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Lengert L, Tomanek M, Ghoncheh M, Lohmann H, Prenzler N, Kalies S, Johannsmeier S, Ripken T, Heisterkamp A, Maier H. Acoustic stimulation of the human round window by laser-induced nonlinear optoacoustics. Sci Rep 2024; 14:8214. [PMID: 38589426 PMCID: PMC11001906 DOI: 10.1038/s41598-024-58129-0] [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] [Received: 11/10/2023] [Accepted: 03/26/2024] [Indexed: 04/10/2024] Open
Abstract
The feasibility of low frequency pure tone generation in the inner ear by laser-induced nonlinear optoacoustic effect at the round window was demonstrated in three human cadaveric temporal bones (TB) using an integral pulse density modulation (IPDM). Nanosecond laser pulses with a wavelength in the near-infrared (NIR) region were delivered to the round window niche by an optical fiber with two spherical lenses glued to the end and a viscous gel at the site of the laser focus. Using IPDM, acoustic tones with frequencies between 20 Hz and 1 kHz were generated in the inner ear. The sound pressures in scala tympani and vestibuli were recorded and the intracochlear pressure difference (ICPD) was used to calculate the equivalent sound pressure level (eq. dB SPL) as an equivalent for perceived loudness. The results demonstrate that the optoacoustic effect produced sound pressure levels ranging from 140 eq. dB SPL at low frequencies ≤ 200 Hz to 90 eq. dB SPL at 1 kHz. Therefore, the produced sound pressure level is potentially sufficient for patients requiring acoustic low frequency stimulation. Hence, the presented method offers a potentially viable solution in the future to provide the acoustic stimulus component in combined electro-acoustic stimulation with a cochlear implant.
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Affiliation(s)
- Liza Lengert
- Laser Zentrum Hannover E.V., Hollerithallee 8, 30419, Hannover, Germany
- NIFE, Lower Saxony Center for Biomedical Engineering, Implant Research and Development, Hannover, Germany
| | - Michael Tomanek
- Department of Otorhinolaryngology and Cluster of Excellence "Hearing4all", Hannover Medical School, VIANNA/NIFE, Stadtfelddamm 34, 30625, Hannover, Germany
| | - Mohammad Ghoncheh
- Department of Otorhinolaryngology and Cluster of Excellence "Hearing4all", Hannover Medical School, VIANNA/NIFE, Stadtfelddamm 34, 30625, Hannover, Germany
| | - Hinnerk Lohmann
- Laser Zentrum Hannover E.V., Hollerithallee 8, 30419, Hannover, Germany
| | - Nils Prenzler
- Department of Otorhinolaryngology and Cluster of Excellence "Hearing4all", Hannover Medical School, VIANNA/NIFE, Stadtfelddamm 34, 30625, Hannover, Germany
| | - Stefan Kalies
- Institute of Quantum Optics, Leibniz University Hannover, Hannover, Germany
| | - Sonja Johannsmeier
- Laser Zentrum Hannover E.V., Hollerithallee 8, 30419, Hannover, Germany
- NIFE, Lower Saxony Center for Biomedical Engineering, Implant Research and Development, Hannover, Germany
| | - Tammo Ripken
- Laser Zentrum Hannover E.V., Hollerithallee 8, 30419, Hannover, Germany
- NIFE, Lower Saxony Center for Biomedical Engineering, Implant Research and Development, Hannover, Germany
| | | | - Hannes Maier
- Department of Otorhinolaryngology and Cluster of Excellence "Hearing4all", Hannover Medical School, VIANNA/NIFE, Stadtfelddamm 34, 30625, Hannover, Germany.
