Note: Descriptions are shown in the official language in which they were submitted.
t 31 0069
METHOD AND APPARATUS FOR DELIVERING
A PRESCRIPTIVE ELECTRICAL SIGNAL
BACKGROUND OF_THE INVENTION
Field of the Invention
This invention relates generally to a device for
providing an electrical signal to a patient. More particu-
larly, this invention relates to a device for producing
accurate, particularly complex intermittent electrical
waveforms. Still more particularly, this invention relates
to an apparatus of the type which comprises means for
delivering a programmed prescriptive electrical signal to a
patient by direct application of the prescribed signal via
electrodes placed on one or more selected points of the ear
or the mastoid process or, in the alternative, by radio
transmission of a controlling signal to enable a radio
receiver located at the point or points of application to
receive the prescribed signal.
Means are provided for monitoring the signal applied to
the patient and comparing it with the prescribed charac-
teristics for noting discrepancies and correcting the
applied signal. The differences noted are used to correct
the original output of the delivery device. Stored data
representative of the application of a signal to the patient
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are analyzed and used to improve subsequent programs for
application to that patient. Preferably, the signals are
applied to contact points chosen because of their known
affinity for changing endogenous concentrations of
neurotransmitters and neuromodulators in the brain. The
signals are applied and controlled as the impedance of the
patient at the applied points changes during the procedure.
In this respect, the patient is a conductive medium. The
signal waveform parameters that are prescribed and con-
trolled in their delivery to the patient are frequencies,
positive and negative voltage amplitudes, positive andnegative current amplitudes, net charge delivered in any
pulse, the duration of each particular pulse, the number of
pulses in each packet, the time or pauses between adjacent
packets of pulses, the number of packets in each train, the
time between trains of packets of pulses, and the number of
trains in the prescription. Such synthesized pulses trains
eliminate, to the greatest extent possible, depolarization
or hyperpolarization of the nerve sheath and conditioning of
the patient, while providing the maximum opportunity for
accurate selectable stimulation of the communication proto-
cols of the brain.
DESCRIPTION OF THE PRIOR ART
In the prior art, processes and devices are known for
the application of electrical signals to humans for various
purposes. Among these processes, transcutaneous electrical
nerve stimulation (TENS) has been used for applying a signal
voltage to a patient by electrodes placed at the site of
local pain. In the "gate" theory of Wall and Melzack, the
resulting afferent sensory signals compete with the pain
signals produced by the human, resulting in analgesia.
Another type of electrical stimulation technique known
to the art, referred to as percutaneous induced
neurostimulation (PINS), has been used to treat intractable
pain following major surgery such as spinal surgery, by the
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application of electrodes implanted beneath the skin and
excited by an external power source.
Still another analgesic technique involves the use of
implanted deep brain probes (DBP) wherein electrodes are
inserted directly into the brain so that when voltage is
applied, analgesia results.
In general, the TENS and PINS processes induce essen-
tially the same mechanism within the human organism. It is
known that pain induces electrical signals which are trans-
mitted to the brain through the spinal chord by a com-
bination of electrical conduction and chemical diffusion
where the pain signals are interpreted at the brain because
of the activities they induce in certain cells. In the TENS
and PINS applications, the pain signals are effectively
diluted because of the competition induced with the afferent
sensor signals produced by the TENS and PINS processes. The
dilution of the pain signals effectively relieves the
extremity of the pain interpreted by the brain.
On the other hand, the DBP process is completely
different. The electrical signals applied directly to the
peri-aqueductual grey space within the brain induce addi-
tional secretion of beta-endorphins which act to inhibit the
reception of the pain signal at the interpretive end (the
Raphe nuclear cells). In effect, the pain signal is blocked
from reaching a destination within the brain where it is
normally interpreted and analgesia results.
Quite clearly, the DBP processes are unsatisfactory
because they require invasive techniques and are generally
limited to terminal patients with extraordinary, intractable
pain. It is desirable to utilize the pain relieving mechan-
ism of the DBP process without the disadvantages of its
invasive application.
Accordingly, it is a general object of this invention
as described in the specification to provide a device for
applying a prescription of electrical signals to a patient
which stimulates the secretion of endorphins and other
neurotransmitters related to induction of analgesia in a
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manner similar to the DBP process. While the TENS and PINS
processes are advantageous in that they are non-invasive,
such processes have limited applicability because of their
limited efficacy. Those processes are limited in the degree
of analgesia produced, the quality of relief obtained, and
the range of applicability of the processes to the broad
spectrum of varieties of pain. Thus, it is another general
object of this invention to provide a device for the appli-
catlon of such electrical signals which are effective for
relieving pain for a wider range of maiadies, conditions,
and syndromes to a degree not heretofore known in the art.
There have also been attempts to treat stress, obesity,
insomnia, and related disorders as well as to treat pain
associated with withdrawal from the effect of nicotine or
other addictive drugs by the use of electrical stimulation.
In this regard, significant research has been conducted
by Dr. Ifor D. Capel, which shows generally that for a set
of unique frequencies, the transcranial voltage induces the
secretion of beta-endorphins in the brain and leads to the
~ 20 same kind of analgesia as DBP processes. Dr. Capel has also
! shown that a different set of frequencies is effective for
treating the pain associated with withdrawal, as well as
treating the physiological symptoms associated with with-
drawal. Such efforts are the suh,ect of United States
patent No. 4,646,744 issued March 3, 1987 to I. Capel and
assigned to the assignee herein.
