U.S. patent number 3,908,669 [Application Number 05/425,695] was granted by the patent office on 1975-09-30 for apparatus for use by physicians in acupuncture research.
This patent grant is currently assigned to American Acupuncture Medical Instruments, Inc.. Invention is credited to Calvin H. Chen, William T. Donofrio, Pang L. Man.
United States Patent |
3,908,669 |
Man , et al. |
September 30, 1975 |
Apparatus for use by physicians in acupuncture research
Abstract
Apparatus for use in research into acupuncture anesthesia or
analgesia and other acupuncture therapy having means to vary the
amplitude, frequency and amperage of electrical impulses applied to
pairs of acupuncture needles. A frequency variable relaxation
oscillator is utilized to trigger at selectively variable intervals
of time a monostable multivibrator which determines the output
pulse interval. The multivibrator output pulse train is shaped and
amplified before being applied to a separate pulse generator and
isolation transformer for each output channel to generate the
output waveform. Each channel includes an attenuator which is used
to vary the amplitude of the output waveform and thereby vary the
output current. Each channel is also protected against power surges
thereby limiting the maximum output current. The output waveform
which has been found to produce the most effective results is a
steep positive-going pulse having a generally rounded crown
followed in 0.5 millisecond by a steep negative-going pulse of
approximately the same magnitude of negative voltage and abruptly
decaying exponentially to zero in about the same time interval.
Inventors: |
Man; Pang L. (Northville,
MI), Chen; Calvin H. (Northville, MI), Donofrio; William
T. (Toledo, OH) |
Assignee: |
American Acupuncture Medical
Instruments, Inc. (Toledo, OH)
|
Family
ID: |
23687651 |
Appl.
No.: |
05/425,695 |
Filed: |
December 17, 1973 |
Current U.S.
Class: |
607/74; 128/907;
607/66 |
Current CPC
Class: |
A61N
1/32 (20130101); Y10S 128/907 (20130101) |
Current International
Class: |
A61N
1/32 (20060101); A61N 001/36 () |
Field of
Search: |
;128/1C,2.1C,2.1R,419R,421,422,423,249A |
References Cited
[Referenced By]
U.S. Patent Documents
Other References
Brown, "The Lancet," June 17, 1972, pp. 1328-1330. .
Capperauld et al., "The Lancet," Nov. 25, 1972, pp.
1136-1137..
|
Primary Examiner: Kamm; William E.
Attorney, Agent or Firm: Leonard; Henry K.
Claims
1. An apparatus for generating electrical impulses to be applied to
acupuncture needles placed in selected portions of the body,
comprising:
means for generating a train of trigger pulses;
means for responsive to each of said trigger pulses for generating
a control pulse having a pulse width of a predetermined time
interval;
means responsive to each of said control pulses for generating an
output pulse having a first portion of one polarity with a steep
leading edge and a generally rounded crown initiated at the origin
of said predetermined time interval and a second portion of the
opposite polarity with a steep leading edge initiated at the end of
said predetermined time interval; and
means connecting said output pulse generating means to the
acupuncture
2. An apparatus as defined in claim 1 wherein said second output
pulse
3. An apparatus as defined in claim 1 wherein said trigger pulse
generating means includes means for varying the rate of generation
of said trigger
4. An apparatus as defined in claim 3 wherein said rate varying
means limits the rate of generation of said trigger pulse
generating means to a
5. An apparatus as defined in claim 3 including means responsive to
said control pulses for generating an audible representation of
said rate of
6. An apparatus as defined in claim 1 wherein said means for
generating a
7. An apparatus as defined in claim 6 including a source of direct
current power having positive and negative terminals and wherein
said relaxation oscillator includes a unijunction transistor having
a first base connected to said negative terminal, a second base
connected to said positive terminal and an emitter; a resistor
connected between said positive terminal and said emitter; and a
capacitor connected between said negative
8. An apparatus as defined in claim 1 wherein said means for
generating
9. An apparatus as defined in claim 1 wherein said means for
generating output pulses includes means for limiting output current
below a
10. An apparatus as defined in claim 9 wherein said limiting means
includes
11. An apparatus as defined in claim 9 wherein said limiting means
limits
12. An apparatus as defined in claim 1 wherein said means for
generating
13. An apparatus as defined in claim 1 wherein said means for
generating
14. An apparatus as defined in claim 13 wherein said means for
generating output pulses includes attenuator means connected in
parallel with the secondary winding of said isolation transformer
for varying the amplitude
15. An apparatus as defined in claim 14 wherein said attenuator
means is a
16. An apparatus for generating electrical impulses to be applied
to acupuncture needles placed in selected portions of the body,
comprising:
means for generating a train of trigger pulses;
means responsive to each of said trigger pulses for generating a
control pulse having a pulse width of a predetermined time
interval;
a plurality of means each responsive to each of said control pulses
for generating output pulses having a first portion of one polarity
with a steep leading edge and a generally rounded crown initiated
at the origin of said predetermined time interval and a second
portion of the opposite polarity with a steep leading edge
initiated at the end of said predetermined time interval; and
means connecting said output pulse generating means to the
acupuncture
17. An apparatus as defined in claim 16 wherein said trigger pulse
generating means includes means for varying the rate of generation
of said
18. An apparatus as defined in claim 17 wherein said means for
generating
19. An apparatus as defined in claim 17 including means responsive
to said control pulses for generating an audible representation of
said rate of
20. An apparatus as defined in claim 16 wherein said plurality of
means for generating output pulses includes first, second and third
output channels.
