AU2003203967A1

AU2003203967A1 - Apparatus for administering light stimulation

Info

Publication number: AU2003203967A1
Application number: AU2003203967A
Authority: AU
Inventors: Leon Lack; Leon Snigg
Original assignee: Flinders University of South Australia
Current assignee: Flinders University of South Australia
Priority date: 2003-05-01
Filing date: 2003-05-01
Publication date: 2004-11-18

Description

Regulation 3.2

AUSTRALIA

Patents Act 1990 COMPLETE SPECIFICATION FOR A STANDARD PATENT

(ORIGINAL)

Name of Applicant(s): Actual Inventor(s): The Flinders University of South Australia, ABN 65 542 596 200, of Sturt Road, Bedford Park, South Australia 5042,

AUSTRALIA

Leon LACK Leon SNIGG Address for Service: DAVIES COLLISON CAVE, Patent Attorneys, of 1 Little Collins Street, Melbourne, Victoria 3000, Australia Invention Title: "Apparatus for administering light stimulation" The following statement is a full description of this invention, including the best method of performing it known to us.

-1- Q:\OPER\LKA\12212850 completedoc 1/5/03 P:AOPERLKA\1I2212850 Capdoc25710O- -2- Apparatus for Administering Light Stimulation This invention relates to the presentation of relatively intense visual light stimulation for the treatment of circadian rhythm disorders including sleep onset insomnia and early morning awakening insomnia, jet-lag, shift work fatigue, winter depression or seasonal affective disorder (SAD), and other conditions requiring the re-timing of human circadian rhythms (24-hour body clock).

The timing of the body's circadian rhythms very strongly determines our best times to sleep and to be awake and alert. The anatomical pathways from the retina to the brain and the hormonal and biological mechanisms underlying this biological clock resetting capacity of bright light are well known. It was first demonstrated in 1980 that bright light exposure could have a significant and direct impact on human physiological brain function. Since then the use of bright light stimulation at appropriate times in the 24-hour period has been shown to change the timing of the body's endogenous circadian rhythms. Stimulation in the evening, up to about 4 am, delays circadian rhythms, stimulation in the morning between 6am and phase advances rhythms.

Inappropriate timing of circadian rhythms is implicated in several sleep/wake and mood disorders. Delayed and advanced sleep phase syndromes, which debilitate their sufferers for several hours each day, arise from delayed and advanced circadian rhythms. Research has shown that sleep onset insomnia and early morning awakening insomnia are caused by delayed and advanced circadian rhythms respectively. Many patients with SAD have phase-delayed circadian rhythms.

Several methods have been proposed to deliver visual light stimulation for the adjustment of circadian rhythms. One approach utilises light boxes containing high intensity fluorescent light fixtures. However, these light boxes are large and require domestic high voltage power sources. Users must maintain visual contact P:\OPER\LKA\12212850 Cp do25/)7A)O- -3with the light box when it is in use and as a consequence are restricted in their movement. Although light boxes have been shown to be able to re-time the body clock in experimental conditions, their use in applied settings where the gaze of subjects is not controlled has not been demonstrated.

Another method is the use of a head mounted light visor as disclosed in U.S.

Patent 5,447,528. The light visor mounted at the forehead, well above the normal direction of gaze, is unlikely in most applied settings to stimulate the visual system with adequate light intensity to effect re-timing of the body clock. No study has confirmed their efficacy for this purpose.

The present invention seeks to provide an apparatus for administering sufficient intensity of an appropriate wavelength to effect re-timing of the human body clock, in a convenient and effective manner.

Accordingly, this invention provides an apparatus for administering light to effect re-timing of the human body clock including at least two light emitting diodes having an emission wavelength in the range 450nm to 560nm, a frame adapted to be worn on the face and support one of said light emitting diodes adjacent the surface of each eye to direct light at the pupil of each eye.

Preferably, the frame is in the form of an eyeglass frame supported by the nose in the customary manner. More preferably, the eyeglass frame includes substantially conventional ear stems.

The present invention uses light emitting diodes, preferably light emitting diodes with peak intensity at a wavelength of about 450nm and a secondary smaller peak at about 560nm, or more preferably with a single peak intensity at a wavelength of about 505nm.

P:A\OPER\LKA\12212850 cap.doc25iJ070- -4- Preferably, two light emitting diodes are mounted onto spectacle frames at the bottom branch of each eye frame such that the light output of the light emitting diodes is aimed at the pupils of each eye. A transparent sheath preferably covers each light emitting diode to provide diffusion of the light emitted from the light emitting diodes. Preferably, the distance from the tips of the light emitting diodes to the corneal surface of the eyes is between substantially 10mm and 15mm, and more preferably it is substantially 12mm. The effective intensity at the corneal surface of the light emitting diodes is preferably about 5,000 lux. This intensity approximates that from the prescribed use of light boxes.

In one embodiment the apparatus of the present invention includes regulated electronic circuitry to deliver a constant low current (12 milli amps) from a 9 volt dry cell battery providing a constant current supply for up to 15 hours use.

