Device for silent substitution excitation of melanopsin for human eye

Agrici, Sergiu; Truffer, Frédéric; Balachandran, Chirojean; Kawasaki, Aki; Geiser, Martial

doi:10.1117/12.2511654

Cited by 6 publications

(3 citation statements)

References 23 publications

(27 reference statements)

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“…Maxwellian-view pupillometry The apparatus used for pupillometry is a custom-made six-primary binocular Maxwellian view light stimulation system [40]. The system is optimized to target different photoreceptors in isolation, including melanopsin.…”

Section: Pupillometric Assessment Of Photoreceptor Mechanismmentioning

confidence: 99%

Within-subjects ultra-short sleep-wake protocol for characterising circadian variations in retinal function

Heinrichs,

Spitschan

2024

Preprint

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Prior studies suggest that visual functions undergo time-of-day variations. Under naturalistic entrainment, diurnal changes in physiology may be driven by circadian and/or homeostatic processes, and repeated measurements at different times of day are thus not suitable to draw unambiguous conclusions about circadian effects on visual function. In this study, we disentangle circadian and homeostatic effects on variations of retinal function. We examine the earliest stages of image-forming (temporal contrast sensitivity of the postreceptoral channels) and non-image forming visual functions (pupillary light response) by employing a short forced-desynchrony multiple-naps protocol lasting 40 hours. Participants (n=12, 50% female) will stay in a controlled time-isolating environment under dim light conditions and adhere to an ultra-short sleep-wake cycle, alternating between 2h30m of wake time in dim light and 1h15m hour of sleep in no light. During eleven intervals of wakefulness, participants will undergo psychophysical and pupillometric assessments with silent-substitution stimuli. We hypothesize that the sensitivity of retinal mechanisms undergoes circadian variations. This hypothesis will be investigated by separately determining psychophysical contrast thresholds to parafoveal silent-substitution stimuli targeting the post-receptoral pathways (isoluminant red-green, L-M; isoluminant blue-yellow, S; luminance, L+M+S). We will furthermore measure the pupillary light response to peripheral stimuli (annulus 10°-30°) in comparison to the response to stimuli isolating or including melanopsin stimulation. All stimuli will be delivered at constant retinal irradiance using a Maxwellian view system or artificially restricting pupil size. Additionally, we will quantify and report effects of our test stimuli on the circadian system by comparing the dim-light melatonin onset (DLMO) timing during two supplementary evening sessions, comparing dim-light conditions to such with experimental light exposure. Our work informs the fundamental biological mechanisms underlying the influence of light on the human circadian system. Based on our findings, current models about the sensitivity of the circadian system may need to be modified in order to account for the bidirectional influence of circadian function and photoreception.

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Section: Pupillometric Assessment Of Photoreceptor Mechanismmentioning

confidence: 99%

Within-subjects ultra-short sleep-wake protocol for characterising circadian variations in retinal function

Heinrichs,

Spitschan

2024

Preprint

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“…This device could be used for many applications in vision, in neuro-ophthalmology and in ophthalmology. The presented device is based on a prototype [10] for which the electronics and the software were completely redesigned. This device will be used for experiments in the field of sleep research and in ophthalmology.…”

Section: Conementioning

confidence: 99%

Homogeneous light stimulation of melanopsin and cones with a Maxwellian view device for the human eye

Patrick

Jessica

Gilles

et al. 2021

2021 IEEE International Instrumentation and Measurement Technology Conference (I2MTC)

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We designed and tested a device to stimulate specifically one photoreceptor type, or a combination of some of them, of the human eye by using up to six primaries. The device produces a homogeneous light field over 40 • which is projected onto the retina through a Maxwellian view optical system. It avoids the use of an artificial pupil, does not need pupil dilation and retinal illumination can be easily controlled. We successfully tested it with four primaries for melanopsin and S-cone stimulation while maintaining other photoreceptors at a fixed level in photopic regime.

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“…The primaries should be independently addressable, additive, and ideally stable over time with a linear input–output function. Peak wavelength and bandwidth of the primaries are key considerations that will define the gamut and available contrast ( Evéquoz et al, 2021 ), and the light source should be integrated into an optical system for stimulus delivery ( Barrionuevo et al, 2022 )—usually a Ganzfeld (e.g., Agrici et al, 2019 ; Martin et al, 2021 ), specialized Maxwellian view (e.g., Cao et al, 2015 ; Nugent & Zele, 2022 ), projector ( Allen et al, 2018 ; Allen et al, 2019 ; DeLawyer et al, 2020 ; Hexley et al, 2020 ; Spitschan et al, 2019 ; Yamakawa et al, 2019 ), or display ( Blume et al, 2022 ; Schöllhorn et al, 2023 ) system. In a review on stimulation devices used in the literature, Conus and Geiser (2020) found that in most cases, the device had four or five primaries and was built from scratch using LEDs, optical bench components, and microprocessors (e.g., Arduino) with intensity controlled by pulse width modulation.…”

Section: Introductionmentioning

confidence: 99%

PySilSub: An open-source Python toolbox for implementing the method of silent substitution in vision and nonvisual photoreception research

et al. 2023

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The normal human retina contains several classes of photosensitive cell—rods for low-light vision, three cone classes for daylight vision, and intrinsically photosensitive retinal ganglion cells (ipRGCs) expressing melanopsin for non-image-forming functions, including pupil control, melatonin suppression, and circadian photoentrainment. The spectral sensitivities of the photoreceptors overlap significantly, which means that most lights will stimulate all photoreceptors to varying degrees. The method of silent substitution is a powerful tool for stimulating individual photoreceptor classes selectively and has found much use in research and clinical settings. The main hardware requirement for silent substitution is a spectrally calibrated light stimulation system with at least as many primaries as there are photoreceptors under consideration. Device settings that will produce lights to selectively stimulate the photoreceptor(s) of interest can be found using a variety of analytic and algorithmic approaches. Here we present PySilSub ( https://github.com/PySilentSubstitution/pysilsub ), a novel Python package for silent substitution featuring flexible support for individual colorimetric observer models (including human and mouse observers), multiprimary stimulation devices, and solving silent substitution problems with linear algebra and constrained numerical optimization. The toolbox is registered with the Python Package Index and includes example data sets from various multiprimary systems. We hope that PySilSub will facilitate the application of silent substitution in research and clinical settings.

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Device for silent substitution excitation of melanopsin for human eye

Cited by 6 publications

References 23 publications

Within-subjects ultra-short sleep-wake protocol for characterising circadian variations in retinal function

Within-subjects ultra-short sleep-wake protocol for characterising circadian variations in retinal function

Homogeneous light stimulation of melanopsin and cones with a Maxwellian view device for the human eye

PySilSub: An open-source Python toolbox for implementing the method of silent substitution in vision and nonvisual photoreception research

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