WO1997021165A1

WO1997021165A1 - Switching and/or control method and device which use a computer

Info

Publication number: WO1997021165A1
Application number: PCT/EP1996/005464
Authority: WO
Inventors: Johanna Lorenz; Gabriele Scheugenpflug-Leibig
Original assignee: Johanna Lorenz; Scheugenpflug Leibig Gabriele
Priority date: 1995-12-06
Filing date: 1996-12-06
Publication date: 1997-06-12
Also published as: DE19545392A1; DE19545392B4; AU1177597A

Abstract

The invention concerns a switching and/or control method and device which use a computer and in which the brain waves of a person are detected and converted into digital switching and/or control commands. According to the invention, in order to be able to reproduce output signals more accurately and reliably in a method and device of this type, the brain wave signal pattern (c, d) is compared with a predetermined specimen signal pattern (a, b). Preferably, electrodes (2) secured on a head mounting (1), in particular a head band, are used for this purpose. The comparison is carried out in an evaluation computer (5) with an upstream amplifier (7) and coupled transducer (4).

Description

Description:

Method and device for switching and / or control under

Using a calculator

The invention relates to a method and a device for switching and / or controlling using a computer, wherein the brain waves of a person are detected, which are converted into digital switching and / or control commands.

In WirtschaftsWoche No. 38 of September 14, 1995, pp. 132 and 134, a control system is described with which the computer should be controlled solely with the mind. Human brain waves are directly converted into digital control commands for a computer. A type of thimble is used as a sensor for measuring brain waves, which, when put over a fingertip, measures blood pressure, pulse rate, skin tension and the like. A downstream computer converts these values into control commands. With this finger sensor both type and intensity of thoughts are to be detected. However, this system still requires a considerable amount of hardware and software.

Another system is described on page 134 of this publication, according to which electromagnetic brain waves are measured by means of an electroencephalograph (EEG), which is accommodated in a kind of headband. The measured values are transmitted wirelessly to an evaluation computer and converted into control signals. The type of evaluation of the measured brain waves is not described here. This also applies to the methods or devices according to GB-A-22 20 089, US-A-42 01 224 or WO-A-95/18 565.

In addition, switching and / or control devices are known from the disabled area, which detect the eye movements. However, this type of control requires a very high concentration of the operator, since there is a large number of optical stimuli in the field of vision, which are too false

ORIGINAL DOCUMENTS Can lead to output signals. There is therefore still a considerable error rate in the switching signal or control command obtained therefrom. This applies to the research reports in: "Biomedical engineering", 1992, pp. 303 - 309 and 1994, pp. 264 - 269, according to which the reproducibility of the signals is a maximum of 80%.

Accordingly, the object of the invention is to improve a method and a device for switching and / or controlling using a computer with regard to accuracy and safety of the output signal.

This object is achieved by a method according to the features of claim 1 or by a device with the features of claim 5.

Accordingly, in the proposed method or device, the signal curve of the brain waves is compared with a defined pattern signal curve. This defined pattern signal curve can be stored on a person-specific or individual basis in the evaluation computer and / or can preferably be formed by the input signal or source signal itself that is generated in a targeted manner and recorded by the human senses. Here it is assumed that, for example, an input signal picked up via the ear, such as e.g. B. a Morse signal in the brain wave signal sequence has essentially the same course (frequency, amplitude). By comparing the input signal recorded by the human senses and the brain wave signal curve generated thereby, the correspondence (correlation) can be checked in the evaluation computer to what extent the person has actually consciously recorded the source signal from the environment. In this way, background noises or disturbing light pulses can be filtered out.

As a result, reliably reproducible digital switching and / or control commands can be converted, the source signal being able to be picked up by any human sense, preferably via the ear or the eye. In particular, the capture of the Source signal through the eye has the advantage that light sources and thus certain light pulse sequences can be recorded over a long distance. This means that even complex systems can be controlled, for example hall cranes or vehicles.

A preferred exemplary embodiment is explained and described in more detail below with reference to the drawing. Here show:

1 shows a schematic overall representation of the system; 2 shows a two-channel embodiment with a flow chart; and FIG. 3 shows a single-channel embodiment with a flow chart.

