RU86317U1 - DEVICE FOR DETERMINING BLOOD MICROVOLUMES - Google Patents

Abstract

A device for the study of microvolumes of blood, consisting of a power source, which is a frequency alternating current generator, a measuring cell with electrodes placed in it parallel to each other symmetrically on both sides relative to the center, connected to a power source and a recording unit, characterized in that the measuring cell is a capillary with brass electrodes placed inside it, coated with a layer of gold at least 4 microns thick with a surface area equal to the capillary cross-sectional area , And it spaced at least 5 mm from the edge of the capillary, wherein the electrodes are connected to the recording device by means of contact plates mounted on opposite walls of the capillary and bonded with wires, arranged in a capillary wall.

Description

The invention relates to the field of medical technology, in particular, to devices for measuring the viscosity characteristics of blood and can be used to assess the state of hemostasis.

Changes in the functional state of the hemostatic system and a violation of the rheological properties of blood play an important role in the pathogenesis of many diseases. These changes can be expressed as an increase in the hemostatic potential that underlies the development of thrombosis, and in the insufficiency of these mechanisms leading to bleeding. The frequency of thrombohemorrhagic complications is constantly growing due to an increase in infectious-toxic, radiation, drug effects, and the spread of allergic, autoimmune, immune complex, metabolic and oncological diseases in the population [1, 3].

Specialists in various fields of clinical medicine are found to have abnormalities in the hemostatic system, which may be acute or have a chronic course. In this regard, the requirements for the diagnosis of hemostasis disorders, the development and adequate use of methods for their correction are quite high. This determines the high importance of hemostasiological laboratory studies in medical practice [2, 4]. The special importance of monitoring the state of the blood coagulation system is associated with the active use in clinical practice of modern highly effective direct and indirect anticoagulants, antiplatelet agents and thrombolytics. Often, selective individual sensitivity to drugs of different groups requires accurate individual selection of dosage, duration of therapy, as well as evaluation of its effectiveness [1].

The complexity of the study of the state of the hemostasis system is explained by the fact that this system has high biological variability and instability of its factors, the difficulty of isolating the determined parameter from the cascade of interrelated reactions, the impossibility in many cases of direct measurement of concentrations, methodological and instrumental unification [3]. Today, there is a wide range of methods to assess the functional state of the blood coagulation system, the amount of information received is quite large. However, in order for this information to be of high diagnostic significance, the correct choice of test suite is necessary, while routine tests may not always provide answers to the questions posed, and special, clarifying studies are required. An extensive study of all the links of hemostasis is cumbersome and time-consuming, requires large amounts of blood, is often insufficiently operative and is primarily research rather than applied in nature [2, 4].

The desire for a more economical, focused and operational study of the hemostatic system is quite understandable and justified. In this regard, devices that allow tracking the process of hemocoagulation in real time from the graphic recording of blood coagulation and fibrinolysis can have advantages.

A device for the study of blood [5], containing a power source measuring cell with electrodes placed in it, connected to a power source and a recording device, the power source being a frequency alternating current generator, the electrodes are made in the form of square plates coated with a layer of silver or gold a thickness of at least 0.1 mm, located parallel symmetrically on both sides of the center of the cell at a distance from each other equal to the width of the electrode plate, and the measuring cell and thermostated formed, and a recording unit connected to the outputs of the electrodes.

This device is the closest to the claimed technical essence and is selected as a prototype.

The disadvantage of the prototype is that when conducting research using a known device, large volumes of test blood are used, the study is not efficient enough - the duration of the study takes up to 100 minutes, which does not allow to monitor the hemocoagulation process in real time.

The objective of the proposed device is the ability to track the process of hemocoagulation in real time in the studied blood microvolumes, without trauma to blood cells by reducing the mechanical impact on them.

The problem is solved by a new device for the study of blood microvolumes (0.05-0.1 cm ³ ), consisting of a power source, which is a frequency alternating current generator, a measuring cell with electrodes placed in it parallel to each other symmetrically to the center, connected to the center power source and recording unit. Based on the experimental studies, the authors proposed to use a capillary as a measuring cell, with brass electrodes placed inside it, covered with a layer of gold at least 4 microns thick with a surface area equal to the capillary’s cross-sectional area and located at least 5 mm from the edge of the capillary the electrodes are connected to the recording device by means of contact plates mounted on opposite walls of the capillaries and connected to wires located in Enke capillary.

Using the device proposed as a utility model, it is possible to quickly in real time (within several minutes) from one drop of blood taken from a finger to monitor the patient’s blood coagulation process and immediately carry out the correction of the therapy. This is a convenient and safe way to maintain hemocoagulation parameters in the therapeutic range, which in turn reduces the likelihood of complications (thrombosis, thromboembolism or bleeding).

