Interface detection sensor

Abstract

To provide an interface detection sensor that can detect interfaces with a simple configuration.SOLUTION: An interface detection sensor 1 includes a light emitting unit 10 having a first light emitter 11 that emits first detection light L1 and a second light emitter 12 that emits second detection light L2, a light receiving unit 20 that receives the first detection light and the second detection light and outputs a light receiving signal SG1, and a control unit 40 that controls the light emitting unit so as to emit light in two of the following patterns: an emission pattern in which the light is emitted so that the light receiving unit receives both the first and second detected light simultaneously, an emission pattern in which the light receiving unit receives only the first detection light, and an emission pattern in which the light receiving unit receives only the second detection light. The control unit extracts a feature quantity indicating a label pattern that is a combination pattern of the number of layers of a sample, an upper end position of an identification label 52 and a lower end position of the identification label from the light receiving signal, determines the label pattern based on the feature quantity, and detects an interface of the sample from the light receiving signal based on the label pattern.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present disclosure relates to an interface detection sensor. [Background technology]

[0002] The interface detection sensor is used to detect the interface of a sample contained in a container. The interface detection sensor includes a light-projecting unit that projects two detection lights with different wavelengths, and a light-receiving unit that receives the detection light that has passed through the container and outputs a light-receiving signal based on the received detection light. The transmittance of the detection light differs for each layer of the sample. Therefore, when the detection light passes through the vicinity of the interface of the sample, a change in intensity occurs in the light-receiving signal. In this way, the measurement device detects the interface of the sample contained in the container based on the light-receiving signal.

[0003] If an identification label is attached to the container, the light projected from the light-projecting unit passes through the identification label, reducing the intensity of the received light signal. That is, the identification label causes a change in intensity of the received light signal. Therefore, when detecting the interface of the sample based on the received light signal, it becomes difficult to distinguish between the identification label and the interface of the sample.

[0004] The interface detection sensor described in Patent Document 1 additionally includes a label position measurement unit that measures the position of the identification label. This makes it possible to distinguish between the identification label and the interface of the sample, and therefore the interface of the sample can be detected based on the received light signal. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] JP 2017-211288 A Summary of the Invention [Problem to be solved by the invention]

[0006] The interface detection sensor described in Patent Document 1 needs to have a configuration for separately measuring the position of the identification label in order to detect the interface of the sample, which makes the configuration of the interface detection sensor complicated. [Means for solving the problem]

[0007] The interface detection sensor for solving the above problem is an interface detection sensor for detecting an interface of a sample contained in a container to which an identification label is attached, the interface detection sensor comprising: a light-projecting unit having a first light-projecting element that projects a first detection light of a first wavelength and a second light-projecting element that projects a second detection light of a second wavelength different from the first wavelength; a light-receiving unit that receives the first detection light and the second detection light and outputs a light-receiving signal according to an amount of received light; a light-projecting pattern that projects light such that the light-receiving unit simultaneously receives both the first detection light and the second detection light; and a control unit that controls the light-projecting unit to project light in two light-projection patterns: a light-projection pattern in which light is projected so that the light-receiving unit receives only the second detection light, and a light-projection pattern in which light is projected so that the light-receiving unit receives only the second detection light, wherein the control unit extracts features indicative of a label pattern, which is a combination pattern of the number of layers of the sample, the upper end position of the identification label, and the lower end position of the identification label, from the light-receiving signal, determines the label pattern based on the features, and detects an interface of the sample from the light-receiving signal based on the label pattern.

[0008] The interface detection sensor that solves the above problem is an interface detection sensor for detecting an interface of a sample contained in a container to which an identification label is affixed, and includes a light-projecting unit having a first light-projecting element that projects a first detection light of a first wavelength and a second light-projecting element that projects a second detection light of a second wavelength different from the first wavelength, a light-receiving unit that receives the first detection light and the second detection light and outputs a light-receiving signal according to the amount of light received, and a control unit that controls the light-projecting unit to project light in two light-projection patterns out of a light-projection pattern in which both the first detection light and the second detection light are received simultaneously by the light-receiving unit, a light-projection pattern in which only the first detection light is projected by the light-receiving unit, and a light-projection pattern in which only the second detection light is received by the light-receiving unit, and the control unit detects the interface of the sample by inputting the light-receiving signal to mapping data that defines a mapping in which the light-receiving signal is input and a value indicating the interface of the sample is output. Effect of the Invention

[0009] According to the interface detection sensor of the present disclosure, an interface can be detected with a simple configuration. [Brief description of the drawings]

[0010] [Figure 1] FIG. 2 is a block diagram showing an interface detection sensor according to the first embodiment. [Diagram 2] Cross-section of a test tube containing a blood sample, which consists of two layers. [Diagram 3] Cross-section of a test tube containing a blood sample, which consists of three layers. [Figure 4] Front view of a test tube with an identification label attached. [Diagram 5] FIG. 1 is a graph showing wavelength-transmittance characteristics of a blood sample. [Figure 6] 4 is a timing chart of detected light and received light signals. [Figure 7] FIG. 13 shows data on the amount of light received for a two-layer blood sample. [Figure 8] FIG. 13 shows light reception data for a three-layer blood sample. [Figure 9]1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 10] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 11] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 12] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 13] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 14] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 15] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 16] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 17] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 18] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 19] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 20] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 21] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 22] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 23] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 24] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 25] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 26] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 27] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 28] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Figure 29] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 30] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 31] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 32] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 33] 1 is a cross-sectional view of a test tube showing an example of a label pattern. [Diagram 34] 5 is a flowchart showing the procedure of a process executed by a control unit. [Diagram 35] FIG. 11 is a diagram showing buffered received light amount data. [Diagram 36] FIG. 13 is a diagram showing data on the amount of light received for a blood sample contained in a test tube with an identification label attached. [Figure 37] 10 is a flowchart showing the procedure of a process executed by a control unit according to a second embodiment. [Figure 38] 10 is a flowchart showing the procedure of a process executed by a control unit according to a third embodiment. [Figure 39] 10 is a timing chart showing an example of modification of a light reception signal. [Diagram 40] 10 is a timing chart showing an example of modification of a light reception signal. [Diagram 41] 13A and 13B are schematic diagrams showing modified examples of the light receiving section. [Diagram 42] 10 is a timing chart showing an example of modification of a light reception signal. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the interface detection sensor will be described with reference to the drawings. First Embodiment As shown in Fig. 1, the interface detection sensor 1 is a sensor for detecting the interface of a sample contained in a test tube 50, which is an example of a container. The sample is, for example, a blood sample 60. Therefore, the test tube 50 is, for example, a blood collection tube. The blood sample 60 is composed of multiple layers due to centrifugation performed on the test tube 50. The interface detection sensor 1 detects the interface of the blood sample 60 contained in the test tube 50 in a non-contact manner by projecting detection light onto the test tube 50.

[0012] 2 and 3 show an example of a blood sample 60 contained in a test tube 50. The blood sample 60 is composed of, for example, two or three layers. A cap 51 is attached to the test tube 50. The cap 51 closes the opening of the test tube 50.

[0013] 2 includes a first layer 61 and a second layer 62. The first layer 61 is, for example, a serum layer, and the second layer 62 is, for example, a blood clot layer. The second layer 62 and the first layer 61 are arranged in this order from the bottom surface of the test tube 50 toward the cap 51.

[0014] The blood sample 60 shown in FIG. 3 includes a first layer 61, a second layer 62, and a third layer 63. The third layer 63 is a layer of a separating agent. The separating agent is, for example, an organic separating gel. The third layer 63 is located between the first layer 61 and the second layer 62. That is, the separating agent is located between the serum and the blood clot. From the bottom surface of the test tube 50 toward the cap 51, the second layer 62, the third layer 63, and the first layer 61 are arranged in this order.

[0015] 2 and 3, the test tube 50 contains, for example, air in addition to the blood sample 60. Therefore, an air layer 64 is formed in the test tube 50. The blood sample 60 and the air layer 64 are arranged in this order from the bottom surface of the test tube 50 toward the cap 51.

[0016] 2, the interface detection sensor 1 detects an interface 65 between a first layer 61 and an air layer 64, and an interface 66 between the first layer 61 and a second layer 62. The interface 65 is the upper surface of the first layer 61. The interface 66 is the lower surface of the first layer 61 and the upper surface of the second layer 62.

[0017] 3, the interface detection sensor 1 detects an interface 65 between the first layer 61 and the air layer 64, an interface 67 between the first layer 61 and the third layer 63, and an interface 68 between the third layer 63 and the second layer 62. The interface 67 is the lower surface of the first layer 61 and the upper surface of the third layer 63. The interface 68 is the lower surface of the third layer 63 and the upper surface of the second layer 62.

