RU2552896C1 - Method of diagnosing microcirculation pathology of vessels in lower extremities - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: filming is carried out and S - area of the foot in a visual range of a wavelength is determined. S_t - area of the thermographic figure of feet is determined. Points of the thermogram, which lie beyond the limits of the visual image of the foot, are excluded. A thermographic index is calculated by formula

. If the value B_t<0.9, pathology of the microcirculation of vessels in the lower extremities is diagnosed.

EFFECT: increase of diagnostics accuracy due to the reduction of an error in calculation of the area of the thermographic figure of feet by the exclusion of the thermogram points, lying beyond the limits of the visual foot image and introduction of the index of the visual foot area in the thermographic index.

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Description

The present invention relates to medicine and is intended for the diagnosis of pathology of microcirculation of the vessels of the lower extremities.

There is a thermographic method that allows you to determine the localization, size, shape and intensity of the infrared zone of the studied region [1]. There are three main temperature gradients on the thermogram of the extremities: 1) from the depth of the tissues to the surface of the skin; 2) from proximal to distal extremities (thigh - toes); 3) from finger to finger, starting with I and ending with V.

The disadvantage of this method is the lack of diagnostic accuracy.

The prototype adopted a method for the diagnosis of obliterating diseases of the arteries of the lower extremities (RF Patent No. 2214155, IPC AB 5/00; application. September 20, 2001; published on October 20, 2003), which uses the method of thermography to detect arterial pathology of the lower extremities, the area of the obtained thermographic figure of the feet is determined, the average temperature of the feet and the thermographic index (I _t ) is calculated by the formula

where T _cf - the average temperature of the feet;

S _t is the area of the thermal profile of the feet;

K = 100 - constant magnification factor,

Further diagnosed rate at a value I _t, equal to 0.5-0.6 in men and women 0.6-0.7, at which point a complete stop and thermo diagnosed pathology lower extremities vessels microcirculation at the value I _t ≥0, 7 in men and I _t ≥0.8 in women.

The disadvantage of this method is the lack of diagnostic accuracy due to the use of the absolute value of the area of the thermal profile of the feet, which depends not only on blood circulation and the level of microcirculation of the feet, but most importantly on the S area of the feet themselves, which is not taken into account in the prototype.

The technical result of the invention is to improve the accuracy of diagnosis of pathology of microcirculation of the vessels of the lower extremities.

The essence of the invention consists in the fact that the thermography method is used to detect the pathology of microcirculation of the vessels of the lower extremities, the area of the obtained thermographic figure of the feet is determined S _t and the thermographic index is calculated, the value of the latter is used to diagnose the norm or pathology of microcirculation of the vessels of the lower extremities, determination of the foot area S in the visible wavelength range; thermogram points that go beyond the visual image are excluded Nia foot and thermographic index is calculated by the formula

with a subsequent diagnosis of pathology of microcirculation of the vessels of the lower extremities with a value of B _t <0.9.

A method for diagnosing diseases of an artery of the lower extremities is as follows.

после чего диагностируется патология микроциркуляции сосудов нижних конечностей при значении B_t<0,9.To obtain limb thermograms, a thermal imager is used, combined with a video camera, of the FlirE50 type, with a resolution of up to 0.05 ° C, followed by computer processing of the results using specially created software for this purpose. A black body with a constant temperature of 33 ° C is used to adjust the temperature scale. The examination is carried out in a room with a constant air temperature of 22-24 ° C. Before the study, the necessary temperature adaptation of the patient is carried out for 5 minutes. The subject is located at a distance of 1.0-1.5 m from the receiving camera apparatus. Thermal imaging and video footage are carried out on purpose, thermograms and video are entered into the computer's memory. Software processing of video and thermograms is performed, the boundaries of the image of the feet are highlighted by the frames of the video, the points of the thermogram outside the visual image of the foot are excluded, the areas of the thermographic and visual shapes of the feet in pixels are calculated, and the thermographic index B _{t is} calculated. The calculation is carried out according to the formula

after which the pathology of microcirculation of the vessels of the lower extremities is diagnosed with a value of B _t <0.9.

Unlike the prototype, the average stop temperature is not taken into account in the diagnostic results of the proposed method. This is due to the fact that this value changes slightly during the transition from the norm to pathology and, therefore, is uninformative.

The choice of the boundary value of B <0.9 is made as follows. We rewrite expression (1) differently

With normal blood supply and the level of microcirculation, the equality S _t = S, I _t for men is 0.6. Then we get that

Similarly, we get that with pathology

Для женщин аналогичные значения дают граничное значение B_t=0,875.We substitute in expression (2) and get the boundary value for the proposed method

For women, similar values give a boundary value of B _t = 0.875.

Taking into account a small change in T _cf in the transition from normal to pathology will give a small decrease in the calculated boundary values of I1 _t .

We choose the boundary value of B _t with a small margin of 0.9.

Using the visual figure of the feet allows you to reduce the error in calculating the area of the thermographic figure of the feet by eliminating the points of the thermogram outside the visual image of the foot. In FIG. 1 and FIG. 2, taken from the prototype, errors in determining the thermal boundaries of the foot are clearly visible.

In addition, an increase in diagnostic accuracy is due to the introduction of a visual foot area into the thermographic index. In the prototype, however, a constant averaged value of the visual area of the foot is indirectly laid. We use the expression (3). Then, at T _cf = 37.65 ° C and I _t = 0.6, we get S _t = 6275 with normal blood circulation. Even if T _c = 35.786 ° C obtained from the pathology is put into the calculations, S _t will be equal to 5964. Thus, we can assume that the prototype has a constant boundary area of the thermographic stop figure of 6000 pixels for men. In women, in most cases, the foot is less, therefore, in the prototype I _{t is more} for women. But this is true only for a certain selected group of subjects. A difference from the average values in the foot area of only 15% will lead to an error in the diagnosis. For example, suppose there are two patients with normal blood circulation, the same T _cp = 37,65 ° C and varying square feet, respectively, 6300 and 5355 pixels. For the first patient, we obtain I _t = 0.597, i.e. normal, and for the second, whose foot area is 15% less, we get I _t = 0.7, i.e. pathology.

Thus, the proposed method is characterized by increased accuracy in the diagnosis of pathology of microcirculation of blood vessels.

Information sources

1. RF patent No. 2214155, IPC АВВ 5/00. A method for the diagnosis of obliterating diseases of the arteries of the lower extremities / Makarov I.V., Yarovenko G.V .; declared September 20, 2001; publ. October 20, 2003

Claims (1)

A method for diagnosing pathology microcirculatory vessels of the lower limbs, the method comprising that use thermography method and calculating a thermal index, characterized in that it further surveying and determining S foot area in the visible range of wavelengths determined S _t area thermographic figure stop excluding points thermograms that go beyond the visual image of the foot, and the thermographic index is calculated by the formula

and with a value of B _t <0.9, a pathology of microcirculation of the vessels of the lower extremities is diagnosed.

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