Computerized EMG diagnostic system

• US 6,004,312 A
• Filed: 02/27/1998
• Issued: 12/21/1999
• Est. Priority Date: 04/15/1997
• Status: Expired due to Term

• Current Assignee: Vdi Acquisition Corp.
• Original Assignee: Paraspinal Diagnostic Corporation
• Inventors: Bihari, Thomas E., Finneran, Brenda A., Finneran, Mark T., Pugh, Dennis R.
• Primary Examiner(s): O'Connor, Cary
• Assistant Examiner(s): MARMOR II, CHARLES ALAN
• Application Number:
  US09/032,730
• Time in Patent Office: 662 Days
• Field of Search: 600/544, 600/545, 600/546, 600/547, 600/587, 600/594, 600/595, 600/382, 600/386, 600/388, 600/390, 600/393
• US Class Current: 600/546
• CPC Class Codes: A61B 5/282 Holders for multiple electrodes for introduction into the body A61B5/287
• CPC Class Codes: A61B 5/296 for electromyography [EMG]
• CPC Class Codes: A61B 5/30 Input circuits therefor

Abstract

A generally flat, rectangular rubber pad supports (63) discrete, non-invasive electrodes in a 7 by 9 array and a ground electrode to collect surface electromyographic (EMG) signals from an underlying muscle group of a patient. Electronic apparatus conditions the EMG signals and is programmed to survey the electrode array simultaneously to provide a description of the activity of individual muscles in the muscle group at that point in time. The description is displayed on a video monitor or the like, juxtaposed over a display of normal muscle anatomy, with differences being emphasized by color enhancement. The electrode pad is particularly suited for the lower back muscle groups and may be retained in position by a lumbar support belt having a pad molded to the contours of the human spine.

Claims

1. A system for providing a visual display analogous to a portion of the anatomy of a patient, which display contains information indicative of a status of that portion of the anatomy, comprising:

a plurality of sensors disposed adjacent to the portion of the anatomy of the patient, each sensor developing sensor signals, the sensors being arranged in a predetermined array generally overlying the portion of the patient, and each sensor generally positioned in a unique location relative to the anatomy of the patient;

a plurality of signal conditioners in electrical connection with the sensors, wherein the sensor signals are amplified by the signal conditioners to develop conditioned signals for use at a location remote from the patient;

a signal processor adapted to receive the conditioned signals and convert the conditioned signals to visual display signals; and

a display device, wherein the display device provides a visual display responsive to the display signals, wherein the visual display includes a visible pattern which corresponds with magnitudes of the sensor signals at each of the locations in the array;

a graph device, wherein the graph device is in operative connection with the display device, and wherein the graph device is operative to produce a plurality of electronic images on the display device, wherein each electronic image includes a visual representation of at least one anatomical part located in the portion of the anatomy, and wherein the display device is operative to selectively superimpose each of the electronic images with the pattern, whereby the pattern is enabled to be correlated with the anatomy of the patient.

2. The system according to claim 1 wherein said signal processor comprises a voltage differencer for operating upon said conditioned signals to provide difference signals for each sensor position representative of the difference between a reference sensor and adjacent sensors.

3. The system according to claim 2 wherein said signal processor further comprises an RMS calculator for converting each said difference signal to an RMS signal representative of an averaged level of the difference signal at that sensor position.

4. The system according to claim 3 wherein the signal processor further comprises a converter for changing the RMS signal to line segment signals for display by the display device as line segments between adjacent sensor locations.

5. A system for providing a visual display analogous to a portion of the anatomy of a patient, which display contains information indicative of a status of that portion of the anatomy, comprising:

a plurality of array sensors disposed adjacent to the portion of the anatomy of the patient, each array sensor developing array sensor signals, the array sensors being arranged in a predetermined array generally overlying the portion of the patient, and each array sensor generally positioned in a unique location relative to the anatomy of the patient;

a reference sensor in connection with the anatomy of the patient, wherein the reference sensor is operative to generate a reference signal;

a signal processor in operative connection with each of the array sensors and the reference sensor, wherein the signal processor is operative to generate a plurality of difference signals, wherein each difference signal corresponds to a difference between the reference signal and adjacent array sensor signals, and wherein the signal processor is operative to produce a plurality of line segment signals corresponding to line segments between adjacent sensor locations, wherein each line segment signal is generated responsive to magnitudes of the difference signals at the array sensor locations defining the respective line segment;

a display device in operative connection with the signal processor, wherein the display device generates an output display including a visible grid pattern including the line segments.

