Blood collection system and blood collection method

Abstract

To provide a blood sampling system and a method capable of sampling a sufficient amount of blood by improving blood sampling efficiency.SOLUTION: There are provided a blood sampling system utilized for sampling blood of a subject, and a blood sampling method executed in the blood sampling system. In the blood sampling system, a finger of a subject is punctured with a puncture needle and pressurized air is then supplied into a cuff so that a prescribed pressure is applied to the finger of the subject by expanding the cuff attached so as to wind the finger of the subject.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a blood sampling system and method, and is suitable for use in an authentication blood sampling system that simultaneously performs subject authentication and blood sampling. [Background technology]

[0002] In recent years, the increase in lifestyle-related diseases and those at risk of developing them has become a social problem. Accordingly, there are more and more opportunities to take blood samples to diagnose the presence or absence of lifestyle-related diseases such as diabetes, hyperlipidemia, and liver dysfunction. For example, blood tests are almost always performed during medical checkups and medical examinations.

[0003] In recent years, private comprehensive diagnostic services for lifestyle-related diseases have also begun to be offered, in which booths are set up in shopping malls, sports clubs, entertainment facilities, corporate offices, etc. to provide low-cost health checks, including blood tests (see non-patent document 1).

[0004] As a technique relating to blood tests, Patent Document 1 discloses a technique for authenticating a subject and sampling and measuring blood by utilizing the vein pattern of a hand using a test device equipped with a camera. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Special Publication No. 2020-510812 [Non-patent literature]

[0006] [Non-Patent Document 1] “Preventive medical business”, [online], CarePro Co., Ltd., [searched on September 14, 2021], Internet<https: / / carepro.co.jp / preventive / > Summary of the Invention [Problem to be solved by the invention]

[0007] Incidentally, for example, in Non-Patent Document 1, the subject himself / herself is required to draw blood for blood sampling tests, but when blood is drawn by the subject himself / herself, who is not a professional such as a doctor or nurse, there are cases in which a sufficient amount of blood cannot be drawn.

[0008] The present invention has been made in consideration of the above points, and aims to propose a blood collection system and method that improves blood collection efficiency and enables a sufficient amount of blood to be collected. [Means for solving the problem]

[0009] In order to solve the above problems, the present invention provides a blood collection system used to collect blood from a subject, comprising: Move the needle to puncture the subject's finger. a cuff that is wrapped around the subject's finger and attached to the subject's finger; and a cuff control unit that supplies pressurized air to the cuff so as to inflate the cuff and apply a predetermined pressure to the subject's finger. a light source that irradiates light onto the subject's finger; a camera that captures the light that has passed through the subject's finger; and a blood sampling control unit that determines the puncture position of the puncture needle by the puncture blood sampling mechanism based on the image captured by the camera. Set up The movement range of the puncture needle moved by the puncture blood collection mechanism is limited, and the blood collection control unit detects a position on a thicker finger vein that is within the movement range of the puncture needle as a puncture position of the puncture needle based on the image captured by the camera, and operates the puncture blood collection mechanism to insert the puncture needle into the detected puncture position. I did so.

[0010] The present invention also provides a blood sampling method executed in a blood sampling system used to sample blood from a subject, the blood sampling method including a first step of the blood sampling system inserting a puncture needle into a finger of the subject, and a second step of the blood sampling system supplying pressurized air to a cuff wrapped around the finger of the subject so as to inflate the cuff and apply a predetermined pressure to the finger of the subject. The blood sampling system includes a light source that irradiates light onto the subject's finger, a camera that captures the light that has passed through the subject's finger, and a puncture blood sampling mechanism that moves a puncture needle to puncture the subject's finger, and the range of movement of the puncture needle moved by the puncture blood sampling mechanism is limited, and in the first step, the blood sampling system detects a position on a thicker finger vein that exists within the range of movement of the puncture needle as a puncture position of the puncture needle based on the image captured by the camera, and operates the puncture blood sampling mechanism to insert the puncture needle into the detected puncture position. I did so. Effect of the Invention

[0011] According to the present invention, it is possible to realize a blood collection system and method that improves blood collection efficiency and enables a sufficient amount of blood to be collected. [Brief description of the drawings]

[0012] [Figure 1] 1 is a block diagram showing the overall configuration of a blood sampling system according to an embodiment of the present invention. [Diagram 2] 1A and 1B are a top view and a side view for explaining the puncturing blood sampling mechanism of the blood sampling device. [Diagram 3] 13 is a flowchart showing a processing procedure of subject authentication blood sampling control processing. [Figure 4] 13 is a flowchart showing a processing procedure of a brightness adjustment process. [Diagram 5] FIG. 13 is a diagram showing an example of a fingertip image. [Figure 6] 11 is a graph showing the relationship between the average luminance of a processing area and the amount of dimming. [Figure 7] 13 is a flowchart showing a processing procedure of subject authentication processing. [Figure 8] FIG. 13A is a diagram explaining the puncture needle trajectory, and FIG. 13B is a chart showing puncture needle trajectory coordinate data. [Figure 9] FIG. 13 is a diagram for explaining how to determine a puncture needle trajectory. [Figure 10] 13 is a flowchart showing a processing procedure of a puncture position determination process. [Figure 11] FIG. 13A is a diagram and graph for explaining a technique for extracting puncture position candidates, and FIG. 13B is a diagram for explaining a technique for detecting valleys in the graph. [Figure 12] FIG. 4 is a diagram showing a configuration of a cuff control unit. [Figure 13] (A) is a graph showing the waveform of the control voltage applied to the pump of the cuff control unit, (B) is a graph showing the fluctuation of the cuff pressure, (C) is a graph showing the waveform of the control voltage applied to the infrared LED, and (D) is a graph showing the brightness of the near-infrared light emitted by the infrared LED. [Figure 14] 13(A) and 13(B) are diagrams illustrating the vein enhancement effect obtained by pressing the subject's finger. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] An embodiment of the present invention will now be described in detail with reference to the drawings.