[0018] 4, one or more identification labels 52 are usually affixed to a test tube 50. In the first embodiment, it is assumed that up to three identification labels 52 are affixed to the test tube 50. The identification labels 52 are used to identify the type of test tube 50, the test item, the blood sample 60 which is the specimen, etc. The identification label 52 is, for example, a barcode label.

[0019] The identification label 52 may be attached so as to cover the test tube 50. Therefore, the detection light emitted by the interface detection sensor 1 may be irradiated onto the identification label 52. The detection light has a property of passing through the identification label 52, but is attenuated to a certain extent when passing through the identification label 52. A part of the detection light may be reflected by the identification label 52.

[0020] 1, the interface detection sensor 1 includes a light-projecting unit 10 and a light-receiving unit 20. In the first embodiment, the light-projecting unit 10 and the light-receiving unit 20 are disposed so as to sandwich a test tube 50 therebetween. Furthermore, the interface detection sensor 1 of the first embodiment includes a light merging unit 30 disposed between the light-projecting unit 10 and the test tube 50.

[0021] The interface detection sensor 1 and the test tube 50 are relatively movable in the direction in which multiple layers are stacked in the blood sample 60, that is, in the height direction (Z direction) in the first embodiment. In the first embodiment, the interface detection sensor 1 is moved in the height direction (Z direction) relative to the test tube 50 by a moving mechanism 80. The moving mechanism 80 may move the test tube 50 in the height direction (Z direction) relative to the interface detection sensor 1.

[0022] The light-projecting unit 10 is configured to project a first detection light L1 having a first wavelength and a second detection light L2 having a second wavelength. The light-projecting unit 10 includes, for example, a first light-projecting element 11 and a second light-projecting element 12. The light-projecting unit 10 includes a first driver 13 that drives the first light-projecting element 11 and a second driver 14 that drives the second light-projecting element 12.

[0023] The first light-projecting element 11 projects a first detection light L1. The second light-projecting element 12 projects a second detection light L2. The first driver 13 controls the first light-projecting element 11 to project a pulsed first detection light L1. Similarly, the second driver 14 controls the second light-projecting element 12 to project a pulsed second detection light L2. In this way, in the first embodiment, the first light-projecting element 11 and the second light-projecting element 12 project pulsed detection light.

[0024] The first wavelength of the first detection light L1 and the second wavelength of the second detection light L2 are set according to the characteristics of the sample to be detected. The detection target in the first embodiment is a blood sample 60. The first wavelength of the first detection light L1 and the second wavelength of the second detection light L2 are set so that the amount of transmitted light of the first detection light L1 through the first layer 61 and the second layer 62 is different from the amount of transmitted light of the second detection light L2 through the first layer 61 and the second layer 62. That is, the light projecting unit 10 projects two detection lights with different amounts of transmitted light through serum and blood clots. More specifically, the light projecting unit 10 projects two detection lights with different amounts of transmitted light through serum, blood clots, and a separating agent.

[0025] The first detection light L1 and the second detection light L2 are light having a wavelength in the infrared region. The second detection light L2 is light having a wavelength in a wavelength region longer than the wavelength of the first detection light L1. It is preferable that the first detection light L1 and the second detection light L2 are light having a wavelength in the near-infrared region. In the first embodiment, the first wavelength of the first detection light L1 is not less than 800 nm and not more than 1100 nm. The second wavelength of the second detection light L2 is not less than 1300 nm and not more than 2000 nm. The first wavelength is, for example, 975 nm, and the second wavelength is, for example, 1550 nm.

[0026] FIG. 5 shows the wavelength-transmittance characteristics of a blood sample 60. The transmittance shown in FIG. 5 is the ratio between the amount of detection light received directly by the light receiving element 21 shown in FIG. 1 and the amount of detection light received by the light receiving element 21 after passing through a specimen having a thickness of 16 mm. In FIG. 5, a solid characteristic line A1 indicates the transmittance for the first layer 61, i.e., serum. A dashed characteristic line A2 indicates the transmittance for the third layer 63, i.e., the separating agent. A dashed characteristic line A3 indicates the transmittance for the second layer 62, i.e., the blood clot. A dashed characteristic line A4 indicates the transmittance for the identification label 52.

[0027] 1, the light combining unit 30 combines the first detection light L1 and the second detection light L2 into the same optical path. The same optical path is an optical path that travels from the light combining unit 30 to the light receiving unit 20 by passing through a test tube 50.

[0028] The light combining unit 30 of the first embodiment has a reflecting mirror 31 and a dichroic mirror 32. The light combining unit 30 combines the first detection light L1 and the second detection light L2 into the same optical path by the reflecting mirror 31 and the dichroic mirror 32. The combined first detection light L1 and second detection light L2 are transmitted through the test tube 50 and then enter the light receiving unit 20.

[0029] The light receiving unit 20 has a single light receiving element 21 and an amplifier 22. The light receiving element 21 has a light receiving characteristic of receiving a first detection light L1 and a second detection light L2. The light receiving element 21 outputs a signal at a level corresponding to the amount of light received. The amplifier 22 outputs a light receiving signal SG1 obtained by amplifying the signal output from the light receiving element 21. The signal output from the light receiving element 21 may be the light receiving signal SG1.

[0030] The interface detection sensor 1 includes a control unit 40. The control unit 40 has a function of controlling the light projecting unit 10. The control unit 40 has a function of detecting the interface of the sample based on the light receiving signal SG1 output by the light receiving unit 20.

[0031] The control unit 40 includes a CPU 41, an output unit 42, an amplifier 43, an A / D converter 44, an output unit 45, and a memory 46. The CPU 41 controls the first light-projecting element 11 and the second light-projecting element 12 via the output unit 42, the first driver 13, and the second driver 14. The CPU 41 can control the light-projecting unit 10 so that the light-projecting unit 10 projects the first detection light L1 and the second detection light L2 in three light-projection patterns. That is, the light-projecting unit 10 can project the first detection light L1 and the second detection light L2 in three light-projection patterns.

[0032] The CPU 41 can control the light-projecting unit 10 to project the first detection light L1 and the second detection light L2 in a first light-projection pattern in which the light-receiving unit 20 receives both the first detection light L1 and the second detection light L2 simultaneously, a second light-projection pattern in which the light-receiving unit 20 receives only the first detection light L1, and a third light-projection pattern in which the light-receiving unit 20 receives only the second detection light L2. Therefore, the light-receiving unit 20 can receive both the first detection light L1 and the second detection light L2 simultaneously, and can also receive each of them individually.

[0033] The CPU 41 controls the light-projecting unit 10 so that the light-projecting unit 10 projects the first detection light L1 and the second detection light L2 in two of three light-projection patterns. In the first embodiment, the CPU 41 controls the light-projecting unit 10 so that the light-projecting unit 10 projects the first light-projection pattern and the third light-projection pattern.

[0034] In the first embodiment, the CPU 41 controls the first light-projecting element 11 and the second light-projecting element 12 so that the light-receiving unit 20 receives only the second detection light L2 after simultaneously receiving the first detection light L1 and the second detection light L2. For example, the CPU 41 controls the first light-projecting element 11 and the second light-projecting element 12 so that the light-receiving unit 20 starts receiving the first detection light L1 and the second detection light L2 at the same time. In this case, the amount of light received by the light-receiving unit 20 is represented by a waveform that decreases in stages. This example is not limited to the above, and for example, the CPU 41 may control the first light-projecting element 11 and the second light-projecting element 12 so that the light-receiving unit 20 receives only the second detection light L2 and then simultaneously receives the first detection light L1 and the second detection light L2. In this case, the amount of light received by the light-receiving unit 20 is represented by a waveform that increases in stages. The CPU 41 may or may not synchronize the first light-projecting element 11 and the second light-projecting element 12.

[0035] As shown in Fig. 6, the first detection light L1 and the second detection light L2 are projected at a predetermined period. The first detection light L1 is projected at a first period. The second detection light L2 is projected at a second period. In the first embodiment, the first period coincides with the second period. That is, in the first embodiment, the first detection light L1 and the second detection light L2 are projected at the same period.

[0036] In the first embodiment, the pulse width of the first detection light L1 is different from the pulse width of the second detection light L2. For example, the pulse width of the first detection light L1 is shorter than the pulse width of the second detection light L2. The pulse width of the first detection light L1 may be longer than the pulse width of the second detection light L2.

