RU2774207C1 - Method for research and objective registration of pain syndrome - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: invention relates to medicine, namely to a method for registering a pain syndrome. At the same time, local electrophysical parameters of biological tissues with such pain syndromes as bruises, bruises, sprains, pain in the foot due to flat feet, pain after surgery, pain associated with scoliosis, and pain of the musculoskeletal system of unclear etiology are analyzed. A matrix of nine damped electrical oscillations is registered at nine points, caused by an electrical damped pulse in the pain zone and its surrounding areas. The pulse is characterized by such parameters as duration from 30 to 100 mcs and amplitude from 12 to 20 V. Then the maximum deviation of the abscissas of the first peaks of the graphs from each other is determined and, based on the obtained values, a conclusion is made about the presence and magnitude of the pain syndrome.

EFFECT: accuracy of determining the intensity of the pain syndrome increases with the possibility of clarifying its localization and gradation in magnitude and, as a result, the quality of diagnostics increases in an objective way, in contrast to methods based on questioning or testing the patient and assessing the severity of pain on scales and tables that depend on answers subject and, accordingly, are subjective.

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Description

The invention relates to the field of biophysics, in particular to medical diagnostics, and can be used to determine the presence, magnitude and track the dynamics of pain.

Assessment of the pain syndrome is necessary for the correct medical diagnosis of pathologies and their dynamics. Medical diagnostics in the context of technological progress makes it possible to assess the condition of patients in time and alleviate, cure, and sometimes even prevent the development of the disease. At the moment, there is no convenient and economical way to objectively record the pain syndrome, capable of verifying, localizing and objectively measuring the magnitude of pain.

At the moment, most of the methods for analyzing and recording an already developing pain syndrome are subjective and are questionnaires and scales: a visual analogue scale, a digital rating scale [Breivik H., Borchgrevink C., Allen S.M. et al. Assessment of pain // Br. J. Anaesth. (2008) 101(1). - R. 17-24.].

A known method for assessing pain (patent RU 2251388). The patient is tested on seven scales: frequency, duration, intensity, sensory perception of pain, emotional attitude to pain, level of neuroticism, level of adaptability, and the results are evaluated on the listed scales from 0 to 6 points. At the same time, the scales of sensory perception and emotional attitudes, levels of neuroticism and adaptability are evaluated in accordance with the tables given in the description. Additionally, the severity of the psychogenic component of pain is assessed according to the color choice by the patient depending on at least three choices of the intensity of his pain: “pain at the time of testing”, “no pain”, “severe pain” in accordance with the tables given in the description. After that, according to the test results, the severity of the patient's pain sensations is assessed qualitatively and quantitatively. At the same time, on a scale of frequency, the appearance of pain is assessed from “pain occurs once every few days or less” to “pain is constant”. On a scale of duration, pain is rated from “pain is fleeting” to “pain is constant”. The pain intensity scale ranges from “very mild pain” to “unbearable pain”. According to the neurotization level scale, the main behavioral factors are taken into account - anxiety, emotional lability, aggression, depression, psychogeny, hypochondria.

The disadvantage of this method is the subjective component, and therefore there is the possibility of falsifying the magnitude and nature of pain, associated both with intent and with the patient's personal experience.

Objective is the analysis of thalamic pain activity using neural network processing of MRI data, as well as analysis of blood serum (Method for recording the intensity of chronic neuropathic pain, patent RU 2254574 C1). These methods do not localize pain and are expensive.

There is a method for evaluating local injection anesthesia of the dental pulp (patent RU 2679420 C1), which consists in registering the blood flow in the vascular system of the dental pulp with periodic measurement of its impedance with the introduction of an analgesic. The conclusion about the absence of pain syndrome and the depth of anesthesia is made according to the period during which the impedance remains unchanged. This method is suitable for anesthesia and is specific to the field of dentistry.

A device and a method for measuring autonomic functions for diagnosing and confirming the effectiveness of a course of treatment for a patient and its results are known (patent RU 2722748 C2). The patent proposes a system that uses medical devices to record physiological parameters, information about the relationship of pain with demographics, individual information about the patient and the medical care received by him, etc. The collected data is used by the system to establish baseline levels for patients, and deviations from these levels are indicators of pain. The disadvantage of the invention is the complexity of its implementation and implementation, associated with the need to collect a large amount of information both for general diagnostic statistics and taking into account an individual approach to the patient. In addition to the analysis of brain activity and statistical data, the patent compares indicators of electrodermal activity on symmetrical sides of the body. This technical solution does not provide a quick diagnosis, but requires thorough preparation for measurements, and is also not able to objectively fix the localization of the pain syndrome.

