CN111229108A - Rapid blood-gas mixing method and special device thereof - Google Patents

Abstract

The invention discloses a rapid blood gas mixing method. The blood and gas are respectively introduced into the mixing channel. The mixing channel includes an inner pipe and an outer pipe sleeved outside the inner pipe. The pipe wall of the inner pipe has micropores that are permeable to gas molecules. The sample is inhaled from the inner pipe, and at the same time, pressurized gas is passed between the inner pipe and the outer pipe. The flow direction of the blood is the same as that of the gas, and the pressure of the gas is adjusted by the pressure sensor and the pressure regulating valve at the end of the mixing channel. , so that the gas can pass through the tube wall of the inner tube, slowly infiltrate into the tube from the outside of the inner tube, and mix with the blood in the tube to form a blood-gas mixture. Using this method and its proprietary equipment, the mixing efficiency of the sample is high, and the gas can be quickly saturated in the blood sample, which can effectively shorten the preparation time of the sample and provide more precious time for patient treatment when applied to clinical testing.

Description

A rapid blood gas mixing method and special device thereof

technical field

The present application relates to the technical field of blood mixing, and in particular, to a rapid blood gas mixing method and a dedicated device thereof.

Background technique

Blood gas mixing and blood gas separation have been widely used in biological, pharmaceutical and medical in vitro diagnostic fields, such as the preparation of various concentrations of standard solutions, blood testing, gas purification, etc. The typical application is blood gas mixing.

The main purpose of blood gas mixing is to introduce different concentrations of oxygen, carbon dioxide and other gases into the blood to be tested, and through the blood gas mixing device, the blood to be tested finally contains the oxygen, carbon dioxide and other gases of this concentration, and contains different concentrations of oxygen, carbon dioxide and other gases. The test blood represents the test target in different states (for example, the blood with low oxygen concentration represents the poor oxygen-carrying capacity of the test target, and the blood with high carbon dioxide concentration represents the possibility of carbon dioxide poisoning of the test target, etc.), the instrument detects the blood of different gas concentrations and compares it with the benchmark , so as to confirm whether the instrument parameters are accurate. The main form of blood gas mixing is: infuse the gas to be mixed (mainly oxygen and carbon dioxide) into the container containing the test blood until the blood reaches gas balance (that is, the gas in the blood has reached saturation), there are mainly the following three types of inflation Method: The trachea is directly inserted into the blood to inflate, the trachea is inflated on the surface of the blood, and the centrifugal blood gas is mixed.

With the rapid development of in vitro diagnostic technology, in order to accurately simulate various human conditions in blood gas detection, there are high requirements for testing the method of blood inflation, whether the gas content in the blood is balanced, and the time required to reach equilibrium. Defects in the way of inflating the trachea directly into the blood: During the inflation process, many air bubbles will be generated in the viscous blood, which will cause the red blood cells in the blood to rupture and affect the test for measuring potassium ions in the blood; the deficiencies of the way the trachea is inflated on the blood surface: The gas only contacts the surface of the blood to be tested, so it takes a long time or it is difficult to achieve the overall gas balance of the blood to be tested, which will reduce the blood sugar value and increase the lactic acid value in the test blood, which will seriously affect the measurement results; centrifugal blood gas mixing Disadvantages: The amount of blood samples is large, the preparation time is relatively long, and the device structure is complex, the gas consumption is large, the device manufacturing cost is high, and the replacement of different samples requires cleaning of the mixed container, complicated operations, and cross-contamination. Risk, can not meet the rapid, accurate and low-cost needs of the in vitro diagnostic industry.

Therefore, none of the three blood gas mixing methods commonly used in the market is suitable for accurate blood gas detection.

SUMMARY OF THE INVENTION

In view of the deficiencies in the prior art, the present application provides an extremely fast blood-gas mixing method, with short mixing time, less sample consumption, uniform mixing of gas and blood, simple device structure and low manufacturing cost, which can effectively meet the requirements of in vitro Rapid, accurate and portable requirements in the field of diagnosis.

The rapid blood gas mixing method provided by the present invention is to pass blood and gas into a mixing channel respectively, and the mixing channel includes an inner pipe and an outer pipe sleeved outside the inner pipe. The pipe wall of the inner pipe It has micropores that are permeable to gas molecules, and the blood sample is inhaled from the inner pipe. At the same time, the gas under pressure is passed between the inner pipe and the outer pipe. The flow direction of the blood is the same as the flow direction of the gas, through the tail of the mixing channel. The pressure sensor and pressure regulating valve adjust the pressure of the gas, so that the gas can pass through the wall of the inner pipe, slowly infiltrate into the pipe from the outside of the inner pipe, and mix with the blood in the pipe to form a gas-blood mixture.

