JP2005345145A - Interface detector, volume measuring instrument, and interface detecting method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To precisely detect an interface of a prescribed liquid in a container, without being affected by a label or the like on a container surface. <P>SOLUTION: A waveguide tube 2 having a hollow tubular structure using an electromagnetic wave shielding material as a material is arranged between a microwave transmitting and receiving part 1 and a blood collecting tube 101. A microwave is made to get incident from a side way toward the blood collecting tube 101 while moving vertical-directionally the blood collecting tube 101 with respect to the microwave transmitting and receiving part 1 and the waveguide tube 2, the microwave reflected by air 107, a serum 103 and a separation agent 104 in the blood collecting tube 101 is received via the waveguide tube 2, and the interface of the serum 103 is detected by capturing a change, since the change in reflection intensity gets large in a position of an upper interface 103U of the serum 103 and a position of a lower-interface-positional lower interface 103L of the serum 103, with differences in a reflection characteristics in the air 107, the serum 103 and the separation agent 104. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention is, for example, an interface detection device, a volume measurement device suitable for detecting the serum interface of serum, separation agent, and blood clot that are separated in a blood collection tube, and further for determining the serum volume, And an interface detection method.

  Blood collected from a patient is placed in a blood collection tube together with a separating agent, centrifuged with a centrifuge to separate it into serum, separating agent, and blood clot, and then only the serum is taken out and used for various tests. It has been broken.

  In recent years, in order to reduce the burden on patients, it has been required to reduce the amount of blood collected as much as possible. On the other hand, since there are a wide variety of tests using serum, in order to use limited serum as a test material without excess or deficiency, It is required to accurately grasp the quantity.

  For example, Patent Document 1 discloses a technique for measuring a serum amount by capturing a sample liquid in a state separated into serum, a separating agent, and a blood clot with a color visual sensor and capturing a color image.

Japanese Patent Laid-Open No. 11-37845

  However, a label displaying various information is often attached to the surface of the blood collection tube. In this case, in the method of capturing a captured image as disclosed in Patent Document 1, a label is hindered and a clear image of serum cannot be obtained, and the serum interface may not be detected.

  The present invention has been made in view of the above points, and an object of the present invention is to make it possible to accurately detect an interface of a predetermined liquid in a container without being affected by a label on the surface of the container.

An interface detection device according to the present invention is an interface detection device that detects an interface of a predetermined liquid among at least two types of liquids contained in a container in a state of being vertically separated, and is provided on the side of the container toward the container. A microwave transmitting / receiving means for transmitting microwaves from the side and receiving a microwave reflected by the substance in the container; a microwave transmitted by the microwave transmitting / receiving means; and a substance in the container to be received A waveguide for forming a microwave waveguide to be reflected by the microwave, and an interface detecting means for detecting an interface of the predetermined liquid based on the microwave received by the microwave transmitting / receiving means. Has features.
Another feature of the interface detection apparatus according to the present invention is that it includes moving means for relatively moving the microwave transmitting / receiving means, the waveguide, and the container in the vertical direction.
Another feature of the interface detection device according to the present invention is that the waveguide is a rectangular waveguide having a rectangular cross section.
Another feature of the interface detection apparatus according to the present invention is that the waveguide has a portion in which the width of the hollow portion gradually increases from the microwave transmitting / receiving means side toward the container side. In the point.
Another feature of the interface detection apparatus according to the present invention is that the waveguide is disposed between the microwave transmitting / receiving means and the container.
Another feature of the interface detection device according to the present invention is that an electromagnetic wave absorber is disposed on the opposite side of the microwave transmitting / receiving unit with the container interposed therebetween.
Another feature of the interface detection apparatus according to the present invention is that the waveguide extends to the opposite side of the microwave transmitting / receiving means across the container, and penetrates vertically through the container. The insertion hole is to be formed.
Another feature of the interface detection device of the present invention is that the terminal opening of the waveguide is closed by an electromagnetic wave absorber.
The volume measuring device of the present invention is based on the interface detection device of the present invention, the interval between the upper and lower interfaces of the predetermined liquid detected by the interface detection device, and the inner diameter dimension of the container determined in advance. And a volume calculating means for calculating the volume of the predetermined liquid.
The interface detection method of the present invention is an interface detection method for detecting an interface of a predetermined liquid out of at least two kinds of liquids contained in a container in a state of being vertically separated, and is provided on the side of the container toward the container. A procedure for transmitting microwaves from the side through the waveguide, a procedure for receiving microwaves reflected by the liquid in the container through the waveguide, and the predetermined microwave based on the received microwaves. And a procedure for detecting the interface of the liquid.

