Limits...
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.


Diagram of the experimental surgery setup. a The placement and orientation of the optical fiber. The fiber was inserted into the round window and oriented to the modious. b The retro-auricular incision at the right side of the animal’s head
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig1: Diagram of the experimental surgery setup. a The placement and orientation of the optical fiber. The fiber was inserted into the round window and oriented to the modious. b The retro-auricular incision at the right side of the animal’s head

Mentions: The animals were anesthetized by single intraperitoneal injection of ethyl carbamate solution (1 g/kg body weight in 20 % sterile saline) in first step. Additional dose of 0.2 ml could be needed to ensure deep anesthesia of guinea pigs during the experiment. Once the animals were under deep anesthesia condition, they were then positioned on an operation table with animal heads stabilized in a head holder, preparing for the otologic surgical procedure. Considering the stability of the experiment and animal care, animals were placed in the thermostatic chamber to maintain body temperature at 38 °C. Next, the surgery was carried out. The animal’s bulla was exposed by retro-auricular incisions to provide access to the cochlea. Then the muscle tissue and soft tissue were dissected and the bulla’s posterior-lateral part was opened to get access to the round window niche. Figure 1b shows the surgical incision location and the exposed round window of cochlea.Fig. 1


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)

Diagram of the experimental surgery setup. a The placement and orientation of the optical fiber. The fiber was inserted into the round window and oriented to the modious. b The retro-auricular incision at the right side of the animal’s head
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

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

Fig1: Diagram of the experimental surgery setup. a The placement and orientation of the optical fiber. The fiber was inserted into the round window and oriented to the modious. b The retro-auricular incision at the right side of the animal’s head
Mentions: The animals were anesthetized by single intraperitoneal injection of ethyl carbamate solution (1 g/kg body weight in 20 % sterile saline) in first step. Additional dose of 0.2 ml could be needed to ensure deep anesthesia of guinea pigs during the experiment. Once the animals were under deep anesthesia condition, they were then positioned on an operation table with animal heads stabilized in a head holder, preparing for the otologic surgical procedure. Considering the stability of the experiment and animal care, animals were placed in the thermostatic chamber to maintain body temperature at 38 °C. Next, the surgery was carried out. The animal’s bulla was exposed by retro-auricular incisions to provide access to the cochlea. Then the muscle tissue and soft tissue were dissected and the bulla’s posterior-lateral part was opened to get access to the round window niche. Figure 1b shows the surgical incision location and the exposed round window of cochlea.Fig. 1

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.