In general, Dr. Capel has explored some effects of
electrical signals on the mechanisms for neurotransmission
within the brain. The effect of habituating drugs on brain
chemistry and cellular activity is such that both stimulants
and depressants cause debilitating effects on such neuro
activity which lead to long-~asting physical change and
ultimately to deterioration of the cell afrected. By
utilizing particularly discovered frequencies related to
particular drugs, the debilitating effect can be reversed to
counteract the effect of drugs at the cellular level. Thus,
the application of the teachings of Dr. Capel are both
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beneficial and therapeutic as an aid to recovery from
addiction, from the standpoint of both relief of pain and
attention to the physiological changes associated with
withdrawal from the use of addictive drugs.
Thus, it is another general object of this invention to
provide a device with the capability of providing prescrip-
tive therapeutic voltage signals of duration, amplitude,
frequency, pulse width, and intermittency according to the
teachings of Dr. Capel, as well as to extend these teachings
with the applicant's research.
A number of analog devices for producing waveforms
suitable for the application of the TENS and PINS processes
are known. However, such devices do not produce signals
which are sufficiently reproducible, controllable and
accurate to be merchandized as a reliable medical device.
More critically, analog circuitry cannot match the diversity
of waveforms producible with digital electronics, the
facility for incorporating patient feedback to modify the
signal and the speed with which these processes can be
conducted using digital electronic means.
Accordingly, it is another general objective of the
invention described hereinafter to provide such an instru-
ment which uses a significantly different technology to
achieve optimality in the parameters noted above, and as
more fully described in the specification.
Still further, it is another general objective of this
invention to utilize effectively the state of the art in
digital circuitry, programming techniques, and
micro-processing design to produce an instrument of the type
described for use by an investigator and for application of
such signals to a patient.
SUMMARY OF THE INVENTION
Directed to achieving the above-mentioned objectives
and achieving the aims of the invention, a method and
apparatus according to the invention comprises means for
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:
developing and generating a reliable, reproducible,
program-controlled, prescriptive electrical waveform, having
a desired therapeutic and alagesic effect. The system
according to the apparatus comprises a development station
and a control unit for developing and storing a prescriptive
waveform of the type described, available for insertion into
a personal delivery instrument (PDI).
~, The personal delivery instrument, according to the
invention, comprises means for receiving and storing the
developed prescriptive waveform from the control unit for
delivery of an accurately-controlled waveform to the pa-
tient. The PDI includes a central processing unit, having a
ROM and a RAM for programming a voltage source powered by a
battery, to provide the desired waveform transcranially to
the head of a patient. Means are provided for monitoring
the signal applied to the patient, comparing it with the
prescribed signal characteristic stored according to the
prescription from the control unit and by noting discrep-
ancies, correcting the applied signals. The signal actually
applied to the patient can be recorded. In addition, any
differences from the prescription in the signal actually
delivered to the patient are also recorded for subsequent
use in analyzing and improving subsequent prescriptive
programs for application to that patient and others. The
actually J,~d~elivered signal will be affected by the change
over time of the impedance of the patient and, therefore, if
not corrected, the applied signal will drift away from the
prescriptive signal. Thus, in addition to being recorded
;~ for later study, the actually delivered signal can also be
used as a feedback signal to continuously correct the signal
applied to the patient back to the intended prescriptive
signal.
The PDI includes components for accurately controlling
each of the parameters of a train of pulses and for adjust-
ing the signals so that the net voltage charge applied tothe patient is zero. For purposes of this description, a
set of pulses is referred to as a packet and a train is a
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set of packets. Thus, the definition of the waveform
includes:
(1) the pulse frequency or frequencies, fi, since the
prescription may include pulses delivered at more than one
frequency, where fi is the frequency of the pulses in the
ith packet;
(2) the positive amplitude Apifor each pulse in each
packet of each train forming the prescription;
(3) the positive pulse duration Spi for each pulse in
each packet of each train forming the prescription;
(4) the negative pulse amplitude Ani for each pulse in
each packet of each train forming the prescription;
(5) the negative pulse duration Sni for each pulse in
each packet of each train forming the prescription;
(6) the number ni of pulses in packet i;
(7) the time (i l)ti between packets in the train j;
(8) the number J of trains with i packets;
(9) the number Nj of packets in the train j; and
(10) the time (j l)Tj between the trains in the pre-
scription, which time may vary between respective adjacent
trains during the prescription oflthe J number of trains.
Thus, in the generalized case, the instrument is
capable of delivering a prescriptive programmed waveform
defined by the set of parameters noted above, i.e.
R = (f, A , Sp, An, Sn, ni, ti~_5~J~ Nj, Tj)
In the foregoing summary, it should be noted that the
prescription may include packets and pulses at different
frequencies, where the packets may have different amplitudes
and pulse widths. With this generalization, the instrument
operates to deliver a zero net current so that within any
one packet, ApSp = AnSn, to achieve a zero net charge. Once
Ap and Sp are fixed, the product AnSn is fixed by indepen-
dently setting An and Sll to meet the matching equality
requirement. Secondly, the value of the current may be
changed over the course of a given treatment. Experiment
1 3 1 0 0 6 9 PATENT
has shown optimum results can be obtained with an envelope
of decreasing current values.
