Methods and Apparatus for Electrical Stimulation of Tissues Using Signals that Minimize the Effects of Tissue Impedance

• US 20090030476A1
• Filed: 08/06/2008
• Published: 01/29/2009
• Est. Priority Date: 02/04/2002
• Status: Active Grant

• Current Assignee: Jeffrey B. Hargrove
• Original Assignee: Cerephex Corporation
• Inventors: Hargrove, Jeffrey B.
• Granted Patent: US 8,494,625 B2
• Time in Patent Office: Days
• US Class Current: 607/40
• CPC Class Codes: A61B 5/053 Measuring electrical impedance or conductance of a portion of the body
• CPC Class Codes: A61B 5/145 Measuring characteristics of blood in vivo, e.g. gas concentration, pH value; Measuring characteristics of body fluids or tissues, e.g. interstitial fluid, cerebral tissuemeasuring of blood pressure or blood flow A61B5/02; non-radiation detecting or locating of foreign bodies in blood A61B5/06
• CPC Class Codes: A61B 5/318 Heart-related electrical modalities, e.g. electrocardiography [ECG]
• CPC Class Codes: A61B 5/369 Electroencephalography [EEG] devices for psychotechnics A61B5/16
• CPC Class Codes: A61B 5/374 Detecting the frequency distribution of signals, e.g. detecting delta, theta, alpha, beta or gamma waves
• CPC Class Codes: A61B 5/377 using evoked responses
• CPC Class Codes: A61B 5/378 Visual stimuli
• CPC Class Codes: A61B 5/389 Electromyography [EMG]
• CPC Class Codes: A61B 5/4519 Muscles A61B5/389, A61B5/224 take precedence
• CPC Class Codes: A61B 5/6843 Monitoring or controlling sensor contact pressure
• CPC Class Codes: A61B 5/7257 using Fourier transforms
• CPC Class Codes: A61N 1/36025 for treating a mental or cerebral condition
• CPC Class Codes: A61N 1/36031 using physiological parameters for adjustment
• CPC Class Codes: A61N 1/36034 specified by the stimulation parameters
• CPC Class Codes: A61N 1/36082 Cognitive or psychiatric applications, e.g. dementia or Alzheimer's disease
• CPC Class Codes: A61N 1/37235 Aspects of the external programmer
• CPC Class Codes: A61N 1/37247 User interfaces, e.g. input or presentation means
• CPC Class Codes: G16H 40/63 for local operation
• CPC Class Codes: G16H 50/70 for mining of medical data, e.g. analysing previous cases of other patients

Abstract

A tissue stimulation system that generates an electrical tissue stimulation signal configured to reduce tissue impedance and increase depth of signal penetration. The use of leads is dynamically controlled and altered between conducting biopotential voltages, conducting electrical tissue stimulation signals, and grounding, in response to a computational analysis of biopotential data acquired from a region of tissue to be stimulated.

Claims

1. A tissue stimulation apparatus comprising an electrical stimulation device (101) that includes a stimulation signal generation circuit configured to generate an electrical tissue stimulation signal that reduces tissue impedance and increases depth of signal penetration.

2. A tissue stimulation apparatus as set forth in claim 1 in which the stimulation signal generation circuit is configured to generate an amplitude modulated pulse width modulated (AMPWM) signal.

3. A tissue stimulation apparatus as set forth in claim 1 in which the stimulation signal generation circuit comprises a processor (103) configured to control generation of electrical signals by the electrical stimulation device (101) for tissue stimulation.

4. A tissue stimulation apparatus as set forth in claim 3 in which the tissue stimulation apparatus includes an external computing device electrically coupled to the processor (103) and configured to provide a user interface.

5. A tissue stimulation apparatus as set forth in claim 4 in which the external computing device is configured to exchange data and control signals with the processor.

6. A tissue stimulation apparatus as set forth in claim 4 in which the external computing device is configured to allow a user to modify operational parameters of the electrical stimulation device (101).

7. A tissue stimulation apparatus as set forth in claim 4 in which the external computing device (102) is configured to establish parameters of the electrical signals generated by the device (101).

8. A tissue stimulation apparatus as set forth in claim 4 in which the external computing device (102) is configured to functionally interface with at least one other network computing device.

9. A tissue stimulation apparatus as set forth in claim 8 in which the external computing device (102) is configured to functionally interface with the other network computing device via the Internet.

10. A tissue stimulation apparatus as set forth in claim 9 in which

the external computing device (102) is configured to functionally interface with the other network computing device to determine parametric values of an electrical tissue stimulation signal;

and

to receive subsequent corresponding control data from the other network computing device via the functional interfaces.

11. A tissue stimulation apparatus as set forth in claim 3 in which the stimulation signal generation circuit further comprises a digital-to-analog (D/A) converter (104) configured to receive signal parameters from the processor (103) and to generate a corresponding analog voltage representing an electrical signal for stimulating tissues.

12. A tissue stimulation apparatus as set forth in claim 11 in which the stimulation signal generation circuit further comprises a signal conditioning and amplification circuit (106) configured to receive the analog voltage from the D/A converter (104) and to generate a generally equivalent signal having any one or more advantageous enhancements selected from the group of enhancements consisting of increased voltage amplitude, decrease signal-to-noise ratio, and increased current capability.

13. A tissue stimulation apparatus as set forth in claim 12 in which the tissue stimulation apparatus includes a plurality of stimulation leads (121) and one or more ground leads (20) configured to conduct electrical energy between tissues and the electrical stimulation device (1).

14. A tissue stimulation apparatus as set forth in claim 13 in which the stimulation signal generation circuit is configured to selectively control the delivery of stimulating electrical signals to tissues through one or more selected ones of the stimulation leads (121).

15. A tissue stimulation apparatus as set forth in claim 14 in which the stimulation signal generation circuit further includes a stimulation switching circuit (110) electrically coupled to the processor (103), the processor and stimulation switching circuit being configured to switch signals from the signal conditioning and amplification circuit (106) to independent electrical conduction paths that are electrically coupled with the respective stimulation leads.

16. A tissue stimulation apparatus as set forth in claim 15 in which the stimulation signal generation circuit further includes a first ground switching circuit (119) electrically coupled with the independent electrical conduction paths and with the processor (103), the processor and ground switching circuit being configured to selectively switch the independent conduction paths to at least one system ground point.

17. A tissue stimulation apparatus as set forth in claim 1 in which the electrical stimulation device (101) includes:

a battery 108 connected to other circuits of the apparatus and configured to provide electrical power to other circuits of the electrical stimulation device (101);

a battery charger and switching circuit (107) electrically coupled to the battery 108; and

a processor 103 electrically coupled to the battery charger and switching circuit (107), the processor being configured to command the battery charger and switching circuit (107) to decouple the device (101) from an external power source (105) when isolation is desired and to couple the external power source (105) to the battery 108 to charge the battery when isolation is not desired.

18. A tissue stimulation apparatus as set forth in claim 17 in which the electrical stimulation device (101) includes at least one auxiliary control I/O connector electrically coupled with an input-output (I/O) port of the processor (103), the processor and control I/O connector being configured to provide control signals between the processor and a peripheral device.

