiological correlates of the psychophysical data.
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Affiliation(s)
- Daniel Oberfeld
- Department of Psychology, Section Experimental Psychology, Johannes Gutenberg-Universität Mainz, Mainz, Germany.
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