The method according to the invention is also disclosed
discussing a number of internal tests and verifications for
security and monitoring.
Means are provided for delivering the signals from the
PDI to the patient by leads from a machine attached to the
pinnae, ear lobe, mastoid process, or to other contact
points chosen because of their affinity for changing
endogenous concentrations of neurotransmitters or
neuromodulators.
Electrode design and placement on different parts of
the ears are important features in the overall system.
Placement of the electrodes so that the positive pole is on
the motor-dominant side of the patient is necessary to
achieve optimum result. The electrode must be sharp enough
to deliver a high areal current density but not so sharp
that it will penetrate the skin. The placement is critical.
The electrodes must be placed in contact with points on the
ears which have been tested and display locally greatest
electrical conductivity, and in the general location on the
ear to stimulate one of the selected major cranial nerves
innervating the ears.
An alternative means for delivery, are provided by
using radio transmission of the signal from a separate ;~
computerized controller-transmitter, containing the pa-
tient's program for a particular prescriptive waveform, with
the reception means worn by the patient. The patient
receiver will decode the signal and output the prescribed
waveform.
BRIEF DESCRIPTION OF THE DRAWINGS
So that the manner in which the above-recited features,
advantages and objects of the invention, as well as others
which will become apparent, are attained and can be under-
stood in detail, more particular description of the
invention briefly summarized above may be had by reference
1 31 0069
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to the embodiments thereof which are illustrated in the
drawings, which drawings form a part of the specification.
It is to be noted, however, that the appended drawings
illustrate only preferred embodiments of the invention and
are, therefore, not to be considered limiting of its scope
for the invention may admit to other equally effective
embodiments.
In the Drawings:
Fig. 1 is a block diagram of the system, including the
personal delivery instrument for applying prescriptive
signals transcranially to a patient according to the
invention;
Fig. 2A is a generalized waveform for illustrating the
parameters controlled by the device in Fig. 1 for achieving
an accurate prescription for transmission to a patient and
for analysis showing a typical wave packet i of pulses;
Fig. 2B is a similar generalized waveform of a typical
train of packets j;
Fig. 2C shows a similar generalized waveform of a
typical prescription of trains J;
Fig. 2D is a chart of the parameters of the prescrip-
tion delivered by the instrument;
Fig. 3 is a more complex waveform of the type hereto-
fore applied to a patient capable of being analyzed by the
system according to the invention;
Fig. 4 is a drawing similar to Fig. 3 showing the use
of the device in analyzing the waveform of the type of Fig.
3;
Fig. 5 is an exemplary program sequence fcr inputting
the prescriptive waveform from the control unit to the PDI;
Fig. 6 is an exemplary program sequence for monitoring
the prescriptive waveform delivered from the PDI to a
patient;
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Fig. 7 is a representative drawing showing the applica-
tion of the prescriptive waveform to the Shen Men acupoint
of a patient; as shown With Fig.3;
Figs. 8A-8C are block diagrams showing several modes of
transmitting the prescriptive waveform to a patient; a~ shown
with Fig. 3;
Fig. 9 is a more detailed functional block diagram of
the personal delivery instrument of the type shown in Fig.
1 ;
Fig. 10 is a more detailed functional block diagram of
a controlled signal generator unit of the PDI;
Fig. 11 is a general block diagram illustrating the use
of a monitor for changing the applied signal delivered to a
patient;
Fig. 12 is a graph of an alternate applied signal
current level as applied to a patient;
Fig. 13 is a graphical analysis of the electrochemical
effects created by two different prescriptions in accordance
with the present invention;
Fig. 14 is a graphical comparison of two different
trains in accordance with the present invention and their
resulting effects;
Fig. 15 is an application switching connection scheme
for applying a prescriptive signal in an alternate process
in accordance with the invention;
Fig. 16 is an alternate switching connection scheme for
applying a prescriptive signal in yet another alternate
process in accordance with the invention;
Fig. 17 is yet another alternate switching connection
scheme for applying one or more prescriptive signals in
still another alternate process in accordance with the
invention; and
Fig. 18 is a block diagram of the monitoring and
corrective feedback scheme for use with multiple applied
prescriptive signals.
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1 3 1 00 6q PAT~NT
DETAIL~D DESCRIPTION OF T~E PREFERRED EMBODIMENTS
In Fig. 1, a transcranial electrical nerve stimulator
device and system is generally referred to by the reference
numeral 15, for developing and generating a reliable,
reproducible program-controlled prescriptive electrical
waveform having a therapeutic effect for amelioration of
pain or assistance in ameliorating stress or anxiety related
disorders and relieving drug habituation diseases by the
transcranial application of the prescriptive electrical
waveform to a patient. The system comprises a personal
delivery instrument (PDI) 16, a control unit 1~, and a
development station 20. The PDI 16, when programmed with
the prescriptive electrical waveform, is used to provide
current signals transcranially to the head 21 of a patient
either by direct connection 22, as shown in Fig. 1, or by
radio transmission ~o a device worn by the patient or
implanted in the patient as shown in Figs. 8B-8C. ~he
control unit 18 is usable by medical personnel to program
the required prescriptive signals in the PDI 16. The
development station 20 is used to generate compatible data
to the control unit 18 and to analyze the results from the
control unit 18 and the PDI 16.
