U.S. patent application number 11/204507 was filed with the patent office on 2006-03-09 for evaluation of pain in humans.
Invention is credited to Gady Abramson, David Bruce Ross.
Application Number | 20060052720 11/204507 |
Document ID | / |
Family ID | 52810253 |
Filed Date | 2006-03-09 |
United States Patent
Application |
20060052720 |
Kind Code |
A1 |
Ross; David Bruce ; et
al. |
March 9, 2006 |
Evaluation of pain in humans
Abstract
A method for evaluating pain experienced by a human is
disclosed. The method includes applying a first noxious stimulus to
a normative site on the human, wherein the first noxious stimulus
is applied below a pain threshold of the human and logging a first
information associated with the first noxious stimulus. The method
further includes applying a second noxious stimulus to a source of
the pain in the human, wherein the second noxious stimulus is
applied until pain threshold is reached and logging a second
information associated with the second noxious stimulus. The method
further includes increasing the second noxious stimulus until pain
tolerance is reached and logging a third information associated
with the second noxious stimulus. The method further includes
continuing to apply the second noxious stimulus until the human can
no longer tolerate the second noxious stimulus and logging a fourth
information associated with the second noxious stimulus.
Inventors: |
Ross; David Bruce;
(Southwest Ranches, FL) ; Abramson; Gady;
(Hollywood, FL) |
Correspondence
Address: |
RICHARD S. ROSS, ESQ.
4801 S. UNIVERSITY DR.
# 303
FT. LAUDERDALE
FL
33328
US
|
Family ID: |
52810253 |
Appl. No.: |
11/204507 |
Filed: |
August 17, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60609939 |
Sep 3, 2004 |
|
|
|
Current U.S.
Class: |
600/554 ;
600/595 |
Current CPC
Class: |
A61B 5/4824 20130101;
A61B 5/4519 20130101; A61B 5/0053 20130101; A61B 5/4528 20130101;
A61B 5/00 20130101; A61B 5/0057 20130101; A61B 5/4035 20130101 |
Class at
Publication: |
600/554 ;
600/595 |
International
Class: |
A61B 5/05 20060101
A61B005/05; A61B 5/103 20060101 A61B005/103 |
Claims
1. A method for evaluating pain experienced by a human, comprising
the steps of: applying a first noxious stimulus to a normative site
on the human, wherein the first noxious stimulus is applied below a
pain threshold of the human; logging a first information associated
with the first noxious stimulus; applying a second noxious stimulus
to a source of the pain in the human, wherein the second noxious
stimulus is applied until pain threshold is reached; logging a
second information associated with the second noxious stimulus;
increasing the second noxious stimulus until pain tolerance is
reached; logging a third information associated with the second
noxious stimulus; continuing to apply the second noxious stimulus
until the human can no longer tolerate the second noxious stimulus;
and logging a fourth information associated with the second noxious
stimulus.
2. The method of claim 1, further comprising: withdrawing the
second noxious stimulus; and executing all previous steps.
3. The method of claim 2, further comprising: determining whether
the pain experienced by the human originates from biological,
social or psychological factors, based on the first information,
the second information, the third information and the fourth
information.
4. The method of claim 1, wherein the first step of applying
comprises: applying a first noxious stimulus to a normative site on
the human, wherein the noxious stimulus is applied below a pain
threshold of the human and wherein the first noxious stimulus
comprises any one of: moving a portion of the human; moving a limb
of the human about a joint; applying pressure to a portion of the
human; applying an electrical pulse to a portion of the human; and
allowing the human to push or pull with force using a portion of
the human.
5. The method of claim 4, wherein the first step of applying is
conducted for about one minute.
6. The method of claim 1, wherein the first information, the second
information, the third information and the fourth information each
comprise at least one of: an angle of a portion or a limb of the
human; an amount of pressure applied to a portion of the human; an
amount of electricity applied to a portion of the human; and an
amount of pressure applied by a portion of the human.
7. The method of claim 6, wherein the first information, the second
information, the third information and the fourth information each
comprise at least one of: a degree or radian value; a first
pounds-per-square-inch value; an amperage and/or voltage value; and
a second pounds-per-square-inch value.
8. The method of claim 1, wherein the second step of applying
comprises: applying a second noxious stimulus to a source of the
pain in the human, wherein the second noxious stimulus is applied
until pain threshold is reached and wherein the second noxious
stimulus comprises any one of: moving a portion of the human;
moving a limb of the human about a joint; applying pressure to a
portion of the human; applying an electrical pulse to a portion of
the human; and allowing the human to push or pull with force using
a portion of the human.
9. The method of claim 1, wherein the second step of applying
further comprises: applying a second noxious stimulus to a source
of the pain in the human, wherein the second noxious stimulus is
applied until pain threshold is reached by observing a reaction of
the human, wherein the reaction of the human includes at least one
of: a motor response; a verbal response; a vocal response; a social
response; and efforts to conceal or suppress external signs of
pain.
10. The method of claim 9, wherein the second step of applying is
conducted for about five seconds.
11. The method of claim 9, wherein the step of increasing
comprises: increasing the second noxious stimulus until pain
tolerance is reached by observing a reaction of the human, wherein
the reaction of the human includes at least one of: a motor
response; a verbal response; a vocal response; a social response;
and efforts to conceal or suppress external signs of pain.
12. The method of claim 11, wherein the step of increasing is
conducted for about five seconds.
13. The method of claim 11, wherein the step of continuing
comprises: continuing to apply the second noxious stimulus until
observing a reaction of the human indicating the human can no
longer tolerate the second noxious stimulus, wherein the reaction
of the human includes at least one of: a motor response; a verbal
response; a vocal response; a social response; and efforts to
conceal or suppress external signs of pain.
14. The method of claim 13, wherein the step of continuing is
conducted for about five seconds.
15. A system for evaluating pain experienced by a human,
comprising: a measuring apparatus for measuring information
associated with a first and second noxious stimulus applied to a
human, wherein the first noxious stimulus is applied to a normative
site on the human below a pain threshold of the human, the second
noxious stimulus is applied to a source of the pain in the human
until pain threshold is reached, the second noxious stimulus is
applied until pain tolerance is reached and the second noxious
stimulus is applied until the human can no longer tolerate the
noxious stimulus; and a data storage device for storing a first
information from the measuring apparatus when the first noxious
stimulus is applied below a pain threshold, storing a second
information from the measuring apparatus when the second noxious
stimulus is applied at pain threshold, storing a third information
from the measuring apparatus when the second noxious stimulus is
applied at pain tolerance, and storing a fourth information from
the measuring apparatus when the human can no longer tolerate the
second noxious stimulus.
16. The system of claim 15, further comprising: an information
processing system for determining whether the pain experienced by
the human originates from biological, social or psychological
factors, based on the first information, the second information,
the third information and the fourth information.
17. The system of claim 16, wherein the measuring apparatus is an
inclinometer for measuring an angle of a portion or a limb of the
human.
18. The system of claim 17, wherein the first information, the
second information, the third information and the fourth
information each comprise an angle of a portion or a limb of the
human.
19. The system of claim 16, wherein the measuring apparatus is an
algometer for measuring an amount of pressure applied to a portion
of the human.
20. The system of claim 19, wherein the first information, the
second information, the third information and the fourth
information each comprise an amount of pressure applied to a
portion of the human.
21. The system of claim 19, wherein the first information, the
second information, the third information and the fourth
information each comprise an amount of pressure applied by a
portion of the human.
22. The system of claim 16, wherein the measuring apparatus is an
electric multi-meter.
23. The system of claim 22, wherein the first information, the
second information, the third information and the fourth
information each comprise an amount of electricity applied to a
portion of the human.