[0014] (1) Configuration of the Blood Collection System According to the Present Embodiment 1, the blood sampling system according to this embodiment is generally designated by reference numeral 1. This blood sampling system 1 is a system which simultaneously performs authentication of a subject and blood sampling, and is configured with a subject authentication / blood sampling control device 2 and a blood sampling device 3.

[0015] The subject authentication blood sampling control device 2 is composed of a subject authentication blood sampling control device main body 10, an operator display device 11, and a subject display device 12. The subject authentication blood sampling control device main body 10 is composed of a general-purpose computer device equipped with a CPU (Central Processing Unit) 13, a memory 14, and a storage device 15.

[0016] The CPU 13 is a processor that controls the overall operation of the subject authentication blood sampling control device 2. The memory 14 is composed of, for example, a volatile semiconductor memory, and is used as a work memory for the CPU 13. The storage device 15 is composed of a non-volatile large-capacity storage device such as a hard disk device or SSD (Solid State Drive), and stores various software and various data that need to be stored for a long period of time in advance.

[0017] Various software stored in the storage device 15 is loaded into the memory 14 when the subject authentication blood sampling control device 2 is started up or when necessary, and the CPU 13 executes the programs loaded into the memory 14 to perform various processes of the subject authentication blood sampling control device 2 as a whole, as described below.

[0018] The operator display device 11 is a display device used to display information for an operator who operates the subject authentication blood sampling control device 2, and is configured with a liquid crystal panel, an organic EL (Electro-Luminescence) panel, a touch panel, etc. The subject display device 12 is a display device used to display information for the subject, and is configured with, for example, a touch panel, etc.

[0019] In addition, the memory device 15 of the subject authentication blood sampling control device main body 10 stores subject application software (hereinafter referred to as the subject application) 16, blood sampling application software (hereinafter referred to as the blood sampling application) 17, and an authentication database 18.

[0020] Subject-oriented application 16 is software capable of communicating with blood collection application 17, and in response to instructions from blood collection application 17, displays a signal to start blood collection or a signal to complete blood collection on subject display device 12, and displays various information such as a usage guide on subject display device 12 in response to operational input by the subject on subject display device 12.

[0021] The blood sampling application 17 also performs processes such as adjusting the brightness of the near-infrared light emitted from an infrared LED (Light Emitting Diode) 26 of the blood sampling device 3 described later, authenticating the subject, and determining the position at which to insert the puncture needle into the subject's finger (hereinafter referred to as the puncture position).

[0022] The authentication database 18 is a database in which a pre-registered image of the finger veins of each subject is stored in association with the identifier of the corresponding subject (hereinafter, referred to as a subject ID). The details of the "image of the finger veins" will be described later.

[0023] The blood sampling device 3 is a device for sampling blood from a subject, and is configured to include a cuff 20, a cuff control unit 21, a blood sampling unit 22, and a control unit .

[0024] The cuff 20 is a band-shaped balloon that is worn by wrapping it around the subject's finger 24. The cuff control unit 21 is a drive device for the cuff 20 that injects pressurized air into the cuff 20 to increase the internal pressure of the cuff 20 and inflate the cuff 20, or stops the supply of pressurized air to the cuff 20 to decrease the internal pressure of the cuff 20 and inflate the cuff 20. By inflating or deflating the cuff 20, pressure can be applied to the finger 24 around which the cuff 20 is wrapped, or the pressure can be released.

[0025] Blood sampling unit 22 is a mechanical part that samples blood by inserting a puncture needle into finger 24 of the subject, and is configured with a puncture blood sampling mechanism 25, an infrared LED 26, and an infrared night-vision camera 27.

[0026] 2(A), the puncturing blood sampling mechanism 25 is configured with a turntable 30 provided with a plurality of holders 30A each having a cylindrical recess. Each holder 30A is formed at an equal distance from the center position of the turntable 30.

[0027] A shaft body 31 is fixed to the center of the rotating table 30 coaxially with the rotating table 30. The shaft body 31 is also engaged with an actuator such as a motor (not shown), and by driving this actuator, the shaft body 31 and the rotating table 30 can be rotated integrally about the central axis of the shaft body 31 and the rotating table 30.

[0028] In addition, a finger rest 32 is disposed above the rotating table 30. As shown in Fig. 2, this finger rest 32 is configured to include an inclined portion 32A that inclines downward toward the tip, and a fingertip support portion 32B that is provided continuous with the inclined portion 32A on the tip side of the inclined portion 32A. In addition, an opening 32C is provided in the finger rest 32 at a position facing the finger pad of the finger 24 placed on the finger rest 32 in a predetermined state on the tip side of the first joint.

[0029] As a result, when the subject places finger 24 on finger placement stand 32 in a specified position with the tip of finger 24 abutting against the tip surface of opening 32C as shown in Figure 2 (A), the pad of finger 24 on the tip side beyond the first joint is exposed to the side of turntable 30 through opening 32C.

[0030] The infrared LED 26 is a light source that irradiates near-infrared light having a wavelength of about 940 nm onto the subject's finger 24. The infrared LED 26 is disposed above the finger rest 32 so that the emitted near-infrared light passes obliquely (obliquely with respect to the finger 24) through a portion beyond the first joint of the subject's finger 24 placed on the finger rest 32 as described above, and then exits downward through the opening 32C of the finger rest 32, as shown in FIG.

