RU2302199C1 - Method for investigating biomechanical joint properties - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: method involves investigating biomechanical properties of joints by applying mechanical force with bone tissue change responses being subsequently recorded. Proximal nearest and remote and distal nearest and remote seismic gages are located on each side of articular surface. Graduated stroke is done above the nearest proximal gauge. Then absorption coefficient value of the mechanical impulse passing through a joint is calculated as difference between parameters of the nearest and remote proximal and distal seismic gages. The coefficient value read from the nearest proximal gauge is taken for 100%. Then the received coefficient values are compared to those on symmetric joint or to reference values.

EFFECT: high accuracy of diagnosis; accelerated research procedure.

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Description

The invention relates to medicine, namely to traumatology and orthopedics, and can find application in the diagnosis of injuries and diseases of the joints.

A known method for the study of joints based on ultrasonic echoosteometry, which consists in installing ultrasonic pulses on the surface of the diagnosed area of the emitter and transducer-receiver, receiving, recording ultrasonic pulses and evaluating the condition of the bone tissue, the emitter and the transducer-receiver are installed on one side of the diagnosed area, and as a diagnostic parameter, the half-wavelength of the transmitted pulse is taken (RF patent No. 2071274, АВВ 8/00, 1997).

The ultrasonic echoostometry method has a number of disadvantages, including:

- does not provide a sufficiently accurate topical diagnosis of the localization of pathological processes and osteoporosis;

- diagnostic information is largely dependent on the impedance of paraossal tissues;

- ultrasonic vibrations for bone tissue are subthreshold and quickly decay, which does not allow the full extraction of important diagnostic parameters;

- equipment for ultrasound examination is expensive, cumbersome, requires the presence of a functionalist doctor and specially trained medical personnel, which makes it difficult to use during dynamic observation.

A known method for the diagnosis of degenerative-dystrophic changes in the joints based on the determination of the absorption coefficient of x-ray radiation on a computer tomograph (AS USSR No. 1680082 A61B 6/00). The disadvantages of the method are:

- high radiation exposure to the patient and medical personnel;

- duration of the study;

- high energy intensity;

- the high cost of research, requiring the use of sophisticated equipment;

- the need for the presence of radiologists, specially trained medical personnel.

A known method for the diagnosis of masticatory function, which consists in the fact that they carry out a standard, dosed impact on the lower jaw, followed by the reception of mechanical responses using measuring equipment from the walls of the auditory meatus (RF patent No. 2210309). In this case, the obtained mechanical responses are decrypted according to the maximum, average amplitude and pulse duration. The disadvantage of this method is that a large number of detected parameters significantly increases the study time, complicates interpretation and comparison.

A known method for the diagnosis and controlled differentiated correction of injuries and diseases of the joints (patent application RU No. 93046894), which consists in registering sounds and noises that occur in the joints during movement using an arthro phonograph, after which the obtained parameters are compared with the composition of the synovial fluid .

The disadvantages of the method are:

1. The method is based on the registration of articular noise, while they are difficult to interpret, in some cases they are not at all.

2. The impact is difficult to dose;

3. The revealed parameters are difficult to compare with the opposite limb, because they have various anatomical characteristics and various stages of pathological processes.

All of the above makes a significant portion of subjectivity in the system of interpretation of the obtained parameters.

Closest to the proposed method is the "method of determining the depreciation properties of the supporting apparatus of a person", known from A. with. USSR No. 1761119, А61В 5/11, which consists in the fact that the depreciation properties of the musculoskeletal system are determined by mechanical action, followed by registration of reflected changes from the bone tissue with the installation of sensors over bone landmarks, minimally covered with soft tissues and maximally distant from the tendons, the orientation of the sensors is carried out according to the shortest distance from the distal to the proximal point of propagation of body vibrations in the studied segment with the determination of depreciation according to the degree of damping of the vibrational vibrations of the body examined between the two seismic sensors, the vibrations being excited by lifting them on their toes and then abruptly lowering them on their heels.

