Pixel array with 5×5 spatial highpass filter for a retinal implant

Schutz, Henning; Gambach, Stefan; Kaim, Hans; Rothermel, Albrecht

doi:10.1109/esscirc.2017.8094526

Cited by 5 publications

(1 citation statement)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…2) Neuromorphic Image Processor (NMIP): Fig. 9(a) shows the conventional way to implement a distributed analog image processor by the current mirror topology [18], [19] that faces three main challenges. Firstly, mirrored current variation is 21% in the range of photocurrent from 10 pA to 10 nA, which affects the output distortion.…”

Section: System Architecturementioning

confidence: 99%

1225-Channel Neuromorphic Retinal-Prosthesis SoC With Localized Temperature-Regulation

Park

Tan

et al. 2020

IEEE Trans. Biomed. Circuits Syst.

View full text Add to dashboard Cite

A 1225-Channel Neuromorphic Retinal Prosthesis (RP) SoC is presented. Existing RP SoCs directly convert light intensity to electrical stimulus, which limit the adoption of delicate stimulus patterns to increase visual acuity. Moreover, a conventional centralized image processor leads to the local hot spot that poses a risk to the nearby retinal cells. To solve these issues, the proposed SoC adopts a distributed Neuromorphic Image Processor (NMIP) located within each pixel that extracts the outline of the incoming image, which reduces current dispersion and stimulus power compared with light-intensity proportional stimulus pattern. A spike-based asynchronous digital operation results in the power consumption of 56.3 nW/Ch without local temperature hot spot. At every 5×5 pixels, the localized (49-point) temperatureregulation circuit limits the temperature increase of neighboring retinal cells to less than 1°C, and the overall power consumption of the SoC to be less than that of the human eye. The 1225-channel SoC fabricated in 0.18 µm 1P6M CMOS occupies 15mm 2 while consuming 2.7 mW, and is successfully verified with image reconstruction demonstration.

show abstract

Section: System Architecturementioning

confidence: 99%