GB2529278A

GB2529278A - Retinal sleep lamp V2

Info

Publication number: GB2529278A
Application number: GB1506512.1A
Authority: GB
Inventors: Josef Wolfgang Tainsh
Original assignee: Individual
Current assignee: Individual
Priority date: 2014-08-03
Filing date: 2015-04-16
Publication date: 2016-02-17
Also published as: GB201506512D0; GB201413741D0

Abstract

A retinal sleep lamp that emits light onto the eyes of the user when they are asleep which illuminates the retina through the users closed eye-lids. The lamp is used to light-adapt the eyes retinal rods to treat and prevent forms of eye disease, and regulate sleep patterns. Preferably a plurality of lamps A are positioned at various angles around the users head and may be mounted on a wall, ceiling, bed headboard or post, or freestanding, and the emitted light directed at the users head and pillow region around the head to accommodate head movement. To prevent the pillow blocking the light, the pillow is made at least partially from transparent or translucent material C, alternatively the pillow and/or the bed sheet may be made from optically reflective (B, fig 1) material, as a means to redirect the light onto the eyelids of the user. The pillow may also restrict the movement of the users head, or may include light emitting devices. The lamps can emit continuous, modulated or flashing illumination, and have a wavelength between 460nm to 520nm. The lamp emitting means may be a LED or laser.

Description

Retinal Sleep Lamp

Description:

Background

This invention relates to a retinal sleep lamp system which illuminates the retina through closed eye-lids during sleep. It is utilised to light-adapt the eyes retinal rods which has application to treat and prevent forms of eye disease [Refl][Ref2]. A sleep or light mask performs a similar function [Refl][Ref2] however; this invention is different as it has the advantage of not being attached to the head. The discomfort associated with having to wear a mask whilst sleeping has therefore been removed. Also the situation where head movement may displace an optimum position of a light mask from over the eyes is not an issue.

Another application for the Retinal Sleep Lamp technology is with regulating sleep patterns or circadian rhythms, by shining light through closed eyelids during sleep. This application is achievable because high absorption optical wavelengths of retinal rods, which are emitted from the Retinal Sleep Lamp, closely match the high absorption wavelengths of the retinal ganglion photo-receptors which regulate sleep patterns [Ref3].

This invention proposes luminaries positioned around the bead, which emit light that is directed towards the eyelids and the pillow region around the head.

One issue, which is overcome with this sleep lamp system design, is that during a typical sleep cycle, the head can turn burying one side of the face and therefore the lower eye into the pillow. Due to its weight the head typically sinks into the pillow and the nose and eyebrow can cast a shadow over the lower eye. This can result with the pillow blocking a large portion of light from the lamp directly reaching the lower eye. One method to deal with this issue is to position more lamps around the head at various incident angles. Also, utilising the reflectivity light diffusivity and/or transmission of the, pillow or material below the head, to assist with illuminating the eyelids is part of the retinal sleep lamps system.

One purpose of the retinal sleep lamp system design is to provide exposure of the retina to light emission for any sleeping head position. Part of the system design includes a partially and/or substantially optically reflective and/or transparent pillow material under the head. The pillow also has purpose to restrict the range of possible head movements and to sufficiently support the head comfortably. A glowing light emitting pillow can contribute to the overall illuminance dosage delivered to the closed eyelids during sleep. A partially transparent pillow can provide superior performance if the head is side onto the pillow, as increased transparency reduces light attenuation. If the pillow is non see-through, its partially reflective transmitting and light scattering properties are utilised to increase the abundance of light incident upon an eyelid that is buried into the pillow. With a transparent pillow, the reflectance of a sheet material beneath the pillow and optional additional luminary positioned around the head, are utilised to contribute to the overall illumination.

The principle purpose of the retinal sleep lamp system is to illuminate the retinal photoreceptors during sleep. For example, during the daytime in relatively bright conditions retinal rods remain light-adapted'. As retinal rods are for night vision or, seeing in dim illumination conditions, they naturally activate (dark-adapt) in a dark environment such as at night time. Also, when the eye-lids are closed during sleep, the eye is in a dark environment and the rods become dark-adapted. The retinal-sleep-lamp provides trans-eyelid illumination to light-adapt the retinal rods during sleep when the eyelids are closed.

Introduction to the figures

Sleep is typically undertaken in a bed with a pillow positioned underneath the head although a pillow is not essential to sleep. Figure 1 shows numerous lights (A) positioned around a bed, shining light towards a non-see-through pillow (B). Figure 2 shows luminary (A) positioned around a bed shining light towards a reflective sheet (D) beneath a see-through pillow (C) and optional additional luminary (E) which in the diagram are beneath the pillow. Note the lights (A) can be mounted by any means, such as the wall, on the ceiling, by standalone products such as a tripod or stand next to or attached to the bed headboard or bed posts.