21. An apparatus as defined in claim 20 wherein said first, second
and third output channels each include means for limiting output
current below
22. An apparatus as defined in claim 20 wherein said first, second
and third output channels each include attenuator means for
individually
23. An apparatus as defined in claim 16 wherein said plurality of
means for generating ooutput pulses includes first, second and
third output channels each having means for protecting against
power surges.
Description
BACKGROUND OF THE INVENTION
The ancient Chinese art of acupuncture, sometimes referred to as a
method or means for treating physical and mental illnesses and the
alleviating of pain, was based upon a theory reaching back in
history to as long ago as approximately 2500 B.C. Throughout the
centuries it was believed that there were some 12 pairs of
"meridians" plus two trunk "meridians" which connected all of the
internal organs of the body with different points on the surface of
the body.
It has only been in more recent years, when the medical sciences of
the Western World and in the People's Republic of China have become
aware of each other's existence, that the ancient concept of these
"meridians" has been abandoned and a more scientific analysis has
been reached in an effort to understand the "mechanism" or
physiological and/or neurological effect of acupuncture. Strangely,
there seems to be a surprising coincidence between the locations of
the so-called "meridian points" and the peripheral nerves as
revealed by modern study.
In ancient times the technique of acupuncture was used for the
alleviation of pain, in a sense producing an analgesic effect
limited to only pain response, without incapacitation of the other
functions of the body. This may be explained by the fact that the
acupuncture needles merely were inserted into the body. Sometimes
as many as 8 needles were inserted into a patient in order to
produce the desired pain relief. It was later discovered that by
manual twirling or arcuate oscillation of the needles around their
longitudinal axes, as by the fingers of a trained acupuncture
anethesiologist, the effect of the treatment could be greatly
enhanced.
In itself, however, the "twirling" technique presented a further
problem in that it became very tiring to the hand of the
manipulator and it required a skilled manipulator in order to
obviate the possibility that the needle points might be dislodged
from their proper location, either being inserted more deeply or
withdrawn somewhat during the twirling of the needles. Furthermore,
of course, because even a skilled person has only two hands, only
two needles could be simultaneously twirled by a single operator.
While a single acupuncture analgesic treatment might last only 20
or 30 minutes, if an operator were to continue to treat patients
throughout the day, the total activity of his hands would induce
considerable fatigue. A further problem resulted from the fact that
it was almost impossible for the operator to maintain a desired
frequency of twirling thus to produce a desired or effective
frequency of the impulses resulting from the twirling of the
needles.
Much more recently the Chinese have suggested that the manual
twirling of the needles be replaced by the application of cyclical
electrical stimuli to the needles. The Chinese utilized a nine-volt
stimulating machine provided with circuitry to produce an
alternating current of 300 cycles per second. Each of the two leads
from the machine was attached to one of a pair of needles inserted
subcutaneously at the locations determined by the attending
physician to enhance the pain-blocking effect and, as recently as
1958, the Chinese began to use this technique for surgery in
addition to pain alleviation.
In our lengthy study of the literature and history of acupuncture,
particularly for the alleviation of pain, we have determined that
while the use of cyclical electrical impulses delivered to the
inserted acupuncture needles is a most effective way to create the
necessary stimulation in order to block pain, much more flexibility
is necessary in order to enable skilled physicians to conduct
controlled scientific research into the mechanism of acupuncture
itself, into the reasons underlying its therapeutic effect and to
establish certain criteria which may be utilized by the medical
profession at large.