Specifically, the present invention controls the blood flow rate to be 1-65ml/min. The flow rate is controlled within this range because the flow rate can save blood sample consumption and at the same time can ensure mixing efficiency. The present invention controls the gas flow rate to be 1-50ml/min. When the gas flow rate is less than 50ml/min, adjusting the gas flow rate can prepare blood samples with different gas concentrations. When the gas flow rate exceeds 50ml/min, the blood sample will quickly reach saturation. If the gas flow rate is increased, the gas concentration in the blood sample will not change. ;

Specifically, the present invention can control the pressure of the gas to 10-40 Psi. If the pressure is too low, the gas molecules cannot pass through the inner tube wall, and the gas and blood cannot be mixed; if the pressure is too high, a large amount of gas will quickly pass through the inner tube wall, causing the blood sample in the inner tube to have too high pressure, which will lead to The blood sample is supersaturated, so the air pressure controlled by the present invention is preferably 30-40 PSI.

Specifically, the material of the inner pipe of the present invention is a material that can permeate gas but not liquid, such as: ePTFE microporous material, hollow silicon fiber, GORE-TEX (R) expanded polytetrafluoroethylene, etc. . For the present invention, Teflon AF 2400 capillaries are preferred. The tube wall of Teflon AF2400 has a microporous structure with a size of about 0.3nm. The size of oxygen and carbon dioxide molecules are 0.346nm and 0.33nm respectively. The size of red blood cells, white blood cells and platelets in blood is 1-20um, and the size of smaller water molecules is 0.4nm. , the micropore size is smaller than the size of water molecules, oxygen and carbon dioxide under a certain pressure are more likely to pass through the tube wall, while the water molecules in the blood sample have no pressure inside and are not easy to pass through the tube wall, so TeflonAF2400 is more suitable for the preparation of oxygen and carbon dioxide samples; Secondly, Teflon AF2400 can be processed by melt compression molding, extrusion molding, injection molding, etc., making it easier to process into capillary tubes; again, it has the characteristics of high permanent gas permeability, hydrophobicity, chemical inertness, etc., blood samples flowing through the pipeline are not easy to stick Attached, does not cause pollution, and is conducive to rapid gas penetration.

The present invention also provides a special device for realizing the above mixing method. The device includes a blood inlet channel, a gas inlet channel, a mixer, a mixing channel, a pressure regulating device, and a pressure detection device; the mixing channel includes an inner pipe, and a sleeve The outer pipe is arranged outside the inner pipe. The mixer has 2 inlets and 1 outlet. The 2 inlets are respectively connected with 2 inlet channels, and the outlet is connected with the mixing channel. The rear of the mixing channel is provided with a pressure sensor. and pressure regulating valve.

Specifically, the blood inlet channel and the gas inlet channel include a one-way valve, a soft-hard straight-through joint, and a connecting pipe.

Specifically, the mixing channel is composed of a plurality of straight pipes parallel to each other, and the plurality of straight pipes are connected in series through a U-shaped pipe. The straight pipe is arranged vertically. The blood flows up and down in it, and a laminar flow will be formed inside the liquid, which is more conducive to the rapid mixing of blood and gas.

Specifically, the pressure sensor and the pressure regulating valve can be installed with a four-way connection to the mixing channel.

In the present invention, the mixer can adopt a tee, the inner tube adopts a Teflon AF2400 capillary, the inner tube passes through the tee, and is connected with the blood inlet channel, and the outer tube adopts a Teflon tube, which is sleeved outside the inner tube and connected with the lower end of the tee, Secure with ferrules and ferrules.

More specifically, a typical solution of the present invention is: after the blood sample is inhaled by the peristaltic pump, it flows through the blood inlet channel from the upper end of the three-way into the inner tube and flows forward; The left end flows into the gap between the inner tube and the outer tube, and flows in the gap, and the gas pressure in the gap is controlled by the pressure regulating valve and the pressure sensor; because the inner tube wall has a microporous structure, the microporous structure can allow a certain pressure. The gas molecules in the blood flow through the inner tube wall and enter the blood sample; while the pressure of the blood sample powered by the peristaltic pump is very low, and the red blood cells, white blood cells, platelets and other molecules in the blood are large in size and will not pass through the inner tube wall in reverse. , the blood sample continuously flows forward in the inner tube, and continuously dissolves the gas passing through the tube wall during the flow process; at the same time, because the inner tube diameter is very small, only φ0.45mm, so the blood flowing through the inner tube section per unit time The amount of blood sample is very small, so the blood sample can be saturated in a very short time; because the sample preparation of the device is a continuous process, the blood sample is sucked by the peristaltic pump, and the blood sample can be saturated when it flows through the mixing channel, from the peristaltic pump to the outlet of the pipeline , the entire mixing channel pipeline is about 1.2 meters long, the sample preparation time is about 1 minute, and the minimum blood sample volume is about 2 ml.