  According to the present invention, since the interface of the predetermined liquid in the container is detected using the microwave that transmits the paper or resin that is the material of the label, it is not affected by the label on the surface of the container. A predetermined liquid interface can be detected. In addition, by arranging the waveguide, a microwave waveguide transmitted by the microwave transmitting / receiving means and a microwave waveguide reflected by the substance in the container to be received are formed, and the microwave is transmitted efficiently. At the same time, it is possible to prevent reception of unnecessary microwaves other than the microwave reflected by the substance in the container, and the interface of the predetermined liquid can be detected with high accuracy.

Preferred embodiments of the present invention will be described below with reference to the accompanying drawings.
(First embodiment)
1 and 2 are diagrams illustrating a schematic configuration of the volume measuring apparatus according to the first embodiment. The volume measuring device obtains the interval (height) between the upper and lower interfaces 103U and 103L by detecting the position of the upper interface 103U and the lower interface 103L of the serum 103 in the sample liquid 102 in the blood collection tube 101, and obtains a known collection. This is for calculating the volume (serum amount) of the serum 103 using the inner diameter of the blood vessel 101 and the like.

  First, the blood collection tube 101 containing the sample liquid 102 will be described with reference to FIG. The blood collection tube 101 has a cylindrical shape with a closed lower end, such as a test tube, and is made of a material that can transmit microwaves, such as colorless and transparent glass or resin.

  The sample liquid 102 is composed of blood collected from the subject and a separating agent. As a result of centrifugation, the sample liquid 102 is changed from the bottom of the blood collecting tube 101 to the gel-like clot 105, separating agent 104, and serum 103 in descending order of specific gravity. It is in a separated state.

  As shown in FIGS. 1 and 2, a translucent label 106 made of a material that can transmit microwaves, such as paper or resin, is attached to the surface of the blood collection tube 101. On the label 106, information about the subject is displayed by characters, symbols, barcodes, etc. by printing or handwriting.

  Next, the volume measuring device will be described. As shown in FIGS. 1 and 2, a hollow tube made of an electromagnetic wave shielding member (for example, a metal such as copper) between the microwave transmitting / receiving unit 1 and the blood collection tube 101. A waveguide 2 having a structure is provided.

  The waveguide 2 is a rectangular waveguide having a plate shape as a whole. The waveguide 2 used in this embodiment has a uniform thickness, and the height h of the hollow portion 3 having a rectangular cross section is constant, but the width w is the width on the microwave transmitting / receiving unit 1 side. It is narrow and gradually widens from there, and has a certain width on the blood collection tube 101 side. Thus, by making the one end of the waveguide 2 into a narrow shape, the width w of the hollow portion 3 is matched with the dimensions of the transmitter 1a and the receiver 1b of the microwave transmitter / receiver 1 on the microwave transmitter / receiver 1 side. Thus, the loss can be reduced, and the width corresponding to the diameter of the blood collection tube 101 can be secured on the blood collection tube 101 side.

  When the interface is detected by the microwave transmission / reception unit 1, the upper end of the blood collection tube 101 is held by the manipulator 4. The manipulator 4 is movable in two horizontal directions along a conveyance path 5 and a conveyance path (not shown) orthogonal to the conveyance path 5 and can be moved up and down in the vertical direction. In this case, as an actuator for raising and lowering the manipulator 4 (that is, the blood collection tube 101), for example, a pulse motor (not shown) is used, and the elevation position of the blood collection tube 101 is obtained based on the number of pulses generated from the pulse motor. It has become.

  By adopting such a configuration that can move in three axial directions, a desired blood collection tube 101 is taken out from a stocker (not shown), transported to a predetermined position, and moved up and down with respect to the microwave transmitting / receiving unit 1. It can be moved in the direction (arrow Z in FIG. 1), and the conveyance of the blood collection tube 101 between the stocker and the microwave transmitting / receiving unit 1 and the interface detection by the microwave transmitting / receiving unit 1 can be automated.

  Here, the microwave transmission / reception unit 1 detects a microwave received by the reception unit 1b of the microwave transmission / reception unit 1 and converts it into an electric signal, and an electric signal output from the detection circuit 6 The amplifier circuit 7 to be amplified is connected. Further, an interface detection that includes a comparator circuit and detects the position of the upper interface 103U and the lower interface 103L of the serum 103 while referring to the number of pulses from a pulse motor (not shown) based on the electrical signal output from the amplifier circuit 7 The distance (height) between the upper and lower interfaces 103U, 103L is determined from the position of the upper surface 103U and the position of the lower interface 103L detected by the interface 8 and the interface detector 8, and the blood collection tubes stored in the storage unit 10 are obtained. A volume calculation unit 9 that calculates the volume (serum volume) of the serum 103 using the inner diameter dimension of 101 is connected.