The prescriptive waveforms having the extended thera-
peutic effects are disclosed in detail in the
above-mentioned patent of Ifor D. Capel,
while other signal prescriptions have been known to inves-
tigators for research on patients or animals in developing
acceptable prescriptions. It is contemplated ~ at the
device according to the invention is capable of delivering
any of such prescriptive waveforms to a patient, upon
identification of the parameters of the waveform, including
their se~uence.
Starting with a de~-eloped prescriptive waveform having
a desired or intended therapeutic effect for a predetermined
disorder stored for retrieval in the control unit 18, or a
~¦ prescriptive waveform for researGh, the program for that
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! 1 3 1 0069 PATENT
programmed wave~orm is provided by connection between PDI 16
and the control unit 18 through an interfacing connection
17. The PDI 16 includes a delivery control uni' 24 having a
central prGcessing unit 25, a ROM 26, and a RAM 27 for
S precisely programming the operation of a pulse electrical
source 28 connected to a power source 28a to provide the
desired waveform on a output lead 22 connected to the head
of the patient.
Monitoring means 29 are provided for monitoring the
signal applied to the patient and comparing it in the
delivery control unit 24 with the prescribed characteristics
stored therein from the control unit 18 for noting discrep-
ancies and correcting the applied signals. The differences
noted are used to correct the original signal output of the
personal delivery instrument (PDI) 16 for storing data
accurately representative of the actual application of a
signal to the patient for analysis, to develop subsequent
prescriptive programs, and to improve existing prescriptive
programs for application either to that patient or others by
returning the stored data on an output to the control unit
18 for interfacing on lead 31 with the development station
20. As is apparent, a developed or modified prescriptive
; program prepared at the development station 20 may be
. transferred by the interface 19 to the control unit 18, or
to a plurality of such control units located at a number of
locations, such as hospitals.
The control unit 18 also operates with respect to the
PDI 16 to perform a number of additional functions. The
control unit 18 thus may reset the PDI 16 to prepare it for
reception of a new prescriptive program, interrogate for
current operational conditions and errors, perform appro-
priate internal verifications, communicate selected applica-
tions to the PDI in simple or encrypted format, verify the
. correct receipt of the prescriptive program by the PDI 16,
3S communicate a current time, and request statistics from
; the PDI 16.
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1 3 1 9 06 q PATENT
The PDI 16, on the other hand, after communication of a
series of instructions from the control unit 18, outputs an
electrical signal, the basic component of which is a pulse
having a frequency, shape, duration, amplitude and number,
each of which is programmable. It is a feature of the PDI
to provide an output where the time average of the current
passing between the two output electrodes is zero. The PDI
16 may also be programmed to provide either a low frequency
or a high frequency sequence wave modulation to the output
pulse, acting to turn on or off the output pulse so that the
output pulse becomes a modulation envelope for the HF
modulation. The presence and frequency of modulation are
also programmed into the device 16, as is the time to
traverse from zero to nominal amplitude (i.e., ramp time).
The system 15 has the advantage of using currently
available devices. For example, for the PDI, a 146805 CMOS
microcomputer may comprise the CPU 25, interacting ~acting
as a signal source) with a byte wide CMOS RAM 27 and EPROM
26, a programmable D/A converter with low power operational
amplifiers to generate the output signal, and CMOS LSI
logic. The control unit 18, for compatibility, may utilize
a 16 bit computer with floppy discs to store the program
sequence parameters to insure media compatibility with the
development station 20. The development station may com-
prise a personal computer compatible with accompanying
accessories for utilizing stock software readily available
for laboratory analysis and report generation.
A significant feature of the invention resides in its
precise control of each of the particular parameters of a
wave train applied to a patient according to the prescrip-
tion.
Figs. 2A-2D illustrate a generalized depiction of an
electrical waveform for analyzing a train of pulses compris-
ing a plurality of irregularly spaced packets of pulses
wherein the pulses in each packet are also controlled.
Thus, the PDI 16 includes a pulse profile controller which
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produces a waveform, the components of which are shown
respectively in Figs~ 2A, 2B and 2C.
As shown in Fig. 2A, a typical wave packet i of pulses
at a frequency fi are shown having a positive amplitude Ap,
a negative amplitude An, a positive pulse duration Sp, and a
negative pulse duration Sn, for a representative example of
a packet i, for the three pulses shown (ni=3). It should be
noted that the pulse frequency fi may vary either within a
packet i or between adjacent packets so that the prescrip-
tive waveform includes a specification of the pulse fre-
quency or frequencies fi, where fi is the frequency of the
pulses in the i packet.