24. An information processing system for evaluating pain
experienced by a human, comprising: a receiver for receiving a
first information from a measuring apparatus for measuring
information associated with a first and second noxious stimulus
applied to a human, wherein the first noxious stimulus is applied
to a normative site on the human below a pain threshold of the
human, receiving a second information from the measuring apparatus
when the second noxious stimulus is applied to a source of the pain
in the human at pain threshold, receiving a third information from
the measuring apparatus when the second noxious stimulus is applied
at pain tolerance, and receiving a fourth information from the
measuring apparatus when the human can no longer tolerate the
second noxious stimulus; a data storage device for storing the
first information, the second information, the third information
and the fourth information; and a processor configured for
determining whether the pain experienced by the human originates
from biological, social or psychological factors, based on the
first information, the second information, the third information
and the fourth information.
25. The information processing system of claim 24, further
comprising: a display for displaying a result of the step of
determining whether the pain experienced by the human originates
from biological, social or psychological factors.
26. The information processing system of claim 24, wherein the
measuring apparatus is an inclinometer for measuring an angle of a
portion or a limb of the human.
27. The information processing system of claim 26, wherein the
first information, the second information, the third information
and the fourth information each comprise an angle of a portion or a
limb of the human.
28. The information processing system of claim 24, wherein the
measuring apparatus is an algometer for measuring an amount of
pressure applied to a portion of the human.
29. The information processing system of claim 28, wherein the
first information, the second information, the third information
and the fourth information each comprise an amount of pressure
applied to a portion of the human.
30. The information processing system of claim 28, wherein the
first information, the second information, the third information
and the fourth information each comprise an amount of pressure
applied by a portion of the human.
31. The information processing system of claim 24, wherein the
measuring apparatus is an electric multi-meter.
32. The information processing system of claim 31, wherein the
first information, the second information, the third information
and the fourth information each comprise an amount of electricity
applied to a portion of the human.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application claims priority to U.S. provisional patent
application Ser. No. 60/609,939 filed Sep. 3, 2004. The
aforementioned U.S. provisional patent application is hereby
incorporated by reference in its entirety.
STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT
[0002] Not Applicable.
INCORPORATION BY REFERENCE OF MATERIAL SUBMITTED ON A COMPACT
DISC
[0003] Not Applicable.
FIELD OF THE INVENTION
[0004] The invention disclosed broadly relates to the field of
medicine, and more particularly relates to the field of pain
management.
BACKGROUND OF THE INVENTION
[0005] Pain is defined as an unpleasant sensory or emotional
experience associated with actual or potential tissue damage. It is
epidemic in our country. It is the single most common complaint
seen in healthcare. Pain-related prescriptions account for more
than one of seven medical prescriptions written each year. The
national medical costs alone exceed 100 billion dollars annually.
The overall costs are several times greater when social costs of
lost productivity, disability indemnity, legal settlements, fraud
and other issues are factored into the complex physiologic and/or
psychological pain experience. Of the categories of pain,
musculoskeletal and neuropathic pains are among the most vexing.
These pains often result from alleged injuries where the
psychosocial milieu is most intricate. In these settings, questions
of etiology, prognosis, treatment, impairment, disability,
depression, anxiety, liability, and fraud often coexist. These
issues are compounded because the pain complaint is largely
subjective and is difficult to assess in an un-biased, qualitative
and quantitative fashion.
[0006] This problem is made worse when pain becomes chronic. In
most circumstances, acute pain is self-limited and will resolve.
For example, 80% of all Americans experience low back pain at least
once during their lifetime. For the majority, these pain attacks
will improve within four weeks to the point that individuals return
to their activities (such as work). Twenty-five percent of all
lower back injuries persist for more than one month; this minority
account for 75% of all healthcare and other expenses related to low
back injuries. Each year, 3-4% of the population will be disabled
temporarily (largely due to musculoskeletal injury) and 1% of the
working-age population is permanently and totally disabled.
[0007] The problem is of great national concern. The Joint
Commission on Accreditation of Healthcare Organizations (JCAHO) has
suggested that pain is the fifth vital sign and should be monitored
as vigilantly as blood pressure, pulse, temperature and respiratory
rate. Pain, however, is often inadequately evaluated and managed by
healthcare professionals because of the complex intermix of
components that underlie the individual patient's pain experience.
Unlike the other "vital signs [that are quantifiable and unitary],"
pain complaints have been difficult to analyze in a pragmatic and
cost-effective fashion. Better methodologies are needed to address
this national epidemic.
[0008] A brief review of the more complete definition of pain
offers a starting point to the complex issues involved. According
to the International Association of Pain (IASP), pain can be
defined as "An unpleasant sensory and emotional experience
associated with actual or potential tissue damage, or described in
terms of such damage." The subsequent notations add the following
clarifications and distinctions:
[0009] "Pain is always subjective. Each individual learns the
application of the word through experiences related to injury in
early life. Biologists recognize that those stimuli which cause
pain are liable to damage tissue. Accordingly, pain is that
experience we associate with actual or potential tissue damage. It
is unquestionably a sensation in a part or parts of the body, but
it is also always unpleasant and therefore also an emotional
experience. Experiences which resemble pain but are not unpleasant,
e.g., pricking, should not be called pain. Unpleasant abnormal
experiences (dysesthesias) may also be pain but are not necessarily
so because, subjectively, they may not have the usual sensory
qualities of pain.
[0010] Many people report pain in the absence of tissue damage or
any likely pathophysiological cause; usually this happens for
psychological reasons. There is usually no way to distinguish their
experience from that due to tissue damage if we take the subjective
report. If they regard their experience as pain and if they report
it in the same ways as pain caused by tissue damage, it should be
accepted as pain. This definition avoids tying pain to the
stimulus. Activity induced in the nociceptor and nociceptive
pathways by a noxious stimulus is not pain, which is always a
psychological state, even though we may well appreciate that pain
most often has a proximate physical cause."
[0011] This definition introduces the problems underlying the
proper assessment of the pain experience. A paraphrase of the above
yields the following conceptual framework. An individual's pain
complaint is always an emotional, psychological experience related
to an unpleasant sensation in parts or parts of the body that may
occur in the presence or absence of any pathophysiologic (i.e.,
bioanatomic) cause. One must then factor into the consideration,
the known dilemmas of addiction, secondary gain, factitious
disorders and malingering. The net result is that an individual's
pain complaints can be a complex mixture of pathophysiologic
causes, emotional factors, and social components. Each of these
domains merits some further discussion.
[0012] The pathophysiologic component of the pain experience is the
usual focus of the healthcare professional. Using musculoskeletal
and peripheral neuropathic pain as the model, the standard medical
paradigm seeks to identify the sensitive (i.e., "painful") body
region or part and relieve the tissue sensitivity. This is usually
attempted using one of several approaches: (a) medications, such as
muscle relaxants, anti-inflammatory medications, analgesics,
neuropathic pain medications, and others; (b) physical modalities
(e.g., physical therapy, chiropractic care, massage, acupuncture,
or TENS unit devices); (c) peripheral nerve injections (e.g.,
anesthesiologic techniques such as nerve blocks, sympathetic
ganglia blocks, epidural injections); and (d) surgical techniques
(e.g., orthopedic or neurosurgical techniques such as joint
surgery, spinal surgery, etc.).