[0031] Infrared night vision camera 27 is fixed to turntable 30 of puncturing blood sampling mechanism 25 so that its imaging optical axis overlaps with the optical axis of infrared LED 26 in order to capture near-infrared light that has passed through subject's finger 24 and is emitted downward through opening 32C of finger placement stand 32 as described above. Infrared night vision camera 27 is connected to subject authentication blood sampling control device main body 10 via a USB (Universal Serial Bus) cable 33 (FIG. 1), and image data of the captured image obtained by such imaging is transmitted to subject authentication blood sampling control device main body 10 via USB cable 33 in real time.

[0032] Control unit 23 is a computer device equipped with information processing resources such as a CPU and memory (not shown). Control unit 23 is connected to subject authentication blood sampling control device main body 10 via a LAN (Local Area Network) cable 34 (FIG. 1), and controls puncturing blood sampling mechanism 25 according to instructions given from subject authentication blood sampling control device main body 10 via this LAN cable 34.

[0033] Control unit 23 is also provided with a motor driver 28 and a general purpose input / output (GPIO) interface 29. Control unit 23 controls the drive of pump 60 of cuff control unit 21, which will be described later with reference to Fig. 12, by motor driver 28, and controls the brightness of infrared LED 26 connected to GPIO interface 29, in accordance with instructions provided by subject authentication blood sampling control device main body 10.

[0034] 2(B), in which the same reference numerals are used for parts corresponding to those in Fig. 2(A), shows another example of the configuration of the blood sampling unit 22. This example of the configuration differs from Fig. 2(A) in that the infrared LEDs 26 are arranged so as to transmit the infrared light vertically (vertically to the finger 24) through the part beyond the first joint of the subject's finger 24 placed on the finger placement stand 32.

[0035] Accordingly, the infrared night-vision camera 27 is disposed separately from the rotating table 30 so that its imaging optical axis overlaps with the optical axis of the infrared LED 26. For this reason, the rotating table 30 is provided with a recess 30B to avoid interference with the infrared night-vision camera 27 during rotation.

[0036] In the present embodiment, both of the configurations of Fig. 2(A) and Fig. 2(B) can be used as the configuration of blood collection unit 22, but since the configuration of Fig. 2(A) is more likely to reduce image contrast, the configuration of Fig. 2(B) is generally used in many cases. However, in the present embodiment, the configuration of Fig. 2(A) is given priority because it is easier to simplify and compact the mechanism of blood collection unit 22 than the configuration of Fig. 2(B).

[0037] (2) Processing of subject authentication and blood sampling control device related to subject authentication and blood sampling Next, we will explain the flow of a series of processes (hereinafter referred to as subject authentication blood sampling process) executed in the subject authentication blood sampling control device 2 to authenticate and sample blood from the subject in the blood sampling system 1. In the following explanation, the subject authentication blood sampling process is mainly performed by the blood sampling application 17 (Fig. 1), but it goes without saying that in reality, the CPU 13 (Fig. 1) of the subject authentication blood sampling control device main body 10 (Fig. 1) executes the process based on the blood sampling application 17.

[0038] (2-1) Subject authentication blood sampling control process Fig. 3 shows a series of flows of the subject authentication blood sampling control process. The blood sampling application 17 starts the subject authentication blood sampling control process when the subject places finger 24 in a predetermined position on finger placement stand 32 (Fig. 2(A)) and then a predetermined operation is performed by the operator of subject authentication blood sampling control device 2. Then, blood sampling application 17 first adjusts the brightness of the near-infrared light emitted from infrared LED 26 (Fig. 1) of blood sampling device 3 (Fig. 1) based on the video data of the captured video transmitted from infrared night-vision camera 27 (Fig. 1) of blood sampling device 3 (S1).

[0039] Next, blood sampling application 17 authenticates the subject based on the video data (S2). If the authentication fails, blood sampling application 17 ends the subject authentication blood sampling control process (S3; NO).

[0040] In contrast, if the subject is successfully authenticated in step S2 (S3; YES), blood sampling application 17 determines the position (hereinafter referred to as the puncture position) at which to insert the puncture needle into the finger pad at the tip side of subject's finger 24 exposed to the turntable 30 side through opening 32C (Figure 2(A)) of finger placement stand 32 (S4).

[0041] Next, the blood collection application 17 transmits the coordinate data of the puncture position determined in step S4 (hereinafter referred to as the puncture position coordinate data) to the control unit 23 (FIG. 1) of the blood collection device 3 together with a puncture instruction to insert the puncture needle into the puncture position (S5).

[0042] Thus, the control unit 23 of the blood sampling device 3 that receives this puncture instruction controls the puncture blood sampling mechanism 25 based on the puncture position coordinate data provided at this time, thereby rotating the turntable 30 as necessary so that the puncture needle of a lancet (not shown), which is set so as to fit into one of the holders 30A (Figure 2(A)) of the turntable 30, is positioned directly below the specified puncture position.

[0043] Control unit 23 then raises turntable 30 so that the puncture needle of the lancet is inserted to a depth of about 2 mm into the puncture position on the finger pad at the tip side of finger 24 of the subject placed on finger placement table 32. As a result, the puncture needle of the lancet is inserted into the puncture position determined by blood sampling application 17, and blood is sampled.

[0044] Thereafter, when the puncturing is completed, the control unit 23 of the blood sampling device 3 notifies the subject authentication blood sampling control device 2 of this fact (S6). Then, upon receiving this notification, the blood sampling application 17 of the subject authentication blood sampling control device 2 ends this series of subject authentication blood sampling control processes.