For a packet i of pulses at a frequency fi, the PDI 16
delivers a pulse having a positive pulse amplitude Api for
each pulse in each packet of each train forming the pre-
scription. While Fig. 2A shows positive and negative pulses
Ap, An, of approximately the same respective amplitudes, the
amplitudes may vary between adjacent positive or negative
pulses if the prescription so requires. Similarly, the PDI
16 produces a waveform which includes a specification of the
positive pulse duration Spi for each pulse in each packet of
each train forming the prescription, and the negative pulse
duration Sni for each pulse in each packet of each train
forming the prescription, and the negative pulse duration
Sni for each pulse in each packet of each train forming the
prescription, as well as the number of pulses in each
packet, ni.
As shown in Fig. 2B, the PDI 16 also delivers a train j
of packets i of pulses of the type shown in Fig. 2A. The
PDI 16 thus also controls the respective times between the
delivery of adjacent packets where the time between the
first packet and the second packet, for example, is noted by
lt2 so that for a generalized case, the instrument delivers
packets at the time (i l)ti for packet i-
As shown in Fig. 2C, the instrument 16 also delivers a
prescription of trains J of packets i where the time between
adjacent trains is controlled according to the generalized
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1 3 1 0 0 6 9 PATENT
expression (j 1)Tj, where the time between respective
adjacent trains during the prescription by vary. For the
generalized prescription chart shown in Fig. 2D, the entire
prescription includes M trains and N packets in the pre-
scriptive train j. Thus, in the generalized case, the
instrument is capable of delivering a prescriptive program
waveform defined by the parameters shown in Fig. 2D under
the conditions wherein the product ApSp is equal to AnSn to
deliver a zero net charge.
Such synthesized pulse trains eliminate to the extent
possible a polarization demyelination of the nerve sheath of
the patient, conditioning the patient, and provide the ?
investigator the maximum opportunity for accurate simulation
of the communication protocols of the brain of the patient.
Fig. 3 is a more complex waveform which may also be
analyzed according to the application of the techniques of
the invention. Because the prior art devices for applying
TENS signals to patients tended to output a signal like that
shown in Fig. 3, this particular waveform is of special
interest to investigators.
Such a waveform 33 can be analyzed by the instrument of
the invention by inputting it or a reproduction of the
waveform to the monitoring means 29 to produce a program for
determining by approximation its constituents as shown in
J-~Fig. 4. Thus, the investigator has a common basis for
comparison of new prescriptions with former applications.
Fig. 5 is a program for transferring the signal pre-
scription from the control unit 18 to the PDI 16. For
security, the patient identification, such as name and code
number, is input to the control until 18 and a brief
description and other identifying data concerning the
patient profile are input in steps 36 and 37. The patient
code is checked for accuracy against a user identification
for security in step 39 and, if incorrect, the prescription
will not be loaded from the control unit 18 into the PDI 16
and the program returns to the input step 36. If correct,
the treatment code is input in sequence 38 containing the
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1 3 1 0069 PATENT
prescription for a precise wave train to be applied to the
patient. As will be seen, more than one prescription is
provided by sequentially inputting the frequency, the
amplitude Ap, of the positive pulse, the sequence Spi of the
positive pulse, the amplitude Ani of the negative pulse, and
the duration Sni of the negative pulse in steps 40, 41, 42,
43 and 44. Thereafter, in steps 45, the product of ApiSp
is calculated and the product AniSni is calculated, the
calculated products are compared to provide a net zero
current, and a correction signal is input in step 45a.
Thereafter, the number ni of pulses in each packet, the
number of packets N in the train, the time between packets,
the time between trains, and the number of trains in the
prescription, along with any other necessary parameters and
any additional prescriptions for treatment of the patient in
steps 46 to 52 so that at step 53 the overall voltage
prescription has been input to the PDI 16. An appropriate
final check may be made at step 52 to insure complete
delivery of all prescriptive components, if desired.
Fig. 6 is a block diagram of a representative sequence
for checking and correcting the prescriptive delivery.
After the device is connected to the patient and appropriate
connection confirmed in step 55 and the master clock started
in step 56, the system commanded in step 57 to perform a
sequence of internal delivery service checks of the battery
in sequence 58, of the RAM in sequence 59, of any other
appropriate components 59a, and of the circuit by monitoring
the circuit using test voltages in step 60. Step 55 may
include checks on whether the electrodes are open, loose or
closed, station power delivery is appropriate, and other
preliminary confirmation tests. Performance outside of
predetermined parameters in any of these steps 57-59a
inaugurates a corresponding notice signal 58b, 59b, 60b to
signal operator attention in step 61. If the internal
delivery service checks are accurate and within accepted
norms, the prescriptive wave train stored in accordance with
Fig. 5 is initiated in step 62 and the delivery of that
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1 3 1 0 0 6 q PATENT
prescription is monitored at predetermined intervals by
sequentially interrogating at intervals Q the components of
the system in steps 70-74, followed by a clock test in step
75 whereupon a command is given to go to the next packet or
train of pulses. If any of the parameters is outside of
accepted norms, a correction signal is given and the zero
level reset (for zero net charge) is also periodically
provided, preferably after each pulse, especially for low
frequency transmission. If the signals are within accepted
norms, the delivered data to the patient are then recorded
for subsequent transfer to he control unit 18 and for use at
the development station 20 for analysis.