The non-see-through pillow (B) is reasonably reflective (approximately 30% for a typical white fabric material) and partly transparent and diffusive to optical wavelengths. The see-through pillow (C) will have some absorption although this is considered relatively minor in comparison. If the pillow is see-through (C) such as a gel pillow or a blow up plastic pillow or is made from some other translucent material, a reasonably reflective sheet (D) or material is required beneath the pillow. This is to reflect light from the lamp or lamps towards the eyelid region.

Where a direct line of sight from any distant lamp to the eyelid is not established, the reflectiveness, transmission and/or light scattering properties of the material under the head assist with establishing a dose of light incident upon the lower eyelid. The wall or bed headboard can also act as a reflector as can any other material in the vicinity. Further luminary may be positioned around the head such as below the pillow (F), which is highly applicable if the pillow is see-through and the person sleeps with their eyelids facing downward.

Lamps are positioned to illuminate the closed eyelids and pillow region where the head rests during sleep, covering a sufficient variation to deal with head movement throughout the night. Lamps are spaced to provide an intensity distribution on the eyelids accommodating for the range of possible head movements, considering the nose and/or eyebrows may cast a shadow over a distant eyelid.

The turned head can sink in the pillow and the lower eye is consequently buried into the pillow. In the situation represented in Figure 1. with a non-see-through pillow, the pillow acts as a barrier which can directly block the line of sight from the lamp to the eyelid and attenuate the transmission of incoming light. The lamps are positioned to cater for this detrimental effect in conjunction with utilising the optically reflective, diffusive and transmitting properties of the pillow material to redirect light and therefore indirectly illuminate the eyelids.

The set-up shown in Figure 2 is different to that shown in Figure 1 as the pillow is see-through. Light is reflected from the white sheet or material beneath the pillow and therefore illuminates the eyelid which is buried in the pillow with minimal attenuation. A transparent pillow is similar to the situation where there is no pillow as light similarly passes through air.

Also in this situation, additional luminary positioned beneath the pillow can contribute to the overall intensity reaching the eyelids.

Figure 3 shows the eye-ball (F) with the retina (G) at the back and the eye-lids (H) at the front, which are typically closed during sleep. Light (I) is incident upon the eye-lids and passes through the eye-lids and is then incident upon the retina (J).

Lamps are positioned to shine light in at angles to account for turning of the bead. A single or series of spot-lights, linear light strips and/or panels can be utilised as light sources. These can be placed above the bed, pointing towards the head/pillow region and also to the side of the bed and under or around the pillow region beneath the head and/or on top of the bed. For example a series of light strips could almost completely encircle the bead and therefore illuminate the closed eyelids for almost any sleeping bead position with a direct line of sight.

The lamps can emit continuous or modulated or flash illumination. Flash illumination has the potential advantage to saturate the retinal rod system utilising a retinal rod kinetic response that is similar to light adaption [Ref4][Ref5]. The light from the luminaire is within the absorbing wavelength band of retinal rods which closely matches the absorptive spectrum of ganglion photoreceptors. Retinal rod absorption is approximately between wavelength 460nm and S2Onm and therefore LEDs with peak emission within this wavelength band are highly suitable light generating components. LEDs they emit over a relatively narrow band of wavelengths and remain operational for many years. Lasers are also a potential light source offering a narrower band emission than LEDs.

[Refl] 6 Arden, S Jyothi, C Hogg, "Regression of early diabetic macular oedema is associated with prevention of dark adaptation." National Institute of Health, Eye (Lond). 2011 Dec;25(12):1546-54 [Ref2] "Method and devices for preventing retinal diseases", WO 2005079716 Al, http://www.google.com.ar/patents/W020050797l6 A1?cl=en [Ref 3] Ketema N. Paul, Talib B. Saafir, and Gianluca Tosini "The role of retinal photoreceptors in the regulation of circadian rhythms" Rev Endocr Metab Disord. 2009 Dec; 10(4): 271-278 [Ref 4] S. He and D. MacLeod "Spatial and temporal properties of light adaptation in the rod system" Vision Research 40 (2000) 3073-3081 [Ref 5] T. Kraft and D. Scbneeweis "Visual Transduction in Human Rod Photoreceptors" Journal of Physiology (1993), 464, pp. 747-765