[0037] In the first embodiment, based on the first detection light L1 and the second detection light L2, a light receiving signal SG1 shown in Fig. 6 is output from the light receiving unit 20. The light receiving signal SG1 shown in Fig. 6 is a signal when the test tube 50 is not located between the light projecting unit 10 and the light receiving unit 20.

[0038] In the first embodiment, the light receiving signal SG1 includes joint data D1 and individual data D2. The joint data D1 and the individual data D2 are data representing values ​​indicating the amount of received light. The joint data D1 is data representing values ​​indicating the amount of received light by the first detection light L1 and the second detection light L2 in the light receiving signal SG1. That is, the joint data D1 represents a value indicating the amount of received light by the first light projection pattern. The individual data D2 is data representing values ​​indicating the amount of received light by only the first detection light L1 in the light receiving signal SG1, or data representing values ​​indicating the amount of received light by only the second detection light L2. In the first embodiment, the individual data D2 represents a value indicating the amount of received light by only the second detection light L2, that is, a value indicating the amount of received light by the third light projection pattern. Therefore, in the first embodiment, the light receiving signal SG1 is output from the light receiving unit 20 by the light receiving unit 20 receiving the first detection light L1 and the second detection light L2 projected from the light projecting unit 10 in two light projection patterns.

[0039] In the first embodiment, the CPU 41 controls the first light-projecting element 11 and the second light-projecting element 12 so that the light-receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2. As a result, the light-receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2, and then receives only the second detection light L2.

[0040] 1, the CPU 41 receives the light receiving signal SG1 output by the light receiving unit 20 via the amplifier 43 and the A / D converter 44. Specifically, the light receiving signal SG1 output by the light receiving unit 20 is converted into a digital value by the amplifier 43 and the A / D converter 44. This digital value is input to the CPU 41. The digital value into which the light receiving signal SG1 is converted represents the amount of light received by the light receiving unit 20.

[0041] The CPU 41 detects the interface of the sample based on the amount of light received by the light receiving unit 20. The CPU 41 outputs a detection signal SG2 indicating the interface of the sample from the output unit 45. In the first embodiment, the CPU 41 may output, for example, the number of layers of the sample from the output unit 45 as the detection signal SG2 in addition to the interface of the sample.

[0042] The CPU 41 controls various components by executing programs stored in the memory 46. The memory 46 includes, for example, a ROM, a RAM, and a storage. The memory 46 stores a threshold value to be compared with the amount of light received by the light receiving unit 20. The CPU 41 detects the interface of the sample based on the comparison result between the threshold value and the amount of light received by the light receiving unit 20. The threshold value is set according to the detection target.

[0043] As in the example shown in Fig. 2, when detecting an interface 66 between the first layer 61 and the second layer 62, a threshold value set according to the amount of light received that changes between the first layer 61 and the second layer 62 is used. When detecting an interface 65 between the first layer 61 and the air layer 64, a threshold value set according to the amount of light received that changes between the first layer 61 and the air layer 64 is used. Similarly, as in the example shown in Fig. 3, when detecting an interface 67 between the first layer 61 and the third layer 63, an interface 68 between the third layer 63 and the second layer 62, and an interface 65 between the first layer 61 and the air layer 64, a threshold value set according to the amount of light received that changes between each layer is used.

[0044] Next, a method for detecting the interface of a sample by comparing the amount of received light with a threshold value will be described. First, with reference to Figures 7 and 8, let us consider the case where no identification label 52 is attached to the test tube 50. The received light amount data shown in Figures 7 and 8 is data obtained by measuring the change in the amount of received light from the bottom of the test tube 50 toward the cap 51.

[0045] In the example shown in FIG. 7, a blood sample 60 including a first layer 61 and a second layer 62 is a detection target. FIG. 7 shows the amount of light received at each position, where the positions of the first detection light L1 and the second detection light L2 passing through the detection target are designated as Z positions. Since the first detection light L1 and the second detection light L2 are difficult to transmit through the second layer 62, the amount of light received by the light receiving unit 20 is small. In the first layer 61, the transmittance of the first detection light L1, which is the first wavelength, is high, and the transmittance of the second detection light L2, which is the second wavelength, is low. Therefore, the amount of light received by the light receiving unit 20 in the first layer 61 is greater than the amount of light received by the light receiving unit 20 in the second layer 62. Therefore, the interface 66 between the first layer 61 and the second layer 62 can be detected by a threshold value set according to the amount of light received in the second layer 62 and the amount of light received in the first layer 61.

[0046] The air layer 64 has a high transmittance for the first detection light L1 and a high transmittance for the second detection light L2. Therefore, the amount of light received by the light receiving unit 20 in the air layer 64 is greater than the amount of light received by the light receiving unit 20 in the first layer 61. Therefore, the interface 65 between the first layer 61 and the air layer 64 can be detected by a threshold value set according to the amount of light received in the first layer 61 and the amount of light received in the air layer 64.

[0047] In the example shown in FIG. 8, a blood sample 60 including a first layer 61, a second layer 62, and a third layer 63 is a detection target. FIG. 8 shows the amount of light received at each position, with the positions of the first detection light L1 and the second detection light L2 passing through the detection target being designated as Z positions. The amount of light received at the first layer 61 and the amount of light received at the second layer 62 are the same as those in the example shown in FIG. 7. In the third layer 63, the transmittance of the first detection light L1 and the transmittance of the second detection light L2 may be high. Therefore, the amount of light received by the light receiving unit 20 at the third layer 63 is greater than the amount of light received at the first layer 61 and the amount of light received at the second layer 62. Therefore, an interface 68 between the second layer 62 and the third layer 63 and an interface 67 between the third layer 63 and the first layer 61 can be detected by threshold values ​​set according to the amount of light received at the second layer 62 and the third layer 63 and the amount of light received at the third layer 63 and the first layer 61. 7, the interface 65 between the first layer 61 and the air layer 64 can also be detected in the blood sample 60 shown in FIG.

[0048] Depending on the type of separating agent, the relationship between wavelength and transmittance, for example, a wavelength band with high transmittance and a wavelength band with low transmittance, may differ. Therefore, the wavelengths of the first detection light L1 and the second detection light L2 are selected for each separating agent, taking into consideration the transmittance, absorption, etc.

[0049] As described above, in order to detect the interface of a sample, it is necessary to know the change in the amount of received light of the first detection light L1 and the change in the amount of received light of the second detection light L2. Therefore, the light projecting unit 10 projects the first detection light L1 and the second detection light L2 in two light projection patterns. This makes it possible to grasp the change in the amount of received light of the first detection light L1 and the change in the amount of received light of the second detection light L2. In the first embodiment, the amount of received light by the second light projection pattern, i.e., the amount of received light by the first detection light L1, is obtained by subtracting the amount of received light by the third light projection pattern from the amount of received light by the first light projection pattern.

[0050] Next, a case will be considered in which an identification label 52 is affixed to the test tube 50. When an identification label 52 is affixed to the test tube 50, the amount of the first detection light L1 and the second detection light L2 passing through the identification label 52 decreases, i.e., the amount of light received by the light receiving unit 20 decreases. As a result, the amount of received light changes between the Z position where the detection light passes through the identification label 52 and the Z position where the detection light does not pass through the identification label 52. Specifically, the amount of received light changes at the label bottom, which is the lower end of the identification label 52, and the label top, which is the upper end of the identification label 52, which serve as boundaries.

[0051] When an identification label 52 is affixed to the test tube 50, factors that cause a change in the amount of received light include the interface of the sample, the label bottom, the label top, etc. Therefore, when an identification label 52 is affixed to the test tube 50, it becomes difficult to distinguish between the interface of the sample and the identification label 52 when detecting the interface of the sample based on the change in the amount of received light, i.e., the change in the intensity of the received light signal SG1. In particular, when the label bottom or label top overlaps with the interface of the sample, it becomes even more difficult to distinguish between the interface of the sample and the identification label 52. For this reason, it is essential to specify the position of the identification label 52 in order to detect the interface of the sample.

[0052] When the identification labels 52 are attached so as to cover the test tubes 50, the detection light may pass through one identification label 52 twice. That is, the detection light may pass through two layers of the identification labels 52 for one identification label 52. In the first embodiment, it is assumed that a maximum of three identification labels 52 are attached to the test tube 50, and therefore the detection light passes through a maximum of six layers of the identification labels 52. The amount of light received by the light receiving unit 20 decreases as the number of layers of the identification labels 52 through which the detection light passes increases.