[0013] Each of the aforementioned medical approaches is predicated
on the notion that there is pathophysiologic tissue sensitivity as
the core element underlying the patient's voiced complaint. If the
sensitive tissue is properly identified and treated, then the pain
complaint will be largely improved. Even a cursory review of the
IASP definition of pain quickly demonstrates that the situation
cannot be naively reduced to such a singular perspective. In many
pain models, the emotional and social domains of the pain
experience have been often largely disregarded or ignored during
the traditional medical assessment and management of the patient's
complaints. The net result is that there has been a both an under-
and over-utilization of medical care because of inaccurate or
incomplete diagnoses. Two simple statements should suffice to
illustrate the point. If the major substrate for a patient's voiced
complaint lies in the domain of emotional or social etiology (e.g.,
depression, anxiety, anger, secondary gain), then physical therapy,
epidural steroid injections and low back pain will not effectively
address the symptoms. Alternatively, if a patient's enduring pain
is labeled as emotional, then the pain can go under-managed.
[0014] There are now a large number of population studies that
demonstrate that diagnostic physician errors tend to underestimate
and overestimate the psychosocial factors that impact patient's
pain complaints. For example, 27% of all patients suffering from
chronic arthritis suffer from major depression; many of these
individuals go under treated for their depression. Similar figures
exist for many other chronic musculoskeletal conditions. On the
other hand, other studies find that the majority of patient's with
chronic non-malignant pain do not receive adequate pain control
from their treating physicians. Methodologies that properly
identify and separate the pathophysiologic, emotional and social
components of an individual's pain symptoms will help identify the
appropriate approach to the subject's treatment. There will be more
accurate diagnoses and better utilization of healthcare resources
(with a reduction or cost and an improvement in outcome).
[0015] The co-morbidity of pain and emotional conditions has been
established in almost every population study where it has been
sought. For example, 27% of patients with arthritis suffer from
identifiable depressive disorders and 35% had identifiable anxiety
disorders. There has been a clear link established between
fibromyalgia and psychiatric disorders. Similar juxtapositions have
been found in failed low back syndrome, neuropathic pain syndromes
such as diabetic neuropathy, and others.
[0016] One relevant question is that of etiology: whether the
emotional disorder is caused by or causative of the pain complaint.
Population studies suggest that both situations can arise. There
are certainly cases where the family and personal history of
depressive and anxiety syndromes pre-existed the development of
pain complaints. Alternatively, there are certainly circumstances
where there has been no antecedent psychological history prior to
an identifiable pain syndrome and the subsequent development of a
psychiatric disorder. There are three major divisions of emotional
disorders that will be separated here for nosologic and analytic
purposes.
[0017] These include psychotic disorders, depressive disorders, and
anxiety disorders. They are not mutually exclusive and may
co-exist. Frank psychosis can co-exist with pain syndromes.
Fortunately, this is a relatively rare combination and will not be
discussed further. As mentioned above, anxiety disorders and pain
syndromes can be co-morbid. The anxiety syndrome may be generalized
and have no causative relationship to the specific pain syndrome,
(e.g., a patient with a generalized anxiety disorder may get into a
car accident and then suffer symptom magnification as a
manifestation of the underlying psychiatric syndrome). The anxiety
syndrome might be based on pre-existing phobias and fears that are
situationally specific (e.g., a patient with prior shoulder
problems might become excessively anxious about a new knee injury).
In both these cases, the anxiety syndrome has a primary causative
relationship to the experienced pain symptom. Alternatively, an
individual with a painful back injury may become anxious because
his job security is threatened; this would be an example of a
generalized anxiety secondary to the pain syndrome. Similar
examples can be evoked regarding the co-existence of a depressive
disorder and a pain syndrome. It also should be noted that
anxiety/depression disorders can occur together. Some patients will
have both.
[0018] The above brief outline demonstrates that the clinician
faces a difficult conundrum when confronted with a chronic pain
patient (where these interactive problems may or may not be
manifest). Methodologies that rationally and clearly identify those
individuals with significant emotional components to their pain
complex would again improve diagnostic accuracy and management. As
previously mentioned, 25% of all individuals with low back injuries
fail to return to work within one month of injury. These
individuals account for 75% of all costs associated with the
management of low back problems. Large population studies document
that there is a poor correlation between the severity of the
injury, the pain complaints, radiological findings, and the
outcome. Experience suggests that up to one-half of all these
"treatment failures" may be due to improperly diagnosed and managed
emotional factors.
[0019] Two of the social ills that taint the discipline of pain
management are substance abuse and malingering. Substance abuse can
be subdivided into two categories: social abuse and addiction.
Addiction has a specific diagnosis as "a primary, chronic
neurobiological disease, with genetic, psychosocial and
environmental factors influencing its development and
manifestations." It is characterized by behaviors that include one
or more of the following: impaired control over drug use,
compulsive use, continued use despite harm, and craving." Drug
abuse, on the other hand, is characterized by "the conscious, often
psychosocially motivated use of illicit substances and medications
outside the scope of usual medical practice, but with the ability
to stop drug use when harmed."
[0020] Allied with these are the issues of drug diversion for sale
and distribution. This problem is again epidemic in our nation. In
2002, estimates suggested that 30 million Americans used
prescription pain medications for non-medical purposes. In the same
year, 1.5 million Americans (i.e., 0.5% of the population) abused
or depended on prescription pain medications for non-medical
reasons. Extrapolating from this data, one can estimate that there
is a substantial risk that substance abusers or addicts or others
will present routinely to physicians complaining of chronic pain.
This problem will be even more complex when such individuals have
identifiable anatomic entities that are often correlated with but
are not inevitably associated with pain syndromes (e.g., herniated
spinal discs, arthritic bony changes, fibromyalgia). Some studies
suggest that up to 10% of all patients with chronic pain syndromes
demonstrate aberrant behaviors reflective of possible drug abuse.
Some of this may be due to unmanaged pain, emotional domain issues
or social issues. A key challenge for the future will be the
accurate assessment of this population of individuals.
[0021] Another social ill of our society is malingering for
secondary gain. Malingering is the feigning of disability or
symptoms in the effort to avoid one's duty or to obtain secondary
compensation. It covers a wide spectrum of misbehavior from
complete fabrication (i.e., faking an injury) to partial symptom
magnification of a known and reproducible injury. It must be
distinguished from the emotional disorders discussed above (these
can also be feigned) and true psychiatric disorders (i.e.,
factitious disorders commonly known as Munchausen's syndrome or
Munchausen's by proxy). The prevalence of malingering in our
society is unknown. It is higher in cases of pending litigation and
indemnity. Significant malingering elements may be present in
approximately 5% of all workers' compensation cases. Patient fraud
is rampant in Social Security, Medicare and Medicaid. There is an
estimated $1.6 billion dollars of Medicaid fraud perpetrated in
Florida each year. Again, methodologies that objectively identify
the existence of socially mediated pain complaints will reduce
healthcare and indemnity costs in our nation.
[0022] A final correlate of the emotional and social domains of
pain management is the domain of motivation. It is related but not
completely dependent of the other aspects of pain complaints.
Individuals can suffer pathophysiologic pain complaints and/or
emotive pain complaints; these patients however may or may not be
motivated to improve. For example, a patient with a chronic low
back pain and no emotional overlay may still not be motivated to
rehabilitate. Conversely, a patient with a severe generalized
anxiety disorder may truly wish to improve through medications and
counseling. As an aside, socially-mediated pain complaints do not
require motivation for improvement of their pain symptoms, because
by definition the pain symptoms are largely feigned; the key then
is identification. The old adage states "where there is a will,
there is a way." Conversely, one might state "where there is no
will, there is no way." Once the major domains underlying a
subject's pain symptoms can be identified, then secondary testing
can elucidate whether or not there are issues with motivation.
[0023] Although population studies have clearly identified the
scope of the problem in the assessment of chronic pain, applying
these findings to the individual patient has not been successful.
The complexities of the problem and the limitations of the
"bedside" evaluation have resulted in significant diagnostic
uncertainty and error.
