RU2581712C1 - Method for collection of subcutaneous interstitial fluid and device therefor - Google Patents

Abstract

FIELD: medicine.

SUBSTANCE: group of inventions refers to medicine and can be applied for extraction of subcutaneous interstitial fluid (SIF). Preparation of human skin before SIF sampling is performed with device containing body in form of plate with cylindrical through holes of diameter 3-5 mm, located at distance of 3 mm from each other, and extreme holes relative to end faces of plate are located at distance of 7-10 mm, with the same plane plate is provided with cover installed tightly, to form cavity in 3-8 mm between plane of plate and cover, at that, in cover at end part there is hole for connection to vacuum source. Preparation of human skin to SIF sampling with creation of vesicles is carried out as follows. Upon open skin area plate device is applied by plane with open holes. To cover plate vacuum source is connected in mode of 300 mm Hg. Through 5 minutes vacuum source power is increased to 450 mm Hg and kept in this mode for 30-45 minutes. Then every 10 s vacuum source power is gradually reduced by 50 mm Hg, up to complete stop. Device plate is removed from skin. From each of formed vesicles SIF is sampled by puncture.

EFFECT: group of inventions allows to prevent contamination of SIF samples with capillary blood.

8 cl, 1 tbl, 5 dwg

Description

The invention relates to medicine, in particular to methods and devices for the selection of biological fluids, in particular subcutaneous interstitial fluid, used to determine the level of biochemical parameters. The composition of the subcutaneous interstitial fluid (hereinafter - PI) due to the branching of the subcutaneous capillary network is identical to the set of biomarkers and metabolites in the blood.

The invention can be used for the diagnosis of human diseases.

In Russia, about 60 million blood tests are performed annually to diagnose human diseases. The growth rate of analyzes annually is 15-18%. Existing traditional technologies provide for the selection of biomaterial (blood and subcutaneous interstitial fluid) for research using an injection needle (Patents of the Russian Federation No. 2005111767, 2002128734, 2256396, 2496406), which causes trauma, negative psychological impact, infection risk (up to 30%), the need to perform procedures in licensed medical institutions by trained personnel, significant costs for the disposal of consumables (for 1 syringe at a cost of 4 rubles. costs are about 9 rubles).

One way to solve this problem is to select only subcutaneous interstitial fluid (highly informative biomaterial). Today, active development of technologies is underway around the world that will allow us to select and research this biosubstrate. One of the fundamental tasks in the field of research is the search for comparable indicators in the subcutaneous fluid with indicators of blood serum based on the performance of the comparative analysis procedure using generally accepted biochemical methods. For these purposes, large volumes of biological substrates are required, at least 500 μl.

For example, there are known methods for selecting PIZh and devices for their implementation in the form of microneedle applicators (hereinafter - MIA) for sampling PIZH described in such information sources as: Mukerjee E.V., Collins S.D., Isseroff R.R., Smith R.L. Microneedle array for transdermal biological fluid extraction and in situ analysis // Sensors & Actuators-2004, Vol.114 - P.267; Wang P.M., Cornwell M., Prausnitz M.R. Minimally Invasive Extraction of Dermal Interstitial Fluid for Glucose Monitoring Using Microneedles // Diabetes Technology & Therapeutics - 2005, Vol. 7, No. 1 - P. 131-141.

When implementing the known method, the formation of a plurality of micropores on the skin area is carried out by means of a microneedle applicator containing a number of needles by applying positive pressure to the specified applicator and extracting the subcutaneous interstitial fluid through these micropores into the needles. MIA needles penetrate the keratin layer of the skin and enter the epidermis, the surface layer of living cells in which there are no nerve endings, so their introduction is painless. Also, the use of MIA is safe, since it is in the epidermis that the most important elements of the human immune system, Langerhans cells, are located, and the probability of infection is much less than with conventional subcutaneous injection, when the needle penetrates deeper than this protective layer. Thus, the introduction of MIA into the skin does not require special medical preparation, which makes them especially popular for self-detection systems and large-scale screening.