Fig. 7 shows a portion of the ear of a patient illus-
trating the application of the electrodes 22 to selected
; 15 contact points on the ear of a patient. In the past,
electrical signals or other processes were delivered to a
patient by direct application of the prescribed voltage
through electrodes placed on selected elements of the ear or
the mastoid process. Preferably, the precisely controlled
prescriptive electrical signals according to the invention
are applied to selected points of the ear having`optimal
conductivity. These contact points are chosen because of
their known affinity for changing endogenous concentrations
of neurotransmitters or neuromodulators in the brain. The
application of the prescriptive signals at these points
optimizes the impedance match between the output of the
system 15 and the patient as a conductive medium.
Figs. 8A-8C show alternative modes for providing the
prescriptive electrical signal to a patient without direct
connection to the unit as at lead 22 in Fig. 1. Thus, Fig.
8A contemplates a delivery control unit 24' miniaturized to
`~ be worn by the patient or further miniaturized to become a
part of a non-invasive application appearing similar to a
hearing aid or eyeglasses with enlarged ear lobes. In this
embodiment, the control unit 18', similar to control unit
18, is connected to a RF transmitter 102 for transmitting
all of the signals for loading and applying the prescriptive
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1 3 1 0~6q PA~ENT
waveforms to the unit for reception by an RF receiver 104
connected to the delivery control unit 24'. Thus, when all
of the components of the delivery control unit 24' are in
chip form, the delivery control unit 24' may be loaded and
the prescriptive electrical signal delivered at the patient.
Such radio transmission may require additional security
coding to prevent erasing a preloaded delivery control unit
24'. In a simpler embodiment, the delivery control unit 24'
may comprise a cassette or cartridge preloaded with the
prescriptive electrical signal from a control unit 18' to be
activated by a secured RF transmitted signal. Either of the
foregoing embodiments permits a patient significant increase
in freedom of movement while undergoing treatment.
Fig. 8B is representative of an embodiment wherein a
control unit 18' and a delivery control unit 24' operate as
described in connection with Fig. 1 but where the prescrip-
tive waveform is transmitted by an RF transmitter 102' to be
received by an RF receiver 104' at the patient in a suitable
patient device 105, such an ear piece or radio receiver.
In either of the embodiments of Figs. 8A and 8B, where
monitoring is desired as discussed in connection with Fig.
1, the RF transmitter/receiver pair may comprise a pair of
transceivers suitably secured for two-way communication of
the transmitted and monitored data.
Fig. 8C is similar to Fig. 8B wherein the patient
device is an implant 105a to illustrate an embodiment
wherein the prescriptive waveform is radio transmitted to an
implanted receiver at the patient to achieve the desired
therapeutic effects.
Fig. 9 is a functional block diagram of the PDI 16
according to its presently preferred embodiment for incor-
poration in a portable desk top unit. However, the princi-
ples of the invention may be embodied in a device sized to
be protable with the patient as in Figs. 8A-8C while receiv-
ing the applied signal characteristics, such as discussed in
connection with such illustrations.
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i 1 ~1 0069
PATENT
The embodiment of Fig. 9 is designed to provide the
electrical signal characteristics of the type described, the
power requirements, memory requirements, display, key board,
connectors and operational requirements to achieve the
intended purposes of the invention. The output current
pulse characteristics provided by the unit include a zero
cumulative current with a positive 35 milliamp peak output
current programmable throughout the range of zero to maximum
current with limitations on the maximum output current for
patient safety. The frequencies of the pulses are provided
in a range of 0.5 hz to 500 hz with a one percent deviation
or less from optimum throughout the range of primary inter-
est in implementing the waveform prescription according to
the aforementioned identified patent application of Ifor D.
Capel. The frequency range and pulse shape are programmable
and provided with a 100 microsecond sampling interval, fr
example. Where wave modulation is necessary or desirable,
the modulating wave may be provided in a suitable range, for
example, 5.0 Khz to 100 Khz for high frequency modulation,
whereas low frequency modulation of the output current pulse
is selectable in predetermined time increments, such as 0.1
minutes, up to 20 minutes, on an on/off basis. Preferably,
the ramp time exhibited by the wave pulses (i.e., the time
lapse necessary to change from zero to the programmed output
current) is typically 100 microseconds.
The unit is designed to meet load characteristics
approximately 200,000 ohms in parallel with a 0.10
microfarad capacitance. The unit is preferably powered by
an internal dual power supply having a battery and a backup
to insure data retention in the case of power failure. A
data retention feature is also provided as will be dis-
cussed. Preferably, the internal clock is accurate to 0.1
percent. The display is preferably a one digit LED display
capable of generating numbers zero to nine while the key-
board is preferably a one button unit. The speaker, foremitting audible warning signals, may generate audio signals
; as desired, for example, form two seconds to five minute
--19--
,..... . .
1 3 1 0069 PATENT
increments. Connections of the PDI 16 to the patient are
provided by conventional plugs and jacks and, as described,
the unit is capable of a self-test sequence, a main line
sequence, and data monitoring storage sequencing. AS
described, the unit is capable of generating current pulses
of defined amplitude and duration, with high fre~uency and
low frequency modulation ranging from .05 hz to 500 hz
according to the program stored therein according to the
waveform prescription discussed in connection with Figs.
