Brain wave feedback instrument

• US 3,882,850 A
• Filed: 05/09/1973
• Issued: 05/13/1975
• Est. Priority Date: 05/09/1973
• Status: Expired due to Term

• Current Assignee: Howard Bailin, John Labenski
• Original Assignee: Howard Bailin, John Labenski
• Inventors: Bailin, Howard, Labenski, John
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US05/358,723
• Time in Patent Office: 734 Days
• Field of Search: 128/1C,1R,2.1B 307/301
• US Class Current: 600/545
• CPC Class Codes: A61B 5/291 for electroencephalography [EEG]
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16

Abstract

An electroencephalographic instrument for the bio-feedback of human brain waves within the Alpha and Theta frequency bands utilizes an adjustable headband electrode and a clip-on electrode as its pick-ups and earphones which provide an audible signal to the user. The circuitry of the instrument includes an active filter comprising a band-pass network and an operational amplifier, and an oscillator whose frequency is modulated by the active filter.

Claims

1. A brain wave bio-feedback instrument comprising an adjustable headband, an electrode supported by said headband, a second electrode, means for clipping the second electrode on a subject'"'"''"'"'s ear and including a spring-operated clip, a control device, a first switch mounted on said control device, a single battery cell positioned within said control device and connected to said first switch and to a ground, an operational amplifier having an input and an output, means connecting one of said electrodes in series with said operational amplifier input, means connecting the other electrode to ground, a set of biasing resistors connected to said operational amplifier and biasing said operational amplifier for operation at about the mid-point of the voltage of said battery cell, a resistor-capacitor band-pass means connected between the input and output of said operational amplifier and comprising an active filter network with said operational amplifier, a voltage controlled oscillator, said voltage controlled oscillator being connected to the output of said operational amplifier so that the oscillator'"'"''"'"'s frequency is thereby modulated by the output voltage of said operational amplifier, a sound transducer connected to said voltage controlled oscillator, and a second switch mounted on said control device to provide selection between Alpha and non-Alpha waves and connected to said band-pass means to selectively alter the operating elements of said band-pass means.

2. An instrument as in claim 1 wherein said voltage controlled oscillator comprises a single active device which is a programmable unijunction transistor having an anode, an anode gate and a cathode, wherein said anode gate is connected to the output of said operational amplifier and the cathode is connected to the sound transducer and the anode is connected in series with the battery cell.

3. An instrument as in claim 2 and further comprising a variable resistor connected between said cathode and said ground which variable resistor operates as a volume control.

4. An instrument as in claim 1 wherein said voltage controlled oscillator includes a second operational amplifier having its input and output connected to a resistor-capacitor network.

5. An instrument as in claim 4 wherein said two operational amplifiers are formed as linear integrated circuits on a single chip.

6. An instrument as in claim 1 wherein an amplifier which is a low noise high-gain device is connected between one of the said electrodes and the input of said operational amplifier and the battery cell.

7. An instrument as in claim 1 wherein a complementary pair of transistors is connected in cascade between said device input and said operational amplifier input.

8. An instrument as in claim 1 wherein the sound transducer is an earphone and connected thereto a pair of tubular earphones.