WO2008114998A1

WO2008114998A1 - Blood separator using dissolved air flotation

Info

Publication number: WO2008114998A1
Application number: PCT/KR2008/001536
Authority: WO
Inventors: Yu-Chang Kim; Sang-Jin Park; Pil-Woo Heo; Duck-Jong Kim; In-Sub Park
Original assignee: Korea Institute Of Machinery & Materials
Priority date: 2007-03-21
Filing date: 2008-03-19
Publication date: 2008-09-25

Abstract

A blood separator using flotation of dissolved air, capable of separating only the blood plasma by floating cells in blood using buoyancy of fine air bubbles, is disclosed. According to an embodiment of the present invention, the blood separator for separating blood plasma and blood cells from whole blood using flotation of dissolved air, comprises a tube storing whole blood, in which air bubbles generated by saturating air are attached to blood cells and floated along with the blood cells, thereby separating blood plasma and the blood cells from each other, and a bubble generation unit which generates air bubbles for floating the blood cells contained in the whole blood stored in the tube.

Description

BLOOD SEPARATOR USING DISSOLVED AIR FLOTATION

Technical Field

[1] The present invention relates to a device for separating blood plasma from whole blood, and more particularly to a blood separator using flotation of dissolved air, capable of separating the blood plasma by floating only cells of blood using buoyancy of fine air bubbles.

[2] Furthermore, the present invention relates to a blood separator using flotation of dissolved air, capable of improving a blood separation efficiency by using an effect in which dissolved air becomes air bubbles when inner pressure of a tube storing whole blood is reduced into a vacuum state and the air bubbles are attached to blood cells included in the whole blood and then separated due to buoyancy thereof, in addition to an effect in which the blood cells are apt to move to a lower pressure position, and capable of preventing the blood plasma once separated from being mixed again into the whole blood until being discharged.

[3] In addition, the present invention relates to a blood separator using flotation of dissolved air, generating air bubbles in whole blood by forcibly injecting air into a tube storing the blood such that blood cells are floated in accordance with flotation of the air bubbles and thereby separated. Background Art

[4] Biochemical examinations of body fluids, especially blood, are widely performed as a means for examining health conditions of a human body.

[5] In general, a chromatograph sensor using an antigen-antibody reaction is used to measure and analyze the examination result.

[6] However, types and concentrations of blood ingredients including products of metabolism, protein, fat, electrolytes, enzyme, antigens, antibodies and the likes are difficult to be measured as whole blood. Therefore, a few processes are required. More specifically, according to a conventional blood analyzing method, whole blood collected in advance is separated by a centrifugal separator, and thus-obtained blood plasma or serum are analyzed by an analyzer or a biosensor.

[7] The centrifugal separator for separating blood comprises a bucket for inserting therein a tube that stores a sample, and a rotor for rotating the bucket.

[8] In the centrifugal separator, in order to balance the centrifugal force, another tube of the same weight as the sample-storing tube is required to be inserted in another bucket disposed opposite to the sample-storing tube. Thus, the processes are cumbersome and much time is required. Disclosure of Invention

Technical Problem

[9] Therefore, the present invention has been made in view of the above problems, and it is an object of the present invention to provide a blood separator utilizing buoyancy of air bubbles to separate blood cells such as red blood corpuscles, white blood corpuscles, and thrombocytes from blood plasma.

[10] It is another object of the present invention to provide a blood separator using flotation of air bubbles, capable of improving a blood separation efficiency by using an effect in which air bubbles are generated from dissolved air in blood by reducing inner pressure of a tube storing the blood and the air bubbles are attached to blood cells and then separated by buoyancy thereof.

[11] It is yet another object of the present invention to provide a blood separator using flotation of air bubbles, capable of improving the blood separation efficiency using an effect in which air bubbles are generated as air dissolved by pressure is passed through a nozzle mounted at a lower part of a tube, causing reduction of pressure, and the air bubbles are combined with blood cells and then floated, thereby separating the blood cells through a sieving effect. Technical Solution

[12] In accordance with the present invention, the above and other objects can be accomplished by the provision of a blood separator for separating blood plasma and blood cells from whole blood using flotation of dissolved air, the blood separator comprising a tube storing whole blood, in which air bubbles generated by saturating air are attached to blood cells and floated along with the blood cells, thereby separating blood plasma and the blood cells from each other, and a bubble generation unit which generates air bubbles for floating the blood cells contained in the whole blood stored in the tube.