[0024] The current medical paradigm for the assessment of an
individual presenting with pain symptomatology is quite imprecise.
After a clinical history, the physician attempts to verify the
pathophysiologic pain by a clinical examination. The physician
examines the patient by using an acceptable "painful stimulus"
while monitoring mostly the patient's verbal response and
associated body reactions. The stimulus is usually an unmeasured
physical input such as palpatory pressure, active or passive range
of motion, or a sensory stimulus (such as rubbing or a pin prick).
The patient's monitored response is usually verbal (e.g., "That
hurts") but may be associated with other physical manifestations
such as wincing, withdrawal, or others. There are several
limitations to this paradigm; these will be treated separately.
[0025] One limitation is the ambiguity of the patient response. The
physician is currently largely dependent on the patient's response
to the ungraded stimulus. In cases of substance abuse, addiction,
medication diversion, social secondary gain, malingering, and
factitious disorder, the patient can feign or exaggerate the
response to mislead the physician into an improper assessment as to
diagnosis or severity of the condition. This will lead to
over-prescribing of medications, diagnostic tests or other
treatment. It can lead to unfair compensation or assignment of
social disability.
[0026] Further, in patients with emotional disorders, the pain
symptoms may be tainted by an unconscious exaggeration of the
stimulus and or its consequences. Patients with anxiety will tend
to exaggerate the pathophysiologic intensity of the problem (e.g.,
the person who is afraid of the dentist will jump when the dentist
touches the teeth; this does not mean that the tooth itself is
biologically tenderer. A depressed patient may see the world in
more plaintive and melancholic overtones so that everything "hurts
more." This then can lead to inaccurate assessment of the
underlying biologic component of the pain. Conversely, the patient
with under treated pain may have a secondary anxious and depressive
presentation that leads the doctor to conclude that the problem is
primarily psychological.
[0027] Another limitation is the incomplete assessment of the
patient response. As delineated in the definition of pain, the pain
response has other components to its biological profile. These
include the autonomic and physiologic responses that go largely
unmonitored by the bedside physician. They include changes in
vascular responsiveness (e.g., pulse rate, blood pressure, and
peripheral vascular tone), skin resistance (due to sweating and
other responses as measured by Galvanic changes), and overall
muscle tone (e.g., anticipatory and reactive muscle tensing). These
responses are extremely reproducible and follow very well known
biologic principles and mechanisms. By routinely assessing the
complex pain patient with these additional measures, the physician
will be better able to grade the pain response and its components.
This will be discussed more completely below. These well known
observations will allow an expanded and more precise delineation of
the individual's voiced pain experience.
[0028] Further, the physician must rely on his observational
experience and acumen to assess all factors concerning the pain
response. These include the severity of the response, the presence
or absence of anticipatory (i.e., anxiety-related) phenomena, the
presence or absence of post-stimulus emotive responses, and patient
forthrightness. By monitoring and recording the autonomic and
physiologic parameters just introduced, the physician will be
better able to assess the three major domains of the patient pain
profile.
[0029] Another limitation is the imprecision of the evocative
stimulus. The clinician generally uses non-measured stimuli to
create his observations. They are usually applied once and
therefore do not guarantee reproducibility and accuracy. If the
physician palpates the sore knee once, the patient complains and
the physician infers. This leads to a great deal of imprecision in
the inferences drawn. If a measured stimulus is applied
repetitively in a systematic fashion and then combined with precise
and comprehensive monitoring, then improved diagnostic accuracy
will result.
[0030] The diagnostic uncertainty and error concerning the
individual with pain complaints results in the current quagmire
that confronts the medical community and society in general when
dealing with this epidemic problem. The current quagmire that
confronts the medical community and society in general when dealing
with this epidemic problem.
[0031] Therefore, a need exists to overcome the problems with the
prior art as discussed above, and particularly for a more efficient
way of evaluating pain in humans.
SUMMARY OF THE INVENTION
[0032] Briefly, according to an embodiment of the present
invention, a method for evaluating pain experienced by a human is
disclosed. The method includes applying a first noxious stimulus to
a normative site on the human, wherein the first noxious stimulus
is applied below a pain threshold of the human and logging a first
information associated with the first noxious stimulus. The method
further includes applying a second noxious stimulus to a source of
the pain in the human, wherein the second noxious stimulus is
applied until pain threshold is reached and logging a second
information associated with the second noxious stimulus. The method
further includes increasing the second noxious stimulus until pain
tolerance is reached and logging a third information associated
with the second noxious stimulus. The method further includes
continuing to apply the second noxious stimulus until the human can
no longer tolerate the second noxious stimulus and logging a fourth
information associated with the second noxious stimulus.
[0033] In another embodiment of the present invention, a system for
evaluating pain experienced by a human is disclosed. The system
includes a measuring apparatus for measuring information associated
with a first and second noxious stimulus applied to a human,
wherein the first noxious stimulus is applied to a normative site
on the human below a pain threshold of the human, the second
noxious stimulus is applied to a source of the pain in the human
until pain threshold is reached, the second noxious stimulus is
applied until pain tolerance is reached and the second noxious
stimulus is applied until the human can no longer tolerate the
noxious stimulus. The system further includes a data storage device
for storing a first information from the measuring apparatus when
the first noxious stimulus is applied below a pain threshold,
storing a second information from the measuring apparatus when the
second noxious stimulus is applied at pain threshold, storing a
third information from the measuring apparatus when the second
noxious stimulus is applied at pain tolerance, and storing a fourth
information from the measuring apparatus when the human can no
longer tolerate the second noxious stimulus.
[0034] In another embodiment of the present invention, an
information processing system for evaluating pain experienced by a
human is disclosed. The information processing system includes a
receiver for receiving a first information from a measuring
apparatus for measuring information associated with a first and
second noxious stimulus applied to a human, wherein the first
noxious stimulus is applied to a normative site on the human below
a pain threshold of the human, receiving a second information from
the measuring apparatus when the second noxious stimulus is applied
to a source of the pain in the human at pain threshold, receiving a
third information from the measuring apparatus when the second
noxious stimulus is applied at pain tolerance, and receiving a
fourth information from the measuring apparatus when the human can
no longer tolerate the second noxious stimulus. The information
processing system further includes a data storage device for
storing the first information, the second information, the third
information and the fourth information. The information processing
system further includes a processor configured for determining
whether the pain experienced by the human originates from
biological, social or psychological factors, based on the first
information, the second information, the third information and the
fourth information.
[0035] The foregoing and other features and advantages of the
present invention will be apparent from the following more
particular description of the preferred embodiments of the
invention, as illustrated in the accompanying drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The subject matter, which is regarded as the invention, is
particularly pointed out and distinctly claimed in the claims at
the conclusion of the specification. The foregoing and other
features and also the advantages of the invention will be apparent
from the following detailed description taken in conjunction with
the accompanying drawings. Additionally, the left-most digit of a
reference number identifies the drawing in which the reference
number first appears.
[0037] FIG. 1 is a block diagram generally showing the elements
that are utilized to perform one embodiment of the present
invention.
[0038] FIG. 2 is a flowchart showing the overall control flow of
one embodiment of the present invention.
[0039] FIG. 3 is a flowchart showing the control flow of the data
acquisition process of one embodiment of the present invention.
[0040] FIG. 4 is an information processing system useful for
implementing one embodiment of the present invention.
[0041] FIG. 5 is an exemplary chart that can be used to log
information garnered from measurement apparatus, in one embodiment
of the present invention.
