Patent No. 5409445 Brain wave synchronizer

 

Patent No. 5409445

Brain wave synchronizer (Rubins, Apr 25, 1995)

Abstract

A device for inducing the brain waves of a user to assume a predetermined frequency comprising a playback device, stereo earphones, and at least one light mounted on glasses in front of each eye of the user. Three separate control signals are pre-recorded superimposed onto a single control track. This composite signal is read by the playback device and is decomposed into the separate control signals by filters in a decoder/controller. One control signal drives a first LED and another drives a second LED. The number of sinusoids within the first and second control signal determine the light intensity. The third control signal is passed alternately to two speakers, with the switching between the speakers being controlled by the state of the first and second control signal. Conventional earphones and a conventional tape player may be used. The invention may be used to selectively activate the pins of a parallel port on a personal computer, to which are connected the LEDs. Also, the invention may include a mercury tilt switch mounted to the spectacles worn by the user to determine if he is dozing off and transitioning into the Theta brain wave state. The spectacles have optional peep holes in the lenses.

Notes:

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to an apparatus for inducing desired brain wave frequencies in a user by presenting periodic visual and audio signals to the eyes and ears of the user, respectively.

2. Description of Related Art

It is well known that the human brain generates periodic electrical signals, commonly referred to as "brain waves." These brain waves range in frequency from about 1 Hz to about 36 Hz and, for ease of reference, are commonly divided into four or more groups. "Beta" waves (12 to 36 Hz) tend to dominate in the brain during normal waking activity; "Alpha" waves (8 to 12 Hz) have been discovered to occur most frequently when the person is relaxed; "Theta" waves (4 to 7 Hz) are most common during periods of sleep or deep meditation and also occur during periods of learning or memory recall; and "Delta" waves (1 to 4 Hz) appear most frequently during periods of the deepest sleep. These ranges of frequencies are approximate, but in general, the dominate brain wave frequency increases with increasing mental activity.

Experiments have indicated that when light is repeatedly flashed into the eyes of a subject within this frequency band, the brain waves of the subject tend to assume the frequency of the flashing light. It has also been discovered that such "synchronization" of brain waves may lead to brain seizures in epileptics or in other people who have a history of brain seizures.

On the other hand, experiments have demonstrated that pulsating light and sound can induce a synchronized pattern of brain waves. There is, furthermore, evidence to indicate that by inducing a subject's brain waves to come within the Alpha range, the subject at least will be able to relax better, and may even be able to learn more quickly and permanently. Many researchers also report that a subject whose brain waves are caused to synchronize within the Alpha range or lower are better able to receive subliminal or audible audio messages.

Differential audio frequencies have also been shown to cause similar effects. For example, if the frequency of a tone played into one ear of a subject is 10 Hz higher than the frequency of a tone played into the subject's other ear, experimental evidence indicates that the subject's brain acts in a way similar to a "heterodyne," tending to generate brain waves at a frequency approximately equal to the difference in frequency between the two tones. That is, in this case, 10 Hz. The same result arises when tones are alternately put to the left and right ears with a frequency equal to the desired synchronization frequency.

There are accordingly many devices now available that are designed to present flashing lights, alternating tones, or both, to the eyes and ears of a user. Some devices use "bio-feedback," in which the brain wave frequency of the user is sensed and used to control the frequency of the flashing lights or pulsating tones; the user thereby attempts to train herself to produce the desired frequency, which is reinforced by the flashing lights and pulsating tones. Many other devices, which do not measure the brain waves in an attempt to create a feedback loop, actively control the flashing or switching frequency. Examples of such devices are described in the following U.S. patents:

U.S. Pat. No. Inventor(s) Issue Date

________________________________

5,064,410 Frenkel, et al. Nov. 12, 1991

5,036,858 Carter, et al. Aug. 6, 1991

4,955,389 Schneider Sept. 11, 1990

4,902,274 Gleeson, III Feb. 20, 1990

4,834,701 Masaki May 30, 1989

4,665,926 Leuner, et al. May 19, 1987

4,632,126 Aguilar Dec. 30, 1986

4,456,347 Stahly June 26, 1984

4,396,259 Miller Aug. 2, 1983

4,335,710 Williamson June 22, 1982

4,315,502 Gorges Feb. 16, 1982

4,008,714 Silva, et al. Feb. 22, 1977

3,882,850 Ballin, et al. June 13, 1975

All of these known devices create the synchronizing pulsed light and/or sound by actively generating an electrical pulse at the desired frequency. This electrical synchronization pulse activates a small set of lights in front of the user's eyes, and controls a tone generator whose signal is fed into earphones. In many of these conventional devices, the electrical pulses result from a timing program in the memory of a microprocessor or a computer. In some of these devices, the user herself selects the synchronization frequency. In other devices, one or more frequencies or programs of varying frequency are generated automatically, whereby the user, in some cases, can select which program she wishes to follow.