2A-2C and 5. The self-diagnostic sequence for the unit has
been discussed in connection with Fig. 6. Preferably, the
unit is intended for operation over a five hour period so
that current pulses on the order of or less than 25 micro-
amperes provided to a 200,000 ohms load require a 0.1 watt
signal (because of the unique parameters of the waveforms)
permitting selection of a battery source to meet the operat-
ing parameters.
Thus, as shown in Fig. 9, the PDI 16 comprises a
plurality of functional modules. The controller 80 provides
for the timing and control of all of the units and acts as
an interface between any two modules. The display numeric
module 81 is used as a status indicator, while the keyboard
module 82 is used to command data input to inaugurate the
program sequence described in connection with Fig. 5. The
alarm module 83 may be actuated as described in connection
with Fig. 6 to obtain operator attention, as described in
connection with step 61. Thus, the alarm module not only
functions as an alarm, but also monitors the time between
activities and the starting and stopping time to associate
the data generation with the status of the patient. The
program storage module 84 and the data storage module 85
respectively store the electrical signal prescription and
self-test schedule in the program storage module 84 as well
as the results of the tests and signal schedule in the data
storage module 85.
The battery indicator module 86 monitors the conditions
of the battery source in the system to provide an indication
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1 3 1 0 0 6 ~ PATENT
when the battery needs charging, while the Input/Output port
module 87 outputs the gathered data and receives the inputs
of the new program sequences. The signal generator module
87 generates the electrical signal prescription with the
signal duration and waveform created according to the
discussions of Figs. 1 and 3 by the program sequence. Thus,
the PDI as shown in Fig. 9 is capable of performing program
scheduling, signal generation, self-testing, data output,
and battery charging or changing. Each of these modes have
been described in connection with Figs. 1-8C above.
In particular, the controller 80 may control an 8 bit
CMOS microcomputer of a single chip design to permit signal
generation at random time intervals and to interface between
different modules. Thus, the controller 80 may include the
CPU, ROM, and RAM capabilities discussed in connection with
Fig. 1.
The display module 81 preferably comprises an LCD
character generator driven by a 4 bit word from the micro-
processor in the controller 80. That signal is converted to
proper format and multiplexed to drive the LCD, as is known
in the art. A 32 Khz clock is used to drive the generator.
The clock chip preferably contains an on-chip oscillator to
generate the multilevel waveforms.
The signal generator module 87 is shown in greater
detail in Fig. 10. 3he signal generator comprises an 8 bit
D to A converter 90 to obtain the needed voltage levels,
connected to operational amplifiers 91. The microprocessor
in the controller 80 will program the D to A unit 90 to
provide current at the desired levels. The output levels
from the D to A converters is thus fed into the two opera-
tional amplifiers to generate a electrical differential at
the output. By adjusting the binary number into the D to A
converter 90 from the master control unit 80, a bipolar
signal from the operational amplifiers can generate current
flowing in either direction through the electrodes 22,
connected to terminals E1 and E2. The binary numbers are
selected to generate the pulse or inverse current signal
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1 3 1 n o 6 q PATENT
with an 8 bit resolution. As discussed above, the micropro-
cessor control unit selects the binary number determined by
the software.
Input/output module 87 controls all of the input and
output activity of the PDI. Thus, the output comprises a
plurality of signal channels for output of status informa-
tion and input of programming sequencing, two of which are
dedicated to the use of electrodes and another of which is
for recharging, if a recharge cable battery is selected.
Referring now to Fig. 11, a simplified block diagram of
an apparatus for delivering a prescriptive signal to a human
patient 100 is shown. The system comprises generally a
control computer 102 and a delivery system 104, both of
which can be substantially identical to similar devices
previously described. Monitor 106 shown in Fig. 11 is
connected to contact points of the patient so as to actually
monitor a plurality of the parameters of the signal as they
are applied to the patient. Specifically, the voltage,
current and frequency parameters are monitored. As men-
tioned above, one preferred frequency is approximately 10
Hz, the preferred voltage is in the range of~1 to 4 volts
and the current is in the size range of approximately lO-15
microamperes. It has been discovered that the impedance of
the patient will change over a period of time during the
treatment application of the prescriptive signal.~ It is
important to maintain the precise value of the parameters
which are delivered to the patient, particularly the current
parameter. Therefore, each of the three most sensitive
parameters mentioned above are monitored and fed back to
control computer 102 so that the delivery system adjusts the
signal applied to the patient to be in accordance with the
prescription.
It has been further discovered in performing research
using the apparatus, that treatment can be optimized by
- 35 applying waveforms at correct frequencies that are initially
delivered at around 15 microamperes. When this amplitude is
gradually decreased to approximately 6 microamperes over the
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- 1 31 006q
PATENT
course of a 40 minute treatment period, the resulting
effects are optimized for the entire period. Therefore,
Fig. 12 illustrates that the current level is reduced from a
maximum at the onset of treatment to a minimum at the end of
the treatment. The feedback mechanism of voltage, current
and frequency which was discussed with reference to Fig. 11
are compatible to support the application of current at at
the reduction level over a period of time.
