Fully integrated light-sensing stimulator design for subretinal implants

Hosung Kang, Wajahat H. Abbasi, Seong-Woo Kim, Jungsuk Kim

Research output: Contribution to journalArticle

2 Citations (Scopus)

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 languageEnglish
Article number536
JournalSensors (Switzerland)
Volume19
Issue number3
DOIs
Publication statusPublished - 2019 Feb 1

Fingerprint

Prostheses and Implants
Pixels
pixels
Light
Costs and Cost Analysis
Semiconductors
Corrosion
Oxides
Retina
stimulation
Electrodes
Swine
Metals
CMOS
Technology
Equipment and Supplies
Photodiodes
photodiodes
chips
Tissue

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 journalArticle

Kang, Hosung ; Abbasi, Wajahat H. ; Kim, Seong-Woo ; Kim, Jungsuk. / Fully integrated light-sensing stimulator design for subretinal implants. In: Sensors (Switzerland). 2019 ; Vol. 19, No. 3.
@article{8409c3edb91844e299cf9efe1d2d6d4c,
title = "Fully integrated light-sensing stimulator design for subretinal implants",
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.",
keywords = "Digital controller, Ex-vivo demonstration, High-density pixels, Implantable device, Light sensor, Photodiode, Subretinal prosthesis",
author = "Hosung Kang and Abbasi, {Wajahat H.} and Seong-Woo Kim and Jungsuk Kim",
year = "2019",
month = "2",
day = "1",
doi = "10.3390/s19030536",
language = "English",
volume = "19",
journal = "Sensors (Switzerland)",
issn = "1424-8220",
publisher = "Multidisciplinary Digital Publishing Institute (MDPI)",
number = "3",

}

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

UR - http://www.scopus.com/inward/record.url?scp=85060789976&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85060789976&partnerID=8YFLogxK

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 -