The closest analogue of the claimed invention is the article “Objectification of pain syndrome registration by analyzing changes in the capacitive component of impedance” (A.V. Kozhevnikova, Biophysics, 2018, volume 63, issue 1, pp. 164–167), which considers the possibility of registering pain syndrome by removing the change in the capacitive component of the skin impedance from the projection of the pain zone onto the skin.

For measurements, the DENAS device was used in the "Screening" mode, which reflects the rate of increase of the capacitive component of the impedance during 5 s of testing in the form of ΔLT values. The operation of the DENAS device is based on the principle of monitoring the impedance of the skin surface during stimulation. Using it to search for a connection between the pain syndrome and a certain value that can be taken from the projection on the skin, it was noticed that at the point of localization of muscle pain, the values given by the device deviate from the average, which objectively highlights the pain zone.

The electrical action that occurs when using the device always consists of two phases. The first phase is a rectangular pulse generated by the device with a frequency of 10 Hz, designed to create excitation in a parallel oscillatory circuit formed by the skin and electrodes of the device. The second phase is represented by forced damped sinusoidal oscillations that perform the function of stimulation and at the same time serve as a source of information for assessing the nature of the stimulation process itself. As a characteristic parameter, the amplitude of the damped oscillation in biological tissues is used after the cessation of the supply of a rectangular pulse.

The disadvantage of the closest analogue is the use of the amplitude of the rapidly decaying signal as the analyzed parameter and the conclusion about the presence of pain or the presence of pathology based on comparison with the readings of the symmetrical side of the body. A rapidly decaying signal requires high-precision measurements, and at low pain intensity it is possible to merge the signal of the decaying oscillation with the excitatory rectangular pulse.

Thus, the technical problem is the low accuracy of determining the intensity of the pain syndrome.

To solve this technical problem, an express analysis of local electrophysical parameters of biological tissues is used, which consists in the fact that pre-modeled damped electrical oscillatory pulses of short duration are applied. At the same time, the parameters of the pulses are in the ranges: duration from 30 to 100 µs; amplitude from 12 to 20 V. Resolution from 0.5 to 5 µs (determines the accuracy of plotting).

When a biological object is added to the electrical circuit in parallel by applying electrodes, the shape of the damped oscillations changes and is recorded. Remove fluctuations from pain and surrounding areas, forming a matrix of nine values. The resulting graphs are compared. Based on the deviation of the graphs from each other, a conclusion is made about the presence and magnitude of the pain syndrome. The key parameter in the analysis is the maximum deviation of the first peaks of the obtained oscillations from each other along the abscissa. The more the graph of the pain zone differs from the rest in the removed matrix of values, the more pronounced the pain syndrome.

Thus, the essence of the invention lies in the fact that the method of objective registration of pain syndrome includes the analysis of local electrophysical parameters of biological tissues, while registering a matrix of nine damped electrical oscillations caused by an electrical damped pulse in the pain zone and its surrounding areas. The parameters of this pulse are: duration from 30 to 100 μs, amplitude from 12 to 20 V. Then the maximum deviation of the abscissas of the first peaks of the graphs from each other is determined and, based on the values obtained, a conclusion is made about the presence and magnitude of the pain syndrome.

Due to the use of a damped pulse instead of a rectangular one in the first phase, as well as a matrix reading from nine points and comparing them with each other, an increase in the accuracy of determining the intensity of the pain syndrome is achieved with the possibility of clarifying its localization and gradation in magnitude, and as a result, improving the quality of diagnosis.

The drawings accompanying the description show:

Fig. 1 - Comparison of the input and output signals of the proposed method and the closest analogue

Fig. 2 - Schematic representation of the place of measurements and a set of graphs of damped oscillations in the form of a matrix of measurements in the pain zone

Fig. 3 - Superimposed graphs of measurements within the same pain zone directly on the day of the injury and three weeks after the injury

Figure 1 shows a General view of the proposed signal and the closest analogue. The analog input signal is a rectangular excitation pulse, fig.1a, and the output signal is represented by attenuation after the cessation of the excitation pulse, due to the capacitive nature of biological tissues, fig.1b. It should be noted that the front of the excitation signal is presented in an ideal form, and in practice it will be smoothed out. The input signal of the proposed method is a standard deliberately damped oscillatory pulse, figv. When a biological tissue is added to the chain, the oscillation deviates from the parameters known to us, while maintaining its characteristic shape, Fig.2g. Having received a set of nine modified damped oscillations, they are analyzed in pairs, on the basis of which a conclusion is made about the presence or absence of pathology.

The removal of experimental data is carried out as follows:

1) A volunteer with a developing pain syndrome is interviewed, a brief history is taken and the subjective level of pain is specified on a digital rating scale (CRS) from 0 to 10.

2) The induced damped electrical oscillation is recorded by means of electrodes in the pain zone and surrounding areas, forming a matrix of nine graphs, Fig.2.