19. A tissue stimulation apparatus as set forth in claim 13 in which the apparatus includes at least one lead test port (117) electrically coupled to the processor (103) and configured to electrically couple a conduction interface (122) of the lead (121) to the processor, the processor being configured to test the electrical conducting integrity of the lead.

20. A tissue stimulation apparatus as set forth in claim 19 in which the processor is configured to output an electrical signal of known properties to the lead (121) and to acquire and test the resulting electrical signal conducted through the lead and returned to the processor through the lead test port.

21. A tissue stimulation apparatus as set forth in claim 20 in which processor is configured to determine the electrical conducting integrity of the lead by comparing the electrical signal of known properties to the signal conducted through the lead.

22. A tissue stimulation apparatus as set forth in claim 1 in which the tissue stimulation apparatus includes one or more external stimulation devices (123) electrically coupleable to the electrical stimulation device (101).

23. A tissue stimulation apparatus as set forth in claim 22 in which the external stimulation device (123) includes one or more devices selected from the group of devices consisting of an optical device, an electromagnetic device, and electromechanical device, and an audio device.

24. A tissue stimulation apparatus as set forth in claim 22 in which the external stimulation device (123) includes an optical device comprising eyeglasses adapted to carry illuminating devices.

25. A tissue stimulation apparatus as set forth in claim 22 in which the external stimulation device (123) includes an optical device comprising one or more displays for showing images.

26. A tissue stimulation apparatus as set forth in claim 22 in which the external stimulation device (123) includes an audio device adapted to play music.

27. A tissue stimulation apparatus as set forth in claim 1 in which the tissue stimulation apparatus includes data collection instruments configured to collect data on a subject during periods of therapy and electrically coupled to the electrical stimulation device (101).

28. A tissue stimulation apparatus as set forth in claim 13 in which the tissue stimulation apparatus includes a biopotential acquisition device configured to measure biopotential voltage of tissues to be stimulated.

29. A tissue stimulation apparatus as set forth in claim 28 in which the biopotential acquisition device includes an amplifier module (127) comprising a biopotential amplifier (130).

30. A tissue stimulation apparatus as set forth in claim 29 in which the biopotential acquisition device includes at least one biopotential acquisition lead (125) and at least one ground lead (120).

31. A tissue stimulation apparatus as set forth in claim 30 in which the biopotential amplifier module (127) is electrically couplable to the electrical stimulation device (101) through any one or more connectors selected from the group of connectors consisting of stimulation lead connectors (113), auxiliary power supply connector (114), control I/O connectors (115), and auxiliary I/O connectors (116) of the electrical stimulation device (101).

32. A tissue stimulation apparatus as set forth in claim 31 in which the biopotential acquisition device is configured to measure any one or more biopotential voltages selected from the group of biopotential voltages consisting of electroencephalographic (EEG) voltage, electromyographic (EMG) voltage, and electrocardiographic voltage.

33. A tissue stimulation apparatus as set forth in claim 30 in which the tissue stimulation apparatus is configured for the biopotential amplifier (130) to measure biopotential voltage of tissue as the electrical stimulation device (101) provides stimulation to the tissue.

34. A tissue stimulation apparatus as set forth in claim 33 in which the biopotential acquisition device includes at least one inductor (128) electrically coupled to the electrical stimulation device (101) and operatively coupleable to at least one biopotential acquisition lead (125), the electrical stimulation device and inductor being configured to deliver tissue stimulation signals through the at least one biopotential acquisition lead.

35. A tissue stimulation apparatus as set forth in claim 33 in which the biopotential acquisition device includes one or more inductors (128) electrically coupled to the electrical stimulation device (101) and operatively coupleable to one or more respective biopotential acquisition leads (125), the electrical stimulation device and inductors being configured to selectively deliver tissue stimulation signals through the one or more biopotential acquisition leads.

36. A tissue stimulation apparatus as set forth in claim 33 in which the biopotential acquisition device includes at least one adjunct switching circuit (133) and an adjunct switching control (135) electrically coupled to the electrical stimulation device (101), the adjunct switching circuit being operatively coupleable to at least one biopotential acquisition lead (125), the electrical stimulation device and an adjunct switching control being configured to selectively connect the electrical stimulation device (101) to selected leads to transmit tissue stimulation signals to the selected leads and to connect selected leads to the biopotential amplifier to transmit biopotential voltages to the biopotential amplifier.

37. A tissue stimulation apparatus as set forth in claim 30 in which the electrical stimulation device (1) is configured to use at least one biopotential acquisition lead (125) for both acquiring biopotential voltage and delivering an electrical tissue stimulation signal.

38. A tissue stimulation apparatus as set forth in claim 37 in which the electrical stimulation device (101) is configured to use at least one biopotential acquisition lead (125) for simultaneously acquiring biopotential voltage and delivering an electrical tissue stimulation signal.

39. A tissue stimulation apparatus as set forth in claim 38 in which the electrical stimulation device (101) is configured to selectively sample biopotential voltage data from the biopotential acquisition device at times of minimal electrical stimulation signal amplitude.

40. A tissue stimulation apparatus as set forth in claim 39 in which the electrical stimulation device (101) is configured to selectively sample biopotential voltage data from the biopotential acquisition device over assessment periods of between about 1 second and about 60 seconds.

41. A tissue stimulation apparatus as set forth in claim 39 in which the electrical stimulation device (101) is configured to selectively sample biopotential voltage data from the biopotential acquisition device at times of minimal electrical stimulation signal amplitude within the period of a high frequency signal component of an AMPWM signal.

42. A tissue stimulation apparatus as set forth in claim 1 in which the electrical stimulation device (101) is configured to select the frequencies of a high frequency signal component of an AMPWM signal to be multiples of integral powers of two.

43. A tissue stimulation apparatus as set forth in claim 42 in which the electrical stimulation device (101) is configured to select the frequencies of a high frequency signal component of an AMPWM signal to be integral multiples of (256).

44. A tissue stimulation apparatus as set forth in claim 42 in which the electrical stimulation device (101) is configured to mathematically analyze acquired biopotential voltage data using a Fourier Transform analysis whereupon a number of samples per second is equal to an integral power of two.

45. A tissue stimulation apparatus as set forth in claim 30 in which the tissue stimulation apparatus is configured to use biopotential voltage data to determine parametric values of an electrical tissue stimulation signal.

46. A tissue stimulation apparatus as set forth in claim 45 in which an external computing device (102) is configured to determine parametric value of an electrical tissue stimulation signal in response to biopotential voltage data obtained by the biopotential acquisition device and to send corresponding control data to the processor (103).

47. A tissue stimulation apparatus as set forth in claim 46 in which the biopotential acquisition device is an EEG acquisition device and the external computing device (102) is configured to determine parametric value of an electrical tissue stimulation signal in response to EEG data obtained by the EEG acquisition device and to send corresponding control data to the processor (103).

