Apparatus and method for transcutaneous electrotherapy nerve stimulator

Claim 2

An electrotherapy apparatus for electrically treating a section of the patient's body, said electrotherapy apparatus comprising in combination: first circuit means operatively coupled to a source of electrical energy for generating a squarewave output signal; at least two pad means for being placed in operative electrical communication with the skin adjacent the body section to be treated; and second circuit means having an input operatively coupled to said first circuit means and having an output operatively coupled to said pad means, said second circuit means for amplifying said squarewave signal so as to deliver at said output thereof a constant current squarewave output signal representative of said squarewave signal at the input thereof, with said second circuit means further including current regulator means for holding constant the current level of said constant current squarewave output signal independent of the operative resistance of the body section between said pad means, whereby the area of the body operatively interposed between said pad means will be treated by said constant current squarewave output signal having a predetermined constant current level.

Claim 3

The electrotherapy apparatus as described in claim 1 further comprising frequency variable means operatively coupled to said first circuit means for controlling the frequency of said squarewave output signal and said constant current squarewave output signal.

Claim 4

The electrotherapy apparatus as described in claim 2 wherein the frequency range of said constant current squarewave output signal is continuously variable over the range of at least 5 Hz to 100 Hz.

Claim 5

The electrotherapy apparatus as described in claim 2 wherein said constant current squarewave output signal includes a dc component substantially equal to zero.

Claim 6

The electrotherapy apparatus as described in claim 4 wherein the duty cycle of said constant current squarewave output signal is approximately 50 percent.

Claim 7

The electrotherapy apparatus as described in claim 5 wherein: said second circuit means includes current limiting means for limiting the effective current of said constant squarewave output signal responsive to a first signal; and further including current level means for generating said first signal representative of the desired effective current of said constant current squarewave output signal.

Claim 8

The electrotherapy apparatus as described in claim 6 wherein the effective current of said constant current squarewave output signal is limited by said current limiting means to less than 500 microamperes.

Claim 9

The electrotherapy apparatus as described in claim 6 wherein the peak-to-peak voltage of said constant current squarewave output signal is less than 50 volts.

Claim 10

The electrotherapy apparatus as described in claim 6 further comprising: third circuit means operatively coupled to said second circuit means for generating a current level signal representative of the effective current of said constant current output signal; and fourth circuit means operatively coupled to said third circuit means and to said current level means for generating a discernable status signal responsive to said first signal being generally equal to said current level signal, thereby indicating that the effective current of said constant current output signal is generally equal to a desired effective current.

Claim 11

The electrotherapy apparatus as described in claim 2 wherein each of said pad means includes an electrical insulative surface and a coplanar electrically conductive surface operably coupled to said outputs of said second circuit means.

Claim 12

The electrotherapy apparatus as described in claim 10 wherein said electrically conductive surface is at least 4 square centimeters in area and is sufficiently flexible in order to conform to the shape of the adjacent body surface.

Claim 13

A transcutaneous neuroelectric stimulation apparatus for electrically treating a section of the patient's body, said apparatus comprising in combination: current generator means for generating at output terminals thereof an output signal having a bipolar waveform, with said current generator means including current regulator means for holding constant the current level of said output signal independent of a change in the output load impedance appearing across said output terminals; and a pair of conductive pads electrically coupled to said output terminals of said current generator means for being placed in operative communication with the patient's skin adjacent the body section to be treated, whereby the area of the body interposed between said conductive pads will be treated by said constant current output signal.

Claim 14

A transcutaneous neuroelectric stimulation apparatus for electrically treating a section of the patient's body, said apparatus comprising in combination: current generator means for generating at output terminals thereof an output signal having a bipolar waveform, with said current generator means including current regulator means for holding constant the current level of said output signal independent of a change in the output load impedance appearing across said output terminals; and a pair of conductive pads electrically coupled to said output terminals of said current generator means for being placed in operative communication with the patient's skin adjacent the body section to be treated, whereby the area of the body interposed between said conductive pads will be treated by said constant current output signal.

Claim 15

The transcutaneous neuroelectric stimulation apparatus as described in claim 12 wherein said current generator means comprises in combination: a frequency generator for generating a drive signal representative of said output signal; and amplifier means, having an input coupled to said frequency generator, for generating said output signal at said output terminals thereof.

Claim 16

The transcutaneous neuroelectric stimulation apparatus as described in claim 13 wherein said current regulator means further comprises comparator means having a first input coupled to said current generator means for sensing a voltage equivalent of said output signal, said comparator means having a second input coupled to said frequency generator means for sensing said drive signal, with said comparator means generating a visual warning signal responsive to the signal at said first input being non-proportional to the signal at said second input thereof, whereby said visual warning signal will appear responsive to said current generator means operating in a non-linear mode.

Claim 17

The transcutaneous neuroelectric stimulation apparatus as described in claim 12 or 14 wherein said output signal comprises a generally symmetrical waveform having a 50 percent duty cycle and having substantially no DC components.

Claim 18

The transcutaneous neuroelectric stimulation apparatus as described in claim 12 or 14 wherein said output signal comprises a squarewave signal.

Claim 19

The transcutaneous neuroelectric stimulation apparatus as described in claim 12 or 14 wherein said current generator further includes frequency variable means for controlling the frequency of said output signal.

Claim 20

The transcutaneous neuroelectric stimulation apparatus as described in claim 12 or 14 wherein said output signal is continuously variable in frequency between 5 Hz and 100 Hz, and has a constant current range between 1 and 500 microamperes.

Claim 21

The transcutaneous neuroelectric stimulation apparatus as described in claim 12 or claim 14 wherein said output signal has a maximum peak to peak voltage of greater than 25 volts but less than 47 volts.

Claim 22

A transcutaneous neuroelectric stimulation apparatus for electrically treating a section of the patient's body, said apparatus comprising in combination: frequency generator means for generating a periodic drive signal continuously variable in frequency; amplifier means having output terminals and having an input coupled to said frequency generator means, said amplifier means for generating an output signal at said output terminals, with said output signal being generally symmetrical, bipolar and without a d.c. component, with said amplifier means further including current regulator means for holding constant the current level of said output signal independent of the output load impedance appearing across said output terminals; comparator means having a first input coupled to said amplifier means for sensing a voltage equivalent of said output signal, said comparator means having a second input coupled to said frequency generator means for sensing said drive signal, with said comparator means generating a discernible warning signal responsive to the signal at said first input being non-proportional to the signal appearing at said second input thereof; and a pair of conductive pads electrically coupled to said output terminals of said amplifier means for being placed in operative communication with the patient's skin adjacent the body section to be treated, whereby the area of the body interposed between said conductive pads will be treated by said constant current output signal.

Claim 23

A transcutaneous neuroelectric stimulation apparatus for electrically treating a section of the patient's body, said apparatus comprising in combination: frequency generator means for generating a periodic drive signal continuously variable in frequency; amplifier means having output terminals and having an input coupled to said frequency generator means, said amplifier means for generating an output signal at said output terminals, with said output signal being generally symmetrical, bipolar and without a d.c. component, with said amplifier means further including current regulator means for holding constant the current level of said output signal independent of the output load impedance appearing across said output terminals; comparator means having a first input coupled to said amplifier means for sensing a voltage equivalent of said output signal, said comparator means having a second input coupled to said frequency generator means for sensing said drive signal, with said comparator means generating a discernible warning signal responsive to the signal at said first input being non-proportional to the signal appearing at said second input thereof; and a pair of conductive pads electrically coupled to said output terminals of said amplifier means for being placed in operative communication with the patient's skin adjacent the body section to be treated, whereby the area of the body interposed between said conductive pads will be treated by said constant current output signal.

Claim 26

The method as described in claim 21 wherein step (c) includes a substep of monitoring the current regulation process and generating a warning signal responsive to said output signal current being dependent upon the load impedance.