RU2797989C1 - Automatic device for collecting capillary blood - Google Patents

Abstract

FIELD: medical equipment.

SUBSTANCE: automatic device for collecting capillary blood contains a housing with a mounting pad to the patient's skin, a button for activating the lancet impact mechanism, a non-return valve spring-loaded with a return spring, a sealed chamber whose walls are formed by a silicone membrane, a channel connecting the chamber with a connector for attaching a test tube, and a test tube. The impact mechanism contains a spring and ensures the movement of the lancet from the retracted position to the extended position in which the lancet extends beyond the mounting area. The valve provides the discharge of excess pressure during the movement of the lancet from the withdrawn position to the extended one and the maintenance of negative pressure when moving the lancet from the extended position to the withdrawn one. The mounting platform has a concave shape and contains an adhesive layer, the area of which corresponds to the area of the mounting platform. The connector for attaching the test tube contains a thread. The volume of the test tube does not exceed the sum of the volumes of the chamber and the channel of the device. The channel is made in the form of two truncated cones. The first truncated cone communicates with the device chamber with a large base and the smaller base communicates with the smaller base of the second truncated inclined cone, which is connected with a sealing cylinder connected to a test tube for collecting a blood sample with a large base. The bases of the cones are located in parallel planes.

EFFECT: ensured that damage to the shaped blood elements is prevented by preventing blood drops from "falling" into the test tube, increasing the reliability of the device's attachment to the patient's skin and stable fixation of the test tube on the device body with an increase in the volume of collected material and a reduction in the time of the procedure.

1 cl, 1 dwg

Description

The field of technology to which the invention belongs

The invention relates to means for taking blood samples and is intended for collecting capillary blood using lancets.

Devices for collecting biological fluids such as blood are widely used in both medical facilities and mobile stations. Biological samples are usually collected using simple lancets. The transfer of body fluids into a container for analysis often requires several steps, which can be time consuming and difficult to perform for unskilled users. In addition, the need to transfer a blood sample into a container poses a risk to medical personnel. Also known are automatic blood sampling devices that can be carried in the hand and which allow the patient to take a blood sample without the help of a medical professional. The use of a test tube built into the device ensures that there is no contact with blood, and also provides the possibility of using it in the field.

State of the art

A known system for taking blood samples from a patient through the skin (US 8808202 (B2) - 2014-08-19), which includes a flexible concave element movable between the first configuration and the second configuration, a needle mechanically connected to the flexible concave element, the area an applicator containing a needle and a vacuum chamber in which the pressure is below atmospheric pressure. The system comprises a pierceable surface in fluid communication with the vacuum chamber, and a penetrating element that is positioned to pierce the pierced surface when the penetrating element is moved by the flexible concave element. The system also includes an additional sample collection chamber that is located within the main vacuum chamber and is in fluid communication with it. However, this design reduces the useful volume for the collected material inside the test tube.

A device for collecting blood samples is known (US8827971 (B2) - 2014-09-09), which includes a flow activator designed to ensure the release of blood from a subject, an actuator with an electric motor to actuate the flow activator, a vacuum source that promotes the flow blood into the opening of the device and from the opening to the storage chamber. The electronic control of the drive requires a stationary power supply or a battery and the provision of electrical power to the device. In addition, the use of an electric drive imposes restrictions on the speed control of the flow actuator, since the electric motor provides programmed open or closed loop control to create the desired retraction speed. Whereas a manual actuator allows for user preference, allowing manual control of the flow speed of the flow actuator and thus the amount of negative pressure generated (for example, if the user abruptly releases the device actuator, retraction may be faster).

A device for capillary blood sampling is known (US11478175 (B1) - 2022-10-25), in which the collection cup is provided with a chute for transporting blood down from the blood sampling site. The device contains a housing connected to the bowl and defining the injection cavity, a plunger and several lancet elements attached to it. The presence of the trough avoids uncontrolled capillary flow and directs blood down the epidermis by gravity from the sampling point into the cavity of the container. However, this design requires precise positioning on the patient's body to align the trough with the puncture site on the skin.