48. A tissue stimulation apparatus as set forth in claim 46 in which the tissue stimulation apparatus is configured to use at least one biopotential acquisition lead (125) as either a conduction path for an electrical tissue stimulation signal, a conduction path for carrying a biopotential voltage to the biopotential amplifier (130), or a ground.

49. A tissue stimulation apparatus as set forth in claim 48 in which the processor 103 is configured to selectively switch a biopotential acquisition lead (125) to an apparatus ground point by sending corresponding control signals to the second ground switching circuit (129).

50. A tissue stimulation apparatus as set forth in claim 46 in which the processor 103 is configured to differentially compare biopotential voltages at more than one acquisition site on a tissue by selectively using biopotential acquisition leads (125) as reference leads to the biopotential amplifier (130) or as differential leads to the biopotential amplifier (130).

51. A tissue stimulation apparatus as set forth in claim 1 in which the tissue stimulation apparatus includes an impedance testing circuit (131) configured to monitor the impedance of tissues, the apparatus being configured to determine parametric values of an electrical tissue stimulation signal in response to tissue impedance data acquired by the impedance testing circuit.

52. A tissue stimulation apparatus as set forth in claim 51 in which the impedance testing circuit (131) is coupled to the electrical stimulation device (101) and a biopotential amplifier (130) of a biopotential acquisition device and is configured to monitor the impedance of tissues in contact with at least one ground lead (120) and at least one biopotential acquisition lead (125) of the biopotential acquisition device and to transfer such data to the processor (103).

53. A tissue stimulation apparatus as set forth in claim 51 further including an external computing device (102) coupled to the processor (103) and configured to analyze tissue impedance data and to send corresponding control data to the processor (103) for altering parametric parameters of electrical tissue stimulation signals.

54. A tissue stimulation apparatus as set forth in claim 1 in which the tissue stimulation apparatus includes an impedance testing circuit (131) that is coupled with the biopotential amplifier (130) of a biopotential acquisition device and is configured to monitor biopotential voltage integrity.

55. A tissue stimulation apparatus as set forth in claim 54 in which the tissue stimulation apparatus is configured to indicate to a user when good biopotential voltage integrity is achieved.

56. A tissue stimulation apparatus as set forth in claim 54 in which the tissue stimulation apparatus is configured to generate an alert when biopotential voltage integrity is lost.

57. A tissue stimulation apparatus as set forth in claim 1 in which the tissue stimulation apparatus comprises:

a sensor set (136);

an independent biopotential voltage measurement apparatus (137), and an adjunct electrical stimulation apparatus (132) operatively connected between the sensor set (136) and the independent biopotential voltage measurement apparatus, operatively coupled to the electrical stimulation device (101), and configured to transmit to the sensor set electrical tissue stimulation signals received from the electrical stimulation device, to transmit biopotential voltage from the sensor set to the independent biopotential voltage measurement apparatus, and to receive control signals from a processor (103) of the electrical stimulation device.

58. A tissue stimulation apparatus as set forth in claim 57 in which the biopotential measurement apparatus is an EEG measurement apparatus (137) and the sensor set is an EEG sensor set.

59. A tissue stimulation apparatus as set forth in claim 57 in which the sensor set (136) comprises at least one electrode and a cap configured to position the at least one electrode and to be worn by a subject.

60. A tissue stimulation apparatus as set forth in claim 57 in which in which the adjunct electrical stimulation apparatus (132) includes:

an adjunct switching control (135) operatively coupled to the processor 103 of the electrical stimulation device (101);

a plurality of adjunct switching circuits (133) operatively coupled to the adjunct switching control (135), to the electrical stimulation device (101), to the independent biopotential measurement apparatus (137), and to respective electrodes of the sensor set (136); and

the processor and adjunct switching control are configured to provide selectable conduction pathways for tissue stimulation signals between the electrical stimulation device (101) and the electrodes of the sensor set, and for biopotential voltages between the electrodes of the sensor set and the biopotential voltage measurement apparatus (137).

61. A tissue stimulation apparatus as set forth in claim 60 in which in which the processor (103) and adjunct switching circuits (133) are configured to provide selectable conduction pathways between the electrodes of the sensor set (136) and a ground.

62. A tissue stimulation apparatus as set forth in claim 57 in which the adjunct electrical stimulation apparatus (132) includes:

a ground switching circuit (129) operatively coupled to the processor (103) of the electrical stimulation device (101), to the biopotential amplifier (130), and by conduction paths to respective electrodes of the sensor set;

a plurality of inductors (128) operatively coupled to the electrical stimulation device (101) and to the conduction paths; and

the processor and ground switching circuit are configured to provide selectable conduction pathways for tissue stimulation signals between the electrical stimulation device (101) and the electrodes of the sensor set, and for biopotential voltages between the electrodes of the sensor set and the biopotential voltage measurement apparatus (137).

63. A tissue stimulation apparatus as set forth in claim 62 in which the processor (103) and ground switching circuit (129) are configured to provide selectable conduction pathways between the electrodes of the sensor set (136) and a ground.

64. A tissue stimulation apparatus as set forth in claim 60 in which the adjunct electrical stimulation apparatus (132) includes at least one switching control conductor (141) electrically coupled to an adjunct switching circuit (135) and configured to determine the state of the adjunct switching circuit (133) and a conduction path provided to a corresponding electrode of the sensor set.

65. A tissue stimulation apparatus as set forth in claim 57 in which the processor (103) of the electrical stimulation device (101) and the adjunct switching control are configured to:

direct biopotential voltage from selected electrodes of the sensor set to the biopotential measurement apparatus (137) by selective switching via the adjunct switching control (135) operated by the processor (103) when a biopotential voltage measurement is required;

to direct a tissue stimulation signal from the electrical stimulation device to selected electrodes of the sensor set by selective switching via the adjunct switching control (135) operated by the processor (103) when tissue stimulation is required; and

to couple an electrode of the sensor set to ground by selective switching via the adjunct switching control (135) operated by the processor (103) when grounding of an electrode is desired.

66. A tissue stimulation apparatus as set forth in claim 1 and further comprising:

a mobile apparatus (146) carrying the electrical stimulation device (101); and

a material supplies storage and use apparatus (147) carried by the mobile apparatus and configured to carry consumable supplies for use in administering tissue stimulation signals to a subject.

67. A tissue stimulation apparatus as set forth in claim 66 in which the material supplies storage and use apparatus (147) is configured to carry any number of consumable supplies selected from the group of supplies consisting of conductive pastes, conductive gels, cleaning materials, cleaning agents, and supporting materials.

68. A tissue stimulation apparatus as set forth in claim 66 in which the material supplies storage and use apparatus (147) comprises a plurality of receptacles (148, 149, 150, 151, 152, 153, 154) configured to store any number of items selected from the group of items consisting of a waste, conductive gel, conductive paste, cleaning materials, alcohol, supporting materials, and electrodes.

69. A tissue stimulation apparatus as set forth in claim 66 in which the material supplies storage and use apparatus (147) includes an electrode storage receptacle (154) configured to store and block light from reaching lead electrodes (122) comprising photosensitive materials.

