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Pulsed 980 nm short wavelength infrared neural stimulation in cochlea and laser parameter effects on auditory response characteristics.

Wang J, Lu J, Li C, Xu L, Li X, Tian L - Biomed Eng Online (2015)

Bottom Line: The results showed that the optically evoked auditory brainstem response (OABR) had a similar waveform to the acoustically induced ABR with click sound stimulus.Our study suggests that 980 nm SWIR laser is an effective stimulus for auditory neurons activation in vivo.The evoked OABR amplitude and latency are highly affected by the laser pulse energy, while not sensitive to the pulse width variability in 100-800 μs range.

View Article: PubMed Central - PubMed

Affiliation: School of Information Science and Engineering, Shandong University, 250100, Jinan, Shandong, China. 373759703@qq.com.

ABSTRACT

Background: Auditory neural stimulation with pulsed infrared radiation has been proposed as an alternative method to activate the auditory nerves in vivo. Infrared wavelengths from 1800-2150 nm with high water absorption were mainly selected in previous studies. However, few researchers have used the short-wavelength infrared (SWIR) for auditory nerve stimulation and limited pulse parameters variability has been investigated so far.

Methods: In this paper, we pioneered to use the 980 nm SWIR laser with adjustable pulse parameter as a stimulus to act on the deafened guinea pigs' cochlea in vivo. Pulsed laser light was guided through the cochlear round window to irradiate the spiral ganglion cells via a 105 μm optical fiber, and then the laser pulse parameters variability and its influence to auditory response characteristics were studied.

Results: The results showed that the optically evoked auditory brainstem response (OABR) had a similar waveform to the acoustically induced ABR with click sound stimulus. And the evoked OABR amplitude had a positive correlation, while the OABR latency period showed a negative correlation, with the laser pulse energy increase. However, when holding the laser peak power constant, the pulse width variability ranged from 100 to 800 μs showed little influence on the evoked OABR amplitude and its latency period.

Conclusions: Our study suggests that 980 nm SWIR laser is an effective stimulus for auditory neurons activation in vivo. The evoked OABR amplitude and latency are highly affected by the laser pulse energy, while not sensitive to the pulse width variability in 100-800 μs range.

No MeSH data available.


I/O curves of OABR wave III amplitude and latency as a function of laser pulse width. The individual data measured across animals (n = 4) are shown by the different dash lines, and the mean is shown by the solid diamond with the standard error. During the stimulation process, the laser pulse repetition rate was set at 11 Hz and the laser output peak power at 1 W (0.2 mJ/pulse laser pulse energy at 200 μs pulse width). The pulse width was varied from 100 to 800 μs. a The OABR wave III amplitude kept steady with the pulse width widened in 100–800 μs range. b The OABR wave III latency period basically maintained stable with the pulse width widened in 100–800 μs range
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Fig6: I/O curves of OABR wave III amplitude and latency as a function of laser pulse width. The individual data measured across animals (n = 4) are shown by the different dash lines, and the mean is shown by the solid diamond with the standard error. During the stimulation process, the laser pulse repetition rate was set at 11 Hz and the laser output peak power at 1 W (0.2 mJ/pulse laser pulse energy at 200 μs pulse width). The pulse width was varied from 100 to 800 μs. a The OABR wave III amplitude kept steady with the pulse width widened in 100–800 μs range. b The OABR wave III latency period basically maintained stable with the pulse width widened in 100–800 μs range

Mentions: In the second optical stimulation step, we set pulse repetition rate at 11 Hz and laser output peak power at 1 W (0.2 mJ/pulse laser pulse energy at 200 μs pulse width), while varied the pulse width to investigate its effects on OABR amplitude and latency. The I/O curves showed that in the 100–800 μs pulse width range, the OABR wave III peak amplitude (0.81 ± 0.05 μV) and latency time (4.09 ± 0.09 ms) basically maintained stable, which were shown in Fig. 6a, b, respectively. The results indicated that the pulse width variation between 100 and 800 μs had no remarkable effects on the OABR parameters. The data difference between individual animals was not significant (ANOVA, P > 0.05).Fig. 6


Pulsed 980 nm short wavelength infrared neural stimulation in cochlea and laser parameter effects on auditory response characteristics.