  Hereinafter, with reference to FIG. 4, processing until the interface position of the serum 103 is detected and its volume is obtained will be described. The principle of the detection of the interface of the serum 103 utilizes the fact that the microwave reflection characteristics differ depending on the dielectric constant of the medium substance. That is, when microwaves are incident from the side toward the blood collection tube 101 while relatively moving the microwave transmitting / receiving unit 1 and the blood collection tube 101 in the vertical direction, each layer (air 107, serum 103, Due to the difference in reflection characteristics between the separating agent 104 and the blood clot 105), the intensity (reflection intensity) of the microwave received by the microwave transmitting / receiving unit 1 changes at the interface of each layer.

  Specifically, the air 107 and the separating agent 104 in the blood collection tube 101 have a relatively small dielectric constant, the relative dielectric constant of air is close to 1, and the relative dielectric constant of the separating agent is about 5. Therefore, when microwaves are incident on them, they are transmitted at a large rate, in other words, hardly reflected, so that the intensity (reflection intensity) of the microwaves received by the microwave transmitting / receiving unit 1 is as shown in FIG. As shown in FIG.

  In contrast, serum 103, which is an aqueous solution, has a relatively large dielectric constant, and its relative dielectric constant is about 50 or more. Therefore, when the microwave is incident on it, the intensity (reflection intensity) of the microwave that is reflected at a large ratio and received by the microwave transmission / reception unit 1 is shown in FIG. Or higher than the separation agent 104 in the lower layer. Although not shown in FIG. 4B, the clot 105 also has a relatively large dielectric constant (relative dielectric constant of about 50 or more), and the intensity of the microwave (reflection intensity) received by the microwave transceiver 1. ) Is similarly high.

  Due to the difference in reflection characteristics, reflection occurs at the interface (upper interface 103U) position (state a) between the serum 103 and the air 107 and at the interface (lower interface 103L) position (state b) between the serum 103 and the separating agent 104. Since the change in intensity becomes large, the interface of the serum 103 can be detected by capturing the large change.

  Thus, when microwaves are incident on each layer in the blood collection tube 101, the dielectric constant of the blood collection tube 101 itself or the label 106 is small (for example, the relative dielectric constant of glass or paper is about 5 or less), and the microwave is incident on them. However, since most of the light is transmitted, the influence of the blood collection tube 101 itself and the label 106 can be ignored.

  Here, it is desirable to use a transmitter having a directivity as much as possible as the transmitter 1a of the microwave transmitter / receiver 1. However, since the main lobe is still wide, microwaves can be transmitted / received without using the waveguide 2. Only by performing this, the microwave incident on the blood collection tube 101 becomes weak. Moreover, there is a possibility that microwaves are also emitted to the surroundings and reflected by surrounding objects and received by the microwave transmitting / receiving unit 1. Furthermore, the microwave transmitted from the peripheral device or the like may be received by the microwave transmitting / receiving unit 1. Therefore, as shown by the dotted line in FIG. 4B, the reflection intensity is lowered as a whole, and the waveform of the reflection intensity becomes unclear due to unnecessary microwaves other than the microwave reflected by the substance in the blood collection tube 101. Therefore, it becomes difficult to detect the interface accurately.

  On the other hand, by arranging the waveguide 2 as described in the present embodiment, the microwave transmitted by the microwave transmitting / receiving unit 1 and the microwave reflected by the substance in the blood collection tube 101 are received. Since the waveguide is formed, as shown by the solid line in FIG. 4B, the microwaves can be transmitted efficiently and the reflection intensity can be increased as a whole. Further, it is possible to prevent the microwave from being reflected by a surrounding object and received by the microwave transmitting / receiving unit 1 or the microwave transmitted from a peripheral device or the like being received by the microwave transmitting / receiving unit 1. Since the intensity waveform becomes clear, it becomes easier to capture the waveform change.

  Based on the interface detection principle described above, the microwave transmission / reception unit 1 and the blood collection tube 101 are moved relative to each other in the vertical direction, and the microwave received by the microwave transmission / reception unit 1 is detected and detected by the detection circuit 6. When the signal is converted into a signal, smoothed as necessary, and the electric signal output from the detection circuit 6 is amplified by the amplifier circuit 7, a waveform as shown by a solid line in FIG. 4B is obtained.