70. A tissue stimulation apparatus as set forth in claim 66 in which the tissue stimulation apparatus (144) includes one or more sensors NOT SHOWN carried by the material supplies and use apparatus (147) and configured to sense the quantities of materials stored in receptacles of the material supplies storage and use apparatus (147).

71. A tissue stimulation apparatus as set forth in claim 66 in which the tissue stimulation apparatus (144) includes an external computing device (102) NOT SHOWN coupled to the one or more sensors and configured to manage inventory in response to signals acquired from the one or more sensors.

72. A tissue stimulation apparatus as set forth in claim 71 in which the tissue stimulation apparatus is configured to generate an alert when inventory of any material reaches a predetermined low point.

73. A tissue stimulation apparatus as set forth in claim 71 in which the tissue stimulation apparatus is configured to order materials necessary to replenish inventory when a predetermined low point is reached.

74. A tissue stimulation apparatus as set forth in claim 71 in which the tissue stimulation apparatus is configured to order materials by interfacing with a communications network.

75. A tissue stimulation apparatus as set forth in claim 66 in which the electrical stimulation apparatus (144) is configured to provide stimulation through composite stimulation leads (145), the composite stimulation leads comprising a combination of stimulation leads (121) and ground leads (120).

76. A tissue stimulation apparatus as set forth in claim 75 in which the composite stimulation leads (145) include external stimulation device cables (124).

77. A tissue stimulation method comprising the steps of:

providing a tissue stimulation apparatus configured to dynamically alter the use of leads between conducting biopotential voltages, conducting an electrical signal for stimulating tissues, and grounding, in response to a computational analysis of biopotential data acquired from a region of tissue to be stimulated;

acquiring biopotential data from a region of tissue to be stimulated;

performing a computational analysis of the acquired biopotential data;

in response to the analysis, identifying and placing sufficient leads so as to provide a number of possible conduction paths passing in near proximity to a region of tissue of interest; and

dynamically controlling electrical signal delivery to the region of tissue of interest by selectively switching the use of the leads as conductors and grounds.

78. The tissue stimulation method of claim 77 including the additional step of assessing subsequently acquired data for the purpose of subsequent altering of lead use.

79. The tissue stimulation method of claim 77 in which the step of dynamically controlling electrical signal delivery includes generating and applying an electrical tissue stimulation signal that reduces tissue impedance and increases depth of signal penetration.

80. The tissue stimulation method of claim 79 in which the step generating and applying an electrical tissue stimulation signal includes generating and applying an AMPWM signal.

81. The tissue stimulation method of claim 80 in which the step of generating and applying an AMPWM signal includes varying the time-averaged current flow of an electric tissue stimulation signal by modifying the duty cycle of the high frequency component of an AMPWM signal.

82. The tissue stimulation method of claim 81 including the additional step of varying stimulation intensity provided to a subject by the external stimulation device (123).

83. The tissue stimulation method of claim 81 including the additional step of varying stimulation intensity of one or more external stimulation devices (123) selected from the group of external stimulation devices consisting of an optical stimulation device, an electromagnetic field-producing device, an electromechanical stimulation device, and an audio stimulation device.

84. The tissue stimulation method of claim 77 in which the electrical stimulation apparatus is configured to identify a subject.

85. The tissue stimulation method of claim 84 in which the electrical stimulation apparatus is configured to identify a subject by examining any one or more identification media selected from the group of media consisting of visual media, electronic media, and magnetic media.

86. The tissue stimulation method of claim 84 in which the electrical stimulation apparatus is configured to identify a subject by examining a digital photograph of a subject.

87. The tissue stimulation method of claim 77 in which the electrical stimulation apparatus is further configured to use a digital photograph of the subject to identify proper locations for lead placement.

88. A tissue stimulation method including the steps of:

determining parametric values of an electrical tissue stimulation signal by;

obtaining biopotential voltage data from a region of tissue to be stimulated; and

determining parametric values of an electrical tissue stimulation signal in response to the biopotential voltage data; and

generating and applying to the region of tissue an electrical stimulation signal having the determined parametric values.

89. The tissue stimulation method of claim 88 in which:

the step of obtaining biopotential voltage data includes measuring the EEG activity of at least a portion of a subject'"'"'s brain; and

the step of determining parametric values includes analyzing the data.

90. The tissue stimulation method of claim 89 in which the step of analyzing the data includes the use of any one or more biopotential voltage measuring methods selected from the group of methods consisting of measuring biopotential voltage in single frequency components, measuring biopotential voltage in composites of multiple frequencies, and measuring biopotential voltage in frequency band ratios obtained at an EEG site.

91. The tissue stimulation method of claim 89 in which the step of analyzing the data includes analyzing data obtained at multiple EEG sites.

92. The tissue stimulation method of claim 89 in which the step of analyzing the data includes statistical analyses involving measured EEG voltages and their frequency and phase components.

93. The tissue stimulation method of claim 89 in which the step of analyzing the data using statistical analyses includes measures of variance, correlation, and/or coherence.

94. The tissue stimulation method of claim 89 in which the step of analyzing the data includes analyses that provide indication of the spatial origin and/or source localization of the measured EEG.

95. The tissue stimulation method of claim 89 in which the step of analyzing the data includes performing an “

inverse EEG”

analysis.

96. The tissue stimulation method of claim 89 in which the step of determining parametric values includes making comparisons between the findings of the EEG data analysis and similar measures known to represent normal brain activity in a healthy normal population of living beings.

97. The tissue stimulation method of claim 89 in which the step of determining parametric values may further include:

quantifying differences between the measured EEG of a subject and the EEG expected in normal brain activity; and

using such differences to identify particular brain sites or regions where frequency and amplitude components of the subject'"'"'s EEG are either excessive, diminished, or highly variable.

98. The tissue stimulation method of claim 89 in which the step of determining parametric values includes:

selecting quantities such as the frequency, amplitude, and phase components of the low frequency component of an AMPWM signal based on such comparisons in an attempt to achieve normal EEG presentation; and

controlling the time-averaged current deliverable by an electrical signal of relatively high frequency by using pulse width modulation for the purpose of varying the duty cycle of that electrical signal.

99. The tissue stimulation method of claim 98 in which the step of selecting quantities includes selecting the pulse width duty cycle of the high frequency component of an AMPWM signal based on such comparisons to affect the time averaged current delivered by the AMPWM signal in an attempt to achieve normal EEG presentation.

100. The tissue stimulation method of claim 88 in which the step of determining parametric values includes selecting frequencies for low frequency signal components of an electrical tissue stimulation signal to modulate either excessive or diminished EEG activity, as determined by the comparative analysis.

101. The tissue stimulation method of claim 100 in which the step of selecting frequencies for low frequency signal components includes selecting a lower frequency as the low frequency component of the electrical signal for stimulating a region of a brain where excessively high frequency EEG activity is found.

102. The tissue stimulation method of claim 88 in which the step of determining parametric values includes using a progressively lower frequency in therapeutic activity until excessive EEG activity in a region of a brain reduces to a more normal level.

103. The tissue stimulation method of claim 89 in which the method of determining parametric values includes determining the effectiveness of therapeutic activity by monitoring EEG of a brain during therapeutic activity.