[0045] (2-2) Brightness adjustment process Fig. 4 shows specific processing contents of the brightness adjustment processing executed by blood sampling application 17 in step S1 of the subject authentication blood sampling control processing described above with reference to Fig. 3. Blood sampling application 17 adjusts the brightness of the near-infrared light emitted by infrared LED 26 of blood sampling device 3 according to the processing procedure shown in Fig. 4.

[0046] In practice, when the blood sampling application 17 proceeds to step S2 of the subject authentication blood sampling control process, it starts this brightness adjustment process, and first captures an image of the subject's fingertip (hereinafter referred to as the fingertip image) based on the video data of the captured image transmitted from the infrared night vision camera 27 (S10).

[0047] 5 shows an example of a fingertip image 50 captured at this time. This fingertip image 50 shows the tip of the subject's finger 24 exposed to the infrared night-vision camera 27 through the opening 32C (FIG. 2(A)) of the finger placement stand 32 (FIG. 2(A)), and the shadow of the finger vein 51 present within the tip.

[0048] In this case, since the present embodiment uses infrared LED 26 that emits near-infrared light with a wavelength of about 940 nm, only the shadow of finger vein 51 located at a depth of about 2 mm from the surface of the finger pad at the tip of subject's finger 24, that is, at the same position as the depth at which the lancet needle is inserted into subject's finger 24 in this embodiment, is displayed in fingertip image 50.

[0049] Next, blood sampling application 17 cuts out a predetermined area of ​​captured fingertip image 50 corresponding to the vicinity of the tip of subject's finger 24 as processing area 52 in which processing from step S12 onwards is to be performed (S11), and calculates the average luminance within cut-out processing area 52 (S12).

[0050] Next, blood sampling application 17 calculates the dimming amount according to the calculated average luminance in processing area 52 (S13). The method of calculating the dimming amount at this time will be described later. Then, blood sampling application 17 transmits an instruction to adjust the brightness of the near-infrared light emitted by infrared LED 26 (hereinafter, this will be referred to as a dimming instruction) to control unit 23 of blood sampling device 3 together with the dimming amount at this time calculated in step S13 (S14). Thus, upon receiving this notification, control unit 23 of blood sampling device 3 controls infrared LED 26 to change the brightness by the notified dimming amount.

[0051] Thereafter, blood sampling application 17 determines whether or not the brightness adjustment of the near-infrared light emitted by infrared LED 26 has been completed (S15). Specifically, blood sampling application 17 captures a new fingertip image 50, calculates the average luminance within processing region 52 cut out from captured fingertip image 50, in the same manner as steps S10 to S13, and determines whether or not the calculated average luminance falls within a predetermined range from a preset target luminance.

[0052] If blood sampling application 17 obtains a negative result in this determination, it returns to step S10, and thereafter repeats the processes of steps S10 to S15 until it obtains a positive result in step S15. If blood sampling application 17 eventually obtains a positive result in step S15 by the average luminance of processing area 52 of fingertip image 50 falling within a predetermined range from the target luminance, it ends this brightness adjustment process.

[0053] Here, a description will be given of the specific processing content of blood sampling application 17 in step S13 of the brightness adjustment processing. Fig. 6 shows the relationship between the average luminance in processing area 52, which is preset in blood sampling application 17, and the dimming amount of near-infrared light emitted by infrared LED 26 relative to the average luminance in the present embodiment.

[0054] In this embodiment, the average luminance in the processing area 52 is divided into three areas, a high-luminance nonlinear area, a linear area, and a low-luminance nonlinear area, and a different calculation method for the dimming amount is applied to each of the high-luminance nonlinear area, the linear area, and the low-luminance nonlinear area. However, this area classification is a guideline assuming a standard case.

[0055] 6, curve K1 indicates a relationship between the average luminance in the processing area 52 and the dimming amount of the infrared LEDs 26 relative to the average luminance, assuming a finger smaller than the standard size, curve K2 a finger of standard size (hereinafter referred to as the standard finger), and curve K3 a finger larger than the standard size. Here, it is assumed that the slopes of the curves K1 to K3 are approximately the same regardless of the size of the finger.

[0056] When the average luminance calculated in step S12 of the brightness adjustment process (FIG. 4) is within the high luminance nonlinear region and exceeds a preset maximum luminance B1 (FIG. 6), blood sampling application 17 calculates the dimming amount as 1 / 2 of the average luminance at that time.

[0057] Furthermore, when the average luminance calculated in step S12 is within the low luminance nonlinear region, blood sampling application 17 prorates the adjustable maximum dimming amount (hereinafter referred to as the maximum dimming amount) based on the ratio between initial luminance B3 (FIG. 3), which is the boundary between the linear region and the low luminance nonlinear region, and the above-mentioned maximum luminance B1, and sets the dimming amount to the amount that corresponds to maximum luminance B1 among the maximum dimming amounts after proration.

[0058] Furthermore, when the average luminance is in the linear region, blood sampling application 17 gradually increases the dimming amount until the average luminance calculated in step S12 reaches the preset target luminance B2 so that the brightness of the near-infrared light emitted by infrared LED 26 gradually approaches target luminance B2 (FIG. 6). Specifically, blood sampling application 17 calculates the dimming amount by the following equation, where a is the slope of the linear region of curves K1 to K3 in FIG.

number

number

[0059] (2-3) Subject authentication process Fig. 7 shows specific processing contents of the subject authentication processing executed by blood sampling application 17 in step S2 of the subject authentication blood sampling control processing described above with reference to Fig. 3. Blood sampling application 17 authenticates the subject who has placed finger 24 on finger placement platform 32 at that time, according to the processing procedure shown in Fig. 7.

[0060] In practice, when the blood sampling application 17 proceeds to step S2 of the subject authentication blood sampling control process, it starts this subject authentication process, and first creates a feature image by extracting the features of the subject's finger vein from a frame image (i.e., fingertip image 50 (Figure 5)) based on the video data transmitted from the infrared night vision camera 27 (S20).