As an example, we present data on the objectification of pain symptoms in lumbar bruises. As a result of each measurement carried out during the presence of a pronounced pain syndrome, a set of graphs was obtained, Fig. 3a. For ease of analysis of the obtained results and their mutual deviations, the graphs were combined into groups of nine pieces.

Measurements were taken again 3 to 6 weeks after the first measurement. The results of measurements with a decrease in the severity of the pain syndrome are shown in Fig. 3b.

The key indicator is the maximum deviation of the time of occurrence of the first peaks in the resulting array from each other.

To analyze the dependence of the parameters of the change in the studied signal on the presence and magnitude of the pain syndrome, studies were conducted on a total of 76 patients with various complaints about the presence of pain in the musculoskeletal system.

Table 1 - The interval of the maximum difference between the first peaks of induced oscillations in the pain zone and a description of pain symptoms (30 patients).

No. Interval during the presence of pain symptoms, μs Interval after subsidence of pain symptoms, microseconds Brief description of pain symptoms on a digital rating scale (CRS) one 14.2 4.7 M, 42, bruised hip, passed in 1 month
From 6/10 to 0/10 according to TsRSh 2 10.2 3.1 M, 28 y.o., bruise on leg and measurements in a month
From 4/10 to 0/10 according to TsRSh 3 16.8 10.0 M, 28 y.o., knee surgery, measurements immediately after surgery and 1.5 months later
From 7/10 to 3/10 according to TsRSh four 9.2 4.4 F, 29 y.o., pain of unclear etiology in the region of the scapula
From 4/10 to 3/10 according to TsRSh 5 18.7 5.5 M, 23, shoulder dislocation (after insertion and a month later)
From 8/10 to 0/10 according to TsRSh 6 9.4 8.5 M, 25 y.o., complaints of pain in the neck and shoulder blade
From 4/10 to 3/10 according to TsRSh 7 16.5 9.1 F, 21 years old, sprain and one month after
From 7/10 to 2/10 according to TsRSh eight 7.6 3.9 F, 55 y.o., complaints of back pain after sleep
From 4/10 to 1/10 according to TsRSh 9 10.0 2.1 F, 29 y.o., pain in the wrist after a fall and 1.5 months later
From 5/10 to 0/10 according to TsRSh ten 10.9 8.3 M, 24, pain in the neck after long sedentary work
From 4/10 to 0/10 according to TsRSh eleven 17.5 3.4 F, 79 y.o., pain after surgery on the femoral neck and 2 months later
From 8/10 to 2/10 according to TsRSh 12 9.5 5.4 M, 25 y.o., complaints of recurrent pain in the scapula. Scoliosis 2 tbsp.
From 4/10 to 2/10 according to TsRSh 13 16.8 3.6 F, 26 y.o., a bruise near the waist and after 1.5 months
From 9/10 to 1/10 according to TsRSh fourteen 9.6 7 F, 29 y.o., complaints of periodic heaviness and pain in the calf muscles
From 4/10 to 2/10 according to TsRSh fifteen 5.5 3 M, 18 y.o., periodic discomfort in the scapula
From 3/10 to 1/10 according to TsRSh 16 11.3 8.6 F, 55 y.o., bruise on thigh due to contusion
From 5/10 to 2/10 according to TsRSh 17 11.7 6.8 M, 22 g, bruised shoulder, 1 month between measurements
From 5/10 to 0/10 according to TsRSh eighteen 20.1 8.9 F, 29 y.o., lumbar contusion, 1 month between measurements
From 9/10 to 2/10 according to TsRSh 19 16.6 7.9 M, 29, hip contusion, 1 month between measurements
From 5/10 to 0/10 according to TsRSh twenty 11.4 8.2 F, 24, bruise on thigh, 2 weeks between measurements
From 4/10 to 0/10 according to TsRSh 21 10.9 5.9 F, 27 y.o., back pain (scoliosis grade 1), before and after exercise therapy
From 3/10 to 0/10 according to TsRSh 22 8.2 5.7 M, 25, discomfort in the shoulder of unknown etiology
From 2/10 to 0/10 according to TsRSh 23 12.3 6.4 M, 29 l, lumbar contusion, month between measurements
From 6/10 to 1/10 according to TsRSh 24 12.9 8.5 F, 30 y.o., knee injury
From 5/10 to 0/10 according to TsRSh 25 16.6 7.3 M, 24 years old, shoulder pain after sports injury and measurement when symptoms subside
From 5/10 to 0/10 according to TsRSh 26 12.1 9.2 M, 23 years old, knee pain after a sports injury, measurements at the time of pain and on subsidence of symptoms
From 4/10 to 1/10 according to TsRSh 27 6.4 4.3 F, 30 y.o., periodic pain in the wrist (hygroma)
From 4/10 to 1/10 according to TsRSh 28 7.2 2.8 M, 42, periodic discomfort in the neck
From 3/10 to 0/10 according to TsRSh 29 8.1 4.9 F, 31 years old, aching pain in the elbow joint of unclear etiology
From 3/10 to 0/10 according to TsRSh thirty 11.3 4.9 F, 27 y.o., periodic pain in the wrist (hygroma)
From 4/10 to 0/10 according to TsRSh

