Hybrid FPGA-CPU pupil tracker DOI Creative Commons
Bartlomiej Kowalski, Xiaojing Huang, Samuel Steven

et al.

Biomedical Optics Express, Journal Year: 2021, Volume and Issue: 12(10), P. 6496 - 6496

Published: Sept. 14, 2021

An off-axis monocular pupil tracker designed for eventual integration in ophthalmoscopes eye movement stabilization is described and demonstrated. The instrument consists of light-emitting diodes, a camera, field-programmable gate array (FPGA) central processing unit (CPU). raw camera image undergoes background subtraction, field-flattening, 1-dimensional low-pass filtering, thresholding robust edge detection on an FPGA pixel stream, followed by least-squares fitting the coordinates to ellipse CPU. Experimental data suggest that proposed algorithms require images with minimum ∼32 gray levels achieve sub-pixel center accuracy. Tests two different cameras operating at 575, 1250 5400 frames per second trained model achieved 0.5-1.5 μm estimation precision 0.6-2.1 ms combined download, CPU latency. Pupil tracking from fixating human subject show operation only requires adjustment single parameter, namely intensity threshold. latency limited download time (latency) sensitivity (precision).

Language: Английский

IPSC-Derived Human Neurons with GCaMP6s Expression Allow In Vitro Study of Neurophysiological Responses to Neurochemicals DOI Creative Commons

Adelya A. Galiakberova,

Alexander Surin, З. В. Бакаева

et al.

Neurochemical Research, Journal Year: 2021, Volume and Issue: 47(4), P. 952 - 966

Published: Dec. 2, 2021

The study of human neurons and their interaction with neurochemicals is difficult due to the inability collect primary biomaterial. However, recent advances in cultivation stem cells, methods for neuronal differentiation chimeric fluorescent calcium indicators have allowed creation model systems vitro. In this paper we report on development a method obtain GCaMP6s indicator, based iPSC line TetON-NGN2 transgene complex. protocol developed allows us quickly, conveniently efficiently significant amounts suitable various effects specific neurophysiological activity, which can be easily registered using fluorescence microscopy. obtained, glutamate (Glu) induces rises [Ca2+]i are caused by ionotropic receptors Glu, predominantly NMDA-type. Taken together, these facts allow consider created useful successful technology.

Language: Английский

Citations

6
Hybrid FPGA-CPU pupil tracker DOI Creative Commons
Bartlomiej Kowalski, Xiaojing Huang, Samuel Steven

et al.

Biomedical Optics Express, Journal Year: 2021, Volume and Issue: 12(10), P. 6496 - 6496

Published: Sept. 14, 2021

An off-axis monocular pupil tracker designed for eventual integration in ophthalmoscopes eye movement stabilization is described and demonstrated. The instrument consists of light-emitting diodes, a camera, field-programmable gate array (FPGA) central processing unit (CPU). raw camera image undergoes background subtraction, field-flattening, 1-dimensional low-pass filtering, thresholding robust edge detection on an FPGA pixel stream, followed by least-squares fitting the coordinates to ellipse CPU. Experimental data suggest that proposed algorithms require images with minimum ∼32 gray levels achieve sub-pixel center accuracy. Tests two different cameras operating at 575, 1250 5400 frames per second trained model achieved 0.5-1.5 μm estimation precision 0.6-2.1 ms combined download, CPU latency. Pupil tracking from fixating human subject show operation only requires adjustment single parameter, namely intensity threshold. latency limited download time (latency) sensitivity (precision).

Language: Английский

Citations

4