[0061] Specifically, the blood sampling application 17 sequentially performs an inter-frame averaging process on the subject's fingertip image 50, which averages the brightness of pixels at the same position across multiple frames, a Gaussian filter process on the fingertip image 50, which removes noise from the fingertip image 50, and an image reduction process on the fingertip image 50, and creates a feature image by extracting features from the reduced image of the fingertip image 50 thus obtained.

[0062] Next, the blood sampling application 17 compares the created characteristic image with each of the subjects' characteristic images stored in the authentication database 18 (FIG. 1) (S21), and determines whether the characteristic image created in step S20 matches any of the characteristic images registered in the authentication database 18 (S22).

[0063] If the blood sampling application 17 obtains a positive result in this determination, it instructs the subject-oriented application 16 (FIG. 1) to display a message on the subject display device 12 (FIG. 1) to confirm whether the current subject is the subject corresponding to the characteristic image on the authentication database 18 that matches the characteristic image created in step S20 and the characteristic image in the authentication database 18 that matched in the comparison in step S21 (S23), and then terminates the subject authentication process.

[0064] Thus, in this case, a message such as "You are Mr. / Ms. XX" is displayed on the subject display device 12 by the subject-oriented application 16. Note that "XX" is the name of the subject corresponding to the characteristic image on the authentication database 18 that matches the characteristic image created in step S20 in the comparison in step S21.

[0065] On the other hand, if the blood sampling application 17 obtains a negative result in the determination in step S22, it calls an attendant (S24), and then ends this subject authentication process.

[0066] (2-4) Puncture position determination process Next, a description will be given of the puncture position determination process executed by blood sampling application 17 in step S4 of the subject authentication blood sampling control process described above with reference to Fig. 3. In this regard, first, the puncture needle trajectory will be described.

[0067] As described above, in blood collection system 1 of this embodiment, a lancet (not shown) is inserted and set in holder 30A of turntable 30 described above with reference to Figure 2(A), and then turntable 30 is raised so that the lancet's puncture needle is inserted into the pad of the subject's fingertip exposed through opening 32C (Figure 2(A)) of finger placement table 32 (Figure 2(A)).

[0068] Therefore, since the puncture needle moves on a circumference centered on the central axis of the rotating table 30 by rotating the rotating table 30, the puncture needle in the fingertip image 50 (FIG. 5) when the rotating table 30 is rotated moves along an arc-shaped trajectory (hereinafter referred to as the puncture needle trajectory) L1 as shown in FIG. 8(A). Therefore, the puncture needle trajectory L1 can be said to be a collection of positions where the puncture needle of the lancet set in the holder 30A of the rotating table 30 can puncture.

[0069] In this case, when the position of the infrared night vision camera 27 relative to the rotating table 30 is fixed, the puncture needle trajectory L1 is always at the same position in the fingertip image 50. Therefore, the puncture needle trajectory L1 in the fingertip image 50 can be obtained by the following method.

[0070] First, a felt-tip pen is fixedly set in holder 30A of turntable 30 so that the pen tip is located at the same position as the puncture needle of a lancet set in holder 30A of turntable 30. Next, finger 24 is placed in a predetermined state on finger rest 32, and turntable 30 is rotated with the pen tip of the felt-tip pen in contact with the pad of finger 24 exposed from opening 32C of finger rest 32. In this way, an arc-shaped marker (hereinafter referred to as a trajectory marker) L2 is drawn on the pad of finger 24 as shown in FIG.

[0071] 9, for ease of understanding, the trajectory marker L2 and the puncture needle trajectory L1 are depicted separately, but in reality, the trajectory marker L2 is part of the puncture needle trajectory L1, and therefore the trajectory marker L2 completely overlaps with the puncture needle trajectory L1. Therefore, the puncture needle trajectory L1 in the fingertip image 50 can be obtained based on the trajectory marker L2.

[0072] In this embodiment, the control unit 23 of the blood sampling device 3 prestores the puncture needle trajectory L1 thus obtained as coordinate data of each point on the puncture needle trajectory L1 as shown in Fig. 8(B) (hereinafter, these will be collectively referred to as puncture needle trajectory coordinate data). Note that the puncture needle trajectory coordinate data shown in Fig. 8(B) is obtained by obtaining the coordinates of each position on the puncture needle trajectory L1 (the 0th pixel, 1st pixel, 2nd pixel, ... in the horizontal direction) when the image size of the fingertip image 50 is 640 x 480 pixels and the size of the processing area is 320 x 220 pixels as shown in Fig. 8(A).

[0073] Here, Fig. 10 shows specific processing contents of the puncturing position determination processing executed by blood sampling application 17 in step S4 of the subject authentication blood sampling control processing described above with reference to Fig. 3. Blood sampling application 17 determines the puncturing position of finger 24 placed on finger placement platform 32 according to the processing procedure shown in Fig. 10.

[0074] In practice, when the blood sampling application 17 proceeds to step S4 of the subject authentication blood sampling control process, it starts this puncture position determination process, and first sequentially performs the above-mentioned inter-frame averaging process and Gaussian filter process on the fingertip image based on the video data transmitted from the infrared night vision camera 27 of the blood sampling device 3 (S30, S31).

[0075] The blood sampling application 17 also accesses the control unit 23 of the blood sampling device 3 to obtain the puncture needle trajectory coordinate data described above with reference to Figure 8 (B) (S32), and sequentially performs a minimum value filter process on the obtained puncture needle trajectory coordinate data, which compares the values ​​of surrounding pixels to convert them into the pixel with the smallest value, and a tone curve conversion process, which converts the shade of the image (S33, S34).

