Apparatus and method for screening and diagnosing trauma or disease in body tissues

• US 5,415,164 A
• Filed: 03/08/1993
• Issued: 05/16/1995
• Est. Priority Date: 11/04/1991
• Status: Expired due to Fees

• Current Assignee: Biofield Corporation
• Original Assignee: Biofield Corporation
• Inventors: Faupel, Mark L., Hahn, deceased, Steven
• Primary Examiner(s): Kamm, William E.
• Assistant Examiner(s): Parker, Marianne
• Application Number:
  US08/027,539
• Time in Patent Office: 799 Days
• Field of Search: 128/733, 128/734, 128/736, 128/630, 128/653.1, 128/639, 128/897, 128/898
• US Class Current: 600/372
• CPC Class Codes: A61B 2562/0238 Optical sensor arrangements for performing transmission measurements on body tissue
• CPC Class Codes: A61B 2562/08 Sensors provided with means for identification, e.g. barcodes or memory chips
• CPC Class Codes: A61B 5/05 Detecting, measuring or recording for diagnosis by means of electric currents or magnetic fields; Measuring using microwaves or radio waves impedance plethysmography A61B5/0295; measuring movement of the entire body or parts thereof A61B5/11; detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof A61B5/24
• CPC Class Codes: A61B 5/24 Detecting, measuring or recording bioelectric or biomagnetic signals of the body or parts thereof
• CPC Class Codes: A61B 5/2415 Measuring direct current [DC] or slowly varying biopotentials
• CPC Class Codes: A61B 5/25 Bioelectric electrodes therefor
• CPC Class Codes: A61B 5/259 using conductive adhesive means, e.g. gels
• CPC Class Codes: Y10S 607/901 Cancer detection

Abstract

The apparatus and method for screening and diagnosing trauma or disease in body tissues involves the use of DC biopotential sensing electrodes having DC offset potentials within an acceptable range and electrical characteristics which enhance the accuracy of the biopotential measurement. The apparatus checks the electrodes connected thereto prior to a measurement cycle and will not initiate the measurement cycle if improper electrodes are present. The electrodes may be formed to selectively pass only certain ions thereby enhancing the sensitivity of the electrodes.

Claims

1. An apparatus for determining a condition at a test site on a human or animal subject by measuring electrical potentials which are a function of an electromagnetic field present in the subject at said test site comprising:

an electrode sensing assembly operating to detect DC biopotentials indicative of said electromagnetic field and provide output test potentials, said electrode sensing assembly including at least two DC biopotential sensing electrodes to form at least one electrode pair including a reference electrode and a test electrode, each such electrode including an electrode element, an electroconductive contact material mounted in contact with the electrode element to facilitate ion migration between the subject and the electrode element and an electrode terminal for conducting test potentials from said electrode element, each electrode pair of said electrode sensing assembly further having a DC offset potential within a limited range of from 0 to 1.0 millivolts DC, and

processing means connected to receive said test potentials from said electrode sensing assembly and operating during a test period to sample a plurality of test potentials from said electrode sensing assembly, said processing means operating to initiate at least a first test period and at least a first monitoring period of a predetermined length prior to said first test period and operating during each said monitoring period to sample and receive a plurality of test potentials from said electrode sensing assembly and to average said test potentials to obtain an average value therefor, said processing means further operating during each said monitoring period to compare each of the test potentials obtained during said monitoring period to said average value to obtain a difference value and to determine whether or not each such difference value falls within a predetermined tolerance range of values relative to said average value, the processing means operating to initiate said first test period when each said difference value falls within said predetermined tolerance range of values.

2. The apparatus of claim 1 wherein each pair of such biopotential sensing electrodes is formed to have a DC resistance within a range of from 0-50 ohms.

3. The apparatus of claim 1 wherein each pair of such biopotential sensing electrodes is formed to have an AC impedance/frequency cure within ranges of

0-50 ohms at 10 Hz

0-15 ohms at 100 Hz

0-30 ohms at 1000 Hz

0-25 ohms at 10,000 Hz

0-25 ohms at 100,000 Hz.