SUMMARY OF THE INVENTION
The present invention relates to an apparatus for use in research
into acupuncture anesthesia or analgesia and acupuncture therapy
and specifically to circuitry for generating electrical impulses of
a form which has been found to produce the most effective results.
A unijunction transistor relaxation oscillator having a variable
frequency rate from approximately 2 to 150 hertz is utilized to
trigger a monostable multivibrator to produce a square wave having
a predetermined timing interval, typically 0.5 milliseconds. The
square wave is shaped and amplified to provide an input signal to
separate pulse generators and isolation transformers for each of
three output channels. Each output channel includes protection
against power surges and output current limiting devices as well as
attenuators for varying the amplitude of the output waveform and
thereby the output current.
The output voltage of any channel is applied to a pair of
acupuncture needles which are inserted in a portion of the body.
Since each output channel is independent of the others, selected
portions of the body may be stimulated by electrical impulses
differing in strength with the variations in each not effecting
operation of the others. Provision is also made for monitoring the
output waveforms by use of suitable means, such as an oscilloscope,
and monitoring average output current by use of a microammeter.
Accordingly it is the principal object of the invention to provide
an apparatus for utilization by physicians in acupuncture research
more fully to study the neurophysiological aspects of the technique
by providing the physician with means to vary the strength,
quantity and rapidity of the electrical inpulse delivered to the
acupuncture needles as indicated during the course of
treatment.
It is a further object of the instant invention to provide such an
apparatus in which the wave form delivered to the needles is
closely controlled to that which we have learned produces the more
effective results.
And it is yet another object of the instant invention to provide
such an apparatus having inherent control which precludes the
possibility of the so-called "avalanche effect", limiting the
output of the machine to a maximum of 50 microamperes, thus to
pprotect a patient being treated from the danger of excessive
electrical current.
Yet another object of the instant invention is to provide an
apparatus with a plurality of output circuits, each of which may be
independently controlled and varied as desired by the attending
physician in order that a plurality of pairs of acupuncture needles
inserted into selected positions in the body may be stimulated by
stimuli differing in strength, quantity and frequency, each of the
several output circuits being controllable independently of the
others and the variations in each not effecting the operationof the
others.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram of the wave form generating circuit of
the present invention;
FIG. 2 is a schematic diagram of the circuit represented by the
block diagram of FIG. 1;
FIG. 3 is the voltage wave form generated by the multivibrator of
FIGS. 1 and 2;
FIG. 4 is the voltage wave form generated by the wave shaper of
FIGS. 1 and 2;
FIG. 5 is the voltage wave form generated at the inputs to the
pulse generator and isolation transformers of FIGS. 1 and 2;
FIG. 6 is the voltage wave form generated at the inputs to the
Darlingtion pair amplifiers included in the pulse generators and
isolation transformers of FIGS. 1 and 2;
FIG. 7 is the output voltage wave form available from each channel
of present invention; and
FIG. 8 is a front elevation of the control panel of the present
invention.
DESCRIPTION OF THE PREFERRED EMBODIMENT
In order to better understand the apparatus embodying the instant
invention, as it will hereinafter be described in detail, it is
believed desirable to explain in brief the theory which we have
developed during the course of our research and study and which we
believe is the best available explanation of the mechanism of
acupuncture, and thus the reasons why we have developed the
apparatus to be described.
It appears now to be accepted among students and research
scientists into the field of acupuuncture that, in general, the
peripheral nervous system comprises what may be called both large
and small fibers, i.e., each individual nerve is comprised of both
types of fibers and they are intermingled with each other in the
body of the nerve. It has also been discovered that the large
fibers do not, in themselves, deliver pain sensations and that the
pain sensations delivered to the brain travel in the small fibers
of the nerve. We have also discovered that the large fibers of the
nerve require a small amount of stimuli and that the stimuli travel
in the larger fibers at a higher rate of speed. Conversely, the
smaller fibers of the nerve require a greater degree of stimulation
and the stimuli travel in the smaller fibers at a lower rate of
speed.
