Method and device for producing a desired brain state

• US 6,488,617 B1
• Filed: 10/13/2000
• Issued: 12/03/2002
• Est. Priority Date: 10/13/2000
• Status: Expired due to Term

• Current Assignee: Universal Hedonics
• Original Assignee: Universal Hedonics
• Inventors: Katz, Bruce F.
• Primary Examiner(s): Shaver, Kevin
• Assistant Examiner(s): Veniaminov, Nikita R
• Application Number:
  US09/687,599
• Time in Patent Office: 781 Days
• Field of Search: 600/9-15, 600/300, 600/544, 600/545, 600/26-27, 600/409, 128/897, 607/45
• US Class Current: 600/26
• CPC Class Codes: A61B 5/375 using biofeedback
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61M 2021/0055 with electric or electro-magnetic fields
• CPC Class Codes: A61M 21/00 Other devices or methods to cause a change in the state of consciousness; Devices for producing or ending sleep by mechanical, optical, or acoustical means, e.g. for hypnosis
• CPC Class Codes: A61M 2205/52 with memories providing a history of measured variating parameters of apparatus or patient
• CPC Class Codes: A61M 2230/10 Electroencephalographic signals

Abstract

A method and device for the production of a desired brain state in an individual contain means for monitoring and analyzing the brain state while a set of one or more magnets produce fields that alter this state. A computational system alters various parameters of the magnetic fields in order to close the gap between the actual and desired brain state. This feedback process operates continuously until the gap is minimized and/or removed.

Claims

1. A method for producing a desired brain state in an individual by measuring and controlling a brain signal comprising;

measuring a brain signal indicating a brain state of an individual;

comparing characteristics of the measured brain state to characteristics of a desired brain state to determine the difference between the measured brain state and the desired brain state;

selecting a magnetic field having at least one parameter selected from the group consisting of magnet position, field magnitude, pulse frequency, and pulse train duration to alter the brain state, wherein the at least one parameter is selected to most reduce the gap between the measured and desired brain states;

applying the selected magnetic field to the brain of the individual;

measuring a brain signal indicating the altered brain state, the altered brain state corresponding to the application of the magnetic field;

comparing the characteristics of the altered brain state to characteristics of the desired brain state to determine the difference between the altered brain state and the desired brain state; and

repeating the selecting, applying, and measuring a brain signal indicating the altered brain state steps until an acceptable brain state is achieved.

2. The method of claim 1 wherein the steps are under computer control and the steps are performed continuously.

3. The method of claim 1 wherein the brain signal is measured by a technique selected from the group consisting of an electroencephalography, magnetoencephalography, and functional magnetic resonance imaging.

4. The method of claim 1 wherein the brain signal is an electroencephalogram signal measured by electrodes positioned on the head of the individual and the magnetic field is generated by magnets positioned on the head of the individual.

5. The method of claim 4 wherein the electroencephalogram signal is amplified and converted into a digital signal.

6. The method of claim 5 wherein at least one parameter is varied to alter the brain state.

7. The method of claim 6 wherein a gradient descent algorithm varies the parameters by:

altering a preselected subset of the parameters selected of the group consisting of magnet position, field magnitude, pulse frequency, and pulse train duration;

measuring distance metrices between a desired electroencephalogram signal and each electroencephalogram signal resulting from the alteration of each parameter of the subset of parameters;

choosing the parameter and the parameter alteration having the distance metric with the least value;

adjusting the chosen parameter by the chosen parameter alteration;

measuring a resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the chosen parameter alteration, and a resulting distance metric between the desired electroencephalogram signal and the resulting electroencephalogram signal; and

repeating the adjusting and measuring a resulting electroencephalogram signal steps until a desired threshold is achieved.