DETAILED DESCRIPTION
[0042] According to an embodiment of the present invention, a
method for evaluating the human pain experience is disclosed. The
method combines at lest five elements: (1) a pre-test history and
physical exam (2) the precise application of quantifiable sensory
stimuli (pressure stimuli, active or passive range of motion
stimuli, or the cutaneous sensory stimuli in the form of electrical
current) to the patient; (3) the application of these stimuli to
specific patient-controlled levels of response (i.e., pain
threshold, or pain tolerance levels as defined by the IASP); (4)
the simultaneous recording of the patient's verbal response and
non-verbal body reactions: and (5) the use of the patient as his or
her own control by comparing the "baseline/normative" response
taken at an asymptomatic site versus the specific "painful/test"
site. One embodiment of the present invention (a) precisely
monitors in individuals the temporal and quantifiable relationships
of sensory stimuli with simultaneous verbal and non-verbal patient
responses at internationally recognized pain stimulus levels; and
(b) compares this precision data from body site to body site. This
accuracy yields information about an individual's pain experience
and its components.
[0043] With regard to the history and physical exam, a specific
history and physical data base allows for the standardization of
diagnoses, electrode placements, and the various historical
elements that may influence the testing procedure. By combining
this history and physical information with test results
(specifically on the baseline/normative data), a database on the
variations in human pain experience with gender, age, cultural and
sociologic influence can be created. This database can be used in
the elaboration of more accurate and statistical typing of a new
patient's response for more complete and particular diagnoses.
[0044] With regard to recording techniques, recording electrodes
can be applied to the test subject in specified locations to
maximize information yield. Surface electromyographic activity can
be measured at four sites. Two sites are general and monitor the
subject's overall muscle tension in response to the physical
stressor. Two sites are stimulus specific (i.e., close to the
applied stimulus) to evaluate elements of voluntary or involuntary
guarding that are site specific (i.e., anxiety or feigned
responses). Autonomically-mediated galvanic skin responses can be
measured in the form of skin conductance responses and skin
conductance latencies. Autonomically-mediated vasomotor responses
can be monitored in the form of heart rate, skin temperature, and
pulse height (using plethysmography). These measures are
continuously monitored during a definite test stimulation protocol
to analyze the temporal and quantitative changes from baseline in
response to the exactly applied stimulation.
[0045] With regard to stimulation techniques, exact sensory stimuli
can be first applied to a normative, "pain-free" site to
pre-defined, internationally recognized levels (see below for
detailed explanation). Any one of four sensory stimuli can be
applied: (1) pressure--using standardized algometry equipment,
precise palpation pressure can be applied to a particular body
site; (2) passive range of motion--using an inclinometer, a precise
passive or active range of motion can be measured to a specific
articulation. (3) sensory stimulus--using a biometric electrical
signal generator, a precise superficial sensory stimulus can be
applied; and (4) active resistance--using a pressure gage, the
amount of force required to induce a level of pain experience (be
that threshold or tolerance levels) can be assessed. The choice of
stimulation technique will be dependent on the patient's
presentation and diagnosed pain syndrome. Multiple different
stimuli and sites can be evaluated in a single individual dependent
on the clinical picture. The history and physical examination form
the foundation for the protocol determination.
[0046] With regard to the use of international standards and a
specific protocol, most pain evaluations use only the patient's
evaluation of the overall experience in a unimodal intensity scale
(e.g., a visual analog scale of the pain experience severity). One
embodiment of the present invention uses IASP defined levels of the
pain experience (specifically, pain threshold and pain tolerance
levels). These levels are less variable and avoid some of the
inherent ambiguities of the linear pain scales. The protocols also
repeat each stimulus three times at a given site and then take an
average. This allows for the assessment of consistency and
inconsistency of the response according to known statistical values
of variance. The use of a specific temporal protocol allows
accurate determinations regarding anticipatory responses,
post-response exaggeration, and other temporal relations between
the pain stimuli and the verbal/non-verbal responses.
[0047] One embodiment of the present invention allows the patient
to be their own control. The sensory stimulus is first applied to a
normative, non-painful body site. This first site data sets a
patient-specific baseline that can then be compared to responses in
painful test sites. The use of a patient specific control site
mitigates multiple potential factors such as gender, age,
medications, race, and others. It simplifies the initial
statistical analysis. It also duplicates bedside clinical paradigms
whereby physicians often compare patient responses from one body
region to another.
[0048] The present invention provides an algorithm for the
assessment of an individual subject's pain symptoms. The algorithm
juxtaposes measured evocative stimuli, the patient's voiced pain
response, and measurable autonomic and physiologic responses. These
assessments are performed according to protocols to maximize
reproducibility and diagnostic precision. The algorithm allows the
clinician reader to objectively, accurately, and impartially assess
the underlying components of the pain complaints in terms of its
pathophysiologic, emotional and social domains. The present
invention comprises three test components: the voiced pain
response, the measurable autonomic and physiologic responses, and
the measured evocative stimuli.
[0049] With regards to the patient's voiced pain response, the IASP
defines two different types of standard patient subjective pain
complaints; specifically, the pain threshold and the pain tolerance
level. The algorithm of the present invention identifies a third
patient subjective complaint--the endurance for pain tolerance. A
pain threshold (PTh) is the least experience of pain which a
subject can recognize. A pain tolerance level (PToL) is the
greatest level of pain which a subject is prepared to tolerate. The
endurance of pain tolerance (EPT) is the length of time a subject
is prepared to endure the PToL.
[0050] The IASP emphasizes that each of these levels document the
totality of the patient's personal subjective experience. They are
determined by a mixture of the pathophysiologic domain and
emotional domain as defined previously. The IASP does not
specifically discuss the social domain that taints many clinical
assessments. These established definitions are useful in
establishing standard degrees for the patient's verbal response.
PTh instructions may be: "Indicate when the stimulus intensity
first begins to feel `painful."` PToL instructions may be: "Tell me
when the intensity becomes unbearable." EPT instructions may be:
"Tell me when to stop." Each of these levels is reasonably
reproducible and identifiable. The instructions form the basis on
which other aspects of the algorithm can be accurately measured. In
each embodiment of the present invention, one of these verifiable
subjective pain report levels will provide the basis of the overall
evaluation.
[0051] The term "noxious stimulus" applies to the level of
stimulation that threatens or causes tissue damage. It is often
confused with the above subjective experiences but it is actually
very different. Consider the patient under general anesthesia, a
researcher could still accurately establish the level of a noxious
stimulus (i.e., heat stimulation causes a tissue to injure); the
subjective experience and levels would not apply.
[0052] With regards to the measurable autonomic and physiologic
responses, when the body is subject to a new physical or emotional
stressor, there is inevitably a response. This has been called "the
fight or flight response." It is largely involuntary and mostly
mediated by the autonomic (parasympathetic and sympathetic) system.
There is also a largely involuntary muscle tension response that is
more directly mediated by the somatic nervous system. Over a short
time epoch (seconds to minutes), the response will persist as long
as the stressful stimulus continues. These autonomic and muscle
tension responses are ubiquitous in humans. They form the basis for
biofeedback relaxation training and have been applied
therapeutically in medico-psychological fields for several decades.
There are myriad of such reactions like the vascular responses
(pulse rate, blood pressure, pulse height and others), galvanic
skin responses (skin conductance response, skin conductance
latency), surface electromyography (EMG) recordings, pupillary
responses, piloerection reactions and others.
[0053] Despite decades of utilization of autonomic physiology in
therapeutic venues, this physiology has not been applied to the
diagnostic side of medicine. In the present invention, this
physiology's application to the evaluation of pain symptoms leads
to a paradigm shift and resolves the limitations of the previously
described response ambiguities. Because the autonomic and somatic
neurologic system reacts to perceived (i.e., emotional) stressors
as well as to actual physical stimulation, careful monitoring
autonomic and EMG reactivity allows the observer to unequivocally
identify the emotional domain associated with the pain experience.