[0053] Next, the label pattern indicating the position of the identification label 52 relative to the sample will be described. The label pattern is classified according to the combination of the number of layers of the sample, the position of the label bottom which is the lower end position of the identification label 52, and the position of the label top which is the upper end position of the identification label 52. In other words, the label pattern is determined by the positions of the label bottom and the label top relative to the sample. Examples of different label patterns are shown in Fig. 9 to Fig. 33.

[0054] 9 to 25, the blood sample 60 is composed of three layers, a first layer 61, a second layer 62, and a third layer 63. In the examples shown in Figures 26 to 33, the blood sample 60 is composed of two layers, a first layer 61 and a second layer 62. In the first embodiment, of the one or more identification labels 52 affixed to the test tube 50, the end closest to the bottom surface of the test tube 50 is designated as the label bottom, and the end closest to the opening of the test tube 50, i.e., the cap 51, is designated as the label top.

[0055] 9, 10, and 11, the label bottom overlaps the second layer 62, and the label top overlaps the first layer 61. The three identification labels 52 may be attached overlapping each other without being shifted from each other, or may be attached with a shift from each other.

[0056] 9, 10, and 11, three identification labels 52 are attached to the test tube 50, but two identification labels 52 or only one identification label 52 may be attached. In the first embodiment, the examples shown in Fig. 9, 10, and 11 are all classified as the same label pattern. That is, in the first embodiment, the label patterns are classified by the position of the label bottom relative to the sample and the position of the label top relative to the sample, regardless of the number of identification labels 52.

[0057] In the examples shown in Figs. 12 to 33, a single identification label 52 is shown simply to indicate the positions of the label bottom and the label top. In the label pattern shown in FIG. 12, the label bottom overlaps with the third layer 63, and the label top overlaps with the air layer 64.

[0058] In the label pattern shown in FIG. 13, the label bottom overlaps the air layer 64, and the label top overlaps the air layer 64. In the label pattern shown in FIG. 14, the label bottom overlaps with the second layer 62, and the label top overlaps with the air layer 64.

[0059] In the label pattern shown in FIG. 15, the label bottom overlaps the third layer 63 and the label top overlaps the first layer 61. In the label pattern shown in FIG. 16, the label bottom overlaps with the first layer 61, and the label top overlaps with the air layer 64.

[0060] In the label pattern shown in FIG. 17, the label bottom overlaps the second layer 62 and the label top overlaps the first layer 61. In the label pattern shown in FIG. 18, the label bottom overlaps the interface 67, ie, the lower surface of the first layer 61, and the label top overlaps the air layer 64.

[0061] In the label pattern shown in FIG. 19, the label bottom overlaps the first layer 61, and the label top overlaps the first layer 61. In the label pattern shown in FIG. 20, the label bottom overlaps with the third layer 63 and the label top overlaps with the interface 65, that is, the top surface of the first layer 61.

[0062] In the label pattern shown in FIG. 21, the label bottom overlaps the interface 67, that is, the lower surface of the first layer 61, and the label top overlaps the first layer 61. In the label pattern shown in FIG. 22, the label bottom overlaps with the interface 65, that is, the upper surface of the first layer 61, and the label top overlaps with the air layer 64.

[0063] In the label pattern shown in FIG. 23, the label bottom overlaps with the second layer 62, and the label top overlaps with the interface 65, that is, the top surface of the first layer 61. In the label pattern shown in FIG. 24, the label bottom overlaps the first layer 61, and the label top overlaps the interface 65, that is, the upper surface of the first layer 61.

[0064] In the label pattern shown in FIG. 25, the label bottom overlaps with interface 67, ie, the lower surface of first layer 61, and the label top overlaps with interface 65, ie, the upper surface of first layer 61. Other examples of label patterns in which the blood sample 60 is composed of three layers include, for example, a pattern in which the label bottom overlaps the second layer 62 and the label top overlaps the second layer 62, and a pattern in which the label bottom overlaps the second layer 62 and the label top overlaps the third layer 63.

[0065] In the label pattern shown in FIG. 26, the label bottom overlaps the air layer 64, and the label top overlaps the air layer 64. In the label pattern shown in FIG. 27, the label bottom overlaps with the second layer 62, and the label top overlaps with the air layer 64.

[0066] In the label pattern shown in FIG. 28, the label bottom overlaps with the first layer 61, and the label top overlaps with the air layer 64. In the label pattern shown in FIG. 29, the label bottom overlaps with the second layer 62 and the label top overlaps with the first layer 61.

[0067] In the label pattern shown in FIG. 30, the label bottom overlaps the first layer 61 and the label top overlaps the first layer 61. In the label pattern shown in FIG. 31, the label bottom overlaps with the interface 65, that is, the upper surface of the first layer 61, and the label top overlaps with the air layer 64.

[0068] In the label pattern shown in FIG. 32, the label bottom overlaps with the second layer 62, and the label top overlaps with the interface 65, that is, the top surface of the first layer 61. In the label pattern shown in FIG. 33, the label bottom overlaps the first layer 61, and the label top overlaps the interface 65, that is, the upper surface of the first layer 61.

[0069] Other examples of label patterns in which the blood sample 60 is composed of two layers include, for example, a pattern in which the label bottom overlaps the second layer 62 and the label top overlaps the second layer 62, and a pattern in which the label bottom overlaps the top surface of the second layer 62 and the label top overlaps the air layer 64.

[0070] Next, a specific process for detecting the interface of the sample from the received light signal SG1 will be described. The control unit 40 executes the process shown in Fig. 34 according to a program stored in the memory 46. This program may be stored in the memory 46 by the control unit 40 reading it from an external storage medium such as a flash memory or a hard disk. Also, the program may be stored in the memory 46 by the control unit 40 reading it from a server connected via a network. The process shown in Fig. 34 is a process for detecting the interface of the sample.

[0071] The control unit 40 identifies the position of the identification label 52 based on the intensity of the light receiving signal SG1, i.e., the amount of light received by the light receiving unit 20, by the process shown in Fig. 34. That is, the control unit 40 detects the identification label 52 based on a signal for detecting the interface of the sample. In the first embodiment, the control unit 40 always executes the process shown in Fig. 34.

[0072] As shown in Fig. 34, the control unit 40 executes a separation process in step S11. The separation process is a process for separating the received light reception signal SG1 into joint data D1 and individual data D2. The control unit 40 acquires the joint data D1 and the individual data D2 from the light reception signal SG1. That is, the control unit 40 acquires from the light reception signal SG1 the amount of received light indicated by the joint data D1, i.e., the amount of received light by the first detection light L1 and the second detection light L2, the amount of received light indicated by the individual data D2, and the amount of received light by the second detection light L2.

[0073] In step S12, the control unit 40 buffers the amount of received light indicated by the joint data D1 and the amount of received light indicated by the individual data D2 separated in step S11 at a predetermined interval. In step S12, the control unit 40 buffers at intervals of, for example, 1 millisecond. By buffering the amount of received light indicated by the joint data D1 and the amount of received light indicated by the individual data D2, received light amount data such as that shown in FIG. 35 is obtained for the joint data D1 and the individual data D2. This received light amount data is updated every 1 millisecond. This makes it possible to grasp the change in the amount of received light indicated by the joint data D1 and the change in the amount of received light indicated by the individual data D2.

[0074] In step S13, the control unit 40 executes a detection process based on the buffered amount of received light, i.e., the data on the amount of received light obtained in step S12. The detection process is a process for detecting the test tube 50. The control unit 40 compares the amount of received light indicated by the joint data D1 with a detection threshold value for detecting the test tube 50. The control unit 40 compares the amount of received light indicated by the independent data D2 with the detection threshold value.

[0075] In step S14, the control unit 40 judges whether or not a test tube 50 is present based on the comparison result in step S13. The control unit 40 judges that a test tube 50 is present when both the amount of received light indicated by the joint data D1 and the amount of received light indicated by the individual data D2 are below the detection threshold value. In this case, the control unit 40 judges that a test tube 50 is detected, and proceeds to step S15. By comparing both the amount of received light indicated by the joint data D1 and the amount of received light indicated by the individual data D2 with the detection threshold value, the detection sensitivity (detection accuracy) of the test tube 50 is improved compared to the case where either one of the amount of received light indicated by the joint data D1 or the amount of received light indicated by the individual data D2 is compared with the detection threshold value.

[0076] 35, when the bottom surface of the test tube 50 is located between the light-projecting unit 10 and the light-receiving unit 20, both the amount of received light indicated by the joint data D1 and the amount of received light indicated by the individual data D2 are greatly reduced. This is because a blood sample 60 is contained in the test tube 50. That is, the control unit 40 detects the test tube 50 when the amount of received light is reduced by the blood sample 60.

