Blood collection method and blood collection device

Abstract

The present invention provides a blood collection method and a blood collection device capable of identifying a factor causing a blood collection failure in advance and stably performing blood collection at low cost from a finger of a suitable subject and in a suitable blood collection condition. The blood collection method is for determining a puncture depth of a puncture needle with respect to a finger of a person subjected to blood collection, and collecting blood from the finger. The method comprises: a step for capturing a finger stereo image obtained by imaging a blood vessel of the finger of the person subjected to blood collection at mutually different parallaxes; a step for calculating the distance between an image-capturing position and the blood vessel on the basis of one or more of the distance between image-capturing positions obtained by capturing the finger stereo image, the focal length, the parallax, and a parameter in a relationship that makes these calculations possible; and a step for determining whether the puncture depth of the puncture needle with respect to the finger falls within a range of a preset target puncture depth on the basis of the calculation results. The blood collection device comprises: a stereo image-capture device; a distance calculation unit that calculates the distance between an image-capturing position and a blood vessel; a puncture depth determination unit; and a control unit that controls a blood collection operation.

Description

Blood collection method and blood collection device

[0001] The present invention relates to a blood collection method and a blood collection device for collecting blood from the fingers of a subject while determining whether or not there is a disorder related to blood collection.

[0002] Blood sampling devices have been developed that automatically sample blood from the subject's fingers. Some blood sampling devices detect the location of blood vessels in the fingertip and insert a puncture needle into the detected blood vessel. Technology for detecting the location of blood vessels in the fingertip is used in the fields of blood sampling from fingers, vascular diagnosis, and biometric authentication. Optical sensors that utilize near-infrared light absorption, microscopes, etc. are used to detect the location of blood vessels.

[0003] Patent Literature 1 describes a health condition diagnosis device that uses biometric authentication based on the vein pattern of the palm. This device measures the vein pattern of the palm by detecting ultrasound echoes or near-infrared light reflection. This device monitors the autonomic nervous function of the subject based on the morphology and diameter of the veins and arteries.

[0004] Patent Document 2 describes an observation device for observing and measuring capillaries in the nail cuticle. In this device, capillaries in the nail cuticle, which have been coated with observation oil, are observed using a microscope with a specified objective lens. Such a microscope generally observes the flow of fine particles flowing through the capillaries as blood flow.

[0005] Patent Literature 3 describes a biometric information extraction method for extracting biometric information from a fingertip, a biometric identification method, a biometric identification device, a health measurement method, and a health measurement device. In these methods and devices, a fingerprint sensor measures the contact area of ​​a finger when the finger is pressed against an inspection surface and the color of the finger at the contact point. The resistance to blood flow when the finger is pressed against the inspection surface is used as an index of health as the stiffness of the blood vessels.

[0006] JP 2010-279651 A JP 2002-277747 A WO 2006 / 030781 A

[0007] Compared to drawing blood from the forearm, finger blood sampling reduces the risk of complications such as vasovagal reflex and pain from the needle. However, it has drawbacks, such as the small amount of blood collected and the inconsistent amount of blood collected. Blood circulation in the fingers and the depth of the veins vary depending on the individual and the individual's physical condition. If blood circulation in the fingers is poor, it can be difficult to obtain the amount of blood needed for blood tests.

[0008] Furthermore, when collecting blood from the subject's finger, it is necessary to insert the needle into the finger just enough. If the needle is not inserted deep enough, the tip of the needle may not reach the vein or the required amount of blood may not be collected, so it is necessary to ensure a sufficient puncture depth. On the other hand, if the needle is inserted too deeply, it may cause severe pain, so a puncture depth greater than necessary should be avoided.

[0009] Therefore, when collecting blood from the fingers of a subject, it is desirable to identify and avoid in advance factors that hinder blood collection from the fingers, such as poor blood circulation in the fingers or conditions in which the puncture needle cannot reach the depth of the blood vessels.There is a need for technology that quantitatively identifies factors that hinder blood collection from the fingers and, based on the results, optimizes the subjects and blood collection conditions for finger blood collection.