The disadvantages of the method are:

- during its implementation, it is impossible to ensure the accuracy and repeatability of exposure conditions;

- shock impact on the musculoskeletal system of the proposed method is weak and quickly fades;

- the effect carried out in this way creates a large number of interference and artifacts, since it is known that heel fat, capsule-ligamentous apparatus of the joints of the lower limbs have pronounced damping properties;

Thus, the use of this method is not very informative, since the shock effect is undosed and difficult to interpret.

The technical result when using the invention is to increase the accuracy of diagnosis and reduce the time of research on the biomechanical properties of joints.

The indicated technical result is realized by the fact that, according to the method for registering the biomechanical properties of joints, a mechanical action is performed followed by registration of reflected changes from the bone tissue, according to the invention, the absorption coefficient of the mechanical impulse passing through the joint is calculated by integrating the module of mechanical responses recorded at the test points, with subsequent comparison of the obtained parameters with a symmetric joint and with the reference ones.

Studies on patent and scientific and technical sources of information have shown that the proposed method is not known and does not follow explicitly from the studied prior art, i.e. meets the criteria of "novelty" and "inventive step".

The method is as follows.

Before the examination, the patient undergoes a standard anthropometric study, including measurement of height, body weight, limb length, length of individual segments, the circumference of a healthy and affected limb at different levels. The obtained parameters are entered into the database. Then, the meaning of the study is explained to the patient, after which a group of broadband seismic sensors is installed at certain points that palpate under the skin.

- For example, for the knee joint these are the epicondyles of the femur, the patella, the condyles of the tibia, the head of the fibula.

- For the hip joint - a large trochanter of the femur, the anterior superior and posterior superior axes of the pelvis.

- For the ankle joint - ankles, foot bones.

- For the wrist joint - styloid process of the radial bone, wrist bone.

In this case, the seismic sensors are located on both sides of the articular surface, for example, a seismic sensor located on the medial epicondyle of the femur, above which a strike is applied, is conventionally designated as the “proximal nearest” seismic sensor 1, and seismic sensor 2 located on the lateral epicondyle of the hip is conventionally designated as " proximal distant. " A seismic probe 3 located on the medial condyle of the tibia is designated as “distal closest”. A seismic sensor 4 located on the lateral condyle of the tibia is designated as “distal distant” (FIG. 1).

Figure 1 shows the location of the diagnostic seismic sensors (black arrows), the location of the diagnostic blow (gray arrow); figure 2 - analysis of waveforms of signals from seismic sensors; figure 3 - analysis of the absorption coefficient in a healthy joint; figure 4 - characteristic joint with osteoarthritis; figure 5 - characteristic parameters of sound conduction in osteoporosis; Fig.6 is a sound characteristic for intraarticular fractures.

After installing the seismic sensors produce a standard dosed impact, after which they receive, amplify and analyze mechanical responses, followed by the interpretation of the obtained parameters (figure 2). After a diagnostic shock, the signals from all sensors located at the test points have the form of a damped sine wave, conventionally designated as a function of "y" (Fig 2.1). On the basis of the obtained function, the function f (x) = | y | is built, which is the module of the function "y", that is, it has only positive values of the variables (Fig 2.2.). Subsequently, the area of the figure limited by the graph of the function f (x) and the abscissa is determined by integrating the function f (x), that is, the area of the desired figure "S" is equal to the integral of the function f (x) (Fig. 2.3., 2.4.) . Moreover, the indicator obtained at the nearest proximal seismic sensor (1) is taken as 100%. The absorption coefficient of the mechanical impulse transmitted through the joint is calculated as the difference between the parameters from the nearest and distant lateral and medial seismic sensors. The revealed parameters are compared with the opposite joint in case of its intactness, if the process is two-way, then the comparison is made with the reference parameters, i.e. the average obtained by examining healthy individuals of the appropriate gender, age and constitution.