Each of the peripheral nerves leads to the substantia gelatinosa of
the spinal cord, i.e., the synapse. Our theory is based upon the
concept that at the substantia gelatinosa there is located what may
be called a "gate". The large non-pain fibers of the nerve are
stimulated by the acupuncture treatment to a degree determined by
the strength, quantity and frequency of the electrical impulses
delivered to the needles and these stimuli reach the "gate" very
quickly, thus closing the "gate". The subsequent delivery by the
smaller or pain delivering fibers of the pain stimuli to the pain
centers of the brain is thus blocked from reaching the brain by the
closing of the gate resulting from the stimuli delivered to the
gate through the high steep, low stimuli-responsive, larger
fibers.
Because of the variation in pain threshold known to exist between
patients, resulting from many factors readily understood by
neurologists such as attitude, distraction, conditioning, hypnotism
(self-induced or not), religious and political convictions, fear,
fatigue, illness, etc., no absolute criteria can be established
upon which to base treatment of different persons even for the same
problem.
The theory so far described explains why pain otherwise delivered
to the responsive centers of the brain by the smaller fibers of a
peripheral nerve is successfully blocked by proper acupuncture
treatment of that nerve to close the gate at the substantia
gelatinosa of the spinal cord. It does not explain how acupuncture
treatment can be utilized with the needles located in one portion
of the body and pain blocked in another portion of the body as, for
example, the insertion of needles into the appropriate location in
the hand of the patient to block pain otherwise resulting from a
tooth extraction.
Our theory, however, is based upon hypothecation of a second or
main gate in the neurological system of the body. It is known that
the larger fibers of the peripheral nerves not only send branches
to the upper segments thereof but they also send branches via the
dorsal column to nuclei gracilis and cuneatus where the impulses
are relayed to the posterolateral ventral nucleus of the thalamus.
Delivery of the stimuli along the larger fibers to the thalamus
closes this second or main gate and thus produces analgesia or,
anesthesia, if the acupuncture needles are properly inserted into a
peripheral nerve.
In the apparatus embodying the invention which has been developed
by use in order to test and to prove the theories briefly outlined
above, we have provided means whereby more than one pair of needles
simultaneously may be inserted into selected positions in the body
without requiring the tedious twirling so that a single apparatus
may be utilized by a physician for the application of varying
stimuli to various selected points or areas of the body as he
determines in his research and experimentation. Such research and
study indicated that the use of our apparatus appears to be very
effective for blocking the sensation of pain, either from that part
of the body directly associated with the locations into which the
needles are inserted, or even to other parts of the body
dramatically remote from the areas of locations into which the
needles are inserted.
For further discussion of the "Two-gate Control Theory" reference
may be had to the article by Drs. Man and Chen published in
"Diseases of the Nervous System", Vol. 33, pp. 730-735, November,
1972, (Physicians Post Graduate Press, Irvington, N.J.).
Referring to FIG. 1, there is shown a block diagram of the present
invention in its preferred embodiment. Relaxation oscillator 10,
monostable multivibrator 11 and wave shaper 12 produce a train of
electrical impulses to pulse generators and isolation transformers
13, 14 and 15 of output channels 1, 2 and 3. Each output channel is
connected to a pair of needles adapted to be inserted into selected
portions of the body and the amount of applied current is adjusted
by attenuators 16, 17 and 18. Each output pulse is comprised of a
steep positive-going portion having a generally rounded crown and
which decays in approximately 0.5 millisecond as a steep transition
from the crown to negative peak of about the same absolute value as
to the top of the crown. The steep negative peak decays
exponentially in approximately 0.5 millisecond.
As illustrated more specifically in FIG. 1, a suitable direct
current power source, typically portable batteries not shown, is
utilized to energize relaxation oscillator 10 at input 19.
Oscillator 10 is adjustable to generate a train of pulses having a
pulse rate variable within predetermined limits. This train of
pulses is applied to the trigger input of monostable multivibrator
11 which generates a square wave, that is a wave with a steep rise
and fall at a pulse rate equal to the rate of the pulse train from
oscillator 10. Multivibrator 11 has a predetermined timing cycle
which determines the duration of each square wave. The square wave
output of multivibrator 11 is applied to wave shaper 12 which
produces a positive-going pulse above a bias voltage which is equal
in duration to the square wave.
The pulses from wave shaper 12 are applied to pulse generators and
isolation transformers 13, 14 and 15 where they are utilized to
produce output pulses which are applied to outputs 21, 22 and 23
through attenuators 16, 17 and 18. The steep leading edge of the
waveform issued by wave shaper 12 defines the instant the output
pulse develops its steep leading edge, t.sub.1 in FIGS. 4-7 and the
steep negative going transition defines the instant t.sub.2 in
which the output pulse initiates its negative going transient. Each
channel is independent from the others and each output current may
be adjusted separately. Pulse generators and isolation transformers
13, 14 and 15 also include current limiting devices to protect
against power surges.