Characteristics of the signal generated by the device:

1. (pos. 1 - 5): duration 30 µs, amplitude 12 V;

2. (pos. 6 - 10): duration 30 µs, amplitude 20 V;

3. (pos. 11 - 15): duration 50 µs, amplitude 12 V;

4. (pos. 16 - 20): duration 50 µs, amplitude 20 V;

5. (pos. 21 - 25): duration 100 µs, amplitude 12 V;

6. (pos. 26 - 30): duration 100 µs, amplitude 20 V.

Resolution - 1 µs.

Based on the data of 30 paired measurements in the presence and disappearance of the pain syndrome, it was noted that:

- in 29 cases, the decrease or disappearance of the pain syndrome corresponded to a decrease in the distance between the peaks;

- pains greater than 5/10 according to TsRS have values from 10 microseconds;

- values from 7.2 µs to 10 µs correspond for the most part to the absence or slight presence of pain.

However, some values below 10 µs were also regarded as the presence of pain or discomfort, but were not noted as severe pain. This can be explained by individual differences in patients, the subjective assessment of their symptoms, and measurement inaccuracies. At the moment, there are all sorts of explanations for differences in pain sensitivity, ranging from empirical and sociocultural differences in the experience of pain to hormonally and genetically determined sex differences in brain neurochemistry. [Jeffrey S Mogil, Sex differences in pain and pain inhibition: multiple explanations of a controversial phenomenon, Nat Rev Neurosci 2012 Dec;13(12):859-66]

Measurements were taken in 46 areas subjectively described by the subjects as painful. Bruises, bruises, sprains, pain in the foot due to flat feet, pain after surgery, pain associated with scoliosis and pain of the musculoskeletal system of unclear etiology were analyzed, Table 2.

Table 2 - Data on the intervals between the analyzed peaks in the subjective presence of pain (46 patients).

experience number Intervals between peaks, μs experience number Intervals between peaks, μs one fourteen 24 16 2 8.2 25 15.4 3 18.1 26 3.5 four 8.5 27 11.5 5 7.9 28 15.9 6 12 29 14.5 7 15.7 thirty 8.6 eight 15.4 31 16.3 9 9.1 32 11.1 ten 5.5 33 18.2 eleven 12.6 34 12.6 12 16.1 35 15.3 13 6.5 36 10.4 fourteen 12.3 37 4.9 fifteen 16.7 38 9.8 16 11.9 39 8.8 17 14.9 40 9.4 eighteen 7.8 41 12.7 19 8.7 42 fourteen twenty 11.4 43 6.7 21 11.3 44 9.1 22 13.8 45 9.3 23 11.8 46 twenty

In 41 cases out of 46, the primary conclusion about the characteristic deviation between the peaks was confirmed. In 12 cases, the values fell into the range from 7.2 to 10 μs, which corresponds to the presence of a weak pain syndrome or the absence of it. In 29 cases, peak-to-peak values were greater than 10.4 µs, confirming the subjective description of pain.

Thus, out of 76 cases of subjective description of the presence of pain, 63% confirmed the presence of a pain syndrome, 26% confirmed the possibility of a mild pain syndrome, 11% of pain syndromes were not identified using the proposed method.

In the proposed method, for the first time, the analysis of the capacitive characteristics of biological tissues is used for verification, quantitative measurement and search for the localization of pain syndrome caused by a local pathological process. The method is also distinguished by the removal of a matrix (grid) of the values of the analyzed changes with the determination of the maximum deviation of the abscissas of the first peaks of the graphs by the removed matrix, which ensures an individual approach.

Claims (1)

A method for recording a pain syndrome, including analysis of local electrophysical parameters of biological tissues with such pain syndromes as bruises, bruises, sprains, pain in the foot due to flat feet, pain after surgery, pain associated with scoliosis, and pain of the musculoskeletal system of unclear etiology, characterized in that a matrix of nine damped electrical oscillations is registered at nine points, caused by an electrical damped pulse in the pain zone and its surrounding areas, while the pulse is characterized by such parameters as duration from 30 to 100 μs and amplitude from 12 to 20 V, then, the maximum deviation of the abscissas of the first peaks of the graphs from each other is determined and, based on the obtained values, a conclusion is made about the presence and magnitude of the pain syndrome.

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