104. The tissue stimulation method of claim 89 in which the step of determining parametric values includes determining a plurality of desirable stimulation frequencies to be applied to brain tissue by EEG analysis of the brain tissue

105. The tissue stimulation method of claim 88 in which:

the step of determining a plurality of desirable stimulation frequencies to be applied to brain tissue includes applying inverse Fourier Transform methods, and

the step of applying an electrical stimulation signal includes generating a form of an AMPWM signal.

106. The tissue stimulation method of claim 105 in which the step of generating a form of an AMPWM signal includes creating a low frequency component waveform featuring multiple frequency components, as determined by the inverse Fourier Transform methods.

107. The tissue stimulation method of claim 88 in which the step of generating and applying an electrical stimulation signal includes generating and applying an electrical tissue stimulation signal that reduces tissue impedance and increases depth of signal penetration.

108. The tissue stimulation method of claim 107 in which the step generating and applying an electrical tissue stimulation signal includes generating and applying an AMPWM signal.

109. The tissue stimulation method of claim 106 in which:

the step of applying inverse Fourier Transform methods includes using inverse Fourier Transform computation to determine from the plurality of desirable stimulation frequencies a single waveform of multiple low frequency components; and

the step of generating and applying an electrical stimulation signal includes using the single waveform to create and use an AMPWM signal to stimulate brain tissue.

110. The tissue stimulation method of claim 88 in which:

the step of obtaining biopotential voltage data includes acquiring EEG data of brain tissue during therapeutic stimulation signal application activity; and

the step of determining parametric values includes analyzing the EEG data as the stimulation signal is being applied.

111. The tissue stimulation method of claim 88 in which the step of analyzing EEG data includes:

making comparisons between an acquired EEG presentation and a desired EEG in a normal presentation; and

the step of generating and applying a signal includes attempting to achieve a normal EEG presentation by altering frequency, amplitude, and/or phase components of the low frequency component of an AMPWM signal based on these comparisons.

112. The tissue stimulation method of claim 88 in which the step of generating and applying a signal includes attempting to achieve a normal EEG presentation by affecting the time averaged current delivered by the AMPWM signal by altering the pulse width duty cycle of the high frequency component of an AMPWM signal based on the comparisons.

113. The tissue stimulation method of claim 88 in which the step of determining parametric values includes:

obtaining sensory inputs quantifying the functional state of a subject; and

determining parametric values for the purpose of stimulating brain tissue in response to the sensory inputs.

114. The tissue stimulation method of claim 88 in which the step of obtaining sensory inputs includes obtaining any one or more sensory inputs selected from the group of such inputs consisting of tissue impedance, temperature, oxygen saturation, EMG activity, electrocardiographic activity, biochemical levels, and measures involving respiration patterns.

115. The tissue stimulation method of claim 88 in which the step of generating and applying includes controlling the application time of the signals.

116. The tissue stimulation method of claim 115 in which the step of controlling signal application time includes predetermining signal application time programmatically based on empirical data.

117. The tissue stimulation method of claim 115 in which the step of controlling signal application time includes starting and then automatically stopping an electrical tissue stimulation signal in response to the achievement of certain desired measures of tissue electrical properties.

118. The tissue stimulation method of claim 115 in which the step of controlling signal application time includes:

acquiring EEG data from brain tissue during therapeutic electrical tissue stimulation activity;

analyzing the acquired EEG data as the stimulation signal is being applied; and

stopping the electrical signal application when one or more predetermined EEG properties are achieved.

119. The tissue stimulation method of claim 115 in which the step of controlling signal application time includes terminating signal application in response to any one or more measures of sensory input selected from the group of such inputs consisting of tissue impedance, temperature, oxygen saturation, EMG activity, electrocardiographic activity, biochemical levels, and measures involving respiration patterns.

120. The tissue stimulation method of claim 119 in which the step of controlling signal application time further includes predetermination of a maximum time for signal application such that the electrical signal will not exceed a predetermined time if desired electrical properties of the tissue are not achieved.

121. A tissue stimulation method including the steps of:

determining parametric values of an electrical tissue stimulation signal by;

taking measures of electrical properties of a region of tissue to be stimulated;

making statistical comparisons between the measures and measures known to represent normal tissue electrical properties in a healthy normal population of living beings;

determining parametric values of an electrical tissue stimulation signal in response to the comparisons; and

generating and applying to the region of tissue an electrical stimulation signal having the determined parametric values.

122. The tissue stimulation method of claim 121 in which the region of tissue to be stimulated is a region selected from the group of tissue types consisting of muscle, bone, tendon, ligament, cartilage, fascia, dermis, and internal organs.

123. The tissue stimulation method of claim 121 in which the step of determining parametric values includes attempting to achieve normal tissue electrical property presentation by selecting frequency, amplitude, and/or phase components of the low frequency component of an AMPWM signal based on the statistical comparisons.

124. The tissue stimulation method of claim 121 in which the step of determining parametric values includes attempting to achieve normal tissue electrical property presentation by controlling the time-averaged current deliverable by an AMPWM signal by using pulse width modulation to vary the duty cycle of a high frequency component of the AMPWM signal.

125. The tissue stimulation method of claim 121 in which the step of generating and applying an electrical stimulation signal includes generating and applying an electrical tissue stimulation signal that reduces tissue impedance and increases depth of signal penetration.

126. The tissue stimulation method of claim 125 in which the step generating and applying an electrical tissue stimulation signal includes generating and applying an AMPWM signal.

127. The tissue stimulation method of claim 124 in which the step of controlling the time-average current deliverable by an AMPWM signal includes selecting the pulse width duty cycle of the high frequency component of an AMPWM signal based on the statistical comparisons.

128. A tissue stimulation method including the steps of:

determining parametric values of an electrical tissue stimulation signal by;

taking measures of biochemicals from tissues and/or fluids relevant to the tissues to be stimulated;

analyzing the measures; and

determining parametric values of an electrical tissue stimulation signal in accordance with the analysis of the measures; and

generating and applying to the region of tissue an electrical stimulation signal having the determined parametric values and configured to reduce tissue impedance and increase depth of signal penetration.

129. The tissue stimulation method of claim 128 in which the step generating and applying an electrical tissue stimulation signal includes generating and applying an AMPWM signal.

130. The tissue stimulation method of claim 128 in which the step of taking measures of biochemicals includes taking measures of neurochemicals.

131. The tissue stimulation method of claim 130 in which the step of taking measures of biochemicals includes taking measures of neurotransmitters.

132. The tissue stimulation method of claim 128 in which:

the step of analyzing the measures includes making comparisons between the measures of biochemicals and similar measures known to represent normal levels of the biochemicals in a healthy normal population of living beings; and

the step of determining parametric values in accordance with the analysis includes determining parametric values of an electrical tissue stimulation signal in response to the comparisons.

133. The tissue stimulation method of claim 132 in which the step of making comparisons includes quantifying differences that indicate amounts of certain biochemicals different than normal.