FIG. 2 is a schematic diagram of the waveform generating circuit
represented by the block diagram of FIG. 1. Direct current power
source 24, typically a nine volt mercury battery, is connected to
input 19 through "ON-OFF" switch 25. When switch 25 is closed
current will flow through pilot light 26 to provide a visual
indication that the circuit is energized. Current also will flow
through zener diode 27, resistor 28 and battery charge indicator
29. As power source 24 discharges, the battery voltage will fall
until a critical level is reached at which the circuit can no
longer deliver full output power. When a nine volt mercury battery
is utilized this critical level is approximately six volts. Between
nine volts and six volts current will flow through zener diode 27
and resistor 28 to provide a visual indication from battery charge
indicator 29. When the power source voltage falls below six volts,
zener diode 27 will block all but a very small reverse current and
battery charge indicator 29 will indicate that replacement
batteries are required.
Variable resistor 31, capacitor 32, unijunction transistor 33 and
resistor 34 form relaxation oscillator 10 of FIG. 1. Capacitor 32
is charged through variable resistor 31 to the peak emitter voltage
of transistor 33. During this charging period only a small emitter
leakage current will flow and the transistor is in its cut-off
region so that effectively there is no current flow through
resistor 34 and the base of transistor 35 is at ground. When the
capacitor voltage reaches the peak voltage the emitter will become
forward biased and the emitter current will flow. At the peak
voltage, transistor 33 enters a negative resistance region in which
the emitter to base one (connected to resistor 34) resistance
decreases so that as the emitter current increases the emitter
voltage decreases. Therefore, capacitor 32 discharges through
transistor 33 and resistor 34 to the valley voltage at which the
transistor enters the saturation region where the emitter to base
one resistance becomes positive. The decrease in resistance between
the emitter and base one will increase the current flow through
transistor 33 and resistor 34 until the voltage drop across
resistor 34 is high enough to reverse bias the emitter and return
transistor 33 to the cut-off region. Capacitor 32 will again charge
to the peak voltage and the cycle will be repeated. During the
discharge of capacitor 32, current flow through resistor 34 will
produce a positive-going pulse at the base of transistor 35.
Capacitor 36 is connected across relaxation oscillator 10 to filter
out any voltage variations created by the turning on and off of
unijunction transistor 33 as the output pulses are generated.
Variable resistor 31 may be adjusted to change the charging rate of
capacitor 32 and thereby obtain various pulse rates, typically two
to one hundred fifty hertz, for the pulse train applied to
transistor 35. During the absence of a pulse at its base,
transistor 35 is in the cut-off region so that no current is
flowing in resistor 37 and the input of monostable multivibrator
11, which is connected to the collector of transistor 35, is at the
power source voltage. When relaxation oscillator 10 generates a
pulse, transistor 35 is placed in a conducting state and the input
to multivibrator 11 is drawn toward ground. After the pulse at its
base, transistor 35 returns to cut-off thereby generating a square
wave at the input to multivibrator 11.
Multivibrator 11 includes timer 38, timing resistor 39 and
capacitor 41 and control voltage capacitor 42. Timer 38 has an
internal flip-flop which places a short circuit across capacitor 41
at discharge input 38-7 and ground 38-1, to drive output 38-3 low.
When transistor 35 turns on and the voltages at trigger input 38-2
begins to decrease, the flip-flop releases the short circuit across
capacitor 41 and drives the voltage at output 38-3 high. The
voltage across capacitor 41 increases exponentially with a time
constant equal to the product of the capacitance of capacitor 41
and the resistance of charging resistor 39. When this voltage
reaches two-thirds of the power source voltage applied at input
38-8 it is sensed at threshold input 38-6 and flip-flop resets to
short circuit capacitor 41 which discharges through discharge input
38-7. The voltage at output 38-3 then goes low forming a square
wave. Timer 38 triggers when the voltage at trigger input 38-2
falls to one-third of the power source voltage. Since the charge
rate and the threshold voltage are both proportional to the power
source voltage, the timing interval is independent of the power
source voltage and is equal to 1.1 times the time constant for
charging capacitor 41. FIG. 3 shows the square wave output voltage
at output 38-3 with the interval between t.sub.1 and t.sub.2 being
the timing interval, typically 0.5 millisecond which determines the
interval between the positive and negative going transients of the
output pulses. Timer 38 may be reset at reset input 38-4 during the
charging of capacitor 41. Therefore, input 38-4 is connected to the
power source to prevent any possibility of false triggering.