  The interface detection unit 8 detects the position of the upper interface 103U and the position of the lower interface 103L of the serum 103 with reference to the number of pulses from a pulse motor (not shown) based on the electrical signal output from the amplifier circuit 7. In this case, as shown in FIG. 4B, the reflection intensity at the interface between the serum 103 and the air 107 (upper interface 103U) and at the interface between the serum 103 and the separating agent 104 (lower interface 103L). Although the change is large, it actually changes with a certain degree of gentleness. Therefore, in order to determine the position of the upper interface 103U and the position of the lower interface 103L of the serum 101, threshold values corresponding to these interfaces 103U and 103L are defined in advance, and are output from the amplification circuit 7 by the comparator circuit of the interface detection unit 8. The position where the electric signal value coincides with the threshold value is obtained by comparing the electric signal to be performed with the threshold value, and the position is detected as the position of the upper interface 103U and the position of the lower interface 103L of the serum 103.

  Then, the volume calculation unit 9 obtains an interval (height) between the upper and lower interfaces 103U and 103L from the position of the upper interface 103U and the lower interface 103L detected by the interface detection unit 8, and stores it in the storage unit 10. The volume (serum amount) of the serum 103 is calculated using the inner diameter of the blood collection tube 101 and the like.

  Although the first embodiment has been described above, in addition to the above-described configuration, when the electromagnetic wave absorber 11 is disposed on the side opposite to the microwave transmitting / receiving unit 1 with the blood collection tube 101 interposed therebetween as shown in FIGS. It is effective. In the illustrated example, an electromagnetic wave absorber 11 made of synthetic resin in a plate shape is disposed along the blood collection tube 101. As described above, especially in the air 107 and the separating agent 104, the microwave is transmitted in a large proportion, but the transmitted microwave is reflected by the object on the extension line in the transmission direction, and again passes through the air 107 and the separating agent 104. Then, it may be received by the microwave transmission / reception unit 1 through the waveguide 2 and become noise. Considering this point, if the electromagnetic wave absorber 11 is arranged as shown in FIGS. 1 and 4, the microwave transmitted through the air 107 and the separating agent 104 is absorbed. It is possible to avoid the transmitted microwave from returning to the microwave transmission / reception unit 1.

  FIG. 5 shows an example of the shape of the waveguide 2. FIG. 5A shows a planar shape of the waveguide 2 shown in FIG. 1, but the shape of the waveguide 2 is not limited thereto. For example, the example shown in FIG. 5B is an example of a rectangular waveguide having a certain width, and the example shown in FIG. 5C is narrow in the microwave transmission / reception unit 1 and from there to the blood collection tube 101 side. This is an example of a rectangular waveguide that gradually becomes wider.

(Second Embodiment)
The second embodiment shown in FIGS. 6 and 7 is an example in which a waveguide 12 extending to the opposite side of the microwave transmission / reception unit 1 is disposed with the blood collection tube 101 interposed therebetween. In the following description, differences from the first embodiment will be mainly described, and the same components are denoted by the same reference numerals, and detailed description thereof will be omitted.

  The waveguide 12 is a plate-shaped rectangular waveguide as a whole, and an insertion hole 13 penetrating vertically for inserting the blood collection tube 101 is formed at the center thereof. Similar to the first embodiment, the waveguide 12 has a uniform thickness, and the height h of the hollow portion 14 having a rectangular cross section is constant, but the width w is the microwave transmitting / receiving unit. It is narrow on one side, gradually becomes wider from there, and has a certain width from the middle.

  Furthermore, as shown in FIG. 6, the terminal opening 12a of the waveguide 12 is closed using an electromagnetic wave absorber 15 made of synthetic resin or the like. More preferably, as shown in FIG. 7A, an electromagnetic wave absorber made of a thin synthetic resin is provided in a region 16 on the opposite side of the microwave transmitting / receiving unit 1 across the blood collection tube 101 on the inner surface of the waveguide 12. Processing such as sticking or applying an electromagnetic wave absorber made of a liquid is performed.

  In the first embodiment, as shown in FIG. 1, since the end of the waveguide 2 is located in front of the blood collection tube 101, the end is opened (terminal opening 2a), and the microwave is supplied to the blood collection tube 101. It is necessary to make it incident. Therefore, there is a slight possibility that microwaves in the waveguide 2 are emitted to the periphery or unnecessary microwaves are incident on the waveguide 2 through the terminal opening 2a.