For example, one can apply these principles to the pain threshold
stimuli. When pain threshold amounts of stimuli are applied,
pre-stimulation increases in autonomic and EMG activity reflect
anticipatory depression or anxiety-related phenomena.
Post-stimulation increments these parameters indicate pain-related
anxiety or depressive responses that augment the patient's pain
reaction.
[0054] With regards to the measured "painful" stimulation
technique, the innovative and original testing paradigm utilizes
graded measurable stimuli for four major clinical
stimuli--palpatory pressure (known as algometry or dolorimetry),
range of motion (called goniometry or inclinometry), topical
sensory stimulation (e.g., an electrical current), and force
resistance. Each of these inputs is selective for different
pathophysiologic phenomena. Palpation is often applied for
myofascial type pain syndromes (such as fibromyalgia). Range of
motion is helpful in articular pain syndromes. Electrical current
can be very useful in many neuropathic pain syndromes, especially
those characterized by hyperesthesia, allodynia, and hyperpathia.
Finally, force-related pain can be valuable in any of the above,
and as a graded measure of the motivational aspects associated with
pain syndromes. Each of these stimulation techniques can be applied
in a quantified and reproducible fashion to maximize diagnostic
information. In an embodiment of the present invention, each of
these stimuli is specifically chosen to match the individual
subject's pain syndrome.
[0055] With regards to the integration of the diagnostic components
in a diagnostic algorithm, the embodiment of the present invention
integrates all three testing features into patient specific testing
algorithms. The present invention combines the patient's subjective
pain response with a precise measured stimulus and a
comprehensively monitored physiologic response profile. Each
patient subject acts as his own control. One critical aspect of the
test paradigm is that the chosen painful stimulus is first applied
to a non-painful "normative" test site. The choice of the neutral
site allows the testing algorithm to create a patient-specific
"pain experience" baseline. Thus, this step therefore mitigates
consideration of many pre-existing substrates of an individual's
pain experience (genetics, cultural heritage, and many learned
behaviors). These chronic features have often been evinced as
grounds to confound the correct assessment of the patient's pain
symptomatology. After obtaining the baseline response, attention is
then directed to the patient's painful body region. The stimulation
is then repeated in the same fashion. This changes in stimulus
intensity to reach a given verbalized pain level (be it PTh, PToL,
and EPT) can be documented. Different autonomic and physiologic
response levels and profiles can be documented.
[0056] FIG. 1 is a block diagram generally showing the elements
that are utilized to perform one embodiment of the present
invention. FIG. 1 shows the patient 102 and the physician or
medical worker 104 evaluating the patient 102. The physician
applies various stimuli to the patient 102 during the evaluation
process. The noxious stimuli applied to the patient can include
moving a portion of the human, moving a limb of the human about a
joint, applying pressure to a portion of the human, applying an
electrical pulse to a portion of the human; and allowing the human
to push or pull with force using a portion of the human. Also shown
are various apparatus used to measure the stimuli applied to the
patient 102.
[0057] There are multiple commercially available devices that
measure clinical stimuli used to supplement the clinician's bedside
evaluation. These devices can measure and apply pressure (called
algometry or dolorimetry) and measure range of motion (called
goniometry or inclinometry). Further, there are devices that can
provide graded "painful" sensory stimuli (usually safe amounts of
electrical current).
[0058] Equipment, such as a vasomotor or electrodermal apparatus
120, can be used to monitor autonomic physiologic functions
including pulse rate, blood pressure, skin temperature, skin
conductance level, and skin conductance response. The apparatus 120
also can measure surface electromyography (EMG) activity at two
locations. An inclinometer 114 (or goniometer) measures the incline
or degree of motion of a limb or portion of the patient 102, an
algometer 116 measures the amount of pressure applied to the
patient 102 and an electrode 118 measures the amount of electricity
applied to the patient. Thus, the present invention can accurately
monitor the existence and magnitude of various physiologic
responses of involuntary and voluntary type. This capability allows
more precise characterization of the subject's pain experience as
discussed below.
[0059] FIG. 1 also shows a computer 122 for analyzing the
measurement data garnered from the measuring equipment 114, 116,
118, 120 and determining whether the pain experienced by the human
originates from biological, social or psychological factors, based
on the information garnered. Also shown is a computer display 124
for displaying these results.
[0060] In an embodiment of the present invention, the computer
system of computer 122 is one or more Personal Computers (PCs)
(e.g., IBM or compatible PC workstations running the Microsoft
Windows operating system, Macintosh computers running the Mac OS
operating system, or equivalent), Personal Digital Assistants
(PDAs), hand held computers, palm top computers, smart phones, game
consoles or any other information processing devices. In another
embodiment, the computer system of computer 122 is a server system
(e.g., SUN Ultra workstations running the SunOS operating system or
IBM RS/6000 workstations and servers running the AIX operating
system). An example of a computer 122 is explained in greater
detail below with reference to FIG. 4.
[0061] In an embodiment of the present invention, the computer 122
is connected to a circuit switched network, such as the Public
Service Telephone Network (PSTN). In another embodiment, the
network is a packet switched network. The packet switched network
is a wide area network (WAN), such as the global Internet, a
private WAN, a local area network (LAN), a telecommunications
network or any combination of the above-mentioned networks. In yet
another embodiment, the network is a wired network, a wireless
network, a broadcast network or a point-to-point network.
[0062] The present invention measures pain thresholds using, for
example, pressure, tissue stretch, and electrical noxious stimuli.
The present invention first tests non-injured, asymptomatic areas,
then tests the specific regions of disabling pain complaints, and
finally compares the responses. The test results therefore first
establish the subject's nonspecific pain threshold and pain
tolerance levels. The present invention mitigates the role of the
individual's nonspecific psychosocial background. This allows the
clinician to focus on the specific psychobiological components
underlying the specific disabling pain complaints. A few examples
below elaborate this point.
[0063] In a first example, an individual's general state of anxiety
or depression will modify the pain threshold for all body regions
and not specific to the injured area. Take the case of a patient
with a pre-existing major depression and a newer chronic low back
pain. The patient may complain significantly of the low back pain
with clinical findings of restricted flexion and tender palpation
(via the well-known psychological mechanism of somatization). The
results garnered from the present invention show similar pain
thresholds, tolerance levels, and autonomic responses in the
non-injured and low back regions. Thus, the psychobiologic
responses in both regions are similar to the putative noxious
stimuli. The conclusions are: (a) the low back tissues are not
seriously dysfunctional; (b) the patient does not have a secondary
anxiety due to severe localized tissue pain; (c) the underlying
cause of the pain experience is psychiatric in origin.
[0064] In a second example, a patient's adjustment disorder will
modify results specific to the injured regions. A patient with a
low back injury develops unremitting pain with a secondary
adjustment anxiety disorder. The results garnered from the present
invention show that autonomic responses occur early during stimulus
initiation, even before the patient voices pain commencement. The
local pain threshold and tolerance is approximately the same or
mildly reduced, but the voiced complaints and the autonomic
responses are magnified. The anticipatory and augmented autonomic
changes create inescapable inferences: (a) the subject anticipates
and magnifies the noxious stimulus on a psychobiological level; and
(b) the subject's tissues are not overtly tender from the noxious
stimulus per se.