[0076] Next, the blood sampling application 17 detects several positions on the puncture needle trajectory L1 based on the puncture needle trajectory coordinate data that has been subjected to minimum value filter processing and tone curve conversion processing as described above, within the processing area 52 of the fingertip image 50, where the shadow of the subject's finger vein 51 (Figure 5) intersects with the puncture needle trajectory L1, and determines one position from the coordinates of these detected positions as the puncture position (S35).

[0077] In this way, by setting the puncture position at the position where the shadow of the subject's finger vein 51 intersects with the puncture needle trajectory L1, it is possible to effectively puncture the subject's finger vein 51 to collect blood, thereby allowing more blood to be collected than if blood was collected by puncturing a location other than the finger vein 51.

[0078] Then, blood sampling application 17 notifies control unit 23 of blood sampling device 3 of the coordinates of the puncturing position determined in step S35 (S36), and then ends this puncturing position determination process.

[0079] Thus, upon receiving this notification, the control unit 23 of the blood collection device 3 controls the puncturing and blood collection mechanism 25 of the blood collection unit 22 to position the puncture needle of the lancet set on the turntable 30 at the position notified by the blood collection application 17, and also raises the turntable 30 to perform blood collection by inserting the puncture needle at that position.

[0080] The specific processing content of blood sampling application 17 in step S35 of the puncture position determination process will now be described. As shown in graph K10 in the lower part of Fig. 11(A), the brightness of puncture needle trajectory L1 in processing area 52 is lower than the brightness of the surroundings at the position where it intersects with the shadow of finger vein 51, and the wider the intersecting finger vein 51, the lower the brightness.

[0081] Also, as shown in FIG. 11(B), if the position of the lowest point of the downwardly convex part of the graph shape in graph K10 in FIG. 11(A) (hereinafter referred to as the valley) is denoted as P, the point on graph K10 corresponding to a position a predetermined distance w / 2 away from point P to the right of fingertip image 50 is denoted as Q, and the point on graph K10 corresponding to a position a predetermined distance w / 2 away from point P to the left of fingertip image 50 is denoted as R, then the magnitude of ∠QPR becomes smaller as the depth of the corresponding valley becomes greater (i.e., the lower the brightness of the location in fingertip image 50 corresponding to such lowest point).

[0082] Therefore, the blood sampling application 17 utilizes these principles to extract all valleys in the portion of the puncture needle trajectory L1 that passes through the processing area 52 of the fingertip image 50 that have a brightness that is a predetermined amount lower than the surroundings, and also extracts several (e.g., three) valleys with lower brightness (smaller ∠QPR in Figure 11(B)) from the extracted valleys as candidate puncture positions.

[0083] Then, blood sampling application 17 determines, from among the puncture position candidates extracted in this manner, at least one puncture position candidate that is different from the position where the puncture needle was inserted during the previous blood sampling, as the current puncture position.

[0084] To achieve this, blood sampling application 17 stores the puncture position at the time of the previous blood sampling for each registered subject. Specifically, blood sampling application 17 registers and manages in authentication database 18 (FIG. 1) which puncture position candidate with the lowest luminance, counting from the puncture position candidate with the lowest luminance, was determined as the puncture position at the time of the previous blood sampling in association with the subject, in association with the subject.

[0085] After extracting the puncture position candidates as described above, the blood collection application 17 refers to the authentication database 18 and selects one of the currently extracted puncture position candidates that has a different brightness ranking from the brightness ranking of the previous puncture position using a round robin method or the like, and determines the selected puncture position candidate as the current puncture position.

[0086] In this manner, in the blood sampling system 1 of this embodiment, the puncture position of the puncture needle is selected to be at least a position different from the previous puncture position, thereby reducing the subject's pain caused by repeatedly puncturing the same position during blood sampling.

[0087] (3) The control unit of the blood sampling device controls the cuff pressure and the brightness of the infrared LED Next, there will be explained pressure control of the cuff 20 (FIG. 1) and brightness control of the infrared LEDs performed by the control unit 23 of the blood sampling device 3. In this regard, first, the configuration of the cuff control unit 21 (FIG. 1) will be explained.

[0088] 12 shows the configuration of the cuff control unit 21 of the blood sampling device 3. As shown in this Fig. 12, the cuff control unit 21 is configured to include a pump 60, a check valve 61, an air buffer 62, and a pressure regulating valve 63.

[0089] The pump 60 is an air circuit element that generates pressurized air, the check valve 61 is an air circuit element that prevents backflow of air due to pressure fluctuations in the air circuit, the air buffer 62 is an air circuit element that relieves pain to the subject caused by sudden pressure fluctuations in the cuff 20, and the pressure regulating valve 63 is an air circuit element that is used to prevent the cuff 20 from bursting by releasing excess pressure.

[0090] Furthermore, the pump 60 and the check valve 61, the check valve 61 and the air buffer 62, and the air buffer 62 and the pressure regulating valve 63 are connected by φ3-5 mm PP (Polypropylene) tubes 64A, 64B, and 64C, respectively, and the air buffer 62 and the pressure regulating valve 63 are branched and connected to the cuff 20 via a φ3-5 mm PP tube 64D.

[0091] In addition, the pump 60 is connected to the motor driver 28 of the control unit 23 via a jumper wire 65A. The pump 60 generates pressurized air based on a control voltage provided from the motor driver 28 via the jumper wire 65A, and outputs the generated pressurized air to the check valve 61 via a PP tube 64A. The pressurized air is then injected into the cuff 20 via the check valve 61 and the air buffer 62.