6. The system according to claim 5 wherein the line segments are displayed as line segments having a characteristic related to a level of RMS voltage at the sensor locations defining the line segments.

7. The system according to claim 6 wherein said line segments are displayed in different intensity dependent upon the RMS voltage level at the sensor locations defining said line segments.

8. The system according to claim 7 wherein said sensors are arranged in a seven column by nine row pattern and said grid pattern is in a seven column by nine row pattern.

9. The system according to claim 6 wherein said line segments are displayed in different hues dependent upon the RMS voltage level at the sensor locations defining said line segments.

10. Apparatus for monitoring electrical activity of a portion of the physical structure of a patient and for producing a visual display of the electrical activity in a pattern correlated to the physical structure being monitored, comprising:

a plurality of sensors, wherein the sensors are operative to monitor electrical properties of the patient, the sensors being arranged in a predetermined configuration and providing sensor signals as outputs;

a signal converter responsive to the sensor signals, wherein the signal converter produces electrical display signals corresponding to the sensor signals, the electrical display signals being in correlation with the physical structure of the patient being monitored; and

a display device responsive to the electrical display signals, wherein the display device produces a visual pattern representative of the electrical properties sensed by each of the sensors and a visual representation of the physical structure being monitored.

11. Apparatus as set forth in claim 10, and further comprising

a graph device, wherein the graph device is operative to cause to be produced on the display device a graphic image representative of the anatomy of the patient in a scale correlated to the visual pattern, whereby a direct comparison can be made by an attending physician.

12. Apparatus as set forth in claim 11 wherein the graphic image produced by the graph device is superimposed with the visual pattern on the display device.

13. Apparatus for monitoring electrical activity of a portion of a physical structure of a patient and for producing a visual display of the electrical activity in a pattern correlated to the physical structure being monitored, comprising:

a plurality of sensors, wherein the sensors are operative to monitor electrical properties of the patient, the sensors being arranged in a pattern correlated to the physical structure of the patient and providing sensor signals as outputs;

a signal converter responsive to the sensor signals, wherein the signal converter produces electrical display signals corresponding to the sensor signals in the pattern;

a display device responsive to the electrical display signals, wherein the display device produces a visual representation of electrical activity of the sensors in the pattern; and

a graph device, wherein the graph device is operative to cause to be produced a series comprising a plurality of graphic images representative of various parts of the patient anatomy in a scale correlated to the visual representation of electrical activity of the sensors, and wherein the graph device is operative to cause, each of the graphic images to be selectively alternatively superimposed with the visual representation of electrical activity, whereby an attending physician may scan the series of graphic images for correlation to the electrical activity of the sensors.

14. Apparatus as set forth in claim 13 wherein the signal converter and the display device are manually adjustable to modify the visual representation, to output on the display device at least one alternative visual representation of the electrical activity of the sensors.

15. Apparatus as set forth in claim 14 wherein the signal converter and the display device are selectively adjustable to change either the hue or intensity of the visual representation, whereby such adjustment facilitates ease in making the correlation to the physical anatomy of the patient.

16. Apparatus as set forth in claim 15 wherein the sensors are arranged in a predetermined array and wherein the visual representation corresponds to the array.

17. Apparatus as set forth in claim 15 wherein the visual representation includes a grid pattern comprised of line segments extending between areas in the visual representation, the areas being representative of most closely adjacent sensor locations.

18. Apparatus as set forth in claim 17 wherein the sensors are arranged in a generally rectangular grid pattern and wherein the visual representation corresponds with the rectangular grid pattern.

19. Apparatus as set forth in claim 18 wherein the display device is operative to display the line segments in different hues responsive to the signal levels received from respective sensors corresponding to areas in the visual representation defining a beginning and an end of each of the line segments.