[0077] 34, in step S14, the control unit 40 determines that the test tube 50 is not present if the amount of received light indicated by the joint data D1 is equal to or greater than the detection threshold value, or if the amount of received light indicated by the individual data D2 is equal to or greater than the detection threshold value. In this case, the control unit 40 determines that the test tube 50 has not been detected, and returns the process to step S11. That is, the control unit 40 repeats the processes from step S11 to step S14 until the test tube 50 is detected.

[0078] In step S15, the control unit 40 acquires data on the amount of received light. The data on the amount of received light is data indicating the variation in the amount of received light for the blood sample 60, and is, for example, data as shown in Figs. 7 and 8. The control unit 40 executes separation processing and buffering, for example, in the same manner as in steps S11 and S12. Here, the control unit 40 buffers at intervals longer than in step S12. The control unit 40 buffers at intervals of, for example, 10 milliseconds. This allows for the acquisition of data on the amount of received light indicating the variation in the amount of received light over the entire length of the test tube 50, as shown in Fig. 36.

[0079] In step S15, the control unit 40 obtains the received light amount data based on the joint data D1 and the received light amount data based on the individual data D2. In the first embodiment, the received light amount data based on the first detection light L1 can be obtained by calculating the difference between the received light amount data based on the joint data D1 and the received light amount data based on the individual data D2.

[0080] In step S15, the control unit 40 determines a data range to be used for subsequent processing, for example, a data range to be used for detecting the interface of the sample or determining the label pattern, for the acquired received light amount data. The control unit 40 compares the received light amount data with a threshold value stored in the memory 46, and determines the data range from the bottom surface of the test tube 50 to the lower end of the cap 51.

[0081] 36, the amount of received light is drastically reduced at the cap 51, so the control unit 40 can detect the cap 51 based on the received light amount data and the threshold value. In step S16 and after, data within the data range of the received light amount data is simply represented as received light amount data.

[0082] As shown in Fig. 34, in step S16, the control unit 40 extracts features from the received light amount data. These features are features that indicate the label pattern. That is, these features include a feature that indicates the number of layers of the sample, a feature that indicates the position of the label bottom, and a feature that indicates the position of the label top. The label pattern is, for example, a pattern shown in Fig. 9 to Fig. 33.

[0083] In step S16, the control unit 40 extracts features by differentiating the received light amount data, determining a threshold value, and so on. The control unit 40 extracts features based on the array of peak values ​​obtained by differentiating the received light amount data, for example. The array of peak values ​​indicates the array of changes in the received light amount. The array of changes in the received light amount indicates the array of the interface, label bottom, and label top of the sample. In this way, since the received light amount data contains information indicating the label pattern, features indicating the label pattern can be extracted from the received light amount data.

[0084] In step S17, the control unit 40 determines the label pattern from the extracted feature amount. Specifically, the control unit 40 determines the number of layers of the sample from the feature amount. At this time, the control unit 40 determines, for example, whether the number of layers of the sample is two layers or three layers. The control unit 40 also determines the positions of the label bottom and the label top from the feature amount. At this time, the control unit 40 determines which layers of the sample the label bottom and the label top overlap with.

[0085] In step S17, the control unit 40 executes a process for determining the number of layers of the sample and a process for determining the positions of the label bottom and the label top. In this way, the control unit 40 determines the label pattern of the test tube 50 containing the sample. That is, the control unit 40 determines, from the feature amount, which of the label patterns shown in Figs. 9 to 33 the label pattern of the test tube 50 containing the blood sample 60 corresponds to. The control unit 40 determines the label pattern, for example, by referring to table data in which values ​​indicating each label pattern are stored. The table data is stored, for example, in the memory 46.

[0086] In step S18, the control unit 40 detects the interface of the sample based on the determined label pattern and the acquired data on the amount of received light. Once the label pattern is specified, the interface of the sample and the identification label 52 can be distinguished based on the data on the amount of received light. Therefore, the interface of the sample can be detected by the same method as when the identification label 52 is not attached to the test tube 50. For example, the control unit 40 detects the interface of the sample by comparing a threshold value associated with each label pattern with the data on the amount of received light. This threshold value is stored in table data, for example, in a state associated with a value indicating the label pattern. The control unit 40 can calculate the position of the interface of the sample by detecting the interface of the sample.

[0087] In step S19, the control unit 40 outputs a detection signal SG2. The control unit 40 outputs a value indicating, for example, the number of layers of the sample, the interface position of the sample, etc. from the output unit 45. After completing the process of step S19, the control unit 40 starts the process shown in FIG.

[0088] An uncentrifuged blood sample 60 may be set in the interface detection sensor 1. For example, in step S17, when there is no corresponding label pattern from the extracted feature amount, i.e., when the label pattern cannot be determined, the control unit 40 may determine that the blood sample 60 has not been centrifuged. The control unit 40 may output the centrifugal separation state of the blood sample 60 as a detection signal SG2.

[0089] According to the first embodiment, the following effects can be obtained. (1-1) The interface detection sensor 1 includes a light-projecting unit 10 having a first light-projecting element 11 that projects a first detection light L1 and a second light-projecting element 12 that projects a second detection light L2, a light-receiving unit 20 that receives the first detection light L1 and the second detection light L2 and outputs a light-receiving signal SG1 according to the amount of received light, and a control unit 40 that controls the light-projecting unit 10 to project light in two light-projection patterns out of a first light-projection pattern that projects light so that the light-receiving unit 20 receives both the first detection light L1 and the second detection light L2 simultaneously, a second light-projection pattern that projects light so that the light-receiving unit 20 receives only the first detection light L1, and a third light-projection pattern that projects light so that the light-receiving unit 20 receives only the second detection light L2. The control unit 40 extracts, from the received light signal SG1, a feature amount indicating a label pattern, which is a combination pattern of the number of layers of the sample, the upper end position of the identification label 52, and the lower end position of the identification label 52. The control unit 40 determines the label pattern based on the feature amount. The control unit 40 detects the interface of the sample from the received light signal SG1 based on the label pattern.

[0090] The control unit 40 determines the label pattern based on the light receiving signal SG1 for detecting the interface of the sample. The label pattern indicates the position of the identification label 52 relative to the sample. Therefore, by determining the label pattern, the control unit 40 can distinguish whether the intensity change of the light receiving signal SG1 is due to the identification label 52 or due to the interface of the sample. That is, when detecting the interface of the sample based on the light receiving signal SG1, the control unit 40 can distinguish between the identification label 52 and the interface of the sample. Thus, according to the above configuration, it is not necessary to provide a separate configuration for detecting the identification label 52, and the interface of the sample can be detected with a simple configuration.

[0091] (1-2) The control unit 40 has an output unit 45. After detecting the interface of the sample, the control unit 40 outputs from the output unit 45 a detection signal SG2 indicating the number of layers of the sample and the interface of the sample. According to the above configuration, even if the sample in the container cannot be visually confirmed by the identification label 52, the user can grasp the number of layers of the sample and the interface of the sample by the detection signal SG2.

[0092] (1-3) The control unit 40 controls the first light-projecting element 11 to project the first detection light L1 in a pulsed manner. The control unit 40 controls the second light-projecting element 12 to project the second detection light L2 in a pulsed manner. The control unit 40 controls the first light-projecting element 11 and the second light-projecting element 12 so that the light-receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2 and then receives only the second detection light L2.

[0093] According to the above configuration, the first detection light L1 and the second detection light L2 projected in the first light projection pattern and the third light projection pattern are received by the light receiving unit 20. The first detection light L1 and the second detection light L2 can be received by the light receiving unit 20 in two different light projection patterns.

[0094] (1-4) The first light-projecting element 11 projects the first detection light L1 at a first period. The second light-projecting element 12 projects the second detection light L2 at a second period that coincides with the first period. The pulse width of the second detection light L2 is longer than the pulse width of the first detection light L1. The control unit 40 controls the first light-projecting element 11 and the second light-projecting element 12 so that the light-receiving unit 20 starts receiving the first detection light L1 and the second detection light L2 at the same time.

[0095] The light receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2. Since the pulse width of the first detection light L1 is longer than the pulse width of the second detection light L2, the light receiving unit 20 subsequently stops receiving the first detection light L1 while continuing to receive the second detection light L2. That is, the light receiving unit 20 receives the first detection light L1 and the second detection light L2 projected in the first light projection pattern and the third light projection pattern. According to the above configuration, the light receiving unit 20 can receive the first detection light L1 and the second detection light L2 by the two light projection patterns simply by making the pulse widths of the first detection light L1 and the second detection light L2, which have the same period, different from each other.