And the MIA, which is required to implement the known method, consists of a substrate on which a number of polymer needles are placed, which have the ability to diffuse PIW when these needles penetrate the skin.

However, there is no universal methodology for the selection of PIs using MIA, the implementation of which would be obtained physiological fluid PiS in the right amount for various diagnostic directions with a minimum number of used MIA, because there are difficulties in extracting the PIW from the needles. And it is almost impossible to obtain for research in a known manner using the well-known MIA PIZH, with a volume of at least 500 μl. In addition, there is no 100% guarantee that the PIW selected by this method will not be contaminated with capillary blood, which may affect the accuracy of subsequent studies of the characteristics of PIU.

The specified method is adopted for the closest analogue prototype for the proposed method.

At the same time, no known medical devices have been identified from the prior art that make it possible to prepare human skin for the selection of subcutaneous interstitial fluid, therefore, it is not possible to select the closest analogue to the claimed technical object - a device of this purpose.

A single technical result achieved by the proposed method, implemented using the inventive device, is to expand the range of the volume of the selected PiZh samples and the guaranteed elimination of contamination of PiZha samples with capillary blood.

The specified technical result is achieved by the proposed method for the selection of subcutaneous interstitial fluid, including the selection of subcutaneous interstitial fluid from under the human skin, while it is new that human skin is prepared for sampling of the subcutaneous interstitial fluid of the PIW by creating vesicles on the skin and subsequent sampling PIW by penetrating through the dermal layer of each vesicle with a penetrating probe and taking a puncture from it, while preparing human skin for sampling P W is carried out by a device containing a housing in the form of a plate with cylindrical through holes with a diameter of 3-5 mm, located at a distance of 3 mm from each other, and the holes that are extreme with respect to the ends of the plate are located at a distance of 7-10 mm, and on one plane the plate is provided with a cover, installed tightly, with the formation of a cavity of 3-8 mm between the plane of the plate and the cover, while in the cover from the end part a hole is made for connection to a vacuum source, and the preparation of human skin for the selection of PI the vesicles are made by applying a device plane with open holes onto the open skin area of the device, connect a vacuum source in the mode of 300 mmHg to the plate cover, after 5 minutes increase the power of the vacuum source to 450 mmHg. and kept in this mode for 30-45 minutes, and then every 10 s successively reduce the power of the vacuum source by 50 mm Hg, until it is completely turned off, then remove the device plate from the skin and select PIG by puncture from each formed vesicle.

The specified technical result is also achieved by the proposed device for preparing human skin for the selection of subcutaneous interstitial fluid, characterized in that it contains a housing in the form of a plate with cylindrical through holes with a diameter of 3-5 mm, located at a distance of 3 mm from each other, and extreme relative to the ends the hole plates are located at a distance of 7-10 mm, and on one plane the plate is equipped with a lid mounted hermetically, with the formation of a cavity with a height of 3-8 mm between the plane of the plate They also have a lid, while in the lid from the end part a hole is made for connection to a vacuum source.

Each through hole on the plane side of the plate with open holes is provided with a circular shoulder 0.5-1.0 mm high.

The cover is made integral with the housing plate.

Its plate and cover are made of polystyrene or polyvinyl chloride.

In shape, the plate is made in the form of a rectangle, or square, or circle, or oval.

Cylindrical through holes in the plate are located symmetrically or asymmetrically.

The hole in the cover for connection to the vacuum pump is made in the direction perpendicular to the direction of the holes in the plate.

The specified technical result is achieved due to the following.

The implementation of the proposed method is carried out essentially in two stages: the preparation of human skin for selection by the claimed device and the selection itself.

Due to the fact that the preparation of human skin for sampling is carried out by creating vesicles on the skin, it becomes possible to repeatedly increase the volume of the selected sample (since the subsequent selection will be made from each vesicle) in comparison with known methods. Moreover, the selected volume of PIW can be varied over a wide range, by performing a puncture only from the desired number of vesicles.