20. Apparatus for monitoring EMG activity of a patient for analysis of underlying musculature, comprising:

an array of electrodes adapted for placement in a predetermined array pattern on the surface of a patient, overlying musculature to be analyzed, the electrodes adapted to provide EMG signals representative of underlying muscle activity;

a signal conditioning system coupled to said electrodes, wherein the signal conditioning system renders the EMG signals in a format useful for operative analysis;

a signal processing system, wherein the signal processing system operates upon the conditioned signals to convert the signals to data signals representative of the degree of electrical activity at each of said electrodes in the array of electrodes; and

a display device, wherein the display device is operative responsive to the data signals to produce a visual display representative of the degree of electrical activity at each of the electrodes in the array of electrodes, and in a visual format representative of the pattern of the electrodes in the array so that a correlation is made between the visual display and the location of the electrodes.

21. Apparatus for monitoring EMG activity of a patient for analysis of underlying musculature, comprising:

an array of electrodes adapted for placement in a predetermined array pattern on the surface of a patient, overlying musculature to be analyzed, the electrodes adapted to provide EMG signals representative of underlying muscle activity, wherein the electrode array is positioned in a specific location on the patient relative to the underlying musculature;

a signal conditioning apparatus in operative connection with the electrodes, wherein the signal conditioning apparatus renders the EMG signals in a format useful for analysis;

a signal processing apparatus in operative connection with the signal conditioning apparatus, wherein the signal processing apparatus is operative responsive to the conditioned signals to produce data signals representative of a degree of electrical activity at each of the electrodes in the array of electrodes; and

a first display device, wherein the first display device is operative responsive to the data signals to produce a visual display representative of the degree of electrical activity at each of the electrodes in the array of electrodes, and in a visual format corresponding to the array pattern of the electrodes;

a second display device, wherein the second display device is operative to cause a graphic image of the underlying musculature which is superimposed with the visual display and in registration with the specific location, whereby a correlation can be made between the visual display and the underlying musculature.

22. Apparatus as set forth in claim 21 wherein the second display device provides a plurality of different graphic images representative of different portions of the underlying musculature, wherein the display device is operative to alternatively resister different ones of the images with the visual display whereby correlation with different musculature portions is achieved.

23. Apparatus as set forth in claim 21 wherein said electrodes are arranged in a rectangular array of columns and rows, and said visual display is provided in a corresponding rectangular configuration.

24. Apparatus as set forth in claim 23 wherein said visual display comprises a plurality of line segments representative of interconnecting most closely adjacent electrode locations in a rectangular configuration conforming to the array of electrodes.

25. Apparatus as set forth in claim 24 wherein said line segments are of different hues related to a parameter of said data signals derived from said electrodes defining the location of the respective line segments.

26. Apparatus as set forth in claim 25 wherein said different hues are related to the RMS value of said data signals.

27. Apparatus as set forth in claim 26 wherein said visual display is a full matrix of line segments interconnecting all most closely adjacent electrode locations.

28. Apparatus as set forth in claim 27 wherein the completeness of pattern of said visual array may be adjusted by the attending physician.

29. Apparatus as set forth in claim 27 wherein the hues of said visual array may be adjusted by the attending physician.

30. Apparatus for monitoring electrical activity of a patient for analysis of underlying anatomy, comprising:

an array of electrodes adapted for placement in a predetermined array pattern on the surface of a patient, overlying anatomy to be analyzed, the electrodes adapted to provide electrical signals representative of the activity of underlying anatomy;

a signal conditioning system coupled to the electrodes, wherein the signal conditioning system is operative to produce conditioned signals for analysis at a remote location;

a signal processing system, wherein the signal processing system is operative responsive to the conditioned signals to produce data signals representative of the degree of electrical activity at the electrodes; and

a display device, wherein the display device is operative to convert the data signals to a visual display including visual outputs representative of the degree of electrical activity at each of the electrodes in the array, and in a visual format representative of the pattern of the electrodes in the array.

31. Apparatus as set forth in claim 30 wherein said signal processing system comprises an RMS calculator for providing data signals representative of the RMS level of signals at said electrodes.

32. Apparatus as set forth in claim 31 wherein said electrode signals are referenced to a common ground and are compared with common reference signals to provide difference signals for each electrode location, said difference signals being applied to said RMS calculator.