[13] The bubble generation unit may comprise a decompression-type bubble generation unit which generates and floats air bubbles in the whole blood by reducing inner pressure of the tube, or a pressurizing-type bubble generation unit which forcibly injects air into the tube so that the whole blood becomes saturated with the air.

Brief Description of the Drawings

[14] The above and other objects, features and other advantages of the present invention will be more clearly understood from the following detailed description taken in conjunction with the accompanying drawings, in which:

[15] FIG. 1 is a view showing the structure of a blood separator according to an embodiment of the present invention;

[16] FIG. 2 is a structural view of a blood separator according to another embodiment of the present invention; [17] FIG. 3 is a structural view of a blood separator according to yet another embodiment of the present invention;

[18] FIG. 4 illustrates the processes of blood separation, and more particularly,

[19] FIG. 4A shows a state before air bubbles are generated in whole blood,

[20] FIG. 4B shows a state where air bubbles are generated in the whole blood, and

[21] FIG. 4C shows a state where blood plasma or blood cells are separated by flotation of the air bubbles generated in the whole blood, [22] FIG. 5 is a structural view of a blood separator according to yet another embodiment of the present invention; and [23] FIG. 6 illustrates the blood separation processes using the blood separator of FIG. 5, and more particularly,

[24] FIG. 6A shows a state before air bubbles are generated in whole blood,

[25] FIG. 6B shows a state where air bubbles are generated in the whole blood, and

[26] FIG. 6C shows a state where blood plasma or blood cells are separated by flotation of the air bubbles generated in the whole blood. Best Mode for Carrying Out the Invention [27] Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. [28] FIG. 1 is a view showing the structure of a blood separator according to an embodiment of the present invention. FIG. 2 is a structural view of a blood separator according to another embodiment of the present invention. FIG. 3 is a structural view of a blood separator according to yet another embodiment of the present invention. FIG. 4 illustrates the processes of blood separation. FIG. 5 is a structural view of a blood separator according to yet another embodiment of the present invention, and FIG. 6 illustrates the blood separation processes using the blood separator of FIG. 5. [29] Referring to FIG. 1 through FIG. 5, the blood separator using flotation of air bubbles, according to the embodiments of the present invention, comprises a tube 1 storing whole blood therein, and a bubble generation unit 2. In the tube 1, air bubbles generated from saturating air are attached to blood cells and floated along with the blood cells, thereby separating the blood plasma and blood cells from each other. The bubble generation unit 2 generates the air bubbles for floating the blood cells in the whole blood stored in the tube 1.

[30] The blood separator can be classified into two types according to a structure of the bubble generation unit 2. FIG. 1 to FIG. 4 show an exemplary structure of a decompression-type bubble generation unit which extracts inner air from the outside. FIG. 5 shows an exemplary structure of a pressurizing-type bubble generation unit which injects air. First, the blood separator equipped with the decompression-type bubble generation unit will be described hereinafter.

[31] As shown in FIG. 1, the blood separator using flotation of air bubbles according to an embodiment of the present invention comprises the tube 1 in which air bubbles are generated by reduction of solubility according to reduction of pressure and the air bubbles are attached to blood cells to give buoyancy to the blood cells, such that the blood cells are floated and only blood plasma finally remains at a lower part thereof. The blood separator also comprises a vacuum generation device 21 as the bubble generation unit 2, which generates the air bubbles in the whole blood by vacuumizing an inside of the tube 1.

[32] The tube 1 has a tubular form with an opened top to store the whole blood therein.

[33] For storage of the blood therein, the tube 1 is structured to be openable and closable. For this, the top of the tube 1 is opened and mounted with an openable lid 11 capable of hermetically sealing the tube 1 so that air cannot get in and out between the tube 1 and the lid 11.

[34] As shown in FIG. 1, the vacuum generation device 21 may be constituted by a single unit, that is, a vacuum pump 210 that forcibly draws and discharges an inner air of the tube 1, thereby vacuumizing the tube 1.