A typical number of pulses in a packet is 256. The
typical positive cycle of the pulse is about six times the
amplitude of the negative cycle of the pulse. The durations
of the cycles are reversed so that ApSp=AnSn, as previously
discussed. This yields a zero net charge for an entire
pulse.
With the pulse configurations established as above, it
has been discovered that different frequencies induce
different behavioral and biochemical effects generally from
patient to patient. It has also been discovered that each
frequency or repetition rate of pulses relates favorably to
a uniqùe ratio of pulses per packet and pauses between
packets to achieve optimal results. Referring to Figs. 13
and 14, please note that a packet of a burst of pulses all
of the same width, exhibiting a zero net charge characteris-
tic and constant in frequency as previously described
differs in making an effect on the patient merely because
the pauses between packets in the train are different. This
is illustrated for achieving a first effect and a second
effect as shown in Fig. 14. Fig. 13 illustrates that a
prescription with shorter pauses between packets will excite
the beta endorphins to a greater level than a prescription
with greater pauses between identical packets. On the other
hand, the adrenocortico trophid hormone (ACTH) is excited in
reverse.
It has further been discovered that electrode design
has progressed to the point where molds can be made of the
contour of '.he individual patient's pinnae. Contact elec-
trodes are embedded in the molds with locations that
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-`` 1 3 1 0 0 6 9 PATENT
correspo;;d to the contact point or points on the skin of the
ear that show the greatest electrical conductivity. These
points as previously mentioned are those points selected
because of their known affinity for changing the endogenous
concentrations of neurotransmitters and neurom3dulators in
the brain. The molds can be removed and reinserted many
times and the electrodes will return to the correct contact
point positions. Molds can be made to accommodate multiple
electrodes to access more than one contact point simul-
taneously, if desired.
Experiments have further shown that the same electrica~prescription applied to different points on the ears will
produce different chemical and behavioral effects. Addi-
tionally, different frequencies applied to different points
lS produce distinguishable differences. Prescriptions have
been individualized to provide appropriate therapy for
different conditions. For example, the prescription for
chronic pain due to arthritis is different in both elec-
trical content and electrode application than the prescrip-
tion to assist patients in the withdrawal from smoking. Asshown in Fig. 15, a given prescription A 108 can be applied
through switch 110 so as to be applied to a first pair of
contact points 112 to achieve a first effect or alternately
to a second pair of contact points 114 for accomplishing a
desired second effect.
Fig. 16 illustrates the capability of switching between
a prescription A having a first pulse frequency provided by
memory device 116 and a second prescription B having a pulse
frequency at a second frequency stored in a control device
118. Prescription A for causing a first effect can be
applied through switch 120 to a first pair of contact points
or alternately through switch 120 to a second pair of
contact points to cause a second effect on the patient. In
similar fashion, prescription B can be selected from device
118 through switch 122 to be applied to the first pair of
contact points or alternately to the second pair of contact
points. Hence, a total of four effects can be obtained by
-24-
.
, .
-- 1 3 1 0 0 6 9 PATENT
the use of the devices in connections illustrated. If
desired, switches 120 and 122 can be electronic switches
that cycle on a time shared basis between the two positions
with each set of contacts at the respective switches.
Hence, generally, to accommodate delivery of different
electrical signals to different contact point pairs, the
prescription delivery system is desirably capable of gen-
erating each different waveform, outputting them to the
appropriate electrode pair and monitoring the output so as
to maintain the parameters within the limits of accuracy
required. Generally, therefore, the simplified block
diagram shown in Fig. 17 accomplishes this. The prescrip-
tion delivery system 124 produces up to four different
electrical prescriptions through an appropriate switching
combination 126 so as to apply the prescriptions simultan-
eously or in sequence to four electrode pairs 128. Each of
these electrode pairs is appropriately monitored by monitor-
ing device 130, the output of which is fed back to the
prescription delivery system.
Fig. 18 illustrates the effect of the feedback mechan-
ism for correcting the signals delivered to the patient.
Storing means 130, including controlling means 132, is
connected to the delivery means 134, including at least two
siynal sources 136 and 138. As mentioned above, it is
J~25 common for there to be up to four signal sources in an
actual delivering means 134. The output from signal source
136 and signal source 138 are initially determined by the
prescriptive input from controlling means 132 which is
applied to patient 140. The output from the patient is
detected by voltage, current, frequency (V,I,F) monitor 142
for the first signal and by V,I,F monitor 144 for the second
signal. The feedback from these respective monitors are
applied to comparison means 146 and 148, respectively, in
the delivering means. The output from the comparison means
is applied to a correcting means 152 and 154, respectively,
for modifying the output signals from signal sources 136 and
138, respectively. Hence, each of the prescriptions is
.
, ~
-25-
. .
-` i 1 31 006~
PATENT
delivered to the patient within the prescribed parameters of
the prescription at all times.
The invention may be embodied in other specific forms
without departing from its spirit or essential characteris-
tics. The present embodiments are, therefore, to be con-
sidered in all respects as illustrative and not restrictive,
the scope of the invention being indicated by the claims
rather than by the foregoing description and all changes
which come within the meaning and range of the equivalents
of the claims are therefore intended to be embraced therein.
\
J~
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