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A novel in vitro sensing configuration for retinal physiology analysis of a sub-retinal prosthesis.

Koo KI, Lee S, Yee JH, Ryu SB, Kim KH, Goo YS, Cho DI - Sensors (Basel) (2012)

Bottom Line: This paper presents a novel sensing configuration for retinal physiology analysis, using two microelectrode arrays (MEAs).Results show that the geometrical relation between the stimulation microelectrode locations and the response locations seems very low.These results provide useful guidelines for developing a sub-retinal prosthesis.

View Article: PubMed Central - PubMed

Affiliation: Inter-university Semiconductor Research Center, Automation System Research Institute, School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151-744, Korea. kkin76@snu.ac.kr

ABSTRACT
This paper presents a novel sensing configuration for retinal physiology analysis, using two microelectrode arrays (MEAs). In order to investigate an optimized stimulation protocol for a sub-retinal prosthesis, retinal photoreceptor cells are stimulated, and the response of retinal ganglion cells is recorded in an in vitro environment. For photoreceptor cell stimulation, a polyimide-substrate MEA is developed, using the microelectromechanical systems (MEMS) technology. For ganglion cell response recording, a conventional glass-substrate MEA is utilized. This new sensing configuration is used to record the response of retinal ganglion cells with respect to three different stimulation methods (monopolar, bipolar, and dual-monopolar stimulation methods). Results show that the geometrical relation between the stimulation microelectrode locations and the response locations seems very low. The threshold charges of the bipolar stimulation and the monopolar stimulation are in the range of 10~20 nC. The threshold charge of the dual-monopolar stimulation is not obvious. These results provide useful guidelines for developing a sub-retinal prosthesis.

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Related in: MedlinePlus

The dual-monopolar stimulation results. (a) The spatial response map of the dual-monopolar stimulation. (b) The contour diagram of the dual-monopolar stimulation. The numbers on the contour diagram are the evoked RGC spike numbers with respect to 50 μA current stimulation. (c) Electrode indices.
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f7-sensors-12-03131: The dual-monopolar stimulation results. (a) The spatial response map of the dual-monopolar stimulation. (b) The contour diagram of the dual-monopolar stimulation. The numbers on the contour diagram are the evoked RGC spike numbers with respect to 50 μA current stimulation. (c) Electrode indices.

Mentions: Figure 7(a) shows the spatial response map of the dual-monopolar stimulation. The dual-monopolar stimulation (Figure 7(a)) is performed immediately following the bipolar stimulation (Figure 6(c)). Therefore, the three experiments (the monopolar stimulation, the bipolar stimulation and the dual-monopolar stimulation) have the same microelectrodes locations at the same retinal patch. The height from the stimulating MEA to the recording MEA is also about 150 μm. One of the two stimulating working microelectrodes (red circle with dots) is at the upper and right part near the 6–2 microelectrode, and the other of the two stimulating working microelectrodes (red donut with dots) is outward from the 1–5 and 1–6 microelectrodes.


A novel in vitro sensing configuration for retinal physiology analysis of a sub-retinal prosthesis.

Koo KI, Lee S, Yee JH, Ryu SB, Kim KH, Goo YS, Cho DI - Sensors (Basel) (2012)

The dual-monopolar stimulation results. (a) The spatial response map of the dual-monopolar stimulation. (b) The contour diagram of the dual-monopolar stimulation. The numbers on the contour diagram are the evoked RGC spike numbers with respect to 50 μA current stimulation. (c) Electrode indices.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3376591&req=5

f7-sensors-12-03131: The dual-monopolar stimulation results. (a) The spatial response map of the dual-monopolar stimulation. (b) The contour diagram of the dual-monopolar stimulation. The numbers on the contour diagram are the evoked RGC spike numbers with respect to 50 μA current stimulation. (c) Electrode indices.
Mentions: Figure 7(a) shows the spatial response map of the dual-monopolar stimulation. The dual-monopolar stimulation (Figure 7(a)) is performed immediately following the bipolar stimulation (Figure 6(c)). Therefore, the three experiments (the monopolar stimulation, the bipolar stimulation and the dual-monopolar stimulation) have the same microelectrodes locations at the same retinal patch. The height from the stimulating MEA to the recording MEA is also about 150 μm. One of the two stimulating working microelectrodes (red circle with dots) is at the upper and right part near the 6–2 microelectrode, and the other of the two stimulating working microelectrodes (red donut with dots) is outward from the 1–5 and 1–6 microelectrodes.

Bottom Line: This paper presents a novel sensing configuration for retinal physiology analysis, using two microelectrode arrays (MEAs).Results show that the geometrical relation between the stimulation microelectrode locations and the response locations seems very low.These results provide useful guidelines for developing a sub-retinal prosthesis.

View Article: PubMed Central - PubMed

Affiliation: Inter-university Semiconductor Research Center, Automation System Research Institute, School of Electrical Engineering and Computer Science, Seoul National University, Seoul 151-744, Korea. kkin76@snu.ac.kr

ABSTRACT
This paper presents a novel sensing configuration for retinal physiology analysis, using two microelectrode arrays (MEAs). In order to investigate an optimized stimulation protocol for a sub-retinal prosthesis, retinal photoreceptor cells are stimulated, and the response of retinal ganglion cells is recorded in an in vitro environment. For photoreceptor cell stimulation, a polyimide-substrate MEA is developed, using the microelectromechanical systems (MEMS) technology. For ganglion cell response recording, a conventional glass-substrate MEA is utilized. This new sensing configuration is used to record the response of retinal ganglion cells with respect to three different stimulation methods (monopolar, bipolar, and dual-monopolar stimulation methods). Results show that the geometrical relation between the stimulation microelectrode locations and the response locations seems very low. The threshold charges of the bipolar stimulation and the monopolar stimulation are in the range of 10~20 nC. The threshold charge of the dual-monopolar stimulation is not obvious. These results provide useful guidelines for developing a sub-retinal prosthesis.

Show MeSH
Related in: MedlinePlus