[size=28pt]Apparatus and method for remotely monitoring and altering brain waves
US 3951134 A[/size]

ABSTRACT
Apparatus for and method of sensing brain waves at a position remote from a subject whereby electromagnetic signals of different frequencies are simultaneously transmitted to the brain of the subject in which the signals interfere with one another to yield a waveform which is modulated by the subject's brain waves. The interference waveform which is representative of the brain wave activity is re-transmitted by the brain to a receiver where it is demodulated and amplified. The demodulated waveform is then displayed for visual viewing and routed to a computer for further processing and analysis. The demodulated waveform also can be used to produce a compensating signal which is transmitted back to the brain to effect a desired change in electrical activity therein.


What is claimed is:
1. Brain wave monitoring apparatus comprising means for producing a base frequency signal, means for producing a first signal having a frequency related to that of the base frequency and at a predetermined phase related thereto, means for transmitting both said base frequency and said first signals to the brain of the subject being monitored, means for receiving a second signal transmitted by the brain of the subject being monitored in response to both said base frequency and said first signals, mixing means for producing from said base frequency signal and said received second signal a response signal having a frequency related to that of the base frequency, and
means for interpreting said response signal.

2. Apparatus as in claim 1 where said receiving means comprises means for isolating the transmitted signals from the received second signals.

3. Apparatus as in claim 2 further comprising a band pass filter with an input connected to said isolating means and an output connected to said mixing means.

4. Apparatus as in claim 1 further comprising means for amplifying said response signal.

5. Apparatus as in claim 4 further comprising means for demodulating said amplified response signal.

6. Apparatus as in claim 5 further comprising interpreting means connected to the output of said demodulator means.

7. Apparatus according to claim 1 further comprising
means for producing an electromagnetic wave control signal dependent on said response signal, and
means for transmitting said control signal to the brain of said subject.

8. Apparatus as in claim 7 wherein said transmitting means comprises means for directing the electromagnetic wave control signal to a predetermined part of the brain.

9. A process for monitoring brain wave activity of a subject comprising the steps of
transmitting at least two electromagnetic energy signals of different frequencies to the brain of the subject being monitored,
receiving an electromagnetic energy signal resulting from the mixing of said two signals in the brain modulated by the brain wave activity and retransmitted by the brain in response to said transmitted energy signals, and,
interpreting said received signal.

10. A process as in claim 9 further comprising the step of transmitting a further electromagnetic wave signal to the brain to vary the brain wave activity.

11. A process as in claim 10 wherein the step of transmitting the further signals comprises obtaining a standard signal, comparing said received electromagnetic energy signals with said standard signal, producing a compensating signal corresponding to the comparison between said received electrogagnetic energy signals and the standard signal, and transmitting the compensating signals to the brain of the subject being monitored.

DESCRIPTION
BACKGROUND OF THE INVENTION
Medical science has found brain waves to be a useful barometer of organic functions. Measurements of electrical activity in the brain have been instrumental in detecting physical and psychic disorder, measuring stress, determining sleep patterns, and monitoring body metabolism.

The present art for measurement of brain waves employs electroencephalographs including probes with sensors which are attached to the skull of the subject under study at points proximate to the regions of the brain being monitored. Electrical contact between the sensors and apparatus employed to process the detected brain waves is maintained by a plurality of wires extending from the sensors to the apparatus. The necessity for physically attaching the measuring apparatus to the subject imposes several limitations on the measurement process. The subject may experience discomfort, particulary if the measurements are to be made over extended periods of time. His bodily movements are restricted and he is generally confined to the immediate vicinity of the measuring apparatus. Furthermore, measurements cannot be made while the subject is conscious without his awareness. The comprehensiveness of the measurements is also limited since the finite number of probes employed to monitor local regions of brain wave activity do not permit observation of the total brain wave profile in a single test.