In addition, the formation of vesicles on the skin (vacuum parameters, time, sequence of increasing and decreasing the pressure of the vacuum source) plays a very important role. Due to the fact that the initial evacuation is carried out in the regime of 300 mm Hg, increasing after 5 minutes the power of the vacuum source to 450 mm Hg, followed by standing in this mode for 30-45 minutes, a rather visible formation of vesicles on the skin is necessary convexity, but without breaking the subcutaneous capillaries, which will guarantee the avoidance of contamination of the PIW samples with capillary blood.

And due to the fact that subsequently every 10 s the power of the vacuum source is reduced by 50 mm Hg, up to a complete shutdown, a gentle mode of removing the vesicles from under pressure is ensured. The main thing is that the vesicles in this mode do not "collapse", but keep their shape even after removing the claimed device from the skin for a period of time sufficient for subsequent sampling. That is, they are ready for puncture of them PIW. The subsequent puncture is carried out by the traditional method, for example, using a sterile needle. In this case, only the wall of the bubble (vesicles) is punctured. This procedure is completely painless. The liquid is not squeezed out, but is collected with a dispenser, for example, an automatic dispenser with a plastic tip (for example, a pipette dispenser 1-channel BIOHIT (Finland)).

But the proposed method can be implemented only through the inventive device for preparing human skin for the selection of subcutaneous interstitial fluid.

The execution of the body of the device in the form of a plate is due to ensure a more stable position of the plate on the skin of a person and allows you to expand the "zone" of the selection of PIW, and therefore its volume.

The placement on the plate of cylindrical through holes in the form of an array with such parameters as the diameter of the hole 3-5 mm, located at a distance of 3 mm from each other, allows to obtain, upon evacuation, vesicles (bubbles on the skin) of optimal size, which will be sufficiently convex tubercles, moreover without violating the subcutaneous capillaries in these areas, in order to subsequently take the PIW from each of them, and at the same time, vesicles of this dimension will not “fall off” when the vacuum is removed. Studies have shown that if the diameter of these holes is more than 5 mm, then the vesicles (tubercles on the skin), after removing the plate, “fall off”, which does not allow to remove the PIW, and if the diameter of the holes is less than 3 mm, the vesicles are “thick” for patients they do not form, and with "thin" skin - its damage is possible.

Due to the fact that the extreme holes in the plate relative to the ends of the plate are located at a distance of 7-10 mm, the uniform distribution of negative pressure across all through holes of the plate is ensured. At this distance of less than 7 mm, the resulting vesicles will be most convex at the outer holes, which is fraught with skin damage in these places (especially for thin skin), and with this distance of more than 10 mm, the vacuum efficiency decreases due to an increase in the useless area on the plate and reduction of the effect vacuum on the holes.

The supply of the plate (case) with one cover plane, mounted rigidly and tightly (also in some cases, can be performed with it at the same time), with the formation of a cavity with a height of 3-8 mm between the plane of the plate and the cover, allows you to create a vacuum space when connecting a vacuum source to a device, due to which the skin will "climb" into the holes and form vesicles. The implementation of this cavity with a height of more than 8 mm will not provide the necessary vacuum power, and at a height of less than 3 mm, the lid may break due to the creation of a very large vacuum index.

The hole in the plate cover from the end of the hole for connection to a vacuum source allows you to create the specified vacuum space between the plane of the plate and the cover (of course, subject to the application of the second plane of the plate with open holes on the skin of a person), and also allows you to create a uniform negative pressure.

Due to the fact that each through hole on the plane side of the tablet with open holes is provided with a circular rounded shoulder 0.5-1.0 mm high, the fact of integrity of the skin will be ruled out, which means that the likelihood of capillary blood getting into the PIW sample will be excluded.

The implementation of the body plate and the cover of polystyrene or polyvinyl chloride allows, firstly, to visually monitor the formation of vesicles, and secondly, it is easy to sterilize the device.

The fact that the longitudinal section of the plate can be made in the form of a rectangle, or a square, or a circle, or an oval, expands the range of the proposed device and ensures the convenience of using it by patients if the latter have any “interfering” parts of the toilet, for example, a watch, a bracelet and etc.

Making holes in the plate symmetrically or asymmetrically is also aimed at expanding the range of the device.