[0010] In Patent Document 1, measurements are taken on the palm of the hand, making it difficult to apply to finger blood sampling. Furthermore, in Patent Documents 1 and 2, the diameter of blood vessels and blood flow themselves are measured, making it difficult to quantify the measurement results and objectively assess poor blood circulation in the fingers. Furthermore, blood flow observed with a microscope may not necessarily reflect the amount of blood that can be sampled. Patent Document 3 requires measurement of the contact area when pressing the finger, resulting in the problem of high equipment costs.

[0011] Therefore, the present invention aims to provide a blood collection method and blood collection device that can identify factors that hinder blood collection in advance and perform stable and low-cost blood collection from the fingers of subjects and blood collection conditions that are appropriate.

[0012] In order to solve the above problems, the blood sampling method of the present invention is a blood sampling method for determining the puncture depth of a puncture needle into the fingers of a person to be sampled and sampling blood from the fingers, and includes the steps of: capturing stereo images of the blood vessels of the person to be sampled with images of the blood vessels of the person to be sampled at different parallaxes; calculating the distance between the imaging positions where the stereo images of the blood vessels were captured and the blood vessels based on one or more of the distance between the imaging positions, focal length, parallax, and parameters that have a relationship that allows these to be calculated; and determining, based on the result of the calculation, whether the puncture depth of the puncture needle into the finger is within a predetermined target puncture depth range; and selectively performing blood sampling on the finger, canceling blood sampling on the finger, or changing blood sampling conditions depending on the result of the determination. Also, there is a blood collection method for determining the state of blood circulation in the fingers of a person to be blood-collected and collecting blood from the fingers, which includes the steps of irradiating near-infrared light onto the fingers of the person to be blood-collected, detecting the near-infrared light that has passed through the blood vessels of the fingers, and capturing a finger vascular image that represents the course of the blood vessels in the fingers using pixel contrast, and determining whether the blood circulation in the fingers is poor based on the intensity of the pixels representing the blood vessels in the finger vascular image, and selectively performing blood collection from the fingers, canceling blood collection from the fingers, or changing the blood collection conditions depending on the result of the determination.

[0013] Furthermore, the blood collection device of the present invention is a blood collection device that collects blood from the fingers of a person to be collected, and includes: a stereo imaging device that captures stereo images of the blood vessels of the person to be collected with different parallaxes; a distance calculation unit that calculates the distance between the imaging positions where the stereo images of the fingers were captured and the blood vessels based on one or more of the distance between the imaging positions, focal length, parallax, and parameters that have a relationship that allows these to be calculated; a puncture depth determination unit that determines whether the puncture depth of the puncture needle into the finger is within a predetermined target puncture depth range based on the result of the calculation; and a control unit that controls the blood collection operation based on the result of the determination by the puncture depth determination unit. Also, a blood collection device that collects blood from the fingers of a person to be blood-collected includes a light source that irradiates near-infrared light onto the fingers of the person to be blood-collected, a near-infrared light imaging device that detects near-infrared light that has passed through the blood vessels of the fingers and captures a finger vascular image that represents the course of the blood vessels in the fingers with pixel contrast, a blood circulation determination unit that determines whether the blood circulation in the fingers is poor based on the intensity of the pixels representing the blood vessels in the finger vascular image, and a control unit that controls the blood collection operation based on the result of the determination by the blood circulation determination unit.

[0014] According to the present invention, it is possible to provide a blood collection method and blood collection device that can identify factors that hinder blood collection in advance and perform stable and low-cost blood collection from the fingers of subjects and blood collection conditions that are appropriate.