[0096] (1-5) The control unit 40 detects the container based on the light receiving signal SG1, and then extracts the feature amount from the light receiving signal SG1. The intensity of the light receiving signal SG1 changes between when the light receiving unit 20 directly receives the detection light and when the light receiving unit 20 receives the detection light that passes through a container that contains a sample. Therefore, the control unit 40 can detect the container based on the light receiving signal SG1. With the above configuration, it is possible to reduce the possibility that the interface detection sensor 1 will operate to detect the interface of the sample even when a container is not set.

[0097] <Second embodiment> Next, a second embodiment will be described. The second embodiment differs from the first embodiment only in the content of the process executed by the control unit 40 to detect the interface of the sample. Therefore, the second embodiment will be mainly described with respect to the points different from the first embodiment.

[0098] In the second embodiment, the control unit 40 starts a process for detecting the interface of the sample when a start signal is input. For example, the start signal may be input to the control unit 40 when a test tube 50 is set between the light projecting unit 10 and the light receiving unit 20. For example, the start signal may be input to the control unit 40 when a user of the interface detection sensor 1 operates a controller. When the start signal is input, the control unit 40 starts the process shown in FIG.

[0099] In the second embodiment, unlike the first embodiment, the light projecting unit 10 does not always project light at a predetermined cycle, but starts projecting light onto the light receiving unit 20 when a start signal is input to the control unit 40. That is, when a start signal is input, the control unit 40 operates the light projecting unit 10. When a start signal is input to the control unit 40, the light projecting unit 10 projects detection light at a predetermined cycle.

[0100] 37, in step S21, the control unit 40 acquires data on the amount of received light, similarly to step S15. That is, in the second embodiment, unlike the first embodiment, there is no processing from step S11 to step S14. This is because in the second embodiment, processing is started not in response to detection of a test tube 50 but in response to input of a start signal. For example, when the control unit 40 acquires data on the amount of received light, it stops the light projector 10.

[0101] In step S22, the control unit 40 extracts a feature amount, similarly to step S16. In step S23, the control unit 40 determines the label pattern, similarly to step S17.

[0102] In step S24, the control unit 40 detects the interface of the sample, similarly to step S18. In step S25, the control unit 40 outputs the detection signal SG2. After completing the process of step S25, the control unit 40 ends the process shown in FIG.

[0103] According to the second embodiment, the following effects can be obtained. (2-1) The control unit 40 operates the light projecting unit 10 when a start signal for starting a process for detecting the interface of the sample is input.

[0104] According to the above configuration, the operating time of the light projecting unit 10 can be reduced compared to the first embodiment, and therefore the power consumption of the interface detection sensor 1 can be reduced. As another effect, the life of the light projecting unit 10 can be extended.

[0105] <Third embodiment> Next, a third embodiment will be described. The third embodiment differs from the first embodiment only in the content of the process for detecting the interface of the sample. Therefore, the third embodiment will be mainly described with respect to the points different from the first embodiment.

[0106] In the third embodiment, similarly to the first embodiment, the control unit 40 constantly causes the light projecting unit 10 to project a pulsed detection light at a predetermined cycle. In the third embodiment, the control unit 40 causes the light projecting unit 10 to project a detection light with a smaller light intensity than in the first embodiment until the test tube 50 is detected.

[0107] As shown in FIG. 38, in step S30, the control unit 40 performs a separation process in the same manner as in step S11. In step S31, the control unit 40 performs buffering in the same manner as in step S12.

[0108] In step S32, the control unit 40 performs the detection process in the same manner as in step S13. In step S33, the control unit 40 determines whether or not the test tube 50 is present, similarly to step S14. If the control unit 40 determines that the test tube 50 is present, the control unit 40 shifts the process to step S34. If the control unit 40 determines that the test tube 50 is not present, the control unit 40 returns the process to step S30.

[0109] In step S34, the control unit 40 increases the amount of detection light projected by the light projecting unit 10. At this time, the control unit 40 increases the amount of detection light to an extent that appropriate light-receiving amount data can be obtained for detecting the interface of the sample. This increases the amount of first detection light L1 projected by the first light-projecting element 11 and the amount of second detection light L2 projected by the second light-projecting element 12.

[0110] In step S35, the control unit 40 acquires data on the amount of received light, similarly to step S15. At this time, the control unit 40 acquires data on the amount of received light based on the first detection light with an increased amount of light and the second detection light with an increased amount of light. After acquiring the data on the amount of received light, the control unit 40 may reduce the amount of detection light projected by the light projector 10.

[0111] In step S36, the control unit 40 extracts a feature amount in the same manner as in step S16. In step S37, the control unit 40 determines the label pattern, similarly to step S17.

[0112] In step S38, the control unit 40 detects the interface of the sample, similarly to step S18. In step S39, the control unit 40 outputs the detection signal SG2, similarly to step S19. After completing the process of step S39, the control unit 40 starts the process shown in FIG.

[0113] According to the third embodiment, the following effects can be obtained. (3-1) When a container is detected, the control unit 40 increases the amount of the first detection light L1 projected by the first light-projecting element 11 and the amount of the second detection light L2 projected by the second light-projecting element 12. The control unit 40 then extracts a feature from the light-receiving signal SG1 based on the first detection light L1 with the increased amount and the second detection light L2 with the increased amount.

[0114] According to the above configuration, since the container is detected with a smaller amount of light than when the interface of the sample is detected, it is possible to reduce the power consumption of the interface detection sensor 1. As another effect, the life of the light projecting unit 10 can be extended.

[0115] The first, second and third embodiments can be modified as follows: The first, second and third embodiments and the following modifications can be combined with each other to the extent that there is no technical contradiction.

[0116] As shown in FIG. 39, the light receiving signal SG1 may be changed. In the modification shown in FIG. 39, the pulse width of the first detection light L1 is equal to the pulse width of the second detection light L2. The period of the second detection light L2 is 1 / 2 the period of the first detection light L1. That is, the second period is 1 / 2 the first period. The first period may be 1 / 2 the second period. The control unit 40 controls the first light emitting element 11 and the second light emitting element 12 so that the light receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2. As a result, the light receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2, and then receives only the second detection light L2.

[0117] 39, the light receiving section 20 receives the first detection light L1 and the second detection light L2 projected in the first light projection pattern and the third light projection pattern. Therefore, the received light signal SG1 is composed of joint data D1 and individual data D2.

[0118] According to this modification, the following effects can be obtained. The light receiving unit 20 simultaneously receives the first detection light L1 and the second detection light L2. Since the second period is 1 / 2 of the first period, the light receiving unit 20 then receives only the second detection light L2. That is, the light receiving unit 20 receives the first detection light L1 and the second detection light L2 projected in the first light projection pattern and the third light projection pattern. According to the above modification, the light receiving unit 20 can receive the first detection light L1 and the second detection light L2 by the two light projection patterns by simply setting the second period to 1 / 2 of the first period for the first detection light L1 and the second detection light L2 whose pulse widths are the same.

[0119] As shown in FIG. 40, the light receiving signal SG1 may be changed. In the modification shown in FIG. 40, the pulse width of the first detection light L1 and the pulse width of the second detection light L2 are the same. The period of the first detection light L1 coincides with the period of the second detection light L2. That is, the second period coincides with the first period. The control unit 40 controls the first light projecting element 11 and the second light projecting element 12 so that the light receiving unit 20 alternately receives the first detection light L1 and the second detection light L2. For example, the control unit 40 controls the first light projecting element 11 and the second light projecting element 12 so as to shift the timing of projecting the first detection light L1 and the timing of projecting the second detection light L2. As a result, the light receiving unit 20 alternately receives the first detection light L1 and the second detection light L2.

[0120] In the modification shown in FIG. 40, the light receiving section 20 receives the first detection light L1 and the second detection light L2 by the second light projection pattern and the third light projection pattern. The received light signal SG1 is composed of individual data D2. In this modification, the individual data D2 includes the first individual data D21 and the second individual data D22. In detail, the received light signal SG1 is composed of the first individual data D21 representing a value indicating the amount of received light by the first detection light L1, and the second individual data D22 representing a value indicating the amount of received light by the second detection light L2. The control section 40 obtains the received light amount data by the first detection light L1 and the second detection light L2 by taking the sum of the received light amount data by the first detection light L1 and the received light amount data by the second detection light L2.

[0121] According to this modification, the following effects can be obtained. The first detection light L1 and the second detection light L2 projected in the second light projection pattern and the third light projection pattern are received by the light receiving unit 20. According to the above modification, the first detection light L1 and the second detection light L2 can be received by the light receiving unit 20 in two different light projection patterns.