Thus, the inventive method, implemented using the proposed device, provides not only an extension of the range of the volume of the taken sample of PIW to 500-1500 μl, but also guarantees the exclusion of blood contamination of the sample, which in the future can lead to inaccurate analyzes, and therefore to incorrect diagnostics diseases.

When implementing the proposed method, the following operations are performed in the following sequence:

- on the open skin area, pre-treated with an alcohol wipe, the device plate is installed with a plane with open holes. The plate is made, for example, of polystyrene and can contain, for example, 100 through holes located in the form of a symmetrical array, each hole with a diameter of 3-5 mm The device is hermetically fixed to the skin by negative pressure;

- a vacuum source, for example Pump-7e vacuum aspirator (Armed, Russia), which allows creating a vacuum with a pressure of up to 600 mm Hg, is connected to the end hole in the cover of the device through a hose, for example, 30 cm long. Set its mode to 300 mm Hg .;

- after 5 minutes, increase the power of the vacuum aspirator to 450 mm Hg;

- stand in this mode for 30-45 minutes;

- visually fix the formation of vesicles (tubercles on the skin). Moreover, the formation time of vesicles in different people is different. It depends on the type of skin, the thickness of the subcutaneous fat, the water load, etc .;

- and then successively every 10 s reduce the power of the vacuum aspirator by 50 mm Hg, up to a complete shutdown;

- then gently remove the device plate from the skin. At this stage, the preparation of the skin for the selection of PIW is completed;

- further, from each of the formed vesicles, PIG is selected by puncture, for example, with an automatic dispenser with a plastic tip (such a dispenser, for example, can be a pipette dispenser 1-channel BIOHIT (Finland). The average volume of the selected subcutaneous interstitial fluid varies from 500 to 1500 μl . and depends on the individual characteristics of the skin and subcutaneous fat of a person. You can select a smaller volume of PIW, depending on what is required for research.

The invention is illustrated by drawings, where figure 1 shows the proposed device for the preparation of human skin for the selection of subcutaneous interstitial fluid in section and a through hole with a shoulder; figure 2 is a section bb In figure 1; figure 3 - plate from the side of the open holes; figure 4 - the application of the plate on the skin and the formation of vesicles (30th minute of exposure of the plate on the skin); figure 5 - collecting PIZH automatic dispenser with a plastic tip after turning off the vacuum source after 40 minutes of exposure on the skin.

The inventive device comprises a housing in the form of a plate 1 (its thickness can vary from about 12 mm to 16 mm), for example, made of transparent polystyrene or polyvinyl chloride material, with cylindrical through holes 2 with a diameter of 3-5 mm (they can be arranged symmetrically, so and asymmetrically) located at a distance of about 3 mm from each other. Extreme relative to the ends 8 and 7 of the plate 1 of the hole 2 are located at a distance of 12, comprising 7-10 mm Moreover, from one plane 9, the plate 1 is provided with a cover 4, installed hermetically (or in some embodiment, you can perform this cover with it at the same time). Between the plane of the plate 1 and the cover 4 there is a cavity (gap) 3-8 mm high, which, as it were, forms a vacuum space 5. In this case, a hole 6 is made in the cover 4 of the plate 1 from the end part for connection to a vacuum source (in the drawing shown).

Each through hole 2 on the side of the plane 10 of the plate 1 with open holes 2 is equipped with a circular rounded shoulder 3 of a height of about 0.5-1.0 mm, to prevent damage to the skin surface with the sharp ends of the holes 2.

The plate 1 can be made in the form of a rectangle, or a square, or a circle, or an oval, which increases the usability of the inventive device.