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Deng B, Fan Y, Wang J, Yang S. Reconstruction of a Fully Paralleled Auditory Spiking Neural Network and FPGA Implementation. IEEE TRANSACTIONS ON BIOMEDICAL CIRCUITS AND SYSTEMS 2021; 15:1320-1331. [PMID: 34699367 DOI: 10.1109/tbcas.2021.3122549] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
This paper presents a field-programmable gate array (FPGA) implementation of an auditory system, which is biologically inspired and has the advantages of robustness and anti-noise ability. We propose an FPGA implementation of an eleven-channel hierarchical spiking neuron network (SNN) model, which has a sparsely connected architecture with low power consumption. According to the mechanism of the auditory pathway in human brain, spiking trains generated by the cochlea are analyzed in the hierarchical SNN, and the specific word can be identified by a Bayesian classifier. Modified leaky integrate-and-fire (LIF) model is used to realize the hierarchical SNN, which achieves both high efficiency and low hardware consumption. The hierarchical SNN implemented on FPGA enables the auditory system to be operated at high speed and can be interfaced and applied with external machines and sensors. A set of speech from different speakers mixed with noise are used as input to test the performance our system, and the experimental results show that the system can classify words in a biologically plausible way with the presence of noise. The method of our system is flexible and the system can be modified into desirable scale. These confirm that the proposed biologically plausible auditory system provides a better method for on-chip speech recognition. Compare to the state-of-the-art, our auditory system achieves a higher speed with a maximum frequency of 65.03 MHz and a lower energy consumption of 276.83 μJ for a single operation. It can be applied in the field of brain-computer interface and intelligent robots.
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Sorg K, Heimann L, Lana GM, Langenbucher A, Schick B, Arzt E, Wenzel GI. Optoacoustically induced auditory brainstem responses in the mouse model enhanced through an absorbing film. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-210173R. [PMID: 34480448 PMCID: PMC8414560 DOI: 10.1117/1.jbo.26.9.098001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/17/2021] [Indexed: 06/13/2023]
Abstract
SIGNIFICANCE Optoacoustic stimulation offers an alternative stimulation strategy for the hearing organ. To serve as the base for a novel auditory prosthesis, the optoacoustic stimulation must be biocompatible and energy-saving. AIM Enhancing the efficiency of optoacoustic stimulation while reducing the energy input in a suited animal model. APPROACH Optoacoustically induced auditory brainstem responses (oABRs) were recorded after the pulsed laser irradiation of the tympanic membrane (TM) in mice. The results were compared with the ABRs induced through acoustic click stimulation. In addition, self-adhesive absorbing films were applied on the TM before the optoacoustic stimulation to investigate their effect on the resulting ABRs. RESULTS Using an absorbing film on the TM during optical stimulation led to considerably enhanced oABR wave I amplitude values compared with the stimulation of the bare TM. When using our stimulation strategy, we induced oABR waves in the 50% to 60% range of the acoustical stimulation reached with 80-dB SPL click stimuli. CONCLUSIONS The mouse model can be used for certain developmental work for an optoacoustic auditory prosthesis. Using absorbing films on the TM during optical stimulation considerably enhances oABR wave I amplitude. Optimization of the stimulation strategy could further enhance the efficiency within biocompatibility margins.
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Affiliation(s)
- Katharina Sorg
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Larissa Heimann
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Gabriela Moreira Lana
- INM Leibniz Institute for New Materials, Saarbrücken, Germany
- Saarland University, Department of Materials Science and Engineering, Saarbrücken, Germany
| | - Achim Langenbucher
- Saarland University, Department of Experimental Ophthalmology, Homburg, Germany
| | - Bernhard Schick
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
| | - Eduard Arzt
- INM Leibniz Institute for New Materials, Saarbrücken, Germany
- Saarland University, Department of Materials Science and Engineering, Saarbrücken, Germany
| | - Gentiana Ioana Wenzel
- Saarland University Medical Center, Department of Otorhinolaryngology, Homburg, Germany
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Heimann L, Carlein C, Sorg K, Diller R, Langenbucher A, Schick B, Wenzel GI. Wavelength-specific optoacoustic-induced vibrations of the guinea pig tympanic membrane. JOURNAL OF BIOMEDICAL OPTICS 2021; 26:JBO-200335R. [PMID: 33675190 PMCID: PMC7934890 DOI: 10.1117/1.jbo.26.3.038001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Accepted: 01/13/2021] [Indexed: 06/12/2023]
Abstract
SIGNIFICANCE Optoacoustic-induced vibrations of the hearing organ can potentially be used for a hearing device. To increase the efficiency of such a hearing device, the conversion of the light energy into vibration energy within each type of irradiated tissue has to be optimized. AIM To analyze the wavelength-dependency of optoacoustic-induced vibrations within the tympanic membrane (TM), and to define the most efficient and best-suited optical stimulation parameters for a novel auditory prosthesis. APPROACH Single nanosecond laser pulses, continuously tunable in a range of visible to near-infrared, were used to excite the guinea pig TM. The induced vibrations of the hearing organ were recorded at the malleus using a laser Doppler vibrometer. RESULTS Our results indicate a strong wavelength-dependency of the vibration's amplitude correlating with the superposition of the absorption spectra of the different specific tissue components. CONCLUSIONS We investigated the spectrum of the vibrations of the hearing organ that were induced optoacoustically within a biological membrane embedded in air, in an animal model. First applications for these results can be envisioned for the optical stimulation of the peripheral hearing organ as well as for research purposes.