134. The tissue stimulation method of claim 132 in which the step of making comparisons includes determining whether molecular resonant frequencies associated with biochemicals are different than normal.

135. The tissue stimulation method of claim 134 in which the step of determining parametric values in response to the comparisons includes determining electrical signal parameters that will tend to normalize abnormal biochemical levels.

136. The tissue stimulation method of claim 128 in which the step of determining parametric values in response to the comparisons includes attempting to achieve normal biochemical presentation by selecting frequency, amplitude, and/or phase components of a low frequency component of an AMPWM signal based on the molecular resonant frequencies associated with biochemicals to be used.

137. The tissue stimulation method of claim 128 in which the step of determining parametric values in response to the comparisons includes attempting to achieve normal biochemical presentation by affecting time averaged current delivered by the AMPWM signal by selecting the pulse width duty cycle of a high frequency component of an AMPWM signal based on such comparisons.

138. The tissue stimulation method of claim 128 in which the step of taking measures of biochemicals includes monitoring the involved biochemical levels during therapeutic activity.

139. The tissue stimulation method of claim 128 in which the step of determining parametric values of an electrical tissue stimulation signal includes determining the frequencies for a low frequency signal component of an electrical signal based on empirical findings of frequencies that are known to be relevant to stimulating the biochemicals, the frequencies being those potentially different than resonant frequencies associated with the biochemicals.

140. The tissue stimulation method of claim 128 in which the step of determining parametric values of an electrical tissue stimulation signal includes determining the frequencies for a low frequency signal component of an AMPWM electrical signal based on empirical findings of frequencies that are known to be relevant to stimulating the biochemicals, the frequencies being those potentially different than resonant frequencies associated with the biochemicals.

141. The tissue stimulation method of claim 140 in which the step of determining the frequencies for the low frequency signal component of an electrical signal includes selecting frequencies known to modulate diminished levels of the neurotransmitter serotonin.

142. The tissue stimulation method of claim 141 in which the step of selecting frequencies known to modulate diminished levels of serotonin includes selecting a frequency of between about one and 60 hertz.

143. The tissue stimulation method of claim 141 in which the step of selecting frequencies known to modulate diminished levels of serotonin includes selecting a low frequency component of an AMPWM signal to be between about one and 60 hertz.

144. The tissue stimulation method of claim 141 in which the step of selecting frequencies known to modulate diminished levels of serotonin includes selecting a frequency of about 10 hertz.

145. The tissue stimulation method of claim 141 in which the step of selecting frequencies known to modulate diminished levels of serotonin includes selecting a low frequency component of an AMPWM signal to be about 10 hertz.

146. A method of directing electrical stimulation signals through desired tissue regions, the method including the steps of:

placing at least one stimulating lead (121) in proximity to the or each desired tissue region;

placing at least one ground lead (120) in another proximity to the or each desired tissue region such that a vector path extends between the or each stimulating lead and the or each ground lead and passes through the or each desired tissue region; and

introducing an electrical stimulation signal through the at least one stimulating lead such that current is caused to flow along the or each vector path through the or each tissue region between the or each stimulating lead and the or each ground lead.

147. The method of claim 146 in which the step of introducing an electrical stimulation signal includes introducing a signal configured to reduce tissue impedance and increase depth of signal penetration.

148. The method of claim 147 in which the step of introducing an electrical stimulation signal includes introducing an AMPWM signal.

149. The method of claim 148 where the or each desired tissue region includes brain tissue exhibiting abnormal EEG activity.

150. The method of claim 149 including the additional steps of:

providing a stimulation signal generation circuit comprising a stimulation switching circuit (110) and a ground switching circuit (119);

providing a plurality of leads (121) electrically coupled to the stimulation switching circuit and the ground switching circuit; and

selectively controlling the stimulation switching circuit (110) and the first ground switching circuit (119) to cause the leads (121) to serve as either stimulation leads delivering stimulation or as ground leads serving as ground sources in such a way as to create multiple spatial paths of electrical stimulation through tissues.

151. A tissue stimulation method including the steps of:

determining parametric values of an electrical tissue stimulation signal by;

taking measures of electrical properties of a subject;

transmitting the measures to a remote location via a network;

analyzing the measures at the remote location;

remotely determining parametric values of an electrical tissue stimulation signal in response to the analysis;

transmitting the parametric values from the remote location via a network to an electrical stimulation apparatus; and

causing the electrical stimulation apparatus to generate and apply to the region of tissue an electrical stimulation signal having the remotely determined parametric values.

152. The tissue stimulation method of claim 151 in which the step of causing the electrical stimulation apparatus to generate and apply an electrical stimulation signal includes generating and applying a signal configured to reduce tissue impedance and increase depth of signal penetration.

153. The tissue stimulation method of claim 152 in which the step of generating and applying a signal includes generating and applying an AMPWM signal.

154. The tissue stimulation method of claim 151 in which:

the step of transmitting the measures includes transmitting the measures to a remote location via the Internet; and

the step of transmitting the parametric values includes transmitting the parametric values from the remote location via the internet to an electrical stimulation apparatus.

155. The tissue stimulation method of claim 151 in which the step of analyzing the measures includes making statistical comparisons between the measures and measures known to represent normal tissue electrical properties in a healthy normal population of living beings.

156. The tissue stimulation method of claim 151 in which the step of causing the electrical stimulation apparatus to generate and apply a signal includes causing the electrical stimulation apparatus to generate and apply to the region of tissue an AMPWM signal having the remotely determined parametric values.

157. The tissue stimulation method of claim 151 in which the step of determining parametric values includes determining one or more values selected from the group of values consisting of frequency, phase, pulse width duty cycle, and amplitude of electrical signals for tissue stimulating signals.

159. The tissue stimulation method of claim 151 in which the step of taking measures includes acquiring measures of electrical parameters from a subject as a stimulation signal is being applied to the subject.

160. The tissue stimulation method of claim 159 in which the remotely determining step includes altering quantities such as the frequency, phase, pulse width duty cycle, amplitude, start time, and/or stop time parameters of electrical tissue stimulation signals in response to such measures taken as a stimulation signal is being applied.

161. The tissue stimulation method of claim 159 in which changes in measures of electrical parameters taken over time as a stimulation signal is being applied to the subject are transmitted from the remote location via a network to the subject.

162. The tissue stimulation method of claim 159 in which changes in measures of electrical parameters taken over time as a stimulation signal is being applied to the subject are transmitted from the remote location via a network to a person of competence such as a physician.

163. The tissue stimulation method of claim 151 including the additional steps of:

acquiring symptom data from a subject;

transmitting the symptom data via a communication medium to the remote location;

recording the symptom data at the remote location; and

tracking changes in the subject'"'"'s symptoms by repeating the acquiring, transmitting, and recording steps.

164. The tissue stimulation method of claim 163 in which the step of tracking changes includes comparing symptom data to measures of electrical parameters acquired.

165. The tissue stimulation method of claim 164 including the additional step of transmitting the comparison from the remote location to the subject.

166. The tissue stimulation method of claim 164 including the additional step of transmitting the comparison from the remote location to a person of competence.