[0092] The infrared LED 26 is also connected to the GPIO interface 29 of the control unit 23 via a jumper wire 65B. The infrared LED 26 is driven based on a control voltage provided from the GPIO interface 29 of the control unit 23 via the jumper wire 65B, and emits near-infrared light with a brightness according to the control voltage.

[0093] Fig. 13(A) shows the voltage waveform of the control voltage that motor driver 28 of control unit 23 applies to pump 60 via jumper wire 65A, and Fig. 13(B) shows the internal pressure of cuff 20 at this time. As shown in Fig. 13(A), motor driver 28 applies a rectangular wave control voltage having one cycle of, for example, 10 seconds to pump 60.

[0094] In this case, the pump 60 is driven to output pressurized air while the control voltage is at a logic "1" level (e.g., 12 V). This pressurized air is then supplied to the cuff 20 via a PP tube 64A connecting the pump 60 and the check valve 61, a PP tube 64B connecting the check valve 61 and the air buffer 62, and a PP tube 64D connecting the air buffer 62 and the cuff 20. As a result, the internal pressure of the cuff 20 rises and the cuff 20 inflates, applying an appropriate pressure to the finger 24 around which it is wound.

[0095] Furthermore, the pump 60 stops operating while the control voltage falls to a logic "0" level (for example, 0 V). As a result, the internal pressures of the PP tube 64A connecting the pump 60 and the check valve 61, the PP tube 64B connecting the check valve 61 and the air buffer 62, and the PP tube 64D connecting the air buffer 62 and the cuff 20 decrease. As a result, the internal pressure of the cuff 20 also decreases, causing the cuff 20 to contract, and the pressure that the cuff 20 was applying to the finger 24 around which it was wound decreases.

[0096] In blood sampling device 3 of this embodiment, motor driver 28 of control unit 23 applies a rectangular wave control voltage to pump 60, so that cuff 20 repeatedly pressurizes and depressurizes finger 24 around which cuff 20 is wrapped, thereby providing an effect similar to that of a person massaging finger 24 around which cuff 20 is wrapped. By doing this, blood sampling device 3 of this embodiment can increase the amount of bleeding from finger 24 around which cuff 20 is wrapped, and more blood can be collected compared to the case where nothing is done.

[0097] In addition, by compressing the subject's finger 24 with the cuff 20, a vein enhancement effect can be obtained in the fingertip image 50. That is, when the subject's finger 24 is compressed, the pressure causes the subject's finger veins 51 to expand, as shown in Fig. 14(B), and the contrast of the shadow of the finger veins 51 in the fingertip image 50 becomes higher compared to the case where no compression is performed as shown in Fig. 14(A). As a result, when extracting puncture position candidates, it becomes possible to more accurately detect the position where the puncture needle trajectory L1 intersects with the shadow of the subject's finger vein 51.

[0098] On the other hand, Fig. 13(C) shows the voltage waveform of the control voltage applied by the control unit 23 to the infrared LED 26 via the GPIO interface 29 and the jumper wire 65B, and Fig. 13(D) shows the brightness of the near-infrared light emitted from the infrared LED 26 at this time. As shown in Fig. 13(C), the control unit 23 applies a rectangular wave control voltage having one period of, for example, 10 seconds to the infrared LED 26.

[0099] In this case, the infrared LED 26 emits near-infrared light with a constant brightness according to the duty ratio of the period when the control voltage rises to a logical "1" level (e.g., 12 V) and the period when the control voltage falls to a logical "0" level (e.g., 0 V) ​​under PWM (Pulse Width Modulation) control. When this duty ratio is "1", the LED is at its brightest, and when the duty ratio is "0", the LED is turned off.

[0100] (4) Effects of this embodiment As described above, according to the blood sampling system 1 of this embodiment, the cuff 20 of the blood sampling device 3 repeatedly pressurizes and depressurizes the finger 24 around which the cuff 20 is wrapped, thereby providing an effect similar to that of a person massaging the subject's finger 24 around which the cuff 20 is wrapped, and thereby increasing the amount of bleeding from the finger 24.

[0101] In addition, by applying pressure to the subject's finger 24 with the cuff 20 in this manner, the contrast of the shadow of the finger vein 51 in the fingertip image 50 can be increased, and the position where the puncture needle trajectory L1 intersects with the shadow of the subject's finger vein 51 can be detected with greater accuracy. As a result, the puncture needle can be inserted into the subject's finger vein 51 with greater accuracy, and the amount of bleeding can be increased.

[0102] Therefore, according to the present blood collection system 1, it is possible to realize a blood collection system that improves blood collection efficiency and enables a sufficient amount of blood to be collected.

[0103] Furthermore, in this blood sampling system 1, the finger vein 51 at the tip of the subject's finger 24, above the first joint, is utilized to adjust the brightness, authenticate the subject, and determine the insertion position of the puncture needle, thereby making it possible to simplify and compact the device.

[0104] (5) Other embodiments In the above embodiment, the blood collection system 1 is constructed using the subject authentication blood collection control device 2 and the blood collection device 3. However, the present invention is not limited to this. All of the functions of the subject authentication blood collection control device 2 may be installed in the blood collection device 3, and the blood collection system 1 may be constructed using only that blood collection device.

[0105] In addition, in the above-described embodiment, a case has been described in which the blood collection system 1 is equipped with a function for authenticating the subject, but the present invention is not limited to this, and the blood collection system 1 may be equipped with only a blood collection function for collecting blood from the subject.

[0106] Furthermore, in the above-described embodiment, a rectangular wave control voltage having a cycle of 10 seconds as shown in FIG. 13(A) is applied to pump 60 of cuff control unit 21 so that the internal pressure of cuff 20 can be varied as shown in FIG. 13(B). However, the present invention is not limited to this. In short, as long as cuff 20 can apply pressure to subject's finger 24 so as to repeatedly inflate and depressurize the pressure at a constant cycle, the variation pattern of the internal pressure of cuff 20 may be a variation pattern other than that shown in FIG. 13(B).