The foremost drawbacks of known devices for synchronizing brain waves are that they are complicated and expensive. They typically contain many mechanical and electrical components that require careful testing and calibration. Few are suitable for easy use by most individuals, and fewer still are within their budgets. Even the least expensive of these known devices sells at retail for prices on the order of hundreds of dollars.

In order to reduce complexity, at least one device (see the patent to Gleeson) encodes control signals on magnetic tape. Such devices, however, typically require four or more audio channels simultaneously, so that they are not suitable for use in common 2-channel devices such as the portable stereo cassette tape players already owned by a large section of the population. Furthermore, the Gleeson device requires special conditioning circuitry separate from the tape player in order to drive the lights and speakers used; this increases design costs.

It is therefore an object of this invention to provide a device for inducing synchronized brain waves using both flashing lights and pulsating tones that is easy to use and that can be manufactured from inexpensive and compact components so as to make it much more affordable than existing devices. It is another object to adapt the present invention to a personal computer. It is yet another object of the present invention to detect when a user enters the Delta brain wave state.

SUMMARY OF THE INVENTION

The present invention relates to a playback device, stereo earphones, and at least one light mounted on glasses in front of each eye of the user. In an exemplary embodiment, first, second and third control signals are prerecorded superimposed onto a single control track. The playback device, which may be a conventional tape player, reads the control track, and the corresponding electrical composite signal is transmitted via standard connectors to a decoder/controller. The decoder/controller includes one filter (preferably band-pass) for each of the three control signals.

The first control signal, after filtering and extraction from the composite signal goes to an operational amplifier (Op Amp), the construction of which is well known within the art. The Op Amp drives a light. The second control signal drives a second light in a similar manner. The intensity of illumination of the lights is controlled by varying the number of sinusoids in the respective control signal.

The first and second control signals are recorded as "bursts", with a non-zero frequency during active period portions and an amplitude of substantially zero during inactive period portions. The state of each signal controls the states of speaker switches that alternately pass the third control signal to left and right speakers or to both speakers depending on the state of the respective signal. Conventional earphones and a conventional tape player may be used. The invention also includes the method according to which the control signals are prerecorded, played back, filtered, and applied to the lights and speakers.

In an alternative embodiment, the present invention is incorporated into an IBM personal computer, or any similar computing device. A program, stored on a hard drive, floppy disk, CD-ROM, or other media is loaded into the PC's RAM. The operating program contains brain synchronization data and an audio program. Executing the operating program outputs the synchronization program signal and audio program signal through an interface port. In an exemplary embodiment, parallel port pins of the PC are used to conduct the signals to a headset and spectacles with LEDs as arranged above. Specific pins in the parallel port are actuated and the LED in the spectacles are consequently triggered. Similarly, tones in the headset can be generated by triggering select pins in the parallel port. Of course, other interface ports can be used. Thus, the present invention is easily adaptable to the numerous PCs already in many homes.

In yet another alternative embodiment, the present invention provides a Delta wave sensor, which is a simple motion sensor. When a user enters the Delta wave state, he or she becomes drowsy, a sign that the brain is transitioning into the Delta state. If the user is sitting upright, her head inevitable droops forward. Therefore, when the motion sensor is mounted to the spectacles of the present invention, and the user's head droops forward, the motion sensor detects the change in condition and consequently triggers an audible alarm, and/or changes the frequency of the light pulses. Preferably, the motion sensor is a mercury tilt switch known in the art. Once the head of the user droops forward at a 45 degree angle or more, the mercury switch closes a circuit containing a common tone generator, which produces an audible tone. The tone is useful to keep the user awake and out of the Delta state, wherein the user completely loses consciousness falls asleep.

Alternatively, the motion sensor can trigger a circuit known in the art that increases the frequency of the light emitted from the LED, and/or increases the frequency of the audible tone. The overall effect of the increasing frequency of the tone and light prevents the user from transitioning into the Delta state. Hence, the present invention Delta sensor is a useful bio-feedback device for maintaining the user in the Theta brain wave state.

-------------------------------------------------------------------

As a modified bio-feedback device, the present invention can incorporate a circuit known in the art that increases the frequency of the signal output from the tone generator when triggered by the motion sensor. Accordingly, the flashing of the LEDs increases in frequency to keep the user's brain synchronized in the Theta wave state, which user might otherwise have drifted off into the Delta state. Similarly, the motion sensor can trigger an increase in the frequency of the audible tone, again forcing the user back into the Theta wave state.

The motion sensor and tone generator including the power source and speaker can be entirely self-contained, as shown in FIG. 5, or the devices may be separated. For instance, in another alternative embodiment, the tilt switch is used to send a control signal through the parallel port to flag the executing program that the user is close to passing into the Delta wave state. In response, a subroutine in the program can cause an alarm tone to be generated and sent to the headset. This accomplishes the same purpose as the separate tone generator mounted in the spectacles.