Abstract
This paper presents a fully integrated photodiode-based low-power and low-mismatch stimulator for a subretinal prosthesis. It is known that a subretinal prosthesis achieves 1600-pixel stimulators on a limited single-chip area that is implanted beneath the bipolar cell layer. However, the high-density pixels cause high power dissipation during stimulation and high fabrication costs because of special process technologies such as the complementary metal-oxide semiconductor CMOS image sensor process. In addition, the many residual charges arising from the high-density pixel stimulation have deleterious effects, such as tissue damage and electrode corrosion, on the retina tissue. In this work, we adopted a switched-capacitor current mirror technique for the single-pixel stimulator (SPStim) that enables low power consumption and low mismatch in the subretinal device. The customized P+/N-well photodiode used to sense the incident light in the SPStim also reduces the fabrication cost. The 64-pixel stimulators are fabricated in a standard 0.35-µm CMOS process along with a global digital controller, which occupies a chip area of 4.3 × 3.2 mm 2 and are ex-vivo demonstrated using a dissected pig eyeball. According to measured results, the SPStim accomplishes a maximum biphasic pulse amplitude of 143 µA, which dissipates an average power of 167 µW in a stimulation period of 5 ms, and an average mismatch of 1.12 % between the cathodic and anodic pulses.
| Original language | English |
|---|---|
| Article number | 536 |
| Journal | Sensors (Switzerland) |
| Volume | 19 |
| Issue number | 3 |
| DOIs | |
| Publication status | Published - 2019 Feb 1 |
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Keywords
- Digital controller
- Ex-vivo demonstration
- High-density pixels
- Implantable device
- Light sensor
- Photodiode
- Subretinal prosthesis
ASJC Scopus subject areas
- Analytical Chemistry
- Atomic and Molecular Physics, and Optics
- Biochemistry
- Instrumentation
- Electrical and Electronic Engineering
Cite this
Fully integrated light-sensing stimulator design for subretinal implants. / Kang, Hosung; Abbasi, Wajahat H.; Kim, Seong-Woo; Kim, Jungsuk.
In: Sensors (Switzerland), Vol. 19, No. 3, 536, 01.02.2019.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Fully integrated light-sensing stimulator design for subretinal implants
AU - Kang, Hosung
AU - Abbasi, Wajahat H.
AU - Kim, Seong-Woo
AU - Kim, Jungsuk
PY - 2019/2/1
Y1 - 2019/2/1
N2 - This paper presents a fully integrated photodiode-based low-power and low-mismatch stimulator for a subretinal prosthesis. It is known that a subretinal prosthesis achieves 1600-pixel stimulators on a limited single-chip area that is implanted beneath the bipolar cell layer. However, the high-density pixels cause high power dissipation during stimulation and high fabrication costs because of special process technologies such as the complementary metal-oxide semiconductor CMOS image sensor process. In addition, the many residual charges arising from the high-density pixel stimulation have deleterious effects, such as tissue damage and electrode corrosion, on the retina tissue. In this work, we adopted a switched-capacitor current mirror technique for the single-pixel stimulator (SPStim) that enables low power consumption and low mismatch in the subretinal device. The customized P+/N-well photodiode used to sense the incident light in the SPStim also reduces the fabrication cost. The 64-pixel stimulators are fabricated in a standard 0.35-µm CMOS process along with a global digital controller, which occupies a chip area of 4.3 × 3.2 mm 2 and are ex-vivo demonstrated using a dissected pig eyeball. According to measured results, the SPStim accomplishes a maximum biphasic pulse amplitude of 143 µA, which dissipates an average power of 167 µW in a stimulation period of 5 ms, and an average mismatch of 1.12 % between the cathodic and anodic pulses.
AB - This paper presents a fully integrated photodiode-based low-power and low-mismatch stimulator for a subretinal prosthesis. It is known that a subretinal prosthesis achieves 1600-pixel stimulators on a limited single-chip area that is implanted beneath the bipolar cell layer. However, the high-density pixels cause high power dissipation during stimulation and high fabrication costs because of special process technologies such as the complementary metal-oxide semiconductor CMOS image sensor process. In addition, the many residual charges arising from the high-density pixel stimulation have deleterious effects, such as tissue damage and electrode corrosion, on the retina tissue. In this work, we adopted a switched-capacitor current mirror technique for the single-pixel stimulator (SPStim) that enables low power consumption and low mismatch in the subretinal device. The customized P+/N-well photodiode used to sense the incident light in the SPStim also reduces the fabrication cost. The 64-pixel stimulators are fabricated in a standard 0.35-µm CMOS process along with a global digital controller, which occupies a chip area of 4.3 × 3.2 mm 2 and are ex-vivo demonstrated using a dissected pig eyeball. According to measured results, the SPStim accomplishes a maximum biphasic pulse amplitude of 143 µA, which dissipates an average power of 167 µW in a stimulation period of 5 ms, and an average mismatch of 1.12 % between the cathodic and anodic pulses.
KW - Digital controller
KW - Ex-vivo demonstration
KW - High-density pixels
KW - Implantable device
KW - Light sensor
KW - Photodiode
KW - Subretinal prosthesis
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U2 - 10.3390/s19030536
DO - 10.3390/s19030536
M3 - Article
C2 - 30696016
AN - SCOPUS:85060789976
VL - 19
JO - Sensors (Switzerland)
JF - Sensors (Switzerland)
SN - 1424-8220
IS - 3
M1 - 536
ER -