4. The apparatus of claim 3 wherein each pair of such biopotential electrodes is formed to have a DC resistance within a range of from 0-50 ohms.

5. The apparatus of claim 1 wherein said processing means operates when the difference values obtained during a monitoring period do not fall within said predetermined tolerance range of values to initiate a new monitoring period.

6. An apparatus for determining a condition at a test site on a human or animal subject by measuring electrical DC biopotentials which are a function of an electromagnetic field present in the subject at the test site comprising:

an electrode sensing assembly operating to provide an electrical electrode indicator signal, said electrode sensing assembly including at least two DC biopotential sensing electrodes to provide a measuring electrode and a reference electrode, each such electrode including an electrode element, an electroconductive contact material mounted in contact with the electrode element to facilitate ion migration between the subject and the electrode element and an electrode output terminal for conducting electrical potentials from said electrode element, and

processing means connected to receive electrical signals including said electrode indicator signal from said electrode sensing assembly and operating to initiate an electrode test period and a measurement cycle, said processing means operating during the electrode test period to receive said electrode indicator signal and to determine from said electrode indicator signal received from said electrode sensing assembly whether said electrode sensing assembly will provide an effective DC biopotential measurement, said processing means operating to initiate a measurement cycle when an electrode sensing assembly which will provide an effective DC biopotential measurement is connected thereto and to preclude initiation of a measurement cycle when the electrode sensing assembly will not provide an effective biopotential measurement.

7. The apparatus of claim 6 wherein said electrode sensing assembly includes an address means which provides a specific address signal as said electrode indicator signal, said processing means operating upon the receipt of said specific address signal during said electrode test period to initiate said measurement period, and to preclude initiation of said measurement period when said specific address signal is not received during said electrode test period.

8. The apparatus of claim, 7 wherein said electrical electrical indicator signal includes at least one electrode characteristic signal indicative of at least one electrical characteristic of any two of said DC biopotential sensing electrodes, said processing means operating during said electrode test period to determine whether such electrical characteristic signal falls within a predetermined signal range, the processing means operating upon the receipt of said specific address signal and when said electrical characteristic signal falls within said predetermined range to initiate said measurement cycle and to preclude initiation of said measurement cycle when said electrical characteristic signal does not fall within said predetermined range.

9. The apparatus of claim 6 wherein said electrical electrode indicator signal is indicative of at least one electrical characteristic of any two of said DC biopotential sensing electrodes, said processing means operating upon receipt of said electrical electrode indicator signal to determine whether such electrical electrode indicator signal falls within a predetermined signal range, the processing means operating when the electrical electrode indicator signal falls within said predetermined signal range to initiate said measurement cycle and to preclude initiation of said measurement cycle when said electrical electrode indicator signal does not fall within said predetermined signal range.

10. The apparatus of claim 9 wherein said electrical electrode indicator signal includes a plurality of electrical characteristic signals each of which is indicative of a specific electrical characteristic of any two of said DC biopotential sensing electrodes, said processing means operating during the electrode test period to determine whether each of said electrical characteristic signals falls within a predetermined signal range for said electrical characteristic signal, the processing means further operating when all of said electrical characteristic signals fall within the predetermined signal ranges for said electrical characteristic signals to initiate said measurement cycle and to preclude initiation of said measurement cycle when any of said electrical characteristic signals fails to fall within the predetermined signal range for said electrical characteristic signal.

11. The apparatus of claim 9 wherein said any two DC biopotential sensing electrodes operate to produce a DC offset potential at the electrode output terminals thereof, said DC offset potential forming said electrical electrode indicator signal, said processing means including means to provide an offset reference value and operating to compare said DC offset potential with said offset reference value.

12. The apparatus of claim 9 wherein said any two DC biopotential sensing electrodes exhibit a DC resistance, said processor means operating to transmit a test signal to at least two of said DC biopotential electrodes during said electrode test period to generate at the electrode output terminals for said two DC biopotential electrodes an electrical electrode indicator signal indicative of the DC resistance of said two DC biopotential electrodes.