[0065] In a third example, a patient with chronic pain may have
biologically damaged tissue unidentified by current diagnostic
testing. A patient complains of intermittent but persistent low
back pain radiating down the right leg for two months after a
slip-and-fall injury. A Magnetic Resonance Image (MRI) of the back
is fairly unremarkable except for mild, commonly seen arthritic
changes. An EMG/nerve conduction study (NCS) shows mild chronic
denervation in the right L5/S1 myotomes. Clinical exam shows
guarding behavior, limping with positive straight leg raising but a
normal neurologic examination. The results garnered from the
present invention show that there are autonomic changes without
anticipation, decreased pain threshold and tolerance levels upon
right (but not left) straight leg raising and electrical noxious
stimuli. The inferences are that the patient has a significant
peripheral neurogenic pain syndrome despite unremarkable diagnostic
testing.
[0066] The present invention includes clinical modules for
exercising the method of the present invention for the major
subtypes of conditions that are anticipated. Modules exist for each
of the following conditions: (a) general post-traumatic complaints;
(b) myofascial traumatic and non-traumatic conditions; (c)
arthritic traumatic and non-traumatic conditions; (d) neuropathic
traumatic and non-traumatic conditions and (e) voluntary or
involuntary muscle guarding. By using separate modules, there is
flexibility in meeting almost all clinical situations
presented.
[0067] The present invention further includes four major testing
protocols to match each of the major clinical modules. From a
teleologic perspective, the body is most concerned with the
resultant biologic nature of the injuries, i.e., multiple
non-specific traumatic mechanisms, predominantly arthritic (focal
or multi-focal), predominantly myofascial, etc. The testing
protocols are moved from site-to-site and format-to-format as
required by the clinical specificity and diversity. Each testing
protocol is comprised of one or more of five basic testing
paradigms: 1) joint pain (more precisely, range of motion noxious
response), 2) myofascial pain (more precisely, palpatory pressure
noxious response), 3) neuropathic pain (electrical stimulation
response), 4) force output noxious stimuli, and 5) muscle guarding
protocols.
[0068] FIG. 2 is a flowchart showing the overall control flow of
one embodiment of the present invention. The control flow of FIG. 2
begins with step 202 and moves immediately to step 204. In step
204, noxious stimuli are applied to the patient 102 by the
physician 104 and the measurements are taken. This step is
discussed in greater detail with reference to FIG. 3 below. In step
206, the measurement data garnered from the measuring equipment
114, 116, 118, 120 is analyzed (by, for example, a computer 122)
and it is determined whether the pain experienced by the human
originates from biological, social or psychological factors, based
on the information garnered. In step 208, the results of the
determination are presented to the patient 102, the physician 104
or both via, for example, a computer display 124 for displaying
these results. In step 210, based on the results of step 208, the
physician 104 makes recommendations to the patient 102 regarding
treatment of the pain.
[0069] For the noxious stimulus types, pain threshold, pain
tolerance, and maintenance of pain tolerance are measured. In an
embodiment of the present invention, these measurements are
performed according to the following: 1) initial baseline
(approximately one minute), 2) stimulus to pain threshold (five
seconds), 3) stimulus to pain tolerance (five seconds), 4)
maintenance of pain tolerance (five seconds) and 5) rest period
(lasting 30 seconds or more, if needed). Thus, a stimulation cycle
will last approximately 45 seconds. During the first 10 seconds,
there is a relatively quick ramp of increasing noxious stimulation
with monitoring of the patient's voiced response (according to
established principles). The epoch between 10 and 15 seconds, the
patient is asked to maintain his tolerated painful experience. Then
the patient rests with no stimulus. For each type of noxious
stimulation and site, this cycle is repeated three times. The
purpose of the repetition is establishing reproducibility and
patient reliability. In one embodiment of the present invention,
the patient hold a "clicker" device that is clicked to indicate
when he or she achieves the three designated outcomes, i.e., pain
threshold, pain tolerance and termination.
[0070] In another embodiment of the present invention, for each
type of stimulation, the test protocol includes the selection of a
normative, unaffected site on the patient's body followed by the
test, affected site. For example, in an individual with right
shoulder pain, the test protocol would first be performed on the
normative, unaffected left shoulder to establish a patient-specific
response normative baseline. The second part of the test repeats
the same stimulations on the affected right shoulder to assess
differences in autonomic and verbal response.
[0071] Range of motion stimuli is performed using a hand-held
inclinometer 114. For hinge joints, there is only one plane of
motion so the choice of direction is obvious. For rotational or
multiple joint regions (i.e., shoulders, hips and spine), the
clinician/technician can use two planes of motion that are most
applicable to a patient's specific joint/range of motion complaint.
Algometry is performed using a hand held algometer 116 that can be
connected to a computer 122. Electrical stimulation is performed
using an electrode 118 that can also be connected to a computer
122.
[0072] Force testing/joint compression stimulation is used to
establish effort and establish non-specific internal compression
forces. A hand held force gauge (such as an algometer) can be used
and the patient is asked to contract their muscles in a given plane
of motion (i.e., initiating active range of motion) isometrically.
The force output is measured in comparison to the three outcomes of
pain threshold, tolerance and termination.
[0073] Muscle guarding of an involuntary and voluntary type are
very common in musculoskeletal pains. By reviewing EMG readings of
the patient 102, the onset of muscle activity in response to
passive range of motion or algometry stimuli can be assessed. The
onset of this activity is compared with the onset of autonomic
responses to assess whether the muscle activity precedes or follows
our various monitored responses. This assessment is used to
evaluate voluntary versus involuntary guarding.
[0074] FIG. 3 is a flowchart showing the control flow of the data
acquisition process of one embodiment of the present invention. The
flow chart of FIG. 3 provides more detail on step 204 of FIG. 2.
The control flow of FIG. 3 begins with step 302 and moves
immediately to step 304. In step 304, a first noxious stimulus is
applied to a normative site on the human, wherein the first noxious
stimulus is applied below a pain threshold of the human. In step
306, a first information associated with the first noxious stimulus
is recorded. In step 308, a second noxious stimulus is applied to a
source of the pain in the human, wherein the second noxious
stimulus is applied until pain threshold is reached.
[0075] In step 310, a second information associated with the second
noxious stimulus is recorded. In step 312, the second noxious
stimulus is increased until pain tolerance is reached. In step 314,
a third information associated with the second noxious stimulus is
recorded. In step 316, the second noxious stimulus continues to be
applied until the human can no longer tolerate the second noxious
stimulus. In step 318, a fourth information associated with the
second noxious stimulus is recorded. In step 320, steps 302-318 are
repeated once more until three cycles are completed.
[0076] In one embodiment of the present invention, the first
information, the second information, the third information and the
fourth information each comprise at least one of an angle of a
portion or a limb of the human, an amount of pressure applied to a
portion of the human, an amount of electricity applied to a portion
of the human and an amount of pressure applied by a portion of the
human. Therefore, the first information, the second information,
the third information and the fourth information each comprise at
least one of a degree or radian value, a first
pounds-per-square-inch value, an amperage and/or voltage value and
a second pounds-per-square-inch value.
[0077] FIG. 5 is an exemplary chart that can be used to log
information garnered from measurement apparatus, in one embodiment
of the present invention. The chart of FIG. 5 is used to log three
trials of data automatically. Averages can be calculated, and
standard deviation for inter-site comparisons can be figured. Also
intra-trial trends can be seen for accommodation/anticipation and
coefficients of variations for reliability. Subsequent use of other
statistics (Student T-test, Chi-square's, etc.) can be applied to
characterize the patient's autonomic response type, whether the
inter-site variance is significant.
[0078] FIG. 5 includes four separate charts, 502, 504, 506 and 508.
Each of the charts 502, 504 and 506 represent are used to input
data from each of three trials conducted in accordance with the
control flow of FIG. 3. The last chart 508 is used to average the
data in the first three charts. Thus, the data entered into the
cells of chart 508 are not directly from the readings taken but
rather are averages that are garnered from the data in the first
three trials, i.e., from the data in charts 502, 504, 506.
