Brain wave monitoring mechanism and method

• US 4,739,772 A
• Filed: 02/01/1983
• Issued: 04/26/1988
• Est. Priority Date: 02/01/1983
• Status: Expired due to Fees

• Current Assignee: Hokanson D. Eugene, William M. Blackshear Jr
• Original Assignee: Hokanson D. Eugene, William M. Blackshear Jr
• Inventors: Blackshear, William M. Jr., Hokanson, D. Eugene
• Primary Examiner(s): Kamm, William E.
• Application Number:
  US06/462,732
• Time in Patent Office: 1,911 Days
• Field of Search: 128/702-704, 128/710-712, 128/731
• US Class Current: 600/544
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/384 Recording apparatus or displays specially adapted therefor

Abstract

During a surgical operation, a conventional electroencephalograph provides several analog electrical signals of the brain waves of the patient, each signal indicating voltage fluctuations detected at a different area of the patient'"'"'s scalp. The analog signals are converted to digital form for input to a multipurpose computer. The computer is programmed to produce respective reference traces on a video monitor indicating the voltage fluctuations detected during a preceding reference period. While the reference traces continue to be displayed, more current traces are produced on the video monitor in juxtaposed relationship to the reference traces. The current traces indicate the voltage fluctuations detected during the period immediately preceding their display. The current traces are replaced periodically with new current traces indicating more recent information. Any significant change in the patient'"'"'s brain waves is detected by comparing the current traces with the reference traces. At predetermined times, the most recent current traces are recorded by encoding the corresponding digital signals on a disk. Later, the traces can be reproduced on the video monitor for postoperative evaluation.

Claims

1. In mechanism for monitoring electrical brain activity of a patient during a medical procedure including means for detecting the electrical brain activity, the improvement comprising the combination of an electronic video monitor, and means for simultaneously displaying on said monitor in juxtaposed relationship a reference trace indicating electrical brain activity of the patient during a selected reference portion of such procedure and a separate first current trace indicating electrical brain activity of the patient during a subsequent portion of such procedure, said displaying means including means for displaying a separate second current trace on said video monitor in juxtaposed relationship to said reference trace and indicating electrical brain activity of the patient during a portion of the procedure subsequent to the portion represented by said first current trace, and for replacing said first current trace with said second current trace, while continuing to display said reference trace on said video monitor and while the procedure continues.

2. In mechanism for monitoring electrical brain activity of a patient during a medical procedure including means for detecting the electrical brain activity, the improvement comprising an electronic video monitor, and means for continuously displaying on said video monitor in juxtaposed relationship a reference trace indicating electrical brain activity of the patient during a selected reference portion of such procedure and at least one of a series of consecutive separate current traces each indicating the patient'"'"'s electrical brain activity during the immediately preceding portion of such procedure while such procedure continues, said displaying means including means for replacing one of said current traces with another while maintaining said reference trace on said monitor.

3. In the mechanism defined in claim 2, means enabling adjustment of the length of the immediately preceding portion of the procedure represented by each current trace.

4. In the mechanism defined in claim 2, means for automatically recording the most recent current trace at preselected intervals.

5. In the mechanism defined in claim 4, the detecting means including means for providing an analog electrical signal of electrical brain activity of the patient, the displaying means including means for converting said analog signal to a digital signal of the electrical brain activity, and the recording means including means for recording the digital signal.

6. Mechanism for monitoring electrical brain activity of a patient during a medical procedure comprising means for continuously detecting electrical brain activity of the patient during such procedure, means for continuously generating a digital signal of such electrical brain activity as such activity is detected, a computer having a memory, means for continuously storing said digital signal in said memory of said computer as said digital signal is produced, an electronic video monitor having a screen, means for displaying on said screen a reference trace indicating electrical brain activity of the patient during a selected reference portion of the procedure, and means for automatically at preselected intervals recalling the most recent portion of said digital signal stored in said memory of said computer and for immediately using said recalled portion to produce a current trace on said screen of said electronic video monitor so as to indicate in viewable form the electrical brain activity represented by said most recent portion of said signal while the medical procedure continues and while continuing to detect electrical brain activity of the patient, said displaying and recalling means including means for replacing one current trace with a more recent current trace while maintaining the display of said reference trace.

7. In the mechanism defined in claim 6, means for automatically and at uniformly spaced preselected intervals recording the most recent portion of the digital signal while the medical procedure continues so as to create a record of uniformly spaced portions of the digital signal.