167. The tissue stimulation method of claim 163 in which the step of tracking changes includes repeating the acquiring, transmitting, and recording steps periodically during therapeutic electrical signal application.

168. The tissue stimulation method of claim 163 in which the step of tracking changes includes repeating the acquiring, transmitting, and recording steps as a stimulation signal is being applied.

169. The tissue stimulation method of claim 163 in which the step of tracking changes includes the additional step of transmitting a record of the tracked changes from the remote location to a display.

170. The tissue stimulation method of claim 169 in which the step of transmitting a record of tracked changes to a display includes providing a statistical display of the changes.

171. The tissue stimulation method of claim 169 in which the step of transmitting a record of tracked changes to a display includes providing a graphical display of the changes.

172. The tissue stimulation method of claim 169 in which the step of transmitting a record of tracked changes to a display includes providing a visual display of the changes.

173. The tissue stimulation method of claim 169 in which the step of transmitting a record of tracked changes to a display includes providing an audible display of the changes.

158. The tissue stimulation method of claim in which 151 the step of taking measures of electrical properties includes taking measures of one or more properties selected from the group of properties consisting of tissue impedance, temperature, oxygen saturation, EEG activity, EMG activity, electrocardiographic activity, biochemical levels, and measures involving respiration patterns.

174. A method for treatment of conditions using electrical tissue stimulation signals, the method including the steps of:

measuring biophysical activity in a portion of a subject'"'"'s body to be treated;

analyzing the measured biophysical activity;

determining the or each site to which electrical stimulation will be applied;

determining electrical parameters for the electrical signal to be applied to the subject, which will tend to bring the subject'"'"'s biophysical values for the determined site to more normal, desired values;

placing at least one stimulating lead in proximity to the or each determined site;

placing the or each ground lead so as to create a vector direction between the or each stimulating lead and the or each ground lead that will cause at least one path of electrical stimulation to pass through the or each determined site; and

applying through the leads an electrical signal having the determined parameters.

175. The method of claim 174 in which the step of measuring biophysical activity includes measuring one or more biopotential voltages selected from the group of biopotential voltages consisting of EEG and EMG.

176. The method of claim 174 in which in which the step of measuring biophysical activity including measuring such activity in one or more portions of the subject'"'"'s body selected from the group of body portions consisting of a portion of the subject'"'"'s brain, the subject'"'"'s entire brain, body tissue containing an injury, body tissue near a bone injury, body tissue near a muscle injury, body tissue involved in or near a painful condition, and body tissue near a nerve causing health issues.

177. The method of claim 174 in which the analyzing step includes comparing the measured biophysical activity to normal biophysical activity for that portion of the body.

178. The method of claim 174 in which in which the analysis step includes analyzing biophysical values from individual sites.

179. The method of claim 174 in which in which the analysis step includes analyzing biophysical values from multiple sites.

180. The method of claim 174 in which in which the analysis step includes statistical analysis of one or more values selected from the group of values consisting of biophysical voltages, frequency components of biophysical voltages, and phase components of biophysical voltages.

181. The method of claim 174 in which in which the analysis step includes statistical analysis comprising measures selected from the group of measures consisting of variance, correlation, and coherence.

182. The method of claim 174 in which the stimulation application site determination step includes selecting one or more regions where the measured biophysical levels differ from the normal, desired biophysical activity.

183. The method of claim 174 in which where the differences in the biophysical levels are quantified the stimulation application site determination step includes selecting regions where the components of the subject'"'"'s biophysical levels exhibit any one or more deviations selected from the group of deviations consisting of greater values than normal, lower values than normal, and values that fluctuate more than normal.

184. The method of claim 174 in which the stimulation application site determination step includes selecting sites located on one or more tissue types selected from the group of tissue types consisting of muscles, bones, tendons, ligaments, cartilage, fascia, dermis, and internal organs.

185. The method of claim 174 in which the electrical parameter determining step includes the determination of one or more parameters selected from the group of parameters consisting of frequency, phase, pulse width duty cycle, and amplitude.

186. The method of claim 174 in which the signal applying step including the application of an AMPWM signal.

187. The method of claim 174 in which the signal applying step including the application of an AMPWM signal including a high frequency signal component that is amplitude modulated by one or more low frequency components and further pulse width modulated.

188. The method of claim 187 in which the signal applying step includes selecting the high frequency signal component to overcome tissue impedance and a low frequency signal component is selected for therapeutic effect.

189. The method of claim 174 in which the signal applying step includes controlling the time-averaged current deliverable by the signal by using pulse width modulation to vary the duty cycle of the electrical signal of relatively high frequency.

190. The method of claim 174 in which the step of controlling the time-averaged current deliverable includes selecting the pulse width duty cycle of the high frequency component based on the analysis of measured biophysical activity.

191. The method of claim 174 in which the step of selecting the pulse width duty cycle includes selecting a duty cycle of between about 1 percent and about 99 percent.

192. The method of claim 174 in which the signal applying step includes selecting the low frequency component to modulate biophysical activity at the determined site.

193. The method of claim 174 in which the step of selecting a high frequency component includes selecting a high frequency component in a frequency range of between about 100 hertz and about 1,000,000 hertz.

194. The method of claim 174 in which the step of selecting the low frequency components includes selecting low frequency components in a frequency range of between about 1 hertz and about 200 hertz.

195. The method of claim 174 in which the step of selecting the low frequency component includes selecting a low frequency component from the group of low frequency components consisting of a low frequency component optimized to modulate excessive biophysical activity, a low frequency component optimized to modulate diminished biophysical activity, and a low frequency component optimized to modulate variable biophysical activity at the determined site//the step of selecting the low frequency component includes selecting multiple frequency components.

196. The method of claim 174 including the additional step of acquiring information from a sensory input generally concurrent with the application of the electrical signal.

197. The method of claim 174 in which the acquiring information step includes using the information to quantify the condition of the site being treated with the signal.

198. The method of claim 174 in which the acquiring information step includes using the information to quantify the functional state of the subject being treated with the signal.

199. The method of claim 174 in which the acquiring information step includes acquiring information from one or more sensory inputs selected from the group of sensor inputs consisting of measures of biophysical activity, EEG, EMG, tissue impedance, temperature, oxygen saturation, electrocardiographic activity, biochemical levels, and respiratory patterns.

200. The method of claim 174 in which the acquiring information step includes monitoring sensory inputs as a continual process throughout the therapeutic application of the electrical signal.

201. The method of claim 174 in which the acquiring information step includes sampling biophysical activity of the subject at times of minimal electrical stimulation signal amplitude.

202. The method of claim 174 in which the signal applying step includes altering at least one characteristic parameter of the electrical signal based on a comparison of the information acquired from the sensory input and a desired value in a normal subject.

203. The method of claim 202 in which the step of altering at least one characteristic includes altering one or more electrical signal parameters selected from the list of parameters consisting of frequency, phase, pulse width duty cycle, and amplitude of the electrical signal.

204. The method of claim 174 in which the signal applying step includes stopping the application of the electrical signal based on certain measures in tissue electrical properties being achieved//the signal application step includes varying the particular leads used to apply the electrical stimulation.