13. The apparatus of claim 9 wherein said any two DC biopotential sensing electrodes exhibit an AC impedance, said processor means operating to transmit a test signal to at least two of said biopotential electrodes during said electrode test period to generate at the electrode output terminals for said two biopotential electrodes an electrical electrode indicator signal indicative of the AC impedance of said two DC biopotential electrodes.

14. A method for determining a condition at a test site on a human or animal subject by measuring electrical potentials which are a function of an electromagnetic field present in the subject at said test site which includes the steps of

applying to the subject an electrode sensing assembly including at least one pair of DC biopotential sensing electrodes having an electrode pair DC offset potential within a range of from 0-1.0 millivolts,

initiating a measurement period and during such measurement period taking a plurality of electrical potential measurements with said electrode sensing assembly indicative of the electrical potentials of the electromagnetic field present between said electrode pair, and

obtaining from said electrical potential measurements an indication of said condition.

15. The method of claim 14 wherein said electrode sensing assembly includes a plurality of DC biopotential sensing electrodes, any pair of such electrodes having a DC offset potential within a range of from 0-1.0 millivolts, said method including applying said DC biopotential sensing electrodes in spaced relationship to said subject and detecting respective electrical potentials of the electromagnetic field present in the subject between different pairs of said DC biopotential sensing electrodes.

16. The method of claim 15 wherein any two of said DC biopotential sensing electrodes in said electrode sensing assembly have a DC resistance within a range of 0-50 ohms.

17. The method of claim 15 wherein any two of said DC biopotential sensing electrodes in said electrode sensing assembly have an AC pair impedance/frequency curve within the ranges of

0-50 ohms at 10 Hz

0-15 ohms at 100 Hz

0-30 ohms at 1000 Hz

0-25 ohms at 10,000 Hz

- 25ohms at 100,000 Hz.

18. The method of claim 17 wherein any two of said DC biopotential sensing electrodes in said electrode assembly have a DC resistance within a range of 0-50 ohms.

19. The method of claim 14 wherein any two of said DC biopotential sensing electrodes in said electrode sensing assembly have a DC resistance which is within a range of 0-50 ohms.

20. The method of claim 14 wherein any two of said DC biopotential sensing electrodes in said electrode sensing assembly have an AC pair impedance/frequency curve which is within ranges of

0-50 ohms at 10 Hz

0-15 ohms at 100 Hz

0-30 ohms at 1000 Hz

0-25 ohms at 10,000 Hz

0-25 ohms at 100,000 Hz.

21. The method of claim 20 wherein any two of said DC biopotential sensing electrodes in said electrode sensing assembly have a DC resistance which is within a range of 0-50 ohms.

22. The method of claim 14 which includes initiating a predetermined monitoring period after applying said electrode sensing assembly to said subject, taking a plurality of test potentials from said electrode sensing assembly during said monitoring period and averaging said test potentials to obtain an average value therefor, comparing each of said test potentials obtained during said monitoring period to said average value to obtain a difference value, determining whether said difference values are within a predetermined tolerance range for said monitoring period, and initiating a new monitoring period if any of said difference values are not within the predetermined tolerance range or initiating the measurement period when all of said difference values are within said predetermined tolerance range.

23. A method for determining a condition at a test site on a human or animal subject by measuring electrical potentials which are a function of an electromagnetic field present in the subject at said test site which includes the steps of:

applying to the subject an electrode sensing assembly including at least one pair of biopotential sensing electrodes for detecting electrical potentials which are a function of said electromagnetic field,

initiating a predetermined monitoring time period,

(a) detecting a plurality of electrical potentials with said electrode sensing assembly during said monitoring time period,

(b) averaging the electrical potentials detected during said monitoring time period to obtain an average potential value,

(c) separately comparing each of the electrical potentials detected during said monitoring time period to said average potential value to obtain a difference value for each such comparison and a plurality of difference values for said monitoring time period;

(d) determining whether a predetermined number of said difference values are within a predetermined tolerance,

(e) initiating a new monitoring time period and repeating steps (a)-(e) if a predetermined number of said difference values are not within said predetermined tolerance,

initiating a test cycle if a predetermined number of said difference values are within said predetermined tolerance,

detecting a plurality of electrical potentials with said electrode sensing assembly during said test cycle, and

processing the electrical potentials taken during said test cycle to obtain an indication regarding said condition at said test site.