[35] However, when discharging the inner air of the tube 1 directly by the vacuum pump

210, the discharged air amount can hardly be adjusted as desired. Therefore, a vacuum tub 211 may be further comprised between the vacuum pump 210 and the tube 1 as shown in FIG. 3.

[36] The vacuum tub 211 is formed as a tub having a predetermined sealed space and an inside of which is kept under a vacuum by the operation of the vacuum pump 210 discharging the inner air of the vacuum tub 211.

[37] A connection pipe 21a connected between the vacuum tub 211 and the tube 1 is equipped with a valve 21b to adjust the degree of vacuum in the tube 1.

[38] In addition, the lid 11 is connected to an air supplying device 3 such that air generated from the air supplying device 3 is supplied into the tube 1.

[39] The air supplying device 3 is required to be capable of supplying air of as high pressure as possible into the tube 1. To satisfy this, a compressor may be used as the air supplying device 3, the compressor being connected to the lid 11 through a compressed air supplying pipe 31a. Additionally, another valve 31b may be provided in the middle of the compressed air supplying pipe 31a to adjust an amount of the air being supplied.

[40] After an enough amount of air is supplied in the tube 1 by the air supplying device 3 and dissolved, if inner pressure of the tube 1 is reduced by the vacuum generation device 21, air bubbles are generated. The air bubbles are combined with blood cells in the whole blood. In order for the blood cells attached with the air bubbles to float as quickly as possible, it is preferred to lower the inner pressure of the tube 1. To this end, there is provided the vacuum generation device 21 for reducing the inner pressure of the tube, in other words, vacuumizing the inside of the tube 1.

[41] A pressure adjusting pipe 12 is further mounted at an upper part of the tube 1. In addition, a valve 12a is mounted to the pressure adjusting pipe 12.

[42] The pressure adjusting pipe 12 is used as a means for letting external air in by being gradually opened after the blood cells attached with the air bubbles are floated and thus separated. That is, the pressure adjusting pipe 12 functions to restore the inner pressure of the tube 1 to be equivalent to the atmospheric pressure after the blood cells are separated.

[43] As aforementioned, the tube 1 needs to have an openable and closable structure to store the blood therein and to this end, has the opened top side mounted with the openable lid 11 capable of forming a hermetic seal between the tube 1 and the lid 11.

[44] The lid 11 is connected with the compressed air supplying pipe 31a, the connection pipe 21a, and the pressure adjusting pipe 12. Since a pressure sensor 13 for measuring the inner pressure of the tube 1 is mounted, the inner pressure of the tube 1 detected by the pressure sensor 13 can be checked and adjusted as necessary using the valves 12a, 21b and 31b provided to the pipes 12, 31a and 21a, respectively.

[45] Hereinafter, the operation of the above-structured blood separator according to the embodiment of the present invention will briefly be described.

[46] First, blood to be separated is put in the tube 1 and an enough amount of air is supplied into the tube 1 by operating the air supplying device 3, thereby saturating the blood stored in the tube 1 with the air.

[47] More specifically, the blood is saturated with the air under the atmospheric pressure in the tube 1 by closing the valve 21b while opening the other valves 31b and 12a.

[48] When the blood is saturated with the air supplied by the air supplying device 3, the operation of the air supplying device 3 is stopped. Then, in a state where the valves 31b and 12a are closed and only the valve 21b is opened, the vacuum pump 210 is operated such that the air inside of the tube 1 is discharged to the outside.

[49] At this time, the air fully contained in the blood in the tube 1 becomes air bubbles according to reduction of the inner pressure, as shown in FIG. 4B.

[50] Here, in case that the vacuum tub 211 is provided between the tube 1 and the vacuum pump 210, the vacuum pump 210 is operated with the valve 21b also closed. After the air in the vacuum tub 211 is discharged by the vacuum pump 210 until the vacuum tub 211 is vacuumized, the valve 21b is adjusted such that the air in the tube 1 is discharged to the vacuum tub 210.

[51] When the inside of the tube 1 is thus vacuumized, the blood cells are floated according to flotation of the air bubbles. Consequently, all the blood cells are collected to the upper part of the tube 1 as shown in FIG. 4C.

[52] When the blood cells are floated along with the air bubbles and collected at the upper part of the tube 1, the valves 31b and 21b are closed whereas only the valve 12a is opened such that the external air can get into the tube 1.