Beneficial effects: Blood gas detection is a means to understand the human respiratory function and acid-base balance by measuring the H+ concentration of human blood and the gases dissolved in the blood (mainly CO2, O2), which can directly reflect lung ventilation. function and its acid-base balance.

Using the method of the present invention, accurate blood gas mixing can be realized. Using the device of the present invention, when adjusting different flow rates, the blood gas concentration in the blood sample after blood gas mixing has a good linear relationship until the gas in the blood sample is saturated.

The main purpose of blood gas mixing is to introduce different concentrations of oxygen, carbon dioxide and other gases into the blood to be tested to prepare blood gas mixture samples of different concentrations, and through the blood gas mixing device, the blood to be tested finally contains the concentration of oxygen, carbon dioxide and other gases. Test blood containing different concentrations of oxygen and carbon dioxide gas represents test targets in different states (for example, blood with low oxygen concentration indicates that the test target has poor oxygen-carrying capacity, and blood with high carbon dioxide concentration indicates that the test target may be poisoned by carbon dioxide, etc.). Blood gas samples are mixed and compared with benchmarks to confirm whether the instrument parameters are accurate.

In addition, another advantage of the present invention is that it is fast. Using this method, the mixing efficiency of the sample is high, and the gas can be quickly saturated in the blood sample. When applied to clinical detection, the preparation time of the sample can be effectively shortened, and the treatment of patients can be provided. more precious time.

The special device provided by the invention has simple and easy-to-obtain accessories, simple assembly process, easy batch standardized production, low production cost and short production cycle; the pipeline part can be used as a disposable consumable, which can effectively avoid cross-contamination.

Description of drawings

Fig. 1 is the overall structure diagram of the device described in the present application;

Fig. 2 is the connection schematic diagram of the device described in the present application;

Fig. 3 is a schematic diagram of the internal connection of the mixer;

Fig. 4 is a schematic diagram of the tail connection of the mixing channel;

FIG. 5 is a schematic diagram showing the relationship between the oxygen flow rate and the oxygen concentration of the blood sample.

in:

1-blood inlet channel; 2-gas inlet channel; 3-mixer; 4-mixing channel; 5-four-way; 6-pressure sensor; 7-pressure regulating valve;

31-pressing plug joint; 32-pressing ring; 8-inner pipe; 9-outer pipe;

41-Pressure plug connector; 42-Pressure ring; 43-Pressure regulating valve connection channel; 44-Pressure sensor connection channel; 45-Blood outlet channel

Detailed ways

In order to make those skilled in the art better understand the solutions of the present application, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present application. Obviously, the described embodiments are only The embodiments are part of the present application, but not all of the embodiments.

The specific structure is shown in Figures 1 to 3;

Blood sample line:

Connect the one-way valve 1 through two silicone hoses, the outlet end of the one-way valve 1 is connected to the soft and hard butt straight joint 1, the inlet end is connected to the peristaltic pump, and the other end of the soft and hard butt straight joint 1 is connected to the thin Teflon tube 1 ;Put the TeflonAF 2400 capillary into the inside of the outer tube, leaving about 50mm and 100mm at the two ends respectively outside the outer tube; Pass the 50mm end of the Teflon AF 2400 capillary through the T-type tee, and apply an appropriate amount of silica gel to the outer wall of the Teflon AF 2400 capillary (Note that the orifice cannot be blocked), then insert the thin Teflon tube 1. After the silica gel is completely dry, fix it on the T-type tee joint with a pressure ring and a pressure plug connector; pass the 100mm end of the TeflonAF 2400 capillary tube through the Through the four-way joint, fix the outer tube and the four-way joint with the plug joint and the pressure ring; expose the part of the Teflon AF 2400 capillary to the four-way joint, and pass through the thin Teflon tube 2, leaving about 20mm of the Teflon AF 2400 capillary in the thin On the outside of the Teflon tube 2, connect the outer wall of the Teflon AF 2400 capillary to the inner wall of the thin Teflon tube 2 with silica gel (pay attention to keep the Teflon AF 2400 capillary unobstructed). The joint and the pressure ring are fixed on the four-way joint;

Gas line:

Connect the one-way valve 2 through two sections of silicone hoses, one end of which is connected to the soft and hard butt joint 2, the other end is connected to the gas cylinder, and the soft and hard butt joint 2 is connected through the thick Teflon tube 1 and the T-type three-way joint 1. The left end is connected; the pressure regulating valve is connected to the left end of the four-way joint through the thick Teflon pipe 2, and the pressure sensor is connected to the right end of the four-way joint through the thick Teflon pipe 3; the gas enters the T-type through the soft and hard butt straight joint 2 After the three-way joint 1, it flows in the gap between the inner wall of the outer tube and the outer wall of the Teflon AF 2400 capillary tube, and is discharged from the pressure regulating valve through the four-way joint after passing through the thick Teflon tube 2; by adjusting the pressure regulating valve knob and pressure The sensor controls the gas pressure of the pipeline;

