Dr. Ryan Beams Profile

Dr. Ryan Beams

Physicist at US Food and Drug Administration

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Publications (8)

SPIE Journal Paper | 14 September 2024 Open Access

Evaluation of monocular and binocular contrast perception on virtual reality head-mounted displays

Khushi Bhansali, Miguel Lago, Ryan Beams, Chumin Zhao

JMI, Vol. 11, Issue 06, 062605, (September 2024) https://doi.org/10.1117/12.10.1117/1.JMI.11.6.062605

KEYWORDS: Head-mounted displays, Virtual reality, Eye, Image quality, Visualization, Spatial frequencies, Medical imaging, Contrast sensitivity, Optical testing, Color

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Proceedings Article | 3 April 2023 Presentation + Paper

Spatiotemporal image quality in medical extended reality

Chumin Zhao, Ryan Beams, Aldo Badano

Proceedings Volume 12467, 124670N (2023) https://doi.org/10.1117/12.2654303

KEYWORDS: Target detection, Image quality, Signal detection, Eye, Visualization, Virtual reality, Modulation transfer functions, Medical imaging

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Purpose: Unlike conventional displays, medical image perception in medical extended reality (MXR) applications often involves relative motion between the digital content and the subject with additional sources of noise in the spatial and temporal domains that affects the MXR image quality.
Methods: We describe a spatiotemporal image perception model with static and dynamic signal and noise configurations. The 3D spatiotemporal noise is decomposed into 2D spatial noise and time-dependent noise with motion. The noise in the temporal domain is categorized into time-invariant fixed pattern noise (FPN) and temporal noise that varies per display frame. Visual integration of the moving signal and noise emulates the spatiotemporal image perception of dynamic detection targets in a smooth-pursuit event. A target detection model is implemented to compute the detectability of both low-contrast and high-resolution signal-known-exactly/background-known-exactly (SKE/BKE) targets in various static and dynamic imaging configurations using a non-pre-whitening model observer with eye filter (NPWE).
Results: Smooth pursuit of a moving target suppresses the high-frequency dynamic resolution and noise in the orientation tangential to the motion trajectory. For the dynamic signal and noise configuration, the reduction of both resolution and high-frequency noise results in similar target detectability compared to the reference static image perception. On the other hand, the visibility of a moving target with static FPN is enhanced due to noise aliasing. Visual integration for approximately 33 ms of time-variant temporal noise at 90 Hz display refresh rate reduces the effective noise compared to the FPN by temporal fusion of noise in neighboring display frames.
Conclusion: Spatiotemporal integration of dynamic signal and noise can potentially affect image quality. Complete assessment of image quality in MXR devices needs to consider the contributions from 3D spatiotemporal characteristics.

Proceedings Article | 7 March 2022 Poster + Presentation + Paper

Quadrant detector-based method for eye point alignment of augmented and virtual reality head mounted displays

Ashraf Bader, Aldo Badano, Ryan Beams

Proceedings Volume 11931, 119310A (2022) https://doi.org/10.1117/12.2614415

KEYWORDS: Head-mounted displays, Cameras, Sensors, Virtual reality, Augmented reality, Autoregressive models, Eye, Control systems, Image quality, Head

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Proceedings Article | 15 February 2021 Presentation + Paper

Spatiotemporal characteristics of medical extended-reality systems

Andrea Kim, Wei-Chung Cheng, Ryan Beams, Aldo Badano

Proceedings Volume 11599, 1159906 (2021) https://doi.org/10.1117/12.2580736

KEYWORDS: Head-mounted displays, Sensors, Medical imaging, Augmented reality, Visualization, Ultrasonography, Sensor technology, Radiography, Medical devices, Magnetism

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Proceedings Article | 19 February 2020 Paper

Eyebox centering using chromatic aberrations of virtual reality head-mounted displays

Ryan Beams, Andrea Kim, Aldo Badano

Proceedings Volume 11310, 1131009 (2020) https://doi.org/10.1117/12.2543257

KEYWORDS: Head-mounted displays, Cameras, Virtual reality, Chromatic aberrations, Eye, Imaging systems, Image resolution, Optical aberrations, Augmented reality, Image quality

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Proceedings Article | 21 September 2017 Presentation

Patrick Vora, Ryan Beams, Sean Oliver, Jaydeep Joshi, Sergiy Krylyuk, Irina Kalish, Alina Bruma, Iris Stone, Arunima Singh, Francesca Tavazza, Stephan Stranick, Albert Davydov

Proceedings Volume 10349, 1034906 (2017) https://doi.org/10.1117/12.2275340

KEYWORDS: Raman spectroscopy, Phonons, Transition metals, Optical properties, Crystallography, Metalloids, Crystals, Semiconductors, Molybdenum, Metals

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Proceedings Article | 25 August 2017 Paper

Side lobe suppression in phase mask-based nonlinear superresolution microscopy

Ryan Beams, Stephan Stranick

Proceedings Volume 10350, 1035009 (2017) https://doi.org/10.1117/12.2275870

KEYWORDS: Confocal microscopy, Point spread functions, Microscopy, Super resolution, Particles, Gold, Photons, Photomasks, Multiphoton microscopy, Optical parametric oscillators

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Proceedings Article | 11 November 2016 Presentation

Semiconductor-to-metal phase change in MoTe2 layers (Conference Presentation)

Albert Davydov, Sergiy Krylyuk, Irina Kalish, Louisa Meshi, Ryan Beams, Berc Kalanyan, Deepak Sharma, Megan Beck, Hadallia Bergeron, Mark Hersam

Proceedings Volume 9924, 99240D (2016) https://doi.org/10.1117/12.2241809

KEYWORDS: Crystals, Semiconductors, Transition metals, Annealing, Molybdenum, Tellurium, Crystallography, Quartz, Heat treatments, Standards development

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Showing 5 of 8 publications

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