8. The method of claim 6 wherein a gradient descent algorithm varies the parameters by:

altering a preselected subset of the parameters by alteration distances, the parameters being selected from the group consisting of magnet position, field magnitude, pulse frequency, and pulse train duration, wherein more than one parameter is altered at a time,

measuring distance metrices between a desired electroencephalogram signal and each electroencephalogram signal resulting from the alteration of each parameter of the subset of parameters;

realtering the preselected subset of parameters, the parameter realteration distances being decreased from the alteration step, more Man one parameter being realtered at a time; and

measuring a resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the chosen parameter realteration, and a resulting distance metric between the desired electroencephalogram signal and the resulting electroencephalogram signal,

wherein if a desired threshold is not achieved, each parameter of the subset of parameters is realtered a random amount to shift the parameter space and the altering, realteing, and measuring steps are repeated until a desired threshold is achieved.

9. The method of claim 5 wherein at least one parameter is increased and decreased by a fixed amount and the resulting brain state is measured.

10. The method of claim 9 wherein a gradient descent algorithm varies the parameters by:

measuring distance metrices between a desired electroencephalogram signal and each electroencephalogram signal resulting from the increase and decrease of each parameter;

choosing the parameter and the parameter increase or decrease having the distance metric with the least value;

adjusting the chosen parameter by the chosen parameter increase or decrease;

measuring a resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the chosen parameter increase or decrease, and a resulting distance metric between the desired electroencephalogram signal and the resulting electroencephalogram signal; and

repeating the adjusting and measuring a resulting electroencephalogram steps until a desired threshold is achieved.

11. The method of claim 9 wherein a gradient descent algorithm varies the parameters by:

measuring distance metrices between a desired electroencephalogram signal and each electroencephalogram signal resulting from the increase and decrease of each parameter,

choosing for each parameter the parameter increase or decrease having the distance metric with the least value;

adjusting more than one parameter by the chosen parameter increase or decrease having the distance metric with the least value, each parameter being increased or decreased an amount inversely proportional to the measured distance metric for each increase or decrease;

measuring a resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the chosen parameter increase or decrease, and a resulting distance metric between the desired electroencephalogram signal and the resulting electroencephalogram signal; and

repeating the adjusting and measuring a resulting electroencephalogram signal steps until a desired threshold is achieved.

12. The method of claim 9 wherein a gradient descent algorithm varies the parameters by:

measuring distance metrices between a desired electroencephalogram signal and each electroencephalogram signal resulting from the increase and decrease of each parameter;

choosing the parameter and the parameter increase or decrease having the distance metric with the least value;

adjusting the chosen parameter by the chosen parameter increase or decrease;

measuring a resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the chosen parameter increase or decrease, and a resulting distance metric between the desired electroencephalogram signal and the resulting electroencephalogram signal; and

repeating the adjusting and measuring a resulting electroencephalogram steps until a desired threshold is achieved, wherein the adjustment of the chosen parameter decreases for each repeated adjustment step.

13. The method of claim 9 wherein a gradient descent algorithm varies the parameters by:

measuring distance metrices between a desired electroencephalogram signal and each electroencephalogram signal resulting from the increase and decrease of each parameter;

choosing the parameter and the parameter increase or decrease having the distance metric with the least value;

adjusting the chosen parameter by the chosen parameter increase or decrease; and

measuring the resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the chosen parameter increase or decrease, and a resulting distance metric between the desired electroencephalogram signal and the resulting electroencephalogram signal, wherein if a desired threshold is not achieved, each parameter is altered a random amount to shift the parameter space and the increasing, decreasing, first and second measuring, choosing, and adjusting steps are repeated until a desired threshold is achieved.

14. The method of claim 1 wherein the magnets are positioned using a bar holding the magnets, the bar being movable along a track by a motor.

15. The method of claim 1 wherein the brain signal is altered to correct asymmetry in the brain signal between the left and right hemispheres associated with clinical depression.

16. The method of claim 1 wherein alpha rhythms of the brain state are altered to produce a greater degree of relaxation.

17. The method of claim 1 wherein the brain signal is altered to achieve an arbitrary electroencephalogram signal corresponding to a desired brain state.

18. The method of claim 1 wherein the parameters are selected based on known brain signals corresponding to brain states.