Analysis of the absorption coefficient in a healthy joint is presented in figure 3. The absorption coefficient at “3” of the seismic sensor is 70% compared to “1”. Parameters from 2 and 4 seismic sensors are 90 and 60%, respectively, with an error of 5%. In this case, the absorption coefficient is 100-70, 90-60, i.e. 30/30.

With ostearthrosis, there is a decrease in the absorption coefficient to 20/20 (figure 4). With osteoporosis, the absorption coefficient is 40/30 (figure 5). With intraarticular fractures, the absorption coefficient is about 70/10, in addition, there is a significant decrease in the absorption coefficient within the damaged segment, the difference between the parameters from 1 and 2 of the seismic sensor is more than 70% (Fig.6).

The method improves the accuracy of diagnosis of biomechanical properties of joints by analyzing additional parameters of mechanical responses. The method is easily reproducible, non-invasive, does not require preliminary examination, does not bear radiation exposure, has no contraindications, which allows the possibility of use at all stages of medical care, both independently and in combination with routine examination methods, as in outpatient practice in primary diagnostics, when screening or dispensary examinations according to the principle of the patient - healthy, and in stationary conditions for differential diagnosis and dynamic observation in the process cse treatment.

The proposed method is illustrated by the following examples.

Clinical example No. 1. Patient P., 45 years old, complained of pain in the right knee joint, aggravated after physical exertion, starting pain. A survey was carried out according to the proposed method. Seismic sensors are installed at test points, a test hit is made. Based on the recorded mechanical responses, the first stage calculated the modules, the second stage found the area of the figures bounded by the mechanical response module and the abscissa axis. Then, the calculated parameters are compared between the sensors installed before and after the joint space, while the parameter recorded on the proximal nearest sensor 1 is always taken as 100%. Sensor 2 - at the same time there will be a proximal remote, sensor 3 - the nearest distal, sensor 4 - distal remote. When examining the left knee joint, the following parameters were revealed: sensor 1 - 100%, sensor 3 - 70%, sensor 2 - 90%, sensor 4 - 60%, at the last stage the absorption coefficients were calculated as the difference between indicators 1 and 3, 2 and 4 of the sensors : 100-70 = 30%, 90-60 = 30%. Thus, the absorption coefficient is 30/30, which corresponds to the population norm.

When examining the right knee joint, the revealed parameters were: sensor 1 - 100%, sensor 2 - 90%, sensor 3 - 80%, sensor 4 - 70%, absorption coefficients were 20/20, a preliminary diagnosis of osteoarthrosis of the right knee joint was made. X-ray examination confirmed the diagnosis.

Clinical example No. 2. Patient S., 62 years old, complained of pain in both knee joints, pain in the spine. A survey was conducted according to the proposed methodology. Similar parameters were found on both joints: sensor 1 - 100%, sensor 3 - 60%, sensor 2 - 80%, sensor 4 - 50%, absorption coefficient was 40/30, a preliminary diagnosis was made of systemic dishormonal osteoporosis, a computer study densitometer confirmed the diagnosis.

Clinical example No. 3. Patient K, 58 years old, was hospitalized after an accident, edema in the area of the knee joint, pathological mobility in the area of the external condyle of the femur, and multiple skin deposition are clinically determined. A survey was conducted on the proposed methodology. Sensor 1 - 100%, sensor 3 - 30%, sensor 2 - 20%, sensor 4 - 10%, absorption coefficient was 70/10, a preliminary diagnosis was made, a fracture of the external condyle of the femur, an X-ray examination revealed the absence of congruency joint space and confirmed the diagnosis.

Claims (1)

A method for studying the biomechanical properties of joints by performing mechanical action with subsequent registration of reflected changes from the bone tissue, characterized in that the proximal proximal and distant seismic sensors are placed on both sides of the articular surface, and a dosed shock is produced above the proximal proximal sensor, after which calculate the absorption coefficient of the mechanical impulse passing through the joint, as the difference between the near the closest and distant proximal and distal seismic sensors, while the nearest proximal sensor is taken as 100%, after which the obtained parameters are compared with a symmetric joint or with reference parameters.

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