8. In the mechanism defined in claim 7, means enabling adjustment of the interval between consecutive recordings.

9. The method of monitoring electrical brain activity of a patient during a medical procedure which comprises continuously detecting electrical brain activity of the patient during such procedure, continuously generating a digital signal of such electrical brain activity as such activity is detected, continuously storing the digital signal in the memory of a computer as the digital signal is produced, displaying on the screen of an electronic video monitor a reference trace indicating electrical brain activity of the patient during a selected reference portion of such procedure, automatically at preselected intervals recalling the most recent portion of the digital signal stored in the memory of the computer and immediately using such recalled portion to produce a current trace on the screen of the monitor while maintaining the display of the reference trace so as to indicate in viewable form the electrical brain activity represented by such reference and current traces while the medical procedure continues and while continuing to detect electrical brain activity of the patient, and including subsequently replacing the current trace with a more recent current trace while continuing to maintain the display of the reference trace.

10. In the method defined in claim 9, the improvement which further comprises automatically and at uniformly spaced preselected intervals recording in magnetic media the most recent portion of the digital signal while the medical procedure continues so as to create a record of uniformly spaced portions of the digital signal.

11. The method of monitoring electrical brain activity of a patient during a medical procedure which comprises detecting electrical brain activity of the patient during a selected first portion of such procedure, generating a first digital signal of the electrical brain activity detected during such first portion, using the first digital signal to produce a display of a first trace on the screen of an electronic video monitor so as to indicate in viewable form the electrical brain activity detected during such first portion, maintaining the display of the first trace on the screen of the electronic video monitor, detecting electrical brain activity of the patient during a selected second portion of such procedure subsequent to the first portion, generating a second digital signal of the electrical brain activity detected during such second portion, using such second digital signal to produce a second trace on the screen of the electronic video monitor in juxtaposed relationship to the first trace so as to indicate in viewable form the electrical brain activity detected during such second portion for enabling visual comparison of the first and second traces while the medical procedure continues and while continuing to detect electrical brain activity of the patient, detecting electrical brain activity of the patient during a selected third portion of such procedure subsequent to the second portion, generating a third digital signal of the electrical brain activity detected during such third portion, erasing the second trace, and using the third digital signal to produce a third trace on the screen of the electronic video monitor in replacement of the second trace and while maintaining the display of the first trace with the first and third traces in juxtaposed relationship so as to indicate in viewable form the electrial brain activity detected during such third portion for enabling visual comparison of the first and third traces while the medical procedure continues and while continuing to detect electrical brain activity of the patient.

12. A method of monitoring electrical brain activity of a patient during a medical procedure which comprises continuously detecting electrical brain activity of the patient, continuously generating an electrical signal of such electrical brain activity, using the electrical signal to produce a display of a reference trace on the screen of an electronic video monitor indicating the electrical brain activity of the patient detected during a selected reference portion of such procedure, and, while preserving the display of the reference trace on the screen of the electronic video monitor, continuously using the electrical signal to produce a display of a separate live trace on the screen of the electronic video monitor in juxtaposed relationship to the reference trace and indicating current brain activity of the patient for enabling visual comparison of the two traces to detect discrepancies while the medical procedure continues by continuously generating a digital signal of the electrical brain activity, storing the digital signal in the memory of a computer as the digital signal is produced, and automatically at preselected intervals recalling from the memoy of the computer the most recently stored portion of the digital signal indicating current electrical brain activity, immediately using such recalled signal to produce a display of the separate live trace on the screen of the electronic video monitor in juxtaposed relationship to the reference trace, maintaining the display of the separate live trace for a preselected period of time while continuing to store the digital signal in the memory of the computer as the digital signal continues to be produced, and, immediately following such preselected period of time, recalling from the memory of the computer the next portion of the digital signal indicating current electrical brain activity, erasing the display of the previously produced separate live trace and immediately using such next recalled portion of the digital signal to produce a new separate live trace on the screen of the electronic video monitor in juxtaposed relationship to the reference trace.

13. The method defined in claim 12, including automatically and at uniformly spaced preselected intervals recording in magnetic media the most recent portion of the digital signal while the medical procedure continues so as to create a record of uniformly spaced portions of the digital signal.

14. The method defined in claim 12, including continuously detecting electrical brain activity of the patient at a plurality of different areas of the patient'"'"'s head, continuously generating a separate electrical signal of such electrical brain activity detected at each such separate area, using the separate electrical signals to produce a plurality of reference traces indicating, respectively, the electrical brain activity detected during the selected reference portion at such different areas, and, while preserving the displays of the reference traces, continuously using the separate electrical signals to produce displays of separate live traces in juxtaposed relationship to the corresponding reference traces and indicating current brain activity of the patient for enabling visual comparison of the reference and corresponding live traces to detect discrepancies while the medical procedure continues.