The specific working process of the device of the present invention:

Open the external gas cylinders (mainly oxygen and carbon dioxide gas cylinders with different concentrations), and mix the above two gases together through the three-way joint to form a mixed gas with a specified concentration, which enters the inlet of the one-way valve 2, and adjusts the pressure by adjusting the pressure. The valve knob and pressure sensor control the gas pressure of the pipeline and keep the gas flow in circulation; the blood sample is pumped through the peristaltic pump from the inlet end of the one-way valve 1. After the blood sample passes through the thin Teflon tube 1, it is placed in the Teflon AF The 2400 capillary flows, and continuously mixes with the gas passing through the tube wall, and finally reaches saturation; if you need to prepare test samples of different concentrations, you can adjust the gas pressure and the flow rate of the blood sample to achieve;

Use the device of the present invention to carry out sample measurement:

Use this device to prepare blood samples with different oxygen concentrations, and use NOVA blood gas biochemical analyzer to test the blood samples. When no gas is introduced, the initial oxygen content of the blood sample is 196.2mmHg, and the pressure of the gas channel is kept at 40PSI. Adjust the oxygen flow rate and the speed of the peristaltic pump, prepare blood samples with different oxygen concentrations, and detect the oxygen content in the blood samples. The results are as follows:

Through the analysis of the above table, it can be seen that the oxygen content in the blood sample increases with the increase of the input oxygen flow; under the same oxygen flow, the oxygen content in the blood sample is basically the same, but it still shows that the faster the flow rate of the blood sample, The trend of lower oxygen content; plot the above data as a line graph, as shown in Figure 4.

From the analysis of Figure 4, it can be seen that the blood sample is close to saturation when 0.4L/Min of oxygen is introduced, and quickly reaches saturation when 0.5L/Min of oxygen is introduced. The average preparation time of blood samples with saturated oxygen concentration is 48 seconds; and from the initial sample state to before saturation, the oxygen content of the blood sample has a linear distribution relationship with the oxygen flow, and increases with the increase of the oxygen flow; this shows that the oxygen flow can be controlled to achieve different Preparation of blood samples for oxygen concentration;

The above descriptions are only preferred embodiments of the present application, and are not intended to limit the present application.

Claims (9)

1. A rapid blood-gas mixing method is characterized in that blood and gas are respectively introduced into a mixing channel, the mixing channel comprises an inner pipeline and an outer pipeline sleeved outside the inner pipeline, the wall of the inner pipeline is provided with micropores through which gas molecules can permeate, a blood sample is sucked from the inner pipeline, meanwhile, gas with pressure is introduced between the inner pipeline and the outer pipeline, the flow direction of the blood is the same as that of the gas, and the pressure of the gas is regulated through a pressure sensor and a pressure regulating valve at the tail part of the mixing channel, so that the gas can slowly permeate into the tube from the outside of the inner pipeline through the wall of the inner pipeline and is mixed with the blood in the tube to form blood-gas mixed liquid.

2. The rapid blood-gas mixing method according to claim 1, wherein the blood flow rate is 1-65 ml/min.

3. The rapid blood-gas mixing method according to claim 1, wherein the gas flow rate is 1-50 ml/min.

4. The rapid blood-gas mixing method according to claim 1, wherein the pressure of the gas is 10-40 Psi.

5. The method of claim 1, wherein the inner tube is made of Teflon AF2400 capillary.

6. The special device for the rapid blood-gas mixing method of claim 1, which comprises a blood inlet channel, a gas inlet channel, a mixer, a mixing channel, a pressure regulating device, a pressure detecting device; the mixing channel comprises an inner pipeline and an outer pipeline sleeved outside the inner pipeline, the mixer is provided with 2 inlets and 1 outlet, the 2 inlets are respectively connected with the 2 inlet channels, the outlet is connected with the mixing channel, and the tail part of the mixing channel is provided with a pressure sensor and a pressure regulating valve.

7. The special device according to claim 1, wherein the blood inlet channel and the gas inlet channel each comprise a one-way valve, a soft and hard straight joint, and a connecting tube.

8. The special device as claimed in claim 1, wherein the mixing channel is composed of a plurality of parallel straight pipes, and the straight pipes are connected in series through U-shaped pipes.

9. The special device as claimed in claim 1, wherein the pressure sensor and the pressure regulating valve are provided with a four-way valve connected with the mixing channel.

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