[0015] 1 is a flowchart illustrating an example of a blood collection method according to an embodiment of the present invention. FIG. 2 is a flowchart illustrating an example of a blood collection method according to an embodiment of the present invention. FIG. 3 is a flowchart illustrating an example of a blood collection method according to an embodiment of the present invention. FIG. 4 is a diagram illustrating a method for determining circulatory disorders based on finger temperature and body temperature. FIG. 5 is an external view of a blood collection device according to an embodiment of the present invention. FIG. 6 is a cross-sectional view schematically illustrating an example of the arrangement of an image capture device in a blood collection device. FIG. 7 is a cross-sectional view schematically illustrating an example of the arrangement of an image capture device in a blood collection device. FIG. 8 is a cross-sectional view schematically illustrating an example of the arrangement of an image capture device in a blood collection device. FIG. 9 is a block diagram illustrating the functions of a blood collection control device that controls the blood collection device. FIG. 10 is a flowchart illustrating an example of the operation of the blood collection device. FIG. 11 is a diagram illustrating absorption of near-infrared light according to blood circulation in a finger vascular image. FIG. 12 is a diagram illustrating absorption of near-infrared light according to blood circulation in a finger vascular image. FIG. 13 is a diagram illustrating processing for determining the puncture position of a puncture needle. FIG. 14 is a diagram illustrating processing for determining the puncture position of a puncture needle. FIG. 15 is a diagram illustrating the puncture depth of a puncture needle into a finger of a recipient. FIG. 16 is a diagram illustrating the puncture depth of a puncture needle into a finger of a recipient. Fig. 1 is a diagram illustrating stereo images of fingers; Fig. 2 is a diagram illustrating a method for calculating distance based on stereo images of fingers; Fig. 3 is a diagram illustrating a method for calculating distance based on stereo images of fingers; Fig. 4 is a diagram illustrating a method for calculating distance based on stereo images of fingers;

[0016] A blood collection method and a blood collection device according to one embodiment of the present invention will be described below. Note that common components in the following drawings will be given the same reference numerals, and duplicated explanations will be omitted.

[0017] The blood collection method according to this embodiment relates to a method for collecting blood from the fingers of a blood collection subject by determining in advance whether or not there are any obstacles to blood collection. In this blood collection method, factors that may hinder blood collection from the fingers are quantitatively determined for each blood collection subject before blood collection. Based on the quantification results, it is determined whether or not it is possible to properly collect blood from the fingers with a sufficient amount of blood collected. Depending on the determination results, whether or not blood can be collected from the fingers and the blood collection conditions are selected.

[0018] Factors that hinder blood collection from fingers make it difficult to secure the amount of blood needed for blood tests, etc., such as poor blood circulation in the fingers and insufficient penetration depth of the puncture needle into the finger.

[0019] When blood circulation in the fingers is poor, the amount of bleeding after puncturing is small, making it difficult to ensure the amount of blood needed for blood tests, etc. Therefore, the state of blood circulation in the fingers is a factor that determines whether or not blood can be properly drawn from the fingers. Poor blood circulation in the fingers can be caused by an individual's health condition or by individual differences.

[0020] Furthermore, if the puncture depth is insufficient, the blood vessel will not be sufficiently damaged, making it difficult to ensure the required amount of blood to be collected. On the other hand, if the puncture depth is excessive, the subject may experience severe pain from the puncture. Therefore, the puncture depth of the puncture needle is a factor that determines whether or not blood can be properly collected from a finger. Inappropriate puncture depth can occur due to individual differences in the distance from the surface of the finger to the blood vessel, or due to the positioning of the finger relative to the puncture needle.

[0021] In an automatic blood collection device, a lancing device with an attached lancing needle is raised from below a finger placed in a finger rest, and the needle is inserted into the pad of the fingertip. Therefore, the puncture depth is affected by how the finger is placed relative to the initial position of the lancing needle, the distance between the initial position of the lancing needle and the blood vessels of the finger placed in the finger rest, and the amount of movement of the lancing needle relative to the blood vessels of the finger.