[53] Here, an opened degree of the valve 12a is properly adjusted to prevent the separated blood cells in the tube 1 from being mixed again with blood plasma due to a sudden inflow of the external air.

[54] When the inner pressure of the tube 1 thus becomes equal to the atmospheric pressure by properly opening the valve 12a, the lid 11 is opened and the blood cells collected at the upper part of the tube 1 are removed by a tool such as a pipette so that only the blood plasma can be used for the analysis.

[55] Hereinafter, a blood separator having the pressurizing-type bubble generation unit 2 which injects air will be described.

[56] The structure of the blood separator having the pressurizing-type bubble generation unit 2 is as shown in FIG. 5.

[57] The same or similar structural elements as in the blood separator using the decompression-type bubble generation unit 2 will not be explained again. In this blood separator, an air pressurizing device 22 for increasing dissolved air bubbles in the blood by injecting air into the tube 1 is provided as the bubble generation unit 2.

[58] The air pressurizing device 22 comprises a compressor 220 that generates air.

[59] The compressor 220 produces a high-pressure air to be supplied to the tube 1. A general compressor used in generating the high-pressure air may be employed for the compressor 220.

[60] However, in a case where the air pressurizing device 22 solely comprises the compressor 220 and the air generated from the compressor 220 is directly supplied to the inside of the tube 1, the air bubbles may not be fine enough to be combined with fine blood cells. Therefore, the air bubbles may fail in combining with the blood cells but generate foam instead. For this reason, a saturation tub 221 is further provided between the compressor 220 and the tube 1.

[61] The saturation tub 221 is connected with a bottom side of the tube 1 through a co nnection pipe 220a and sealed to prevent discharge of the air supplied therein. The saturation tub 221 stores the air supplied by the compressor 220.

[62] Also, the saturation tub 221 further stores a liquid saturated with air therein. The air supplied by the compressor 220 is fully contained in the liquid.

[63] Here, the liquid stored in the saturation tub 221 may be a liquid which does not react to blood, or blood to be separated.

[64] The saturation tub 221 further comprises a liquid supplying pipe 221a formed at an upper part thereof to put the liquid therein. The liquid supplying pipe 221a is mounted with a valve 221b.

[65] To the connection pipe 22a through which the air-saturated liquid is supplied from the saturation tub 221 to the tube 1, a standard amount injection valve 30 is further mounted to adjust the amount of the air-saturated liquid being supplied from the saturation tub 221 to the tube 1.

[66] Additionally, a nozzle 40 is further mounted between the tube 1 and the connection pipe 22a in order to jet a high-pressure liquid, that is, the air-saturated liquid to the whole blood stored in the tube 1 at a high pressure.

[67] While the air-saturated liquid is thus jetted to the whole blood at a high pressure through the nozzle 40, pressure of the air-saturated liquid is reduced and accordingly, air bubbles are generated from the dissolved air and supplied to the whole blood. Fine air bubbles are attached to the blood cells contained in the whole blood, thereby giving buoyancy to the blood cells. Therefore, the blood cells are moved to the upper part.

[68] As the blood cells are moved upward by buoyancy of the air bubbles, only the blood plasma is left at the lower part of the tube 1.

[69] Hereinafter, the operation of the above-structured blood separator will be briefly described.

[70] First, blood to be separated is put in the tube 1.

[71] The compressor 220 constituting the air pressurizing device 22 is driven, thereby supplying the high-pressure air into the saturation tub 221. Here, the liquid stored in the saturation tub 221 is saturated with the air. In addition, in order to saturate the liquid with the air, the valve 221 of the liquid supplying pipe 221a connected to the saturation tub 221 needs to be opened to allow flow of the air being supplied.

[72] When the inner pressure of the saturation tub 221 becomes high enough, the valve

221b is closed and a predetermined amount of the air-saturated liquid is injected into the tube 1 through the nozzle 40. During this, the standard amount injection valve 30 is properly opened such that the predetermined amount of the air-saturated liquid is correctly injected.

[73] When the liquid containing dissolved air is supplied into the tube 1 through the nozzle 40, the dissolved air becomes air bubbles due to a great difference of pressure between both ends of the nozzle 40 and the air bubbles are attached to the blood cells as shown in FIG. 6B. Consequently, the air bubbles are floated to the upper part of the tube 1 along with the blood cells as shown in FIG. 6C.