According to FIG. 1, the five functions ON, OFF, LIFT, LOWER and ROTATE are available on a control unit 3 in a crane (not shown in more detail). For each function, a light pulse sequence a, b, each with a different frequency and / or amplitude, is preferably emitted in the direct working area of the hall crane, for example by a respective light source as a signal generator 4 with a frequency of the emitted light pulse of, B. 20, 22, 24, 26 and 28 vibrations per minute. Thus, when the operator desires the LIFT function, he looks at the light source 4 with the pulse train of 24 vibrations. By specifically looking at this special light source 4 for the LIFT function, this control command is consciously taken over and subsequently generated with the essentially same pattern in the brain stream. A corresponding sensor, preferably a headband as head holder 1 with an EEG electrode 2 at the visual center, thus detects the signal curve c, d, so that in an evaluation computer 5 this brain wave signal sequence c, d with the defined pattern signal curve a, b of the source signal (e.g. lamp 4 with 24 vibrations) can be compared. If the evaluation computer 5 then detects an at least qualitatively matching signal sequence, the corresponding control command e, here LIFT, is sent to the control unit 3 by cable or radio and executed. This results in remote control for a large number of machines and systems which are controlled by the digital control device 3. The source signals a, b can also be formed by certain sound sequences when recorded by the sense of hearing, for example by known morse signals. So that users of such digital control devices 3 no more input keyboards or control levers are required, so that the proposed switching and / or control device is particularly suitable for the disabled or for work in which the hands are not free or are otherwise required, such as . B. Surgeon or pilot activities.

As already indicated, acoustic or optical stimuli are suitable as source signals a, b, but source signals via the olfactory or sensing organs are also possible, since each of the human senses (seeing, hearing, smelling, feeling, touching) with a corresponding specific stimulus Brain generates a defined brain current as a measurable electrical quantity. These electrical signals can be measured at various locations on the outside of the human head, which are known from medical technology. For example, certain points on the outside of the head are known for the visual center and optical stimuli, as are used in particular in the EEG measurement. By measuring the frequency and the signal pattern of the triggering stimulus, the measured brain current signals c, d can serve to trigger or control switching processes, as will be explained below for the human sense "seeing".

Here, a light source 4 as a signal transmitter, controlled with appropriate software, as represented by the pulse train a ', b' between control unit 3 and evaluation computer 5, sends light pulses of a certain frequency, which is coded, for example, in a type of morse code with changing peaks, and a certain minimum light intensity, which depends on the respective environment. Both eyes of an observer or an operator record the light pulses a, b from this light source 4. This is passed on via the optic nerves Light impulses to the two visual centers in the human brain, where the measurable conversion (photostimulation) of the light impulses takes place in each of the two visual centers. A plurality of electrodes 2, which are preferably arranged on a headband, cap, cap or helmet as head holder 1 and are assigned to certain points on the outside of the head known from medical technology, receive these signals, the radiation power of which is sufficiently high. Suitable electronics in an amplifier 7 can additionally amplify these signals c, d of each visual center to a higher level. The signals of each visual center amplified in this way are then forwarded to the evaluation computer 5, which can also contain the program mentioned at the outset for controlling the light source 4 with the pulse sequence a ', b'. This control program for the light source 4 and the amplifier 7 for evaluating the brain current signal sequence c, d can be components of the evaluation computer 5. The construction is also possible that a microprocessor takes over both the function of the control computer in the control unit 3 for controlling the light source 4 and the task of the evaluation computer 5. In this case the control signals a ', b' corresponding to the source signals a, b 'are sent by the control unit 3 to the evaluation computer 5 by cable or radio in order to form the basis of comparison there.

The evaluation computer 5 first carries out a comparison as to whether the signals c, d from the two halves of the brain of the human being (visual center) are the same in intensity (amplitude) and frequency within an adjustable tolerance quality. If this is the case, it follows that the human being deliberately looks with both eyes at the respective pulsating light source, for example at the light for the control command LIFT.

Then it is checked according to FIG. 2 whether the signal sequence c, d from the visual centers and the emitted light pulses a, b have the same signal sequence and frequency. This comparison is made by simply coupling the evaluation computer 5 and the Control unit 3 possible, as indicated by the double arrow for the pulse train a ', b'. If the comparison correlates within certain limit values, it follows that the person deliberately looks into the corresponding pulsating light source 4 and wishes to trigger the corresponding control command (here: LIFT). In addition to this comparison, a certain time period of, for example, one second can be defined in the evaluation computer 5 as a further condition, so that in order to trigger the switching and / or control command, the respective light source 4 must be consciously considered for about one second so that the brain current Signal sequence c, d in correlation with the input signal sequences a, b or a ', b' is present over a time range of approximately one second.

Are the two above conditions, namely the agreement of right and left vision center d. H. between c and d, as well as the correspondence of the frequency and / or amplitude of the emitted light pulse a, b and the recorded brain flow c, d, the evaluation computer 5 triggers an action assigned to the corresponding light pulse. In the example above, this is the LIFT switching command.

Instead of comparing the two measurement signals at the right and left vision centers, the evaluation computer 5 can also use the stronger of the two signals for evaluation. 3 is therefore also suitable for the visually impaired who have poor visual performance in one eye. In order to increase the switching and / or control security, however, the checking period should be selected to be longer in order to exclude interfering influences, such as accidental viewing of the respective light source.

The source signals a, b, (in the example described the light pulses) can be formed by arranging a plurality of lights 4 with a certain spatial separation. Each of these lights 4 sends a different coding or flashes, for example, in a different frequency or in a special color. This source signal sequence can be transmitted from control unit 3 to the evaluation computer (arrow a ', b' upwards) or the control of the light source 4 can take place from the latter. As a result, the associated switching process can be triggered by deliberate observation of the corresponding luminaire 4, since the evaluation computer 5 can use the respectively emitted source signals a, b as a basis for comparison to check whether a, b = c, d.

Another application to vehicles to prevent so-called second sleep is described below. At the start of the journey, the driver puts on a headband, a cap or a modified pair of glasses as head holder 1 for the electrode (s) 2, the arms of which, for example, are longer and extend to the photostimulation points on the back of the head in order to receive the measurement signals c, d on the right and left vision center. Simultaneously with the placement of such sensors or electrodes 2, the evaluation computer 5 can be adjusted or calibrated to the brain wave intensity of the respective driver by input on the on-board computer of the vehicle. This is particularly necessary because, depending on the driver's condition, the intensity of the brain waves c, d can be different. In this calibration process, for example, the on-board computer of the vehicle flashes a light source or a light-emitting diode 4 at short intervals in the driver's field of vision. With these signals, the evaluation computer 5 is adjusted with regard to its definition of the limit values to the respective driver and his brain waves.

The evaluation computer 5, which can be part of the on-board computer, lights up a lamp or light-emitting diode 4 at regular intervals (program-controlled according to signal sequence a ^/ , b ') in the driver's field of vision (= source signals a, b), for example in the dashboard or in the windshield mirrored. The brain current signal sequence c, d induced thereby is recorded via the electrodes 2 at the visual centers. The evaluation computer 5 in the on-board computer evaluates the signal obtained in this way from the at least one, preferably both vision centers. If the driver has closed his eyes due to tiredness or the beginning of sleep, the output signal c, d is missing or is correspondingly lower than when he is awake. In this case, the on-board computer sends a further sequence of flashes of light to determine whether the driver has only briefly looked in the rear view mirror or has actually fallen asleep. In the first case, the system returns to the normal check status. If the driver does not respond to the increased frequency of the flashes of light (= modified signal sequence a ', b'), the processes programmed for this hazardous situation are initiated, for example activation of an acoustic warning or even the reduction in speed or provocation of misfires with a "jerky" driving style to "wake up" the driver.

In a modified version of these "anti-sleep glasses" for drivers, but also for train drivers, certain brain current signal sequences (wave patterns) of the individual driver can also be set during the calibration process. These are primarily the two variants, the driver looking attentively through the windshield or the other extreme case that the driver has closed his eyes. By carrying out these two extreme examples, the driver detects the threshold value that occurs in each case in the on-board computer and stores it in a memory module 6. With these stored signals, the evaluation computer 5 is thus adjusted to the respective driver and his brain waves. In particular, the threshold values of the two brain wave patterns c, d, on the one hand during normal vision through the windshield and on the other hand with eyes closed, are extremely different, so that reliable statements about the respective condition of the driver can be obtained therefrom.

During the journey, the visual center (or both visual centers) continuously records a large number of light pulses. As long as the evaluation computer 5 this multitude of different light pulses can measure over the electrodes 2 on the driver's head, it is assumed that the driver has opened his eyes and is awake. Suitable alerting measures are only initiated when the evaluation computer 5 detects a reduction in the signals or even the received signals c, d correspond to the "eyes closed" state determined during calibration. It is also essential here that appropriate countermeasures can be initiated even when the brain current activities are reduced in the direction of the brain wave pattern for the “eyes closed” state. For example, the on-board computer can increase the number of pulses of the light pulses a, b emitted by the light source 4 by modifying the control signals a ', b'. The comparison base is adjusted in the evaluation computer 5 in accordance with the change in the control signals a ', b' emitted to the light source 4.

A contactless switching and / or control arrangement can thus be created by this embodiment. This can serve as a replacement for the so-called "dead man's switch" for train drivers, for example. By detecting the brain current signal sequences c, d in the above sense, it can be checked whether the driver is still awake. It is advantageous here that the train driver does not have to operate any actuating elements periodically as before, so that he does not have to take his hands off the operating elements, such as brakes, etc.

The proposed switching and / or control device is particularly advantageous even when working in closed test chambers, with gloves that make the operation of switches extremely difficult. The optical version of the switching device is also particularly suitable here. The arrangement of the sensors can, as described above, be provided on glasses, but also on a headband, a hat or a helmet, which is usually prescribed in such work areas anyway. Thus there is no impairment of the individual's freedom of movement, being for disabled people z. B. arm amputees also implanting such an electrode, e.g. B. is conceivable behind the auricle.

Furthermore, similar to control unit 3 (preferably with an integrated control computer), contactless cursor or keyboard control is possible in that the respective key or cursor arrow points to a specific signal pattern (e.g. frequency, ie specific color, symbolism or oscillation curve) Monitor is assigned. The operator considers z. B. a certain cursor arrow (e.g. upwards) on the monitor, which corresponds here to the light source 4, this results in a certain output signal pattern in brain current, which can then be assigned to this cursor key, because its light frequency (e.g. color red ) is known, in particular is at least qualitatively defined in the memory 6. The evaluation computer 5 can thus detect the specific signal curve c, d of the brain waves, assign it to a specific (cursor) key by using the memory 6, and compare it over a specific period of z. B. perform half a second and trigger a corresponding switching command (here: e.g. cursor up) if they match. This non-contact system is therefore particularly suitable for controlling the so-called window technology on a computer screen.

Claims

claims

1. A method for switching and / or controlling using a computer, wherein the brain waves of a person are detected, which are converted into digital switching and / or control commands, characterized in that the signal curve (c, d) of the brain waves with a predetermined Pattern waveform (a, b) is compared.

2. The method according to claim 1, characterized in that the predetermined pattern signal curve (a, b) corresponds to a stored signal curve (a ', b').

3. The method according to claim 1 or 2, characterized in that the pattern signal curve (a, b) is formed by a signal generator (4) and in a corresponding signal form (a ', b') is fed to an evaluation computer (5).

4. The method according to any one of claims l to 3, characterized in that the signal curve (c) of the right brain is compared with the signal curve (d) of the left brain.

5. Apparatus for carrying out the method according to one of claims 1 to 4, characterized in that the comparison between the signal curve (c, d) of the brain waves with a predetermined pattern signal curve (a, b) takes place in an evaluation computer (5), which is coupled to the signal generator (4).

6. The device according to claim 5, characterized in that the evaluation computer (5) has a memory (6) for storing pattern waveforms (a, b).

7. The device according to claim 5 or 6, characterized in that the signal curve (c, d) of the brain waves, in particular is detected at the visual center with electrodes (2) arranged on a head holder (1).

8. Device according to one of claims 5 to 7, characterized in that a comparator (8) for checking the signal profiles (c) and (d) of the two brain halves upstream of the evaluation computer (5).

9. Device according to one of claims 5 to 8, characterized in that the pattern signal curve (a, b) on a light source (4), in particular a monitor with a plurality of light sources (4) with different signal curves is shown.

10. Device according to one of claims 5 to 9, characterized in that at least one electrode (2) is arranged on a head holder (1) designed as a headband or cap.

11. Device according to one of claims 5 to 9, characterized in that at least one electrode (2) is arranged on a head holder (1) designed as glasses or a helmet.

12. The device according to one of claims 5 to 9, characterized in that at least one electrode (2) is implanted in the brain area.