Preferably, a low battery warning is provided when the battery is coming to the end of its life, by flashing of the light emitting diodes, indicating to the user that they should replace the battery.

At power turn on, there is preferably a ramping up of intensity over about seconds before the light emitting diodes reach the maximum intensity required for effective operation, thus allowing the users eyes to adjust to the light slowly.

It will be apparent that because the apparatus is worn on the head, the spectacle mounted light emitting diodes ensure continued light stimulation irrespective of head movements. Additionally, being placed close to the centre of the visual field and slightly below the centre, the light emitting diodes ensure continued light stimulation irrespective of gaze of the eyes or drooping of the eyelids.

One embodiment of the invention will now be described, by way of example only, with reference to the accompanying drawings in which: PAOPMRLKA\I22I SS csp.doc2d7/0o- Figure 1 is a perspective view of an apparatus for administering light stimulation according to the invention; and Figure 2 is a perspective view from another angle of part of the apparatus shown in Figure 1.

As shown in Figure 1 the apparatus for administering to effect re-timing of the human body clock takes the form of a substantially conventional eyeglass frame 1 having ear stems 2 and a nose bridge 3. The glasses are worn on the head of a patient in the conventional manner. Two light emitting diodes 4, 5 are mounted on bifurcated stems 6, 7 to be located approximately central to the rims 8, 9 of the eyeglass frame 1. The eyeglasses are not fitted with lenses. The diodes 4, 5 are aimed directly at the pupil of the adjacent eye and are positioned at about 12mm from the eye surface. The diodes 4, 5 are a high intensity light emitting diode such as Hewlett Packard HLMP-CE23 diodes that provide a dominant wavelength of about 505nm. The light emitting diodes 4, 5 are powered through conventional wiring 10 connected with a power supply unit 11. The power supply unit 11 provides a current of about 12 milli amps from a 9 volt dry cell battery. This provides up to about 15 hours continuous use.

In tests leading to the present invention, it has been demonstrated that both "white" (emission peaks at 450nm and 560nm) and "blue/green" (emission peak at 505nm) high intensity light emitting diodes have biological effects on the timing of the biological clock. They have the effect of suppressing the production of melatonin from the pineal gland. In a direct test of re-timing capacity one administration of blue/green light emitting diodes light for two hours from midnight to 2am in an applied setting resulted in an average phase delay of the melatonin circadian rhythm of 51 minutes. The same procedure with the white light emitting diodes resulted in an average phase delay of 30 minutes.

The foregoing describes only one embodiment of the invention and modifications can be made without departing from the scope of the invention.

P:AOPER\LKA\IZ212850 cap.doc2370- -6- The reference to any prior art in this specification is not, and should not be taken as, an acknowledgement or any form of suggestion that that prior art forms part of the common general knowledge in Australia.

Claims

2. The apparatus as claimed in claim 1, wherein the frame is in the form of an eyeglass frame supported by a nose in the customary manner.
3. The apparatus as claimed in claim 2, wherein the eyeglass frame includes substantially conventional ear stems.
4. The apparatus as claimed in any one of claims 1 to 3, wherein the light emitting diodes have a peak intensity at a wavelength of substantially 450 nm and a secondary smaller peak at a wavelength of substantially 560 nm.
5. The apparatus as claimed in any one of claims 1 to 3, wherein the light emitting diodes have a single peak intensity at a wavelength of substantially 505 nm.
6. The apparatus as claimed in any one of claims 2 to 5, wherein two light emitting diodes are each mounted at a bottom branch of a respective eye frame of the eyeglass frame such that the light output of each said light emitting diode is aimed at the pupil of a respective eye.
7. The apparatus as claimed in any one of claims 1 to 6, wherein a transparent sheath preferably covers each light emitting diode to provide diffusion of the light emitted from the light emitting diodes.
8. The apparatus as claimed in any one of claims 1 to 7, wherein the distance from the tips of the light emitting diodes to the corneal surface of respective eyes is between substantially 10mm and P:\OPER\LKA\I22121) 0pdo25t/)AKX)- -8-
9. The apparatus as claimed in claim 8, wherein the distance from the tips of the light emitting diodes to the corneal surface of respective eyes is substantially 12mm. The apparatus as claimed in any one of claims 1 to 9, wherein the effective intensity of the light emitting diodes at a corneal surface is substantially 5,000 lux.
11. The apparatus as claimed in any one of claims 1 to 10, further including electronic circuitry to deliver a constant low current from a battery.
12. The apparatus as claimed in claim 11, wherein a low battery warning is provided when the battery is coming to the end of its life.
13. The apparatus as claimed in claim 12, wherein the low battery warning is provided by flashing of the light emitting diodes.
14. The apparatus as claimed in any one of claims 1 to 13, wherein there is a ramping up of intensity over substantially 30 seconds before the light emitting diodes reach the maximum intensity required for effective operation, thus allowing a user's eyes to adjust to the light slowly. An apparatus substantially as described with reference to the drawings and/or examples. DATED this 1st day of May, 2003. The Flinders University of South Australia DAVIES COLLISON CAVE Patent Attorneys for the Applicant