A portable device for testing a patient (GB2546290 (A) - 2017-07-19) is known, containing a portable vacuum syringe with a reservoir, having an internal vacuum chamber, an external recess, a channel leading to the internal vacuum chamber, a seal covering the external recess, and a pair tips of microsyringes or lancets hydraulically connected to the internal vacuum chamber. When the seal is pressed with a fingertip, a pair of microsyringe tips rupture the seal and pierce the skin of the fingertip. The use of a pair of microsyringe tips may reduce pain perception compared to a single puncture point. In addition, the use of two microsyringe tips improves the reliability of blood sampling by doubling the instantaneous impact on the inside of the vacuum chamber. However, the presence of several lancets increases the invasiveness of the procedure and increases the risk of infection of the injured skin area.

Known is a portable laser blood sampling device (KR101251890 (B1) - 2013-04-08) equipped with a double safety device that collects a small amount of blood by stimulating a capillary vessel under the skin with a laser, and a disposable cap used with it. The laser module emits laser radiation in one direction, which allows the user to take a blood sample from a finger. The laser is a laser with a wavelength of 2.94 microns, which allows you to painlessly take blood from the skin using Er:YAG laser technology and does little harm to a person due to the high absorption capacity of water. However, such a design is difficult to manufacture and increases the likelihood of device failure.

Closest to the claimed device is a system for collecting blood (US11510659 (B2) - 2022-11-29), containing a housing and a drive in the form of a button, made with the possibility of moving relative to the housing to actuate the release of blood from the patient. The housing is detachably connected to the reservoir for receiving blood. To collect a blood sample, the device is applied to the body of the patient, while the lower surface of the body is against the skin, and the drive is located away from the skin. Pressing the actuator activates the skin piercing element (eg lancet, blade or needle). Subsequent retraction of the actuator away from the skin creates a vacuum within the device, which directly or indirectly acts on the patient's skin. Blood from the resulting incision is drained into the body and collected in a reservoir. However, due to its design, this system is not able to provide vacuum indicators sufficient to take the material at the required speed, which will reduce the time of the procedure and increase the volume of the collected material.

Thus, the object of the present invention is to overcome these shortcomings of the prior art and to develop a device for taking blood samples with improved characteristics.

Disclosure of the essence of the invention

The technical result of the invention is to prevent damage to blood cells by preventing the "falling" of blood drops into the test tube, increasing the reliability of fastening the device on the patient's skin and ensuring stable fixation of the test tube on the device body with an increase in the volume of collected material and a reduction in the procedure time.

This technical result is achieved by the fact that the claimed automatic device for collecting capillary blood contains a body with a platform for attaching to the patient's skin, a button for actuating the impact mechanism of the lancet, a check valve spring-loaded with a return spring, a sealed chamber, the walls of which are formed by a silicone membrane, a channel connecting a chamber with a connector for attaching a test tube, and a test tube,

wherein the impact mechanism contains a spring and is configured to move the lancet from the retracted position to the extended position, in which the lancet goes beyond the attachment site,

moreover, the valve is configured to release excess pressure in the process of moving the lancet from the retracted position to the extended one and maintain negative pressure when moving the lancet from the extended position to the retracted one,

the mounting area has a concave shape and contains an adhesive layer, the area of which corresponds to the area of the mounting area, the connector for attaching the test tube contains a thread, and the volume of the test tube does not exceed the sum of the volumes of the chamber and the channel of the device,

the channel is made in the form of two truncated cones, wherein the first truncated cone communicates with the chamber of the device with its large base and the smaller base communicates with the smaller base of the second truncated inclined cone, which, with its large base, is connected to a sealing cylinder connected to a blood sample collection tube, while the bases are indicated cones are located in parallel planes.

Brief description of the drawings

The claimed invention is illustrated by a figure, which schematically shows a capillary blood sampling device using the following notation:

1 - body,

2 - check valve,

3 - button,

4 - silicone membrane,

5 - percussion mechanism,

6 - emphasis,

7 - lancet,

8 - return spring,

9 - test tube.

Implementation of the invention

This instrument is a fully mechanical device. Blood sampling can be carried out both independently (without the help of medical personnel) and with the help of a medical worker. For correct operation, it is necessary to hermetically fix the device on the shoulder and press button 3 with a sharp movement. When button 3 is moved, the impact mechanism 5 is cocked by compressing the spring (inside the impact mechanism) on which the lancet 7 is fixed. At the same time, the check valve 2 opens and releases excess pressure from a sealed volume.