Control voltage input 38-5 may receive an amplitude modulated
signal which will vary the output pulse width. Since pulse width
modulation is not required in the present invention, capacitor 42
is connected to input 38-5 to hold the control voltage at
two-thirds of the power source voltage.
The square wave pulse train from timer output 38-3, as shown in
FIG. 3, is applied to wave shaper 12 which comprises capacitor 43
and resistors 44 and 45. Resistors 44 and 45 act as a voltage
divider for the power source voltage biasing the base of transistor
46 at V.sub.B, typically about 0.8 volts, as shown in FIG. 4. When
the leading edge of the square wave from multivibrator 11 appears
at capacitor 43 at time t.sub.1, capacitor 43 is storing a charge
created by the low output voltage from output 38-3 of timer 38 and
the bias voltage across resistor 45. Since the voltage across a
capacitor cannot change instantaneously, the voltage across
resistor 45 will be increased by the amount of change in the output
voltage from output 38--3 of timer 38 at time t.sub.1, as shown in
FIG. 4. Then as capacitor 43 charges toward the higher voltage
level of the square wave, the voltage across resistor 45 will decay
exponentially toward V.sub.B. However, the time constant for the
charging of capacitor 43 is much larger than the time interval of
the square wave and therefore, there will be very little decrease
in the voltage across resistor 45 by time t.sub.2. At t.sub.2 the
square wave returns to the low voltage level and since the voltage
across capacitor 43 cannot change instantaneously, the voltage
across resistor 45 will be decreased by the amount of change in the
output voltage from output 38-3 of timer 38. Then, as capacitor 43
discharges to this lower voltage level, the voltage across resistor
45 will increase exponentially to V.sub.B.
The voltage drop V.sub.B across resistor 45 keeps transistor 46 in
its conducting state so that there is current flow through and a
voltage drop V.sub.C, typically about 2.8 volts across resistor 47.
When the leading edge of the waveform from wave shaper 12 is
applied to the base of transistor 46 at time t.sub.1, transistor 46
will be driven into saturation until the time t.sub.2 when the
trailing edge the waveform from wave shaper 12 occurs, as shown in
FIG. 5. Therefore, transistor 46 functions as a current amplifier
for the output of wave shaper 12 and applies a square wave to the
inputs of blocking oscillators and isolation transformers 13, 14
and 15.
The voltage across resistor 47, typically about 6.3 volts maximum,
is applied to capacitor 48. At time t.sub.1, the leading edge of
the square wave of FIG. 5 will produce a similar voltage increase
at the base of transistor 49 since the voltage across capacitor 48
cannot change instantaneously. As capacitor 48 charges to this
applied voltage, the voltage at the base of transistor 49 will
decay exponentially toward round. However, the charging time
constant for capacitor 48 is much greater than the time interval
t.sub.2 - t.sub.1 and therefore, the voltage at the base of
transistor 49 will decrease by the amount of decrease in the
voltage across resistor 47 at time t.sub.2 to produce the waveform
shown in FIG. 6. Diode 51 has its cathode connected to ground and
its anode connected between capacitor 48 and transistor 49. Diode
51 provides a path to ground for any negative portion of the
waveform at the base of transistor 49 while blocking the positive
portion of the waveform unless it exceeds the reverse breakdown
voltage. Therefore, diode 51 is a safety device which protects
against a sudden power surge in the circuit which could be
reflected in the outputs.
Transistors 49 and 52 have their collectors connected together and
the emitter of transistor 49 is connected to the base of transistor
52 to form a Darlington pair amplifier. This type of amplifier has
the advantages of high current gain and high input impedance. High
current gain is required to provide a fifty microamp maximum output
current since the output voltage is stepped-up from the voltage of
the power source. The high input impedance contributes to the long
time constant for the charging of capacitor 48. The collectors of
transistors 49 and 52 are connected to the primary winding of
transformer 53 which in turn is connected to power source 24.
Before time t.sub.1, the base of transistor 49 will be at ground
placing transistors 49 and 52 in cut-off and preventing current
flow in the primary winding of transformer 53. At time t.sub.1, the
square wave shown in FIG. 6 will turn on transistors 49 and 52.