[0107] Furthermore, in the above embodiment, the case has been described where near-infrared light is irradiated onto finger 24 of the subject, but the present invention is not limited to this, and light other than near-infrared light may be used.

[0108] Furthermore, in the above embodiment, a case has been described in which multiple (e.g., three) puncture position candidates are extracted in step S35 of the puncture position determination process described above with reference to FIG. 10, and one puncture position candidate is determined as the puncture position by a round robin method or the like according to the luminance ranking of the multiple puncture position candidates. However, the present invention is not limited to this, and a puncture position candidate having at least a different luminance ranking from the previous time may be determined as the current puncture position from among the multiple puncture position candidates. [Industrial Applicability]

[0109] The present invention can be applied to a blood sampling system used to sample blood from a subject. [Explanation of symbols]

[0110] 1...Blood collection system, 2...Subject authentication blood collection control device, 3...Blood collection device, 13...CPU, 16...Subject application, 17...Blood collection application, 18...Authentication database, 20...Cuff, 21...Cuff control unit, 22...Blood collection unit, 23...Control unit, 24...Finger, 25...Puncture blood collection mechanism, 26...Infrared LED, 27...Infrared night vision camera, 30...Rotating table, 30A...Holder, 32...Finger placement table, 32C...Opening, 50...Fingertip image, 51...Finger vein, 52...Processing area, L1...Puncture needle trajectory, L2...Trajectory marker, 60...Pump.

Claims

1. A blood collection system for use in collecting blood from a subject, comprising: a puncture blood sampling mechanism that moves a puncture needle to puncture the subject's finger; A cuff that is wrapped around the subject's finger and worn by the subject; a cuff control unit that supplies pressurized air to the cuff so as to inflate the cuff and apply a predetermined pressure to the subject's finger; A light source that irradiates light onto the subject's finger; a camera that captures the light that has passed through the subject's finger; a blood sampling control unit that determines a puncture position of the puncture needle by the puncture blood sampling mechanism based on the image captured by the camera; Equipped with a movement range of the puncture needle moved by the puncture blood sampling mechanism is limited; The blood collection control unit includes: Based on the image captured by the camera, a position on a thicker finger vein within a moving range of the puncture needle is detected as a puncture position of the puncture needle, and the puncture blood collection mechanism is operated to insert the puncture needle into the detected puncture position. A blood collection system comprising:

2. The puncture blood collection mechanism comprises: The puncture needle is moved so as to draw an arc-shaped trajectory relative to the subject's finger that is set to a predetermined position; The blood collection control unit includes: A position where a thicker finger vein intersects with the trajectory of the puncture needle is detected as the puncture position. The blood collection system according to claim 1 .

3. The cuff control unit includes: The pressurized air is supplied to the cuff in a predetermined pattern so that the internal pressure of the cuff repeatedly rises and falls. The blood collection system according to claim 1 .

4. The blood collection control unit includes: A position on the subject's finger that is different from the previous position is determined as the current puncture position. The blood collection system according to claim 1 .

5. The light source irradiates the subject's finger with near-infrared light as the light, The camera is an infrared night vision camera. The blood collection system according to claim 1 .

6. The blood collection control unit includes: The subject is authenticated using the finger vein of the subject photographed by the camera. The blood collection system according to claim 1 .

7. The blood collection control unit is The subject is authenticated and the puncture position is determined using the finger vein of the subject on the finger tip side of the first joint. The blood collection system according to claim 6 .

8. 1. A blood collection method carried out in a blood collection system utilized to collect blood from a subject, comprising: A first step of the blood collection system inserting a puncture needle into the subject's finger; a second step of the blood sampling system supplying pressurized air to a cuff wrapped around the subject's finger to inflate the cuff and apply a predetermined pressure to the subject's finger; Equipped with The blood collection system comprises: A light source that irradiates light onto the subject's finger; a camera that captures the light that has passed through the subject's finger; a puncture blood sampling mechanism that moves a puncture needle to puncture the subject's finger, a movement range of the puncture needle moved by the puncture blood sampling mechanism is limited; In the first step, the blood collection system comprises: Based on the image captured by the camera, a position on a thicker finger vein within a moving range of the puncture needle is detected as a puncture position of the puncture needle, and the puncture blood collection mechanism is operated to insert the puncture needle into the detected puncture position. A blood collection method comprising:

9. The puncture blood collection mechanism comprises: The puncture needle is moved so as to draw an arc-shaped trajectory relative to the subject's finger that is set to a predetermined position; In the first step, the blood collection system comprises: A position where a thicker finger vein intersects with the trajectory of the puncture needle is detected as the puncture position. The blood collection method according to claim 8 .

10. In the second step, The pressurized air is supplied to the cuff in a predetermined pattern so that the internal pressure of the cuff repeatedly rises and falls. The blood collection method according to claim 8 .

11. In the first step, the blood collection system comprises: A position on the subject's finger that is different from the previous position is determined as the current puncture position. The blood collection method according to claim 8 .

12. The light source irradiates the subject's finger with near-infrared light as the light, The camera is an infrared night vision camera. The blood collection method according to claim 8 .

13. In the first step, the blood collection system comprises: The subject is authenticated using the finger vein of the subject photographed by the camera. The blood collection method according to claim 8 .

14. In the first step, the blood collection system comprises: The subject is authenticated and the puncture position is determined using the finger vein of the subject on the finger tip side of the first joint. The blood collection method according to claim 13 .

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