[0079] It is shown that each chart includes five rows for entering
data. The first row in each chart, row 511, 521, 531 and 541 is
used to enter data associated with the baseline reading. The second
row in each chart, row 512, 522, 532 and 542 is used to enter data
associated with the pain threshold reading. The third row in each
chart, row 513, 523, 533 and 543 is used to enter data associated
with the pain tolerance reading. The fourth row in each chart, row
514, 524, 534 and 544 is used to enter data associated with the
pain termination reading. The fifth row in each chart, row 515,
525, 535 and 545 is used to enter data associated with a reading
during a 25 second rest period.
[0080] It is further shown that each chart includes eight columns
for entering data. The first column in each chart, column 551, is
used to enter the amount of time associated with each of the pain
threshold, pain tolerance and pain termination readings. The second
column in each chart, column 552, is used to enter the angle
associated with each of the pain threshold, pain tolerance and pain
termination readings. The third column in each chart, column 553,
is used to enter a first electromyography (EMG) reading associated
with each of the baseline, pain threshold, pain tolerance, pain
termination and rest readings. The fourth column in each chart,
column 554, is used to enter a second EMG reading associated with
each of the baseline, pain threshold, pain tolerance, pain
termination and rest readings. It should be noted that the data
entered into the cells of chart 508 are not directly from the
readings taken but rather are averages that are garnered from the
data in the first three trials, i.e., from the data in charts 502,
504, 506.
[0081] The fifth column in each chart, column 555, is used to enter
a skin conductive response (SCR) reading associated with each of
the baseline, pain threshold, pain tolerance, pain termination and
rest readings. The sixth column in each chart, column 556, is used
to enter a skin conductive latency (SCL) reading associated with
each of the baseline, pain threshold, pain tolerance, pain
termination and rest readings. The seventh column in each chart,
column 557, is used to enter a pulse reading associated with each
of the baseline, pain threshold, pain tolerance, pain termination
and rest readings. The eighth column in each chart, column 558, is
used to enter a pulse pressure reading associated with each of the
baseline, pain threshold, pain tolerance, pain termination and rest
readings.
[0082] Various aspects of the present invention, such as the
determination process of step 206 of FIG. 2, can be realized in
hardware, software, or a combination of hardware and software. A
system according to a preferred embodiment of the present
invention, such as the system of FIG. 1, can be realized in a
centralized fashion in one computer system, or in a distributed
fashion where different elements are spread across several
interconnected computer systems. Any kind of computer system--or
other apparatus adapted for carrying out the methods described
herein--is suited. A typical combination of hardware and software
could be a general-purpose computer system with a computer program
that, when being loaded and executed, controls the computer system
such that it carries out the methods described herein.
[0083] Various aspects of an embodiment of the present invention
can also be embedded in a computer program product, which comprises
all the features enabling the implementation of the methods
described herein, and which--when loaded in a computer system--is
able to carry out these methods. Computer program means or computer
program in the present context mean any expression, in any
language, code or notation, of a set of instructions intended to
cause a system having an information processing capability to
perform a particular function either directly or after either or
both of the following: a) conversion to another language, code or,
notation; and b) reproduction in a different material form.
[0084] A computer system may include, inter alia, one or more
computers and at least a computer readable medium, allowing a
computer system, to read data, instructions, messages or message
packets, and other computer readable information from the computer
readable medium. The computer readable medium may include
non-volatile memory, such as ROM, Flash memory, Disk drive memory,
CD-ROM, and other permanent storage. Additionally, a computer
readable medium may include, for example, volatile storage such as
RAM, buffers, cache memory, and network circuits. Furthermore, the
computer readable medium may comprise computer readable information
in a transitory state medium such as a network link and/or a
network interface, including a wired network or a wireless network,
that allow a computer system to read such computer readable
information.
[0085] FIG. 4 is a high level block diagram showing an information
processing system useful for implementing one embodiment of the
present invention. The computer system includes one or more
processors, such as processor 404. The processor 404 is connected
to a communication infrastructure 402 (e.g., a communications bus,
cross-over bar, or network). Various software embodiments are
described in terms of this exemplary computer system. After reading
this description, it will become apparent to a person of ordinary
skill in the relevant art(s) how to implement the invention using
other computer systems and/or computer architectures.
[0086] The computer system can include a display interface 408 that
forwards graphics, text, and other data from the communication
infrastructure 402 (or from a frame buffer not shown) for display
on the display unit 410. The computer system also includes a main
memory 406, preferably random access memory (RAM), and may also
include a secondary memory 412. The secondary memory 412 may
include, for example, a hard disk drive 414 and/or a removable
storage drive 416, representing a floppy disk drive, a magnetic
tape drive, an optical disk drive, etc. The removable storage drive
416 reads from and/or writes to a removable storage unit 418 in a
manner well known to those having ordinary skill in the art.
Removable storage unit 418, represents a floppy disk, a compact
disc, magnetic tape, optical disk, etc. which is read by and
written to by removable storage drive 416. As will be appreciated,
the removable storage unit 418 includes a computer readable medium
having stored therein computer software and/or data.
[0087] In alternative embodiments, the secondary memory 412 may
include other similar means for allowing computer programs or other
instructions to be loaded into the computer system. Such means may
include, for example, a removable storage unit 422 and an interface
420. Examples of such may include a program cartridge and cartridge
interface (such as that found in video game devices), a removable
memory chip (such as an EPROM, or PROM) and associated socket, and
other removable storage units 422 and interfaces 420 which allow
software and data to be transferred from the removable storage unit
422 to the computer system.
[0088] The computer system may also include a communications
interface 424. Communications interface 424 allows software and
data to be transferred between the computer system and external
devices. Examples of communications interface 424 may include a
modem, a network interface (such as an Ethernet card), a
communications port, a PCMCIA slot and card, etc. Software and data
transferred via communications interface 424 are in the form of
signals which may be, for example, electronic, electromagnetic,
optical, or other signals capable of being received by
communications interface 424. These signals are provided to
communications interface 424 via a communications path (i.e.,
channel) 426. This channel 426 carries signals and may be
implemented using wire or cable, fiber optics, a phone line, a
cellular phone link, an RF link, and/or other communications
channels.
[0089] In this document, the terms "computer program medium,"
"computer usable medium," and "computer readable medium" are used
to generally refer to media such as main memory 406 and secondary
memory 412, removable storage drive 416, a hard disk installed in
hard disk drive 414, and signals. These computer program products
are means for providing software to the computer system. The
computer readable medium allows the computer system to read data,
instructions, messages or message packets, and other computer
readable information from the computer readable medium.
[0090] Computer programs (also called computer control logic) are
stored in main memory 406 and/or secondary memory 412. Computer
programs may also be received via communications interface 424.
Such computer programs, when executed, enable the computer system
to perform the features of the present invention as discussed
herein. In particular, the computer programs, when executed, enable
the processor 404 to perform the features of the computer system.
Accordingly, such computer programs represent controllers of the
computer system.
[0091] What has been shown and discussed is a highly-simplified
depiction of a programmable computer apparatus. Those skilled in
the art will appreciate that other low-level components and
connections are required in any practical application of a computer
apparatus.
[0092] Although specific embodiments of the invention have been
disclosed, those having ordinary skill in the art will understand
that changes can be made to the specific embodiments without
departing from the spirit and scope of the invention. The scope of
the invention is not to be restricted, therefore, to the specific
embodiments. Furthermore, it is intended that the appended claims
cover any and all such applications, modifications, and embodiments
within the scope of the present invention.
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