Since the current flow through an inductor cannot change
instantaneously, the power source voltage will appear across the
primary winding and will be steppedup by the secondary winding of
transformer 53, as shown in FIG. 7, to approximately sixty volts
above the reference level V.sub.REF. This output voltage will decay
exponentially with a time constant which is approximately one
fourth of time interval t.sub.1 to t.sub.2 as the current flow
increases while a magnetic field is established until the only
voltage drop across the primary winding is due to its internal
resistance. At time t.sub.2 the voltage at the base of transistor
49 decreases to turn off transistors 49 and 52 and prevent further
current flow through the primary winding of transformer 53. Now the
magnetic field established in the primary winding by the current
flow will collapse, inducing a negative voltage in the secondary
winding as shown in FIG. 7. The collapse of the field will occur
exponentially to return the output voltage to zero at time t.sub.3
for a total time interval between t.sub.1 and t.sub.3 of
approximately one millisecond. The induced negative voltage of the
field collapse passes through the emitter-collector circuit of
transistor 46 and resistor 47 producing the decay curve following
t.sub.2 in FIG. 2 which is also reflected in the decay at that time
at the base of transistor 49 as shown in FIG. 6.
A secondary winding of transformer 53 is connected in parallel with
resistor 54. The voltage induced in the secondary winding of
transformer 53 produces current flow through resistor 54 and
through a parallel path which includes output jack 55 and resistor
56, which is attenuator 16 of FIG. 1. Terminals 57 and 58 of jack
55 are internally electrically connected by spring contact fingers
to provide a current path from the secondary winding of transformer
53, through the contact fingers, through resistor 56 and through a
portion of resistor 54 between an adjustable tap attached to
terminal 59 and the secondary winding. If plug 61 is inserted into
jack 55, the contact fingers connected to terminals 57 and 58 will
be separated to interrupt the current path through resistor 56. The
contact finger connected to terminal 57 will be in electrical
contact with terminal 59 of jack 55. If terminals 62 and 63 are
then connected to a pair of needles, 64 and 65, by suitable means
such as wire leads and "alligator" clips while the needles are
inserted into a portion of the human body, a current flow path will
be established. The tap point on resistor 54 may be adjusted to
vary the amplitude of the waveform applied to needles 64 and 65
thereby controlling the amount of current which will flow between
them. The value of resistor 54 permits adjustment from near zero
current to a maximum of 50 microamps. Monitor jack 66 is connected
between terminals 57 and 59 of output jack 55 at terminals 67 and
68 rspectively. When plug 69 is inserted into jack 66, contact
fingers will electrically connect terminals 67 to 71 and 68 to 72
respectively to permit the output voltage applied to needles 64 and
65 to be monitored by suitable high impedance means such as
oscilloscope 73.
The voltage waveform across resistor 47, as shown in FIG. 5, is
also applied to pulse generator and isolation transformer 14 of
channel 2. Capacitor 74 produces the waveform shown in FIG. 6 at
the base of transistor 75 which is connected to transistor 76 as a
Darlington pair amplifier. Diode 77 protects against sudden power
surges from the pulse train generating circuitry. Transformer 78
steps-up the voltage and produces the waveform shown in FIG. 7
across resistor 79 which is attenuator 17 of FIG. 1. When plug 81
is inserted into jack 82 the contact fingers connected to terminals
83 and 84 will be separated to interrupt the current path through
resistor 85. The contact fingers connected to terminals 86 and 87
of plug 81 will be electrically connected to contact fingers
connected to terminals 83 and 88 of jack 82 to supply the output
voltage to needles 89 and 91. Terminals 92 and 93 of monitor jack
94 are connected to terminals 83 and 88 of output jack 82
respectively. When plug 95 is inserted into jack 94 contact fingers
connected to terminals 96 and 97 will be electrically connected to
contact finger connected to terminals 92 and 93 respectively to
permit the output voltage applied to needles 89 and 91 to be
monitored by suitable means such as oscilloscope 73.
Also included in the present invention is a speaker which transmits
an audible "click" for each output pulse so that variable resistor
31 may be used to set the pulse train rate by ear. The voltage
waveform across resistor 47 is applied to capacitor 98 to produce a
positive going pulse at time t.sub.1 to turn on transistor 99. At
time t.sub.2 capacitor 98 will produce a negative-going pulse which
will turn off transistor 99 while any portion of that pulse which
extends below the zero voltage level will be conducted to ground
through diode 101 which has its anode connected to the base of
transistor 99. Switch 102 is an "ON-OFF" switch which is closed to
permit current flow from power source 24 through speaker 103 when
transistor 99 is turned on to produce an audible "click". After the
pulse train rate has been set by adjusting variable resistor 31,
switch 102 may be opened to avoid annoyance during use of the
apparatus. Diode 101 also protects transistor 99 against power
surges from the pulse train generating circuitry.