[74] After the blood cells are floated, only the blood plasma remains at the lower part in the tube 1. Then, the tube 1 is separated from the blood separator and the blood cells floating at the upper part are removed, for example, by a pipette. As a result, the blood plasma can be used for analysis. [75] Although the preferred embodiments of the present invention have been disclosed for illustrative purposes, those skilled in the art will appreciate that various modifications, additions and substitutions are possible, without departing from the scope and spirit of the invention as disclosed in the accompanying claims. Industrial Applicability

[76] According to the embodiments of the present invention, whole blood is saturated with air to obtain fine air bubbles from the air, such that the air bubbles are floated as attached to blood cells. Accordingly, the blood cells and the blood plasma can be separated from each other more efficiently.

[77] Since a vacuum generation device which reduces inner pressure of a tube to a vacuum state is used to saturate the whole blood with the air, buoyancy of the air bubbles contained in the blood can be increased, thereby improving buoyancy of the blood cells. As a consequence, the blood separation efficiency can be enhanced.

[78] According to another method for saturating the whole blood with the air, air- saturated liquid is supplied to the blood through a nozzle. Therefore, air bubbles generated from the air due to a pressure reduction are attached to the blood cells and floated along with the blood cells, thereby separating the blood cells from the blood plasma. Thus, the blood separation efficiency can be improved.

Claims

[I] A blood separator for separating blood plasma and blood cells from whole blood using flotation of dissolved air, comprising: a tube storing whole blood, in which air bubbles generated by saturating air are attached to blood cells and floated along with the blood cells, thereby separating blood plasma and the blood cells from each other; and a bubble generation unit which generates air bubbles for floating the blood cells contained in the whole blood stored in the tube. [2] The blood separator using flotation of dissolved air according to claim 1, wherein the bubble generation unit comprises a vacuum generation device forcibly discharging air from the tube and thereby reducing inner pressure of the tube so that the air contained in the whole blood is discharged to the outside. [3] The blood separator according to claim 2, wherein the tube is further connected with an air supplying device which supplies air into the tube so that the whole blood becomes saturated with the air. [4] The blood separator according to claim 3, wherein the air supplying device comprises a compressor connected to a lid of the tube. [5] The blood separator according to claim 4, wherein the vacuum generation device is connected to the lid through a connection pipe. [6] The blood separator according to claim 5, wherein the vacuum generation device comprises a vacuum pump which draws in the air in the tube and discharges the drawn air to the outside. [7] The blood separator according to claim 6, wherein a vacuum tub is further provided disposed between the vacuum pump and the tube. [8] The blood separator according to claim 7, wherein the tube further comprises a pressure adjusting pipe formed at an upper part thereof, the pressure adjusting pipe which adjusts inner pressure of the tube by allowing external air to get in and out therethrough and includes a valve. [9] The blood separator according to claim 8, wherein the lid further comprises a pressure sensor which detects the inner pressure of the tube. [10] The blood separator according to claim 2, wherein the bubble generation unit comprises an air pressurizing device which supplies fine air bubbles into the tube.

[I I] The blood separator according to claim 10, wherein the air pressurizing tube is connected to a lower part of the tube.

[12] The blood separator according to claim 11, wherein the air pressurizing device comprises a compressor which supplies a high-pressure air. [13] The blood separator according to claim 12, wherein the air pressurizing device is connected to a bottom side of the tube through a connection pipe, and further equipped with a sealed saturation tub. [14] The blood separator according to claim 13, wherein the saturation tub stores therein air-saturated liquid supplied by the compressor. [15] The blood separator according to claim 14, wherein the connection pipe is further mounted with a standard amount injection valve to supply a predetermined standard amount of a high-pressure liquid saturated with the air being supplied from the saturation tub to the tube. [16] The blood separator according to claim 15, further comprising a nozzle mounted between the tube and the connection pipe to inject the high-pressure liquid saturated with the air to the whole blood stored in the tube, thereby generating air bubbles by a pressure difference. [17] The blood separator according to claim 16, wherein the saturation tub is further connected a liquid supplying pipe that supplies a liquid into the saturation tub and includes a valve.