GB2352182A

GB2352182A - Photic stimulator with eye-movement cue

Info

Publication number: GB2352182A
Application number: GB9912993A
Authority: GB
Inventors: Peter Carr
Original assignee: Individual
Current assignee: Individual
Priority date: 1999-06-05
Filing date: 1999-06-05
Publication date: 2001-01-24
Also published as: GB9912993D0

Abstract

A photic stimulator which has high intensity L.E.D.'s mounted to the lateral and nasal sides of the eyepieces of goggles in such a manner that the light falls either on the left or on the right sides of the user's visual field. The L.E.D.'s are driven by a pulse generator 14 to flicker at a frequency between 15 and 20 Hz.. The lights to each side of the visual field are further modulated by a second pulse generator 15 to switch alternately on and off every few seconds so as to serve as a cue for the user to make horizontal sweeps of the eyes. A safety cut-out feature is provided by means of two touch-pads, the device only operating when the user's fingers or hand rest upon the touch-pads.

Description

2352182 PHOTIC STIMULATOR WITH EYE-MOVEMENT CUE This invention is an

electronic device for medical use in the treatment of mental disorders. It may also be used without medical super-vision for personal development, self-therapy, and meditation.

The essential feature of this invention for which patent protection is being sought is that it effects two things simultaneously it delivers to the eyes of the user flickering light within a specific frequency range, and secondly, it simultaneously provides a cue stimulus to aid the user in making horizontal sweeps of the eyes from side to side. The originality of the invention resides in its combination of two separate areas of medical research, namely photic stimulation and eye-movement desensitisation.

The availability of increasingly bright Light-Emitting Diodes in recent years has meant 0 that photic stimulation (stroboscopic light) can now be delivered safety and effectively in (Tlasses, uo(.. les, and visors. The application of this technology has, for the most part, sou-1it to entrain the brain's rhythms to theta and alpha frequencies (4-13) Hz.) and thereby produce an "electronic tranquilliser". Many such devices have been manufactured commercially and marketed as aids to relaxation. These devices do not (Tenerally deliver higher frequencies in the 15-20 Hz. range since these are known to be cipitate an epileptic seizure.

potentially the most likely to pre i i This invention, however, does utillse the higher and more activating frequencies in the n beta range (15-20 Hz.) to intentionally mobilise disturbance within the brain and bring ernotionally-charged material into conscious awareness for release and integration. The photic stimulation is used as a non- specific activator of unconscious content.

Since the late 1980's one of the most effective and rapidly proliferating treatment methods to have evolved for the resolution of mental disorders has been eye-movement desensitisation. Lateral sweeps of the eyes during confrontation with traumatic imagery have been found to crucially empower the brain's innate auto-regulatory capabilities for processing disturbance towards integration and resolution. In the clinical method of eye-i-novement desensitisation, the patient is asked to follow with the eyes the horizontal sweeps of the therapist's hand at moments of high emotional charge. The innovative feature of this invention is to so arrange the output of L.E.D.'s within go-Ties or ulasses I - C.C. C.) that this manually produced visual cue be replicated and automated. Thus the activation effects of photic stimulation and the synthesis effects of eye-movements are readily combined to produce a therapeutic device which both mobilises any underlyimz, disturbance within the brain and simultaneously achieves its integration.

Zl Since it delivers the potentially most epileptogenic frequencies of stroboscopic light, this invention incorporates a safety cut-out feature, analogous to the "dead-man's handle" in a train, whereby the device switches off as soon as voluntar,, muscular control is lost should the user fall asleep or begin to suffer an epileptic seizure.

C) 2 According to the present invention there is provided a photic stimulator comprising a mounting positioned in front of the eyes, in the form of glasses, goggles or visor, to hold high intensity Light-Emitting Diodes, the L.E.D.'s arranged in such a manner that their light falls either to the left or to the right sides of the user's visual field, the L.E.D.'s being driven by an electronic frequency generator to flicker at a frequency between 15 Hz, and 210 Hz., the L.E.D"s to each half of the visual field being also alternately switched on and off by a second pulse generator with a period between I second and 20 seconds to act as a cue for the user to inake horizontal sweeps of the eyes by following the light. Instead of LightErnittinu Diodes, the 11-ht sources may be small bulbs, or some form of Liquid Crystal Display. The light may be either white, a colour, or a mix of colours, Diffusion filters may be provided over the light sources. The light sources are arranged in arrays within the

In rnountinc, in such a manner that, when the user fixates the eyes straight ahead, the light sources are seen in the lateral aspects of the visual field to right and left sides. The light sources flicker at a frequency between 15 Hz. and 20 Hz., the frequency of flicker either beinty constant, or adjustable, or varying periodically, so as to fall predominantly within that