Channel 3 is similar to channels 1 and 2 with pulse generator and
isolation transformer 15 receiving the output waveform as shown in
FIG. 5 at capacitor 104. The base of transistor 105 receives the
waveform shown in FIG. 6 and is connected to diode 106 which
protects against sudden power surges from the pulse train
generating circuitry. Transistor 105 is connected to transistor 107
as a Darlington pair amplifier to produce the waveform shown in
FIG. 7 from transformer 108. Resistor 109 which is attenuator 18 of
FIG. 1, is connected across the secondary winding of transformer
108 and also to output jack 111. When plug 112 is inserted into
jack 111 the contact fingers connected to terminals 113 and 114
will be separated to interrupt the current path through resistor
115. The contact fingers connected to terminals 116 and 117 of plug
112 will be electrically connected to contact fingers connected to
terminals 113 and 118 of jack 111 to supply the output voltage to
needles 119 and 121. Terminals 122 and 123 of monitor jack 124 are
connected to terminals 113 and 118 of output jack 111 respectively.
When plug 125 is inserted into jack 124 contact fingers connected
to terminals 126 and 127 will be electrically connected to contact
fingers connected to terminals 122 and 123 respectively to permit
the output voltage applied to needles 119 and 121 to be monitored
by suitable means such as oscilloscope 73.
The output current in any channel may also be monitored by meter
128 which typically may have a zero to one hundred scale. Meter 128
may be inserted into any channel. For example, it can be connected
to channel 1 by breaking the connection between resistor 54 and
terminal 57 and connecting input lead 129 to the broken connection
at resistor 54 while input lead 131 is connected to terminal 57. At
time t.sub.1 as shown in FIG. 7, the positive portion of the
waveform will cause current to flow into lead 129, through diode
132 of a diode bridge, into the positive terminal of meter 128, out
of the negative terminal of meter 128, through diode 133 and out of
lead 131. At time t.sub.2 as shown in FIG. 7, the negative portion
of the waveform will cause current to flow into lead 131, through
diode 134, into the positive terminal of meter 128, out of the
negative terminal of meter 128, through diode 135 and out of lead
129. Capacitor 136 in parallel with meter 128 smooths out these
voltage pulses so that meter 128 reads the average output current
for channel 1. Meter 128 may also be inserted in channel 2 between
resistor 79 and terminal 83 or in channel 3 between resistor 109
and terminal 113.
FIG. 8 is a front elevation view of the control panel of the
present invention. "ON-OFF" switch 25 connects the power source to
the pulse generating circuitry causing pilot lamp 26 to glow.
Battery charge indicator 29 will indicate whether or not the
batteries need to be replaced. Audio switch 102 is placed in the
"ON" position while the pulse train rate is varied by adjusting
variable resistor 31. Next plugs which are connected to pairs of
needles may be inserted into output jacks 55, 82 and 111 which are
the outputs for channels 1, 2 and 3 respectively. The tap points on
resistors 54, 79 and 109 may then be adjusted individually to vary
the output voltage amplitude and thereby the output current for
each channel. Monitor jacks 66, 94 and 124 and speaker 103 are
attached to a side panel, not shown.
In summary, the present invention generates a train of electrical
impulses which are applied to pairs of acupuncture needles placed
in selected portions of the body for research into acupuncture
anesthesia and acupuncture therapy. A relaxation oscillator
generates a trigger pulse train at a rate which may be varied
between predetermined limits. A monostable multivibrator is
responsive to the trigger pulses to produce pulses having a pulse
width of a predetermined time interval which determines the time
between the positive-going and negative-going portions of the
output waveform. Separate output channels are isolated from one
another and include means for adjusting the amplitude of the output
waveform thereby varying the output current. Each channel is also
protected against power surges and limited to a maximum output
current, typically 50 microamperes.
While there is explained and illustrated the preferred embodiment
of our invention, it is to be understood that many variations in
the apparatus for producing the desired waveform are within the
concept of the invention. Accordingly, it is to be appreciated that
the invention may be practiced otherwise than as specifically
illustrated and described.
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