205. The method of claim 174 in which the signal applying step includes applying one or more signals for a treatment time of between about 1 second and about 60 minutes.

206. The method of claim 174 in which:

the step of determining the or each site includes selecting tissues in close proximity to the vagus nerve of the subject; and

the step of applying an electrical signal includes stimulating tissue in close proximity to the vagus nerve using an AMPWM signal.

207. The method of claim 206 in which:

the step of placing at least one stimulating lead includes placing a stimulating lead (121) at the posterior base of the neck of the subject near the first, second, or third cervical vertebrae; and

the step of placing the or each ground lead includes placing a ground lead (20) on tissue in a position creating a vector between electrodes (22) that passes near the vagus nerve.

208. The method of claim 174 in which:

the step of placing at least one stimulating lead includes placing a stimulating lead (121) on tissue of the subject near an area of the subject'"'"'s brain identified as having a dysfunction;

the step of placing the or each ground lead includes placing a ground lead (120) on tissue near the area of the brain identified as having a dysfunction, creating a vector between the electrodes that passes through the area of the brain identified as having the dysfunction; and

the step of applying an electrical signal includes applying an AMPWM signal.

209. The method of claim 208 in which:

the step of measuring biophysical activity includes measuring the EEG of the tissue; and

the step of analyzing the measured biophysical activity includes identifying the area of the brain having a dysfunction via EEG analysis.

210. The method of claim 174 in which:

the step of determining the or each site includes selecting tissues containing an injury; and

the step of applying an electrical signal includes applying a signal configured to reduce tissue impedance and increases depth of signal penetration.

211. The method of claim 210 in which the step of applying an electrical signal includes applying an AMPWM signal.

212. The method of claim 211 in which:

the step of placing at least one stimulating lead includes placing a stimulating lead (21) on tissue of the subject near the location of the injury; and

the step of placing the or each ground lead includes placing a ground lead (120) on tissue near the location of the injury, creating a vector between electrodes (122) that passes through the injury.

213. The method of claim 210 in which in which the injury involves bone tissue and:

the step of placing at least one stimulating lead includes placing a stimulating lead (121) on tissue of the subject near the location of the bone injury; and

the step of placing the or each ground lead includes placing a ground lead (20) on tissue near the location of the bone injury, creating a vector between electrodes (122) that passes through the bone injury.

214. The method of claim 210 in which in which the injury involves muscle tissue and:

the step of placing at least one stimulating lead includes placing a stimulating lead (121) on tissue of the subject near the location of the muscle injury; and

the step of placing the or each ground lead includes placing a ground lead (120) on tissue near the location of the muscle injury, creating a vector between electrodes (122) that passes through the muscle injury.

215. The method of claim 210 in which the injury involves a myofascial trigger point and:

the step of placing at least one stimulating lead includes placing a stimulating lead (121) on tissue of the subject near the myofascial trigger point; and

the step of placing the or each ground lead includes placing a ground lead (120) on tissue near the myofascial trigger point, creating a vector between electrodes (122) that passes through the myofascial trigger point.

216. The method of claim 174 in which:

the step of determining the or each site includes selecting tissues near a location of myofascial pain; and

the step of applying an electrical signal includes applying a signal configured to reduce tissue impedance and increase depth of signal penetration.

217. The method of claim 216 in which the step of applying an electrical signal includes applying an AMPWM signal.

218. The method of claim 217 in which:

the step of placing at least one stimulating lead includes placing a stimulating lead (121) on tissue of the subject near the location of myofascial pain; and

the step of placing the or each ground lead includes placing a ground lead (120) on tissue near the location of myofascial pain, creating a vector between electrodes (122) that passes through the tissue involved in myofascial pain.

219. A method for treating conditions associated with central nervous system dysfunction, the method including applying an electrical tissue stimulation signal to a subject suffering from one or more conditions selected from the group of conditions consisting of fibromyalgia syndrome, chronic pain, traumatic brain injury, affective disorders, such as attention deficit disorder (ADD) and attention deficit hyperactivity disorder (ADHD), chronic fatigue, sleep disorders, obsessive compulsive disorder, Tourette Syndrome, depression, anxiety, and addiction.

220. The method of claim 219 in which the step of applying an electrical signal includes applying a signal configured to reduce tissue impedance and increase depth of signal penetration.

221. The method of claim 220 in which the step of applying an electrical signal includes applying an AMPWM signal.

222. A method for treating conditions associated with abnormal levels of biochemicals in tissues, the method including applying an electrical tissue stimulation signal to a subject suffering from one or more conditions selected from the group of conditions consisting of fibromyalgia syndrome, chronic fatigue, obesity, chronic pain, muscle pain, myofascial pain, myofascial trigger points, and psychological conditions, such as depression.

223. The method of claim 222 in which the step of applying an electrical tissue stimulation signal includes applying a signal configured to reduce tissue impedance increase depth of signal penetration.

224. The method of claim 223 in which the step of applying an electrical signal includes applying an AMPWM signal.

225. A method for enhancing a body'"'"'s own healing mechanisms, the method including applying an electrical tissue stimulation signal to a subject suffering from one or more conditions selected from the group of conditions consisting of broken bones, injured tissues, post-surgical wounds, cuts, muscle pain associated with strains, and spasms.

226. The method of claim 225 in which the step of applying an electrical tissue stimulation signal includes applying a signal configured to reduce tissue impedance increase depth of signal penetration.

227. The method of claim 226 in which the step of applying an electrical signal includes applying an AMPWM signal.

228. A method for improving a body'"'"'s function, the method including applying an electrical tissue stimulation signal to a subject, the signal configured and applied in such a way as to produce one or more effects selected from the group of effects consisting of reducing fatigue, increasing alertness, and increasing mental clarity.

229. The method of claim 228 in which the step of applying an electrical tissue stimulation signal includes applying a signal configured to reduce tissue impedance increase depth of signal penetration.

230. The method of claim 229 in which the step of applying an electrical signal includes applying an AMPWM signal.

231. A method for enhancing performance measures of a subject, the method including applying an electrical stimulation signal to a subject, the signal configured and applied in such a way as to enhance performance measures associated with one or more endeavors selected from the group of endeavors consisting of athletic and academic endeavors.

232. The method of claim 231 in which the step of applying an electrical tissue stimulation signal includes applying a signal configured to reduce tissue impedance increase depth of signal penetration.

233. The method of claim 232 in which the step of applying an electrical signal includes applying an AMPWM signal.

234. A method for enhancing organ function in a subject, the method including applying an electrical stimulation signal to a subject, the signal configured and applied in such a way as to advantageously enhancing the function of an organ.

235. The method of claim 234 in which the step of applying an electrical tissue stimulation signal includes applying a signal configured to reduce tissue impedance increase depth of signal penetration.

236. The method of claim 235 in which the step of applying an electrical signal includes applying an AMPWM signal.

237. The method of claim 236 in which an AMPWM signal is configured and applied to the subject in such a way as to stimulate pancreatic tissues so as to enhance production of insulin.