The proposed device operates as follows. It is used at the stage of preparing human skin for sampling of PIW. For this, a plate 1 of the device with a plane 10 with open holes 2 is mounted on an open area of the skin and is fixed on the skin by the formation of negative pressure. An end source 6 in the cover 4 of the device is connected via a hose (not shown), for example, 30 cm long, a vacuum source (not shown), for example, a Pump-7e vacuum aspirator (Armed, Russia), which allows creating a vacuum with the maximum pressure up to 600 mm Hg Set the mode to 300 mm Hg on a vacuum respirator. and after 5 minutes, increase its power to 450 mm. Hg Stand in this mode for 30-45 minutes. The formation of vesicles 11 is visually fixed on the skin, which are formed by pulling the skin into the open end of the holes 2 under vacuum. Then, after exposure, successively every 10 s, the power of the vacuum aspirator is reduced by 50 mm Hg, until it is completely turned off. Then carefully remove the plate 1 of the device from the skin, freeing the vesicles 11. At this stage, the preparation of the skin for the selection of the PiP is completed.

An example of a specific implementation.

The studies involved men of Russian nationality aged 27-35 years (16 people). In the history of these individuals there were no episodes of deviant behavior, acute diseases (within 1 month before the study) and exacerbation of chronic somatic diseases. Within 1 month before the study, no one took any medications. No injuries exceeding mild severity (within 1 month before the study). No damage to the skin. The results of the studies revealed that the average volume of the selected subcutaneous interstitial fluid in each person was 730 ± 170 μl. It was found that the proposed method allows the formation of vesicles without sweating capillary blood. When assessing pain during the procedure on a scale of 1 to 10 points (10 points - it is impossible to tolerate), all volunteers rated 2 points. Pain was characterized by a slight burning sensation of the skin. Moreover, most of the procedure, pain was absent.

In the course of laboratory tests, the success of the formation of vesicles (skin blisters) under vacuum regimes other than those declared was also determined. The data are shown in table 1.

Claims (8)

1. A method of sampling subcutaneous interstitial fluid, including the selection of subcutaneous interstitial fluid from under human skin, characterized in that the human skin is prepared for sampling of subcutaneous interstitial fluid PIG by creating vesicles on the skin and subsequent sampling of PIG by penetrating through the dermal layer each vesicle with a penetrating probe and taking a puncture from it, while the preparation of human skin for sampling PIW is carried out by a device containing a body in the form of a plate with qi through holes with a diameter of 3-5 mm located at a distance of 3 mm from each other, and the holes that are extreme with respect to the ends of the plate are located at a distance of 7-10 mm, and on one plane the plate is provided with a lid that is sealed to form a cavity of 3-8 mm between the plane of the plate and the lid, while a hole is made in the lid from the end part for connection to a vacuum source, and preparation of human skin for the selection of PIZh with the creation of vesicles is performed by applying a layer to the open area of the skin ina device with a plane with open holes, connect a vacuum source in the mode of 300 mm Hg to the plate cover, after 5 minutes increase the power of the vacuum source to 450 mm Hg. and kept in this mode for 30-45 minutes, and then every 10 s successively reduce the power of the vacuum source by 50 mm Hg, until it is completely turned off, then remove the device plate from the skin and select PIG by puncture from each formed vesicle. 2. A device for preparing human skin for the selection of subcutaneous interstitial fluid, characterized in that it contains a body in the form of a plate with cylindrical through holes with a diameter of 3-5 mm, located at a distance of 3 mm from each other, and the holes extreme to the ends of the plate are located on a distance of 7-10 mm, and on one plane, the plate is provided with a lid mounted hermetically, with the formation of a cavity with a height of 3-8 mm between the plane of the plate and the lid, while an opening is made in the lid from the end part tion for connection to a vacuum source. 3. The device according to p. 2, characterized in that each through hole on the side of the plane of the plate with open holes is provided with a circular shoulder 0.5-1.0 mm high. 4. The device according to p. 2, characterized in that the cover is made integral with the housing plate. 5. The device according to claim 2, characterized in that its plate and cover are made of polystyrene or polyvinyl chloride. 6. The device according to p. 2, characterized in that the shape of the plate is made in the form of a rectangle, or square, or circle, or oval. 7. The device according to p. 2, characterized in that the cylindrical through holes in the plate are symmetrically or asymmetrically. 8. The device according to p. 2, characterized in that the hole in the cover for connecting to a vacuum pump is made in the direction perpendicular to the direction of the holes in the plate.

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