01 ran(re. The 11-1-its to the left and right sides of the visual field may alternately switch completely on and off, or the brightness or colour of the flickering light sources may be modulated so as to alternate back and forth between right and left sides, one side appearing brighter or a different colour from the other to serve as a cue for eye-movements. The lateral alternation has a period that lies within the range of I second to 20 seconds. The lateral alternation may be continuous, or may occur intermittently, either by manual control or automated programming. The period of alternation may be fixed and constant, or it may be adjustable, or it may vary cyclically. Controls for adjusting the stimulation may be integral to the mounting, or they may be on a control box connected to the mounting by a cable, or the mounting may be connected to a computer and serve as a peripheral device controlled by a computer programme. The mounting may be the visor of a helmet or headset which contains other electronics in addition to the present invention, the present invention formim, a self-therapy or detraumatisation facility in a more complex audio, telecommuni cations or military headset. Two surface-mounted electrodes in the form of touch-pads may be provided, either on the control box or on a separate pod, so that the light sources operate only when the user's fingers or hand rest upon the electrodes.

A specific embodiment of the invention will now be described by way of example with reference to the accompanying drawing in whlch- Figure I shows the arrangement of high brightness L.E.D.'s within the eyepieces of Z) 0 standard welding goggles-, FI-ure 2 shows the control box with brightness control and touch-pads-, C> Fh,ure 3 is a diagram of the electronic circuit housed within the control box and its C connection via a cable to the LED's within the goggles; C.

Figure 4 Is a diagram of the additional safety cut-out circuit connected to the touch-pads.

3 Referrino to fi(,Ure I an array of two high intensity L.E.D.'s 10 in series are positioned on the lateral aspect of the left eyepiece of a set of go-des (e.g. standard welding 0 MID (YO(Y(Fles) so that they are seen by the user to be in the left side of the visual field. An n array of two high intensity L.E.D.'s I I in series are positioned on the nasal side of the left eyepiece so as to be seen by the user in the right half of the visual field. Similarly in the right eyepiece of the goggles, two L.E.D.'s 12 are positioned nasally and two L.E.D."s I ') laterally. All LED's are held within diffusion covers.

The LED's in the goggles are connected by a 3-core cable to the control box 17 shown C) 0 in figure 2.

The lateral LED's of one eyepiece are connected together in parallel with the nasal LED's of the other eyepiece. The LED's comprising the left visual field and the LED's

C) comprising the right visual field are connected by the cable to the two respective outputs of the circuit as shown shown in figure 3.

Referrin- to the circuit dia,,ram shown in figure 3 the flicker generator 14 is a 555 timer in a standard astable arrangement with values of external components such that a square wave output of 18 Hz. is produced which drives all eight LED's via a transistor.

C) The modulation clock 15 is another 555 timer in astable mode with values of external components such that a square wave output of period 6 seconds is generated. This is connected via a standard CMOS 4013 flip-flop 16 and transistors to the LED's so that the LED's to the left visual field and the LED's to the right visual field are alternately switched on and off

Two surface-mounted touch-pads 18 are provided on the control box with the accompanying additional circuitry shown figure 4 such that the main circuit as described above only receives power from a standard 12 Volt mains adaptor when two fingers or the hand of the user are resting on the touch-pads.

The brightness knob 19 of figure 2 is attached to the potentiometer 20 of figure 3.

I

Claims

I A photic stimulator comprising a mounting positioned in front of the eyes, in the form of -lasses,,o,,(Tles or visor, to hold high intensity Light-Emitting Diodes, the L.E.D.'s arranged in such a manner that their light falls either to the left or to the right sides of the user's visual field, the L.E.D.'s being driven by an electronic frequency (Tenerator to flicker at a frequency between 15 Hz. and 20 Hz., the L.E.D's to each half of the visual field being also alternately switched on and off by a second pulse (Yenerator with a period between I second and 20 seconds to act as a cue for the user to make horizontal sweeps of the eyes by following the light.

A photic stimulator as claimed in Claim I wherein small light bulbs or Liquid Crystal Displays are used as light sources.

A photic stimulator as claimed in Claim I or Claim 2 wherein the frequency of stimulation is varied, either- manually or by automated control, so as to fall within the specified range 4 A photic stimulator as claimed in any preceding claim wherein the lateral alternation of the lights is produced by a modulation of brightness or colour so as to serve as a cue for eye-movements.

A photic stimulator as claimed in any preceding claim wherein the lateral alternation of the lights occurs only intermittently, either by manual control or by automated programming.

6 A photic stimulator as claimed in any preceding claim wherein the lights are 1-1 C) controlled by a computer to which the mounting is connected.

7 A photic stimulator as claimed in an), preceding claim wherein the mounting is I the visor of a headset comprising other electronic devices such as audio, telecommunications or military equipment.

8 A photic stimulator as claimed in any preceding claim wherein two surfacemounted electrodes comprise a safety cut-out feature whereby the lights only flicker when the the user's fingers or hand rest upon the electrodes.