[0122] The light receiving unit 20 receives the first detection light L1. Next, the light receiving unit 20 receives the second detection light L2. That is, the light receiving unit 20 alternately receives the first detection light L1 due to the second light projection pattern and the second detection light L2 due to the third light projection pattern. According to the above modification, the light receiving unit 20 can receive the first detection light L1 and the second detection light L2 due to the two light projection patterns simply by alternately receiving the first detection light L1 and the second detection light L2 at the light receiving unit 20.

[0123] As shown in FIG. 41, the light receiving unit 20 may have a plurality of light receiving elements 21. In this modification, the light receiving element 21 is referred to as a first light receiving element 21. The light receiving unit 20 has a first light receiving element 21 that receives the first detection light L1 and a second light receiving element 23 that receives the second detection light L2. The first detection light L1 and the second detection light L2 are received by the light receiving unit 20 through different optical paths. That is, the optical path from the first light projecting element 11 to the first light receiving element 21 is different from the optical path from the second light projecting element 12 to the second light receiving element 23. The control unit 40 controls the first light projecting element 11 and the second light projecting element 12 so that the light receiving unit 20 receives the first detection light L1 and the second detection light L2 alternately by shifting the projection timing of the first detection light L1 and the projection timing of the second detection light L2.

[0124] As shown in FIG. 42, in the modification shown in FIG. 41, a plurality of light receiving signals SG1 are output. The first light receiving element 21 receives the first detection light L1 and outputs a first light receiving signal as the light receiving signal SG1. The second light receiving element 23 receives the second detection light L2 and outputs a second light receiving signal as the light receiving signal SG1. The first light receiving signal is composed of first independent data D21 by the first detection light L1. The second light receiving signal is composed of second independent data D22 by the second detection light L2. That is, the light receiving unit 20 receives the first detection light L1 and the second detection light L2 by the second light projection pattern and the third light projection pattern. The control unit 40 obtains the light receiving amount data by the first detection light L1 and the second detection light L2 by taking the sum of the light receiving amount data by the first detection light L1 and the light receiving amount data by the second detection light L2.

[0125] According to this modification, the following effects can be obtained. The first detection light L1 and the second detection light L2 projected in the second light projection pattern and the third light projection pattern are received by the light receiving unit 20. According to the above modification, the first detection light L1 and the second detection light L2 can be received by the light receiving unit 20 in two different light projection patterns.

[0126] The first light receiving element 21 receives the first detection light L1. Next, the second light receiving element 23 receives the second detection light L2. That is, the light receiving unit 20 alternately receives the first detection light L1 based on the second light projection pattern and the second detection light L2 based on the third light projection pattern. According to the above modification, the first light receiving element 21 and the second light receiving element 23 only alternately receive the first detection light L1 and the second detection light L2, so that the light receiving unit 20 can receive the first detection light L1 and the second detection light L2 based on the two light projection patterns.

[0127] As another effect, in the above modification, there is no need to receive detection light of two different wavelengths with a single light receiving element 21. Therefore, a light receiving element specialized for receiving light of the first wavelength can be used as the first light receiving element 21, and a light receiving element specialized for receiving light of the second wavelength can be used as the second light receiving element 23.

[0128] The light receiving unit 20 may receive the first detection light L1 and the second detection light L2 projected in the first light projection pattern and the second light projection pattern. For example, the light receiving unit 20 may simultaneously receive the first detection light L1 and the second detection light L2, and then receive only the first detection light L1. For example, the light receiving unit 20 may receive only the first detection light L1, and then receive the first detection light L1 and the second detection light L2.

[0129] The control unit 40 may detect the interface of the sample based on mapping data that defines a mapping in which the light receiving signal SG1 is input and a value indicating the interface of the sample is output. The mapping data may be data that defines a mapping in which the light receiving signal SG1 is input and the detection signal SG2 is output. The mapping data may be data that defines a mapping in which the light receiving signal SG1 is input and a value indicating the label pattern is output. The mapping data is stored in the memory 46, for example, but may be read from an external storage medium. The mapping data can be obtained by machine learning.

[0130] As a learning method for obtaining the mapping data, for example, supervised learning using a neural network can be used. Using supervised data in which the light receiving signal SG1 and a value indicating the interface of the sample are associated with each other, the correlation between the light receiving signal SG1 and the value indicating the interface of the sample is learned, thereby obtaining the mapping data.

[0131] According to this modification, the following effects can be obtained. The control unit 40 can detect the sample interface from the light receiving signal SG1 for detecting the sample interface even if the identification label 52 is attached to the container. Therefore, it is not necessary to provide a separate configuration for detecting the identification label 52, and the sample interface can be detected with a simple configuration.

[0132] When multiple identification labels 52 are attached to the test tube 50, the control unit 40 may specify the label bottom position and the label top position for each identification label 52. That is, the control unit 40 may determine a more detailed label pattern based on the received light amount data. A difference in the amount of received light occurs between a portion where two identification labels 52 overlap and a portion where there is only one identification label 52. Therefore, the amount of received light changes based on the number of layers of identification labels 52 through which the detection light passes.

[0133] 1, a signal SG3 indicating the amount of received light may be output from the amplifier 43. The signal SG3 may be output from the amplifier 22 of the light receiving unit 20. For example, the signal SG3 may be output to the outside of the interface detection sensor 1.

[0134] The interface of the sample may be detected not only by the amount of light received by the light receiving unit 20 and a threshold value, but also by the amount or rate of change in the amount of light received. For example, in the blood sample 60 shown in FIG. 7, if the amount or rate of change in the amount of light received with respect to the Z position is equal to or greater than a predetermined value, it is possible to detect the presence of an interface at that position. Then, depending on the relative positions (Z position) of the first detection light L1 and the second detection light L2 and the test tube 50, it is possible to determine whether the detected interface is the interface 66 between the second layer 62 and the first layer 61, or the interface 65 between the first layer 61 and the air layer 64. In this case, a predetermined value may be prepared for each label pattern.

[0135] In the interface detection sensor 1, the first light-projecting element 11 and the second light-projecting element 12 may each project light onto the single light-receiving element 21 via separate optical paths. In this case, the interface detection sensor 1 may not have the optical merging unit 30. In this modification, the first detection light L1 and the second detection light L2 projected from the light-projecting unit 10 are received by the light-receiving element 21 of the light-receiving unit 20 via their respective optical paths. In this embodiment, the first light-projecting element 11 is disposed so as to project the first detection light L1 toward the light-receiving element 21, and the second light-projecting element 12 is disposed so as to project the second detection light L2 toward the light-receiving element 21. In other words, the first light-projecting element 11 and the second light-projecting element 12 are disposed so as to project the first detection light L1 and the second detection light L2 toward the single light-receiving element 21. In this modification, since the optical merging unit 30 shown in FIG. 1 is not provided, the interface of the sample can be detected by a simplified configuration.