The hermetic volume is formed by the following components: test tube - 9, body - 1, silicone membrane - 4, check valve - 2.

When button 3 is pressed all the way 6, the impact mechanism 5 is triggered and, due to the built-in spring, pushes the lancet 7 all the way into the lower part of the body 1. In this case, the lancet goes beyond the body by 3 mm and enters the flesh, forming a wound 3 mm long.

When the mechanical action on the button is terminated due to the return spring 8, the button 3 returns to its original position. Lancet 7 also returns to its original position. At the same time, the check valve 2 closes, and due to this, a negative pressure arises inside the sealed volume, which contributes to the release of blood from the wound. As a result, blood enters the test tube.

The use of a device for collecting blood samples of the claimed design provides the following advantages:

– the execution of the platform for attaching the body to the patient's shoulder of a concave shape allows you to increase the area of contact of the device with the skin. This design will allow you to more securely fix the device on your shoulder. In addition, the increased contact area will allow you to apply the adhesive layer on a large surface, which will also increase the reliability of the device during operation. In addition, a good fit reduces pain during the procedure;

– observance of the ratio of the volumes of the body of the device and the blood collection tube provides the necessary negative pressure in the system. The ratio must be equal or the volume of the housing must exceed the volume of the tube. This ratio of volumes makes it possible to increase the level of negative pressure and, as a result, to reduce the time of the procedure due to faster blood sampling, as well as to increase the amount of material collected;

- threaded connection provides convenience and reliability of fixing the test tube on the device body;

– to ensure unhindered delivery of blood to the test tube, the channel is made in the form of an inverted truncated cone, which communicates with a hole in the patient’s skin with a large base, and with a smaller base connected to the upper base of another truncated inclined cone, which, with its lower base, is connected to a sealing cylinder connected to the test tube for collecting a blood sample, wherein the bases of said cones are arranged in parallel planes to allow blood to flow down one side of the housing. This will prevent the droplets of blood from "falling" into the tube.

An exemplary embodiment of the invention

During the development process, 500 final tests of the claimed invention were made. At the first stage, capillary blood was taken from patients, while the time of the procedure and the volume of the collected material were noted. At the second stage, microscopy of the obtained blood samples was carried out in order to determine their quality. The analysis of the obtained results showed that the claimed device, in comparison with the closest analogue, allows to reduce the procedure time by 1/3 and increase the volume of the collected material by 1/3, while maintaining the integrity of blood cells: % of samples with a hemolysis index (HI) in the range of 15 -50 mg / dl (free hemoglobin content in blood serum) was 6.5%, which indicates an acceptable quality of the preanalytical stage of laboratory studies. In addition, the subjects noted the convenience of using the device due to the reliability of fixation and the absence of cases of peeling off at the time of activation of the device, as well as the painlessness of the procedure. The threaded connection of the tube made it possible to minimize the cases of inadvertent tipping of the tube compared to the tight connection, which was used in the closest analogue.

Claims (6)

Automatic capillary blood sampling device, comprising a body with a platform for attachment to the patient's skin, a button for actuating the impact mechanism of the lancet, a check valve spring-loaded with a return spring, a sealed chamber, the walls of which are formed by a silicone membrane, a channel connecting the chamber with a connector for attaching a test tube, and test tube wherein the percussion mechanism contains a spring and is configured to move the lancet from the retracted position to the extended position, in which the lancet goes beyond the attachment site, moreover, the valve is configured to release excess pressure in the process of moving the lancet from the retracted position to the extended one and maintain negative pressure when moving the lancet from the extended position to the retracted one, different in that the mounting area has a concave shape and contains an adhesive layer, the area of which corresponds to the area of the mounting area, the connector for attaching the test tube contains a thread, and the volume of the test tube does not exceed the sum of the volumes of the chamber and the channel of the device, the channel is made in the form of two truncated cones, wherein the first truncated cone communicates with the chamber of the device with its large base and the smaller base communicates with the smaller base of the second truncated inclined cone, which, with its large base, is connected to a sealing cylinder connected to a blood sample collection tube, while the bases are indicated cones are located in parallel planes.

Images