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Affiliation(s)
- Larissa Heimann
- Saarland University, Medical Center, Department of Otolaryngology, Homburg, Germany
| | - Christopher Carlein
- University of Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | - Katharina Sorg
- Saarland University, Medical Center, Department of Otolaryngology, Homburg, Germany
| | - Rolf Diller
- University of Kaiserslautern, Department of Physics, Kaiserslautern, Germany
| | - Achim Langenbucher
- Saarland University, Medical Center, Department of Experimental Ophthalmology, Homburg, Germany
| | - Bernhard Schick
- Saarland University, Medical Center, Department of Otolaryngology, Homburg, Germany
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Raufer S, Gamm UA, Grossöhmichen M, Lenarz T, Maier H. Middle Ear Actuator Performance Determined From Intracochlear Pressure Measurements in a Single Cochlear Scala. Otol Neurotol 2020; 42:e86-e93. [PMID: 33044336 DOI: 10.1097/mao.0000000000002836] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
HYPOTHESIS Intracochlear pressure measurements in one cochlear scala are sufficient as reference to determine the output of an active middle ear implant (AMEI) in terms of "equivalent sound pressure level" (eqSPL). BACKGROUND The performance of AMEIs is commonly calculated from stapes velocities or intracochlear pressure differences (PDiff). However, there are scenarios where measuring stapes velocities or PDiff may not be feasible, for example when access to the stapes or one of the scalae is impractical. METHODS We reanalyzed data from a previous study of our group that investigated the performance of an AMEI coupled to the incus in 10 human temporal bones. We calculated eqSPL based on stapes velocities according to the ASTM standard F2504-05 and based on intracochlear pressures in scala vestibuli, scala tympani, and PDiff. RESULTS The AMEI produced eqSPL of ∼100 to 120 dB at 1 Vrms. No significant differences were found between using intracochlear pressures in scala vestibuli, scala tympani, or PDiff as a reference. The actuator performance calculated from stapes displacements predicted slightly higher eqSPLs at frequencies above 1000 Hz, but these differences were not statistically significant. CONCLUSION Our findings show that pressure measurements in one scala can be sufficient to evaluate the performance of an AMEI coupled to the incus. The method may be extended to other stimulation modalities of the middle ear or cochlea when access to the stapes or one of the scalae is not possible.
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Affiliation(s)
- Stefan Raufer
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover.,DFG Cluster of Excellence, Hearing4all
| | - Ute A Gamm
- Cochlear Deutschland GmbH & Co. KG, Hannover, Germany
| | - Martin Grossöhmichen
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover.,DFG Cluster of Excellence, Hearing4all
| | - Thomas Lenarz
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover.,DFG Cluster of Excellence, Hearing4all
| | - Hannes Maier
- Department of Otolaryngology and Institute of Audioneurotechnology (VIANNA), Hannover Medical School, Hannover.,DFG Cluster of Excellence, Hearing4all
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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. JOURNAL OF BIOMEDICAL OPTICS 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] [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. JOURNAL OF BIOMEDICAL OPTICS 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] [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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