저시력보완을위한 AR/VR 및광학기술 최희진 세종대학교물리천문학과

Transcription

1 저시력보완을위한 AR/VR 및광학기술 최희진 세종대학교물리천문학과

2 Blind?

3 How we can see what the eye sees OS Field

4 How we can see what the eye sees OD Field

5 Whom you cannot help OU Field OS Field OD Field

6 Whom you can help (Patients with Homonymous Hemianopia) OU Field Blind Blind Blind OS Field OD Field Post-Chiasmal Lesions Approximately 0.8% of people over age 49 Cortical Lesion 2011, Eli Peli, Schepens Eye Research Institute

7 What patient with Left HH sees Blind

8 What patient with Left HH cannot see Hidden object with possible collision Blind

9 What can be seen with Peliprism Hidden object with possible collision Blind Expanded visual field (Showing hidden objects by prism power)

10 The 1 st optics you do need to know Direction of incident light ray Medium 1 (refractive index ) Medium 2 Surface of refraction Principle of refraction (refractive index ) = Direction of refracted light ray If the is bigger, the light is slower.

11 How we can help patient with Hemianopia Blind Blind Unseen Seen (Fish) (Image) Blind

12 How we can help patient with Hemianopia δ R δ R : Deflection angle (Prism power) Base Apex Normal incidence Unilateral Peli prism The prism can change the light path

13 Optical distortion δ R4 δ R3 δ R2 δ R1 Various refractive conditions

14 Optical distortion Original Prism view

15 Why mirror-based prism? Conventional prism has optical limitations. No optical power beyond the threshold of TIR (TIR: Total Internal Reflection) Distortion also occurs with an available optical power A mirror is not based on the principle of refraction. No TIR It is based on the principle of reflection. Simpler principle No optical distortion

16 The 2 nd optics you do need to know Principle of reflection Direction of reflected light ray θ θ Surface of reflection (Mirror) Direction of incident light ray

17 Basic principle of mirror-based prism Conventional Prism (Based on Refraction) Mirror-based Prism (Based on Reflection) 1 st Mirror δ R δ M A pair of mirror can also change the path of light as a prism does

18 Find constraints Size of mirror Too short Well designed Too long 2 nd Mirror 3 rd Mirror 1 st Mirror

19 Optimization: δ total = δ M + δ R The 3 rd (last) mathematics you do need to know How to add two variables Optimizing δ M and δ R independently While setting total power δ total to be the same Module 1 30 o o o Module o o o Module o 7.55 o o Module o 3.47 o o

20 How to add: δ total = δ M + δ R Every module can have different δ M Adjusting δ M to set the main structure M n to be less than 20mm (Size) D n to be no less than 16mm (Safety) Total FOV of device to be about 60 o Every module can have different δ R Filling the space between mirrors with PMMA (plastic) Adjusting δ R to compensate the total power Total power δ total to be around 45 o

21 Design of a main structure Mirror 3 Mirror 2 Mirror 5 Mirror 4 Module 4 Module 3 Module 2 Module 1 Mirror 1 < 20mm Module 1 30 o o o Module o o o Module o 7.55 o o Module o 3.47 o o > 16mm 60 o

22 Design with optimization Mirror 3 Mirror 2 Mirror 5 Mirror 4 Module 4 Module 3 Module 2 Module 1 Mirror 1 Additional Prism Power Total Power 45 o Module 1 30 o o o D 5 D 4 D 3 D 2 D 1 Module o o o θ θ 3 θ2 4 θ1 Module o 7.55 o o Module o 3.47 o o Total FOV = 57.1 o

23 What will be seen through Side view effect Without Prism With Prism Image wall Image wall Direction of Sight δ Direction of Sight

24 What will be seen through Side view effect Without Prism With Prism Image wall Direction of Sight δ Direction of Sight

25 What will be seen through (1) Images on wall Image wall Magnified view 6m Virtual Camera 60mm

26 What will be seen through (1) Captured Field (-45 o to +45 o ) Without Prism With Prism Left Hemianopia Blind Blind Normal Vision

27 What will be seen through (2) 90 Magnified view 45 0 Virtual Camera

28 What will be seen through (2) Captured Field (-45 o to +45 o ) Without Prism With Prism Left Hemianopia Blind Blind Normal Vision

29 VR tech. for low vision patients

30 AR tech. for low vision patients Scene without edge enhancement Scene with edge enhancement Luo et al (2005). Optical Engineering 44(2),

31 AR tech. for low vision patients Hwang A. & Peli E. (2014). Optometry & Vision Science, 91(8),

32 AR tech. for low vision patients Augmented vision with minified outlines Directness improves search with the device Early detection of obstacles Bowers, A. R., Luo, G., Rensing, N. M., & Peli, E. (2004). Ophthalmic and Physiological Optics, 24(4),

33 Augmented visual field expansion Augmented vision with minified outlines Directness improves search with the device Early detection of obstacles Bowers, A. R., Luo, G., Rensing, N. M., & Peli, E. (2004). Ophthalmic and Physiological Optics, 24(4),

34 Totally Blind

35 Devices for people with total blindness

36 Confocal de-cluttering Jung, J-H, Aloni, D, Yitzhaky, Y, & Peli, E (2015) Active confocal imaging for visual prostheses. Vision Research, 2015; 111:

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