33. Apparatus as set forth in claim 30, wherein the signal conditioning system includes an oversampling device.

34. Apparatus for monitoring electrical activity of a patient for analysis of underlying anatomy, comprising:

an array of electrodes adapted for placement in a predetermined array pattern on the surface of a patient, overlying anatomy to be analyzed, the electrodes adapted to provide electrical signals representative of the activity of underlying anatomy;

a reference signal source, wherein the reference signal source produces a reference signal;

a signal processing device in operative connection with each of the electrodes and the reference signal source, wherein the signal processor device is operative to generate a plurality of difference signals, wherein each difference signal corresponds to a difference between the reference signal and electrical signals from adjacent electrodes, and wherein the signal processing device is operative to produce a plurality of line segment signals corresponding to line segments between adjacent electrode locations, wherein each line segment signal is generated responsive to magnitudes of the difference signals for the electrodes defining the respective line segment;

a display device in operative connection with the signal processing device, wherein the display device is operative responsive to the line segment signals to produce a visual display, wherein the visual display comprises a plurality of line segments extending between representations of the electrodes wherein the visual display includes a matrix of line segments representative of electrical activity of the underlying anatomy.

35. Apparatus as set forth in claim 34, wherein the line segments are displayed in different hues related to a level of RMS voltage at the respective electrode locations defining the line segments.

36. Apparatus as set forth in claim 35, wherein said visual display may be manually adjusted by the attending physician to alter the hues of said line segments.

37. Apparatus as set forth in claim 35, wherein visual displays of underlying anatomy are superimposed over said visual display of electrical activity for correlation by the attending physician.

38. Apparatus as set forth in claim 37, wherein the electrodes are EMG electrodes adapted for providing signals of underlying muscle activity and the visual display includes a matrix representative of underlying musculature.

39. Apparatus as set forth in claim 38, wherein said electrodes are arranged in a rectangular pattern located in a unique position relative to underlying anatomy so that correlation can be made in the said visual display.

40. Apparatus as set forth in claim 39, wherein said electrodes are arranged in a seven by nine pattern of sixty-three electrodes.

41. A method for monitoring the musculature of a patient, comprising the steps of:

placing an array of electrodes at a predetermined location on a surface of a patient;

gathering surface EMG signals from said electrodes and recording the surface EMG signals to provide a substantially complete representation of the EMG signals for the entire array of the electrodes;

processing EMG signals to provide quantitative signals representative of a degree of electrical activity at each of the electrodes;

converting the quantitative signals to visual signals which may be interpreted by a medical practitioner; and

displaying the visual signals in a pattern representative of the pattern of the electrode array to provide an indication of the degree of electrical activity at each individual electrode and thus at the location of the underlying musculature of the patient.

42. A method as set forth in claim 41 wherein said processing step comprises the step of combining said EMG signals to provide quantitative signals at each said electrode referenced to signals of one or more other said electrodes.

43. A method as set forth in claim 42 wherein said combining step comprises the step of combining said EMG signals as sets of electrode pairs and said step of displaying comprises displaying said visual signals as electrode pair sets in a pattern representative of the pattern of said electrodes in said array.

44. A method comprising the steps of:

placing an array of electrodes at a predetermined location on a surface of a patient;

gathering surface EMG signals from the electrodes and recording the surface EMG signals to provide a substantially complete representation of the EMG signals for the entire array of the electrodes;

processing the EMG signals to provide quantitative signals representative of a degree of electrical activity at each of the electrodes, wherein the EMG signals are combined for sets of electrode pairs to provide quantitative signals at each electrode referenced to signals of one or more other electrodes;

converting the quantitative signals to visual signals which may be interpreted by a medical practitioner; and

displaying the visual signals in a pattern corresponding to the electrodes in the array wherein the visual signals provide an indication of the degree of electrical activity at each individual electrode and thus underlying musculature of the patient wherein the pattern includes a line interconnecting representations of each of the electrodes in each set of electrode pairs.

45. A method as set forth in claim 44 wherein said step of converting said signals comprises converting said signals to lines having a characteristic representative of the degree of electrical activity at said electrodes.

46. A method as set forth in claim 45 wherein said step of converting said signals comprises converting said signals to lines having shape, intensity or hue representative of the degree of electrical activity at said electrodes.