  On the other hand, in the present embodiment, since the terminal opening 12a of the waveguide 12 can be closed using the electromagnetic wave absorber 15, the microwave in the waveguide 12 is emitted from the terminal opening 12a to the outside. Or unnecessary microwaves can be prevented from entering the waveguide 12. Further, as described above, it is possible to avoid the microwave that has passed through the air 107 and the separating agent 104 being reflected by the object on the transmission direction extension line and returning to the microwave transmitting / receiving unit 1.

  FIG. 7 shows an example of the shape of the waveguide 12. FIG. 7A shows the planar shape of the waveguide 12 shown in FIG. 6, but the shape of the waveguide 12 is not limited thereto. For example, what is shown in FIG. 7B is an example of a rectangular waveguide having a certain width, and what is shown in FIG. 7C is narrow in the microwave transmission / reception unit 1 and gradually extends from there to the end. This is an example of a wide rectangular waveguide.

  As mentioned above, although this invention was demonstrated with embodiment, this invention is not limited only to embodiment, A change etc. are possible within the scope of the present invention. For example, in the above embodiment, the blood collection tube 101 is moved in the vertical direction with respect to the microwave transmission / reception unit 1 and the waveguide 2 (12). The waveguide 2 (12) may be moved in the vertical direction.

It is a perspective view showing a schematic structure of a volume measuring device of a 1st embodiment. It is a figure showing the schematic structure of the volume measuring device of a 1st embodiment. It is a figure which shows the blood-collecting tube containing the sample liquid. It is a figure for demonstrating the principle of an interface detection. It is a figure which shows the example of a shape of the waveguide used for the volume measuring apparatus of 1st Embodiment. It is a perspective view which shows schematic structure of the volume measuring apparatus of 2nd Embodiment. It is a figure which shows the example of a shape of the waveguide used for the volume measuring apparatus of 2nd Embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Microwave transmission / reception part 2 Waveguide 3 Hollow part 4 Manipulator 5 Carriage path 6 Detection circuit 7 Amplification circuit 8 Interface detection part 9 Volume calculation part 10 Memory | storage part 11 Electromagnetic wave absorber 12 Waveguide 13 Insertion hole 14 Hollow part 15 Electromagnetic wave Absorber 16 Region where electromagnetic wave absorber is provided 101 Blood collection tube 102 Sample liquid 103 Serum 103U Upper interface 103L Lower interface 104 Separating agent 105 Clot 106 Label 107 Air

Claims (10)

An interface detection device that detects an interface of a predetermined liquid among at least two types of liquids contained in a container in a state of being vertically separated,
Microwave transmission and reception means for transmitting microwaves from the side of the container toward the container and receiving microwaves reflected by the substance in the container;
A waveguide for forming a microwave waveguide reflected by the microwave transmitted by the microwave transmitting / receiving means and received by the substance in the container;
An interface detection device comprising: an interface detection unit configured to detect an interface of the predetermined liquid based on the microwave received by the microwave transmission / reception unit.   The interface detection apparatus according to claim 1, further comprising a moving unit that relatively moves the microwave transmitting / receiving unit, the waveguide, and the container in a vertical direction.   The interface detection device according to claim 1, wherein the waveguide is a rectangular waveguide whose hollow portion has a rectangular cross section.   The interface detection device according to claim 3, wherein the waveguide has a portion in which the width of the hollow portion gradually increases from the microwave transmitting / receiving means side toward the container side.   The interface detection device according to claim 1, wherein the waveguide is disposed between the microwave transmitting / receiving unit and the container.   The interface detection apparatus according to claim 5, wherein an electromagnetic wave absorber is disposed on the opposite side of the microwave transmission / reception unit with the container interposed therebetween.   The said waveguide is extended to the opposite side to the said microwave transmission / reception means on both sides of the said container, The penetration hole penetrated up and down for penetrating the said container is formed, The 1-4 characterized by the above-mentioned. The interface detection apparatus according to any one of the above.   The interface detection device according to claim 7, wherein a terminal opening of the waveguide is closed by an electromagnetic wave absorber. The interface detection device according to any one of claims 1 to 8,
Volume calculating means for calculating the volume of the predetermined liquid based on an interval between the upper and lower interfaces of the predetermined liquid detected by the interface detection device and an inner diameter dimension of the container is provided. Volume measuring device. An interface detection method for detecting an interface of a predetermined liquid out of at least two kinds of liquids contained in a container in a state of being vertically separated,
A procedure for transmitting microwaves through the waveguide from the side of the container toward the container;
Receiving a microwave reflected by the substance in the container via a waveguide;
A method of detecting an interface of the predetermined liquid based on the received microwave.

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