[0136] In the first, second and third embodiments, the detection target is a blood sample 60 including a first layer 61 and a second layer 62, or a blood sample 60 including a first layer 61, a second layer 62 and a third layer 63. An interface is also formed at the boundary between a gas, such as air, and a liquid or a solid. Therefore, the interface detection sensor 1 may detect a sample consisting of only one layer as a detection target, and detect the boundary between the detection target and the external atmosphere as the interface. (Appendix 1) An interface detection sensor for detecting an interface of a sample contained in a container to which an identification label is attached, comprising: a light-projecting unit including a first light-projecting element that projects a first detection light having a first wavelength and a second light-projecting element that projects a second detection light having a second wavelength different from the first wavelength; a light receiving section that receives the first detection light and the second detection light and outputs a light receiving signal according to an amount of received light; a control unit that controls the light projector to project light in two light projection patterns out of a light projection pattern in which the light receiver simultaneously receives both the first detection light and the second detection light, a light projection pattern in which the light receiver receives only the first detection light, and a light projection pattern in which the light receiver receives only the second detection light, The control unit is extracting from the received light signal a feature quantity indicative of a label pattern, which is a combination pattern of the number of layers of the sample, the upper end position of the identification label, and the lower end position of the identification label; determining the label pattern based on the feature amount; The interface of the sample is detected from the received light signal based on the label pattern. Interface detection sensor. (Appendix 2) The control unit has an output unit, After detecting the interface of the sample, the control unit outputs a detection signal indicating the number of layers of the sample and the interface of the sample from the output unit. 2. The interface detection sensor according to claim 1. (Appendix 3) The interface detection sensor according to claim 1 or 2, wherein the control unit makes the first detection light and the second detection light pulsed, and controls the first light-projecting element and the second light-projecting element so that the light-receiving unit simultaneously receives the first detection light and the second detection light and then receives only the second detection light. (Appendix 4) the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that coincides with the first period; a pulse width of the second detection light is longer than a pulse width of the first detection light; The control unit controls the first light-projecting element and the second light-projecting element so that the light-receiving unit simultaneously receives the first detection light and the second detection light. 4. The interface detection sensor according to claim 3. (Appendix 5) the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that is half the first period; a pulse width of the second detection light is equal to a pulse width of the first detection light, The control unit controls the first light-projecting element and the second light-projecting element so that the light-receiving unit simultaneously receives the first detection light and the second detection light. 4. The interface detection sensor according to claim 3. (Appendix 6) The interface detection sensor according to claim 1 or 2, wherein the control unit makes the first detection light and the second detection light pulsed and controls the first light-projecting element and the second light-projecting element so that the light-receiving unit alternately receives the first detection light and the second detection light. (Appendix 7) the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that coincides with the first period; a pulse width of the second detection light is equal to a pulse width of the first detection light, The control unit controls the first light-projecting element and the second light-projecting element such that a projection timing of the first detection light and a projection timing of the second detection light are shifted and the light-receiving unit alternately receives the first detection light and the second detection light. 7. The interface detection sensor according to claim 6. (Appendix 8) the light receiving unit includes a first light receiving element that receives the first detection light and a second light receiving element that receives the second detection light, the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that coincides with the first period; a pulse width of the second detection light coincides with a pulse width of the first detection light, The control unit controls the first light-projecting element and the second light-projecting element such that a projection timing of the first detection light and a projection timing of the second detection light are shifted and the light-receiving unit alternately receives the first detection light and the second detection light. 7. The interface detection sensor according to claim 6. (Appendix 9) The interface detection sensor according to any one of Supplementary Note 1 to Supplementary Note 8, wherein the control unit detects the container based on the light receiving signal, and then extracts the feature amount from the light receiving signal. (Appendix 10) The interface detection sensor described in Appendix 9, wherein, when the control unit detects the container, it increases an amount of the first detection light projected by the first light-projecting element and an amount of the second detection light projected by the second light-projecting element, and then extracts the feature from the light receiving signal based on the first detection light with the increased amount and the second detection light with the increased amount. (Appendix 11) The interface detection sensor according to any one of claims 1 to 8, wherein the control unit operates the light projection unit when a start signal is input to start a process for detecting the interface of the sample. (Appendix 12) An interface detection sensor for detecting an interface of a sample contained in a container to which an identification label is attached, comprising: a light-projecting unit including a first light-projecting element that projects a first detection light having a first wavelength and a second light-projecting element that projects a second detection light having a second wavelength different from the first wavelength; a light receiving section that receives the first detection light and the second detection light and outputs a light receiving signal according to an amount of received light; a control unit that controls the light projector to project light in two light projection patterns out of a light projection pattern in which the light receiver simultaneously receives both the first detection light and the second detection light, a light projection pattern in which the light receiver receives only the first detection light, and a light projection pattern in which the light receiver receives only the second detection light, The control unit detects the interface of the sample by inputting the light receiving signal to mapping data that defines a mapping in which the light receiving signal is input and a value indicating the interface of the sample is output. Interface detection sensor. [Explanation of symbols]

[0137] 1 Interface detection sensor 10 Light projection unit 11 First light emitting element 12 Second light emitting element 13 First Driver 14 2nd Driver 20 Light receiving section 21 Light receiving element (first light receiving element) 22 Amplifier 23 Second light receiving element 30 Light convergence section 31 Reflective Mirror 32 Dichroic mirror 40 Control section 41 CPU 42 Output section 43 Amplifier 44 A / D converter 45 Output section 46 Memory 50 Test Tubes 51 Cap 52 Identification Label 60 Blood Samples 61 1st layer 62 2nd layer 63 3rd layer 64 Air Layer 65 Interface 66 Interface 67 Interface 68 Interface 80 Moving mechanism D1 Joint Data D2 Single Data D21 First independent data D22 2nd Single Data L1 First detection light L2 Second detection light SG1 light receiving signal SG2 detection signal SG3 signal

Claims

1. An interface detection sensor for detecting an interface of a sample contained in a container to which an identification label is attached, comprising: a light-projecting unit including a first light-projecting element that projects a first detection light having a first wavelength and a second light-projecting element that projects a second detection light having a second wavelength different from the first wavelength; a light receiving section that receives the first detection light and the second detection light and outputs a light receiving signal according to an amount of received light; a control unit that controls the light projector to project light in two light projection patterns out of a light projection pattern in which the light receiver simultaneously receives both the first detection light and the second detection light, a light projection pattern in which the light receiver receives only the first detection light, and a light projection pattern in which the light receiver receives only the second detection light, The control unit is extracting from the received light signal a feature quantity indicative of a label pattern, which is a combination pattern of the number of layers of the sample, the upper end position of the identification label, and the lower end position of the identification label; determining the label pattern based on the feature amount; The interface of the sample is detected from the received light signal based on the label pattern. Interface detection sensor.

2. The control unit has an output unit, After detecting the interface of the sample, the control unit outputs a detection signal indicating the number of layers of the sample and the interface of the sample from the output unit. The interface detection sensor according to claim 1 .

3. 3. The interface detection sensor according to claim 1, wherein the control unit controls the first light-emitting element and the second light-emitting element so that the first detection light and the second detection light are pulsed and the light-receiving unit simultaneously receives the first detection light and the second detection light and then receives only the second detection light.

4. the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that coincides with the first period; a pulse width of the second detection light is longer than a pulse width of the first detection light; The control unit controls the first light-projecting element and the second light-projecting element so that the light-receiving unit simultaneously receives the first detection light and the second detection light. The interface detection sensor according to claim 3 .

5. the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that is half the first period; a pulse width of the second detection light is equal to a pulse width of the first detection light, The control unit controls the first light-projecting element and the second light-projecting element so that the light-receiving unit simultaneously receives the first detection light and the second detection light. The interface detection sensor according to claim 3 .

6. 3. The interface detection sensor according to claim 1, wherein the control unit controls the first light-emitting element and the second light-emitting element so that the first detection light and the second detection light are pulsed and the light-receiving unit alternately receives the first detection light and the second detection light.

7. the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that coincides with the first period; a pulse width of the second detection light is equal to a pulse width of the first detection light, The control unit controls the first light-projecting element and the second light-projecting element such that a projection timing of the first detection light and a projection timing of the second detection light are shifted and the light-receiving unit alternately receives the first detection light and the second detection light. The interface detection sensor according to claim 6 .

8. the light receiving unit includes a first light receiving element that receives the first detection light and a second light receiving element that receives the second detection light, the first light-projecting element projects the first detection light at a first period; the second light-projecting element projects the second detection light at a second period that coincides with the first period; a pulse width of the second detection light coincides with a pulse width of the first detection light, The control unit controls the first light-projecting element and the second light-projecting element such that a projection timing of the first detection light and a projection timing of the second detection light are shifted and the light-receiving unit alternately receives the first detection light and the second detection light. The interface detection sensor according to claim 6 .

9. 3. The interface detection sensor according to claim 1, wherein the control unit detects the container based on the light receiving signal, and thereafter extracts the feature amount from the light receiving signal.

10. 10. The interface detection sensor according to claim 9, wherein, when the container is detected, the control unit increases an amount of the first detection light emitted by the first light-emitting element and an amount of the second detection light emitted by the second light-emitting element, and then extracts the feature from the light receiving signal based on the first detection light with the increased amount of light and the second detection light with the increased amount of light.

11. 3. The interface detection sensor according to claim 1, wherein the control unit operates the light projecting unit when a start signal for starting a process for detecting the interface of the sample is input.

12. An interface detection sensor for detecting an interface of a sample contained in a container to which an identification label is attached, comprising: a light-projecting unit including a first light-projecting element that projects a first detection light having a first wavelength and a second light-projecting element that projects a second detection light having a second wavelength different from the first wavelength; a light receiving section that receives the first detection light and the second detection light and outputs a light receiving signal according to an amount of received light; a control unit that controls the light projector to project light in two light projection patterns out of a light projection pattern in which the light receiver simultaneously receives both the first detection light and the second detection light, a light projection pattern in which the light receiver receives only the first detection light, and a light projection pattern in which the light receiver receives only the second detection light, The control unit detects the interface of the sample by inputting the light receiving signal to mapping data that defines a mapping in which the light receiving signal is input and a value indicating the interface of the sample is output. Interface detection sensor.

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