47. A method comprising the steps of:

placing an array of electrodes at a predetermined location on a surface of a patient;

gathering surface EMG signals from the electrodes and recording the surface EMG signals to provide a substantially complete representation of the EMG signals for the entire array of the electrodes;

processing the EMG signals to provide quantitative signals representative of a degree of electrical activity at each of the electrodes;

converting the quantitative signals to visual signals which may be interpreted by a medical practitioner; and

displaying the visual signals in a pattern corresponding to the pattern of the electrode array to provide an indication of the degree of electrical activity at each individual electrode, and thus in the musculature of the patient underlying each electrode;

displaying a visual pattern representative of the musculature of the patient in registration with the pattern of visual signals derived from the EMG signals, whereby the visual signals are enabled to be correlated with patient musculature.

48. A method as set forth in claim 47 wherein said pattern of visual signals derived from said EMG signals comprises a grid of straight lines interconnecting said electrode locations, each of said straight lines being of a hue representative of a signal quantity at each said electrode.

49. A method as set forth in claim 48 wherein said quantitative signals are a representation of the RMS voltage derived for each electrode.

50. A method comprising the steps of:

placing an array of electrodes at a predetermined location on a surface of a patient;

gathering surface EMG signals from the electrodes and recording the surface EMG signals to provide a substantially complete representation of the EMG signals for the entire ray of the electrodes;

processing the EMG signals to provide quantitative signals representative of a degree of electrical activity at each of the electrodes wherein the processing step includes oversampling;

converting the quantitative signals to visual signals which may be interpreted by a medical practitioner; and

displaying the visual signals in a pattern corresponding to the pattern of the electrode array to provide an indication of the degree of electrical activity at each individual electrode and thus in the musculature of the patient underlying each electrode.

51. A method comprising the steps of:

placing an array of electrodes at a predetermined location on a surface of a patient wherein the array comprises a plurality of equally spaced electrodes arranged in a series of parallel rows and aligned in a series of columns orthogonal to the rows;

gathering surface EMG signals from the electrodes and recording the surface EMG signals to provide a substantially complete representation of the EMG signals produced by each of the plurality of electrodes in the array;

processing the EMG signals to provide quantitative signals representative of a degree of electrical activity at each of the electrodes in the array;

converting the quantitative signals to visual signals which may be interpreted by medical practitioner; and

displaying the visual signals in a pattern representative of the pattern of the electrode array wherein the pattern includes indicia representative of the degree of electrical activity at each individual electrode and thus in the musculature of the patient underlying the electrodes.

52. A method as set forth in claim 51 wherein each electrode comprises multiple tips, wherein in the placing step, the multiple tips are placed in operative contact with the surface of the patient.

53. A method comprising the steps of:

a) placing an array including a plurality of electrodes over a surface portion of a patient;

b) gathering surface EMG signals from each of the plurality of electrodes;

c) producing a visual display responsive to the signals, wherein the visual display includes indicia produced responsive to signals from each of the plurality electrodes in the array; and

d) superimposing with the visual display, a plurality of visual representations of anatomical structures of the patient underlying the surface portion.

54. The method according to claim 53 wherein in step (d) visual representations of different anatomical structures are superimposed with the visual display at different times.

55. The method according to claim 53 and further comprising the step of:

e) comparing for correspondence the indicia in the visual display and each of the plurality of superimposed visual representations of underlying anatomical structures.

56. The method according to claim 53 wherein the indicia in the visual display vary in hue responsive to the respective signals from the plurality of electrodes, and further comprising the step of selectively varying the hues of indicia in the visual display responsive to inputs by a user to a device which is operative to cause output of the visual display.

57. A method comprising the steps of:

a) placing an array including a plurality of electrodes on a surface of a patient;

b) gathering surface EMG signals from each of the plurality of electrodes;

c) processing signals corresponding to the surface EMG signals to produce at least one quantitative signal for each electrode in the array, wherein the quantitative signal for an electrode corresponds to a magnitude of the surface EMG signal from the electrode referenced to a surface EMG signal from at least one other electrode in the array; and

d) producing a visual display including indicia corresponding to quantitative signals for each of the plurality of electrodes in the array.