The proposed device will be clear from the following description and the drawings attached to it.

Figure 1 shows a block diagram of a device for the study of blood microvolumes:

1 - capillary;

2 - capillary wall;

3 - electrodes;

4 - connecting wire;

5 - contact plate;

6 - frequency generator;

7 - recording unit.

The device proposed as a utility model (Fig. 1) consists of a capillary 1 in the walls of 2 of which electrodes 3 are placed, by means of wires 4 connected to a contact plate 5 mounted on the opposite wall of the capillary connected to a frequency generator 6 and to a recording unit 7.

The proposed device operates as follows (Fig. 1). A sample of capillary blood with a volume (0.05-0.1 cm ³ ) is placed in the lumen of capillary 1. Next, using an electrode 3, an alternating current with a frequency of 200 Hz is passed through the blood and the blood conductivity is measured. The obtained results in real time in digital form are displayed on the display of the recording unit 7, in parallel, a functional curve (electrocoagulogram) is recorded. Then an analysis is carried out with further interpretation of the obtained graphic images of the functional curve (electrocoagulogram), where A is the amplitude of the decrease in the functional curve, measured in mV; T - time to reduce the amplitude of the functional curve to min, measured in min; A / T - an indicator of the intensity of activation of the blood coagulation process (hypo-, normo-, hypercoagulation), is defined as the max slope of the functional curve and is measured in mV / min.

Example 1. Patient B. 32 ^years, history of disease №342 admitted to the Department of Pharmacology Therapy Research Institute of RAMS clinic. The diagnosis - hr. gastroduodenitis, phase of moderate exacerbation. To assess the functional state of the hemostatic system, the patient underwent studies of the blood coagulation system using conventional methods.

The following results are obtained.

Complete blood count: hemoglobin - 145 g / l, red blood cells - 4.52 T / l, CP-0.96, hematocrit - 43%, leukocytes - 6.4 G / l, ESR - 4 mm / h, platelets - 244 G / l Leukocyte formula: n / a neutrophils - 0%, segmented neutrophils - 48%, eosinophils - 1%, basophils - 0%, lymphocytes - 44%, monocytes - 7%.

Coagulogram: APTT - 36.0 sec, prothrombin time - 16 sec, total fibrinogen - 2.6 g / l, RFMC - neg., Fibrinolytic activity - 190 min.

Platelet Aggregation Study

Aggregation Inductors Light transmission,% Size of units, UE Spontaneous aggregation 0 0.75 ADP, 1.25 mg / ml 24 6.0 ADP, 2.5 mg / ml 31 6.0 ADP, 5 mg / ml 38 6.5 Adrenaline, 2.5 mg / ml 45 7.0 Adrenaline, 5 mg / ml 52 6.8 Collagen 73 5.5

Additionally, a study was conducted using the proposed device, the following results were obtained: A - 15 mV, T - 3.4 min, A / T - 4.4 Mv / min.

According to the research data, deviations in the functional state of blood coagulation were not detected.

Figure 2 shows a graph of patient B.

A total of 20 patient blood samples were used. The utility model proposed by the authors allows one to obtain data on the state of the hemostatic system in real time, without traumatizing blood cells in the studied blood microvolumes.

Bibliography:

1. D.M. Zubairov. Molecular basis of blood coagulation and thrombosis. - Kazan: Feng, 2000 .-- 364 p.

2. A.A. Kishkun. Guide to laboratory diagnostic methods. - M .: GEOTAR. - Media, 2007 .-- 800 s.

3. A.P. Momot. Pathology of hemostasis. Principles and algorithms of clinical laboratory diagnostics. - SPb .: FormT, 2006. - 208 p.

4. Medical laboratory technology and diagnostics: a Handbook. Medical Laboratory Technology / Under. ed. prof. A.I. Karpishchenko. - St. Petersburg: Intermedia, 1999 .-- 656 p. with silt.

5. Patent for utility model, No. 40110. Blood test device. I.I. Tyutrin, V.O. Sorokozherdiev, Yu.A. Ovsyannikov, A.I. Stetsenko Published: 08/27/2004 Bull. Number 24.

Claims (1)

A device for the study of microvolumes of blood, consisting of a power source, which is a frequency alternating current generator, a measuring cell with electrodes placed in it parallel to each other symmetrically on both sides relative to the center, connected to a power source and a recording unit, characterized in that the measuring cell is a capillary with brass electrodes placed inside it, covered with a layer of gold at least 4 microns thick with a surface area equal to the capillary cross-sectional area , And spaced at least 5 mm from the edge of the capillary, wherein the electrodes are connected to the recording device by means of contact plates mounted on opposite walls of the capillary and bonded with wires, arranged in a capillary wall.