24. The method as defined in claim 23, which includes determining whether the difference values for all of said detected signals are within a predetermined tolerance.

25. The method as defined in claim 23, which includes initiating a predetermined monitoring period which is within a ranged 1-5 minutes in duration.

26. The method as defined in claim 25, wherein said predetermined monitoring period is 2 minutes.

27. The method as defined in claim 23, which includes determining whether a predetermined number of said difference values are within a predetermined tolerance within a range of ±

1 mV to ±

100 mV.

28. The method as fined in claim 27, wherein said predetermined tolerance is ±

10 mV.

29. A method for determining a condition at a test site on a human or animal subject as a function of an electromagnetic field present at the test site as sensed by at least two biopotential sensing electrodes each having an electrode element, an electroconductive material in contact with the electrode element to facilitate ion migration between the subject and the electrode element and an output terminal in contact with the electrode element, said method including the steps of

placing two of said electrodes in opposed relationship with the electroconductive material of a first of said electrodes in contact with the electroconductive material of the second of said electrodes,

sensing at least one electrical characteristic of said two electrodes,

comparing said sensed electrical characteristic to a predetermined reference characteristic, and

subsequently initiating a measurement indicative of said electromagnetic field with said electrodes when said sensed electrical characteristic bears a predetermined relationship to said reference characteristic.

30. The method of claim 29 wherein said two electrodes have a DC offset potential, said method including sensing the DC offset potential of said two electrodes and initiating said measurement when said sensed DC offset potential is with a range of 0-1.0 millivolts.

31. The method of claim 29 wherein said two electrodes have a DC resistance, said method including sensing the DC resistance of said electrode pair and initiating said measurement when said sensed DC resistance is within a range of 0-50 ohms.

32. The method of claim 29 wherein said two electrodes have an AC impedance, said method including sensing the AC impedance/frequency curve of said electrode pair and initiating said measurement when said sensed AC impedance/frequency curve is within ranges of

0-50 ohms at 10 Hz

0-15 ohms at 100 Hz

0-30 ohms at 1000 Hz

0-25 ohms at 10,000 Hz

0-25 ohms at 100,000 Hz.

33. A DC biopotential sensing electrode assembly for use with an apparatus for determining a condition at a test site on a human or animal subject as a function of an electromagnetic field present in the subject at that test site comprising a plurality of DC biopotential sensing electrodes forming at least one or more sensing electrode pairs, each electrode of each said sensing electrode pair having a base, an electrode element mounted upon said base, an electroconductive gel mounted in contact with said electrode element, and an electrical terminal connected to said electrode element to conduct an electrical potential, each said electrode pair of said biopotential sensing electrode assembly being formed to have a DC resistance within a range of from 0-50 ohms and an AC impedance/frequency curve within ranges of

0-50 ohms at 10 Hz

0-15 ohms at 100 Hz

0-30 ohms at 1000 Hz

0-25 ohms at 10,000 Hz

0-25 ohms at 100,000 Hz.

34. The biopotential electrode assembly of claim 33 which has been depolarized so as to have a DC offset potential within the range of from 0-1.0 millivolts.

35. The biopotential electrode assembly of claim 33 which includes removable electrical connector means for cooperating with said electrical terminal to complete an electrical connection therewith, said electrical terminal having a predetermined unique shape and said electrical connection means being formed to make an electrical connection with only electrical terminals having said predetermined unique shape.

36. The biopotential electrode assembly of claim 33 which includes an address means to provide an address output signal from said biopotential electrode assembly upon receipt of a specific address signal.