19. The method of claim 18 wherein the brain states are selected from the group consisting of lower frequency states, alpha frequency states, frequencies suppressing activity in the cortex, and frequencies producing excitation of the cortex.

20. The method of claim 1 wherein the parameters of the magnetic field are selected based on treatment regimes for known conditions.

21. A method for producing a desired brain state in an individual by continuously measuring and controlling a brain signal comprising:

measuring an electroencephalogram signal indicating a brain state of an individual by electrodes positioned on the head of the individual;

amplifying the measured electroencephalogram signal;

converting the amplified electroencephalogram signal into a digital signal;

comparing the characteristics of the digital electroencephalogram signal to the characteristics of a desired electroencephalogram signal using a computational system to determine the difference between the digital electroencephalogram signal and the desired electroencephalogram signal;

applying a magnetic field having parameters, the parameters being magnet position, field magnitude, pulse frequency, and pulse train duration, to alter the brain state of the individual by positioning magnets on the head of the individual, wherein a value for at least one parameter is selected to alter the brain state and achieve the desired electroencephalogram signal;

measuring a resulting electroencephalogram signal, the resulting electroencephalogram signal corresponding to the selected value of the at least one parameter; and

comparing the characteristics of the resulting electroencephalogram signal to the characteristics of the desired electroencephalogram signal to determine the need to further alter the brain state, wherein the steps are under computer control, the method is continuous, and the at least one parameter is varied according to a gradient descent algorithm.

22. A device for producing a desired brain state in an individual by measuring and controlling a brain signal comprising;

means for measuring a brain signal indicating a brain state of an individual;

a computational system for comparing characteristics of the measured brain state to characteristics of a desired brain state to determine the difference between the measured brain state and the desired brain state; and

means for applying a magnetic field having parameters to the brain of the individual to alter the brain state, the parameters being magnet position, field magnitude, pulse frequency, and pulse train duration.

23. The device of claim 22 wherein the means for applying a magnetic field are magnets.

24. The device of claim 23 wherein the means for measuring the brain signal is selected from the group consisting of an electroencephalogram, a magnetoencephalogram, and a functional magnetic resonance imager.

25. The device of claim 24 wherein the brain signal is measured by an electroencephalogram using electrodes positioned on the head of the individual.

26. The device of claim 25 further comprising an amplifier for amplifying the electroencephalogram signal.

27. The device of claim 26 further comprising an analog/digital converter to convert the amplified electroencephalogram signal into a digital signal.

28. The device of claim 23 further comprising a positioning apparatus for controlling the position of the magnets on the skull of the individual, the positioning apparatus using a bar holding the magnets, the bar being movable along a track by a motor.

29. The device of claim 28 wherein the positioning apparatus enables movement of the magnets between the front and back of a skull.

30. A device for producing a desired brain state in an individual by measuring and controlling an electroencephalogram signal comprising:

electrodes for measuring the electroencephalogram signal of an individual, the electrodes being adapted to be positioned on the surface of the skull and having wires for relaying the electroencephalogram signal;

a lattice for holding the electrodes on the surface of the skull;

a multi-channel opto-isolation amplifier for receiving the electroencephalogram signal from the wires of the electrodes and amplifying the electroencephalogram signal relayed by the electrodes;

an analog/digital converter for converting the measured signal into a digital signal;

a computational system including quantitative electroencephalogram software for monitoring the electroencephalogram signal and comparing the signal to a desired electroencephalogram signal to determine the difference between the measured electroencephalogram signal and the desired electroencephalogram signal;

a pulse train generator for generating a magnetic field having a field magnitude, a pulse frequency, and a pulse train duration in accordance with the determination of the computational system;

magnets to apply the magnetic field to the brain of the individual to alter the brain state; and

a positioning apparatus for controlling the position of the magnets on the skull of the individual in accordance with the determination of the computational system, the positioning apparatus using a bar holding the magnets, the bar being moveable along a track by a motor, and the positioning apparatus enabling movement of the magnets between the front and back of the skull.