Wang J, Lu J, Li C, Xu L, Li X, Tian L - Biomed Eng Online (2015)

I/O curves of OABR wave III amplitude and latency as a function of laser pulse width. The individual data measured across animals (n = 4) are shown by the different dash lines, and the mean is shown by the solid diamond with the standard error. During the stimulation process, the laser pulse repetition rate was set at 11 Hz and the laser output peak power at 1 W (0.2 mJ/pulse laser pulse energy at 200 μs pulse width). The pulse width was varied from 100 to 800 μs. a The OABR wave III amplitude kept steady with the pulse width widened in 100–800 μs range. b The OABR wave III latency period basically maintained stable with the pulse width widened in 100–800 μs range
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
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getmorefigures.php?uid=PMC4597400&req=5

Fig6: I/O curves of OABR wave III amplitude and latency as a function of laser pulse width. The individual data measured across animals (n = 4) are shown by the different dash lines, and the mean is shown by the solid diamond with the standard error. During the stimulation process, the laser pulse repetition rate was set at 11 Hz and the laser output peak power at 1 W (0.2 mJ/pulse laser pulse energy at 200 μs pulse width). The pulse width was varied from 100 to 800 μs. a The OABR wave III amplitude kept steady with the pulse width widened in 100–800 μs range. b The OABR wave III latency period basically maintained stable with the pulse width widened in 100–800 μs range
Mentions: In the second optical stimulation step, we set pulse repetition rate at 11 Hz and laser output peak power at 1 W (0.2 mJ/pulse laser pulse energy at 200 μs pulse width), while varied the pulse width to investigate its effects on OABR amplitude and latency. The I/O curves showed that in the 100–800 μs pulse width range, the OABR wave III peak amplitude (0.81 ± 0.05 μV) and latency time (4.09 ± 0.09 ms) basically maintained stable, which were shown in Fig. 6a, b, respectively. The results indicated that the pulse width variation between 100 and 800 μs had no remarkable effects on the OABR parameters. The data difference between individual animals was not significant (ANOVA, P > 0.05).Fig. 6

Bottom Line: The results showed that the optically evoked auditory brainstem response (OABR) had a similar waveform to the acoustically induced ABR with click sound stimulus.Our study suggests that 980 nm SWIR laser is an effective stimulus for auditory neurons activation in vivo.The evoked OABR amplitude and latency are highly affected by the laser pulse energy, while not sensitive to the pulse width variability in 100-800 μs range.

View Article: PubMed Central - PubMed

Affiliation: School of Information Science and Engineering, Shandong University, 250100, Jinan, Shandong, China. 373759703@qq.com.

ABSTRACT

Background: Auditory neural stimulation with pulsed infrared radiation has been proposed as an alternative method to activate the auditory nerves in vivo. Infrared wavelengths from 1800-2150 nm with high water absorption were mainly selected in previous studies. However, few researchers have used the short-wavelength infrared (SWIR) for auditory nerve stimulation and limited pulse parameters variability has been investigated so far.

Methods: In this paper, we pioneered to use the 980 nm SWIR laser with adjustable pulse parameter as a stimulus to act on the deafened guinea pigs' cochlea in vivo. Pulsed laser light was guided through the cochlear round window to irradiate the spiral ganglion cells via a 105 μm optical fiber, and then the laser pulse parameters variability and its influence to auditory response characteristics were studied.

Results: The results showed that the optically evoked auditory brainstem response (OABR) had a similar waveform to the acoustically induced ABR with click sound stimulus. And the evoked OABR amplitude had a positive correlation, while the OABR latency period showed a negative correlation, with the laser pulse energy increase. However, when holding the laser peak power constant, the pulse width variability ranged from 100 to 800 μs showed little influence on the evoked OABR amplitude and its latency period.

Conclusions: Our study suggests that 980 nm SWIR laser is an effective stimulus for auditory neurons activation in vivo. The evoked OABR amplitude and latency are highly affected by the laser pulse energy, while not sensitive to the pulse width variability in 100-800 μs range.

No MeSH data available.