[0022] In the blood collection method according to this embodiment, factors that hinder blood collection from fingers are quantitatively measured using an imaging device that captures images of the fingertip. A near-infrared camera can be used to measure the state of blood circulation in the fingers. A stereo camera can also be used to measure the puncture depth of the puncture needle into the finger. Using an imaging device can reduce equipment costs compared to microscopes, ultrasonic echo devices, etc. Furthermore, image processing can easily quantify factors that hinder blood collection as objective numerical values.

[0023] Fig. 1 is a flowchart showing an example of a blood sampling method according to an embodiment of the present invention. Fig. 1 shows the flow of the blood sampling method for determining the state of blood circulation in the fingers of a subject and sampling blood from the fingers. As shown in Fig. 1, the blood sampling method according to this embodiment includes a blood vessel image capturing step S10, a pixel intensity quantification step S11, a blood circulation determination step S12, and blood sampling steps S13 and S14.

[0024] In the blood collection method shown in Figure 1, the determination of the blood circulation state of the fingers and the blood collection from the fingers can be performed by an automatic blood collection device or a blood collection worker. The determination result can be used to determine whether or not blood can be collected from the fingers and to select blood collection conditions. The determination result can also be notified to a control unit that controls the blood collection operation of the blood collection device or to the blood collection worker.

[0025] (Blood Vessel Image Capturing Step S10) In the blood vessel image capturing step S10, a finger blood vessel image is captured, which represents the course of blood vessels in the finger using pixel contrast. The finger blood vessel image can be captured using a near-infrared light capturing device such as a near-infrared camera. In the blood vessel image capturing step S10, near-infrared light is irradiated onto the subject's fingers, and the near-infrared light that has passed through the blood vessels in the fingertip is detected to image the course of blood vessels in the fingertip. The near-infrared light can be irradiated onto the nail side, which is the front side of the fingertip. The transmitted light can be detected on the ventral side, which is the back side of the fingertip.

[0026] A finger vascular image is a two-dimensional image of the fingertip of a blood sample recipient, and shows a signal intensity corresponding to the intensity of transmitted near-infrared light for each pixel that makes up the image. Hemoglobin in blood vessels absorbs near-infrared light, thereby attenuating the intensity of transmitted near-infrared light. Therefore, the blood vessels running through the fingertip can be imaged as a distribution of signal intensity corresponding to the attenuation of the intensity of transmitted light.

[0027] In finger vascular images, the course of blood vessels is represented by the contrast of pixel shading. The signal strength corresponding to the attenuation of the intensity of transmitted light for each pixel is displayed as a difference in pixel brightness. Therefore, blood vessels are displayed as a series of pixels with low transmitted light intensity among surrounding pixels with high transmitted light intensity, and are distinguished by the brightness of the pixels.

[0028] (Pixel Intensity Quantification Step S11) In the pixel intensity quantification step S11, the signal intensity of pixels representing blood vessels in the finger blood vessel image is quantified. In the finger blood vessel image, the signal intensity of pixels representing blood vessels corresponds to the attenuation of the intensity of transmitted near-infrared light, and is correlated with the amount of blood flowing through the blood vessels. When the amount of blood flowing through the blood vessels changes, the pixels representing blood vessels undergo a change in signal intensity that differs from that of surrounding pixels. Therefore, by quantifying the signal intensity of pixels representing blood vessels, the state of blood circulation in the fingers can be quantitatively determined.

[0029] In a finger vascular image, the signal intensity of a pixel representing a blood vessel may be quantified for a two-dimensional processing region including the pixel representing the blood vessel, or for a set of pixels representing the blood vessel. The signal intensity of a pixel representing a blood vessel can be quantified as the average value of multiple pixels constituting a predetermined processing region, the average value of a set of pixels representing the blood vessel, or the like.

[0030] The processing region can be defined as a region of any size that includes pixels representing blood vessels corresponding to multiple blood vessels. When targeting a set of pixels representing blood vessels, the target may be a set of pixels corresponding to multiple blood vessels running through the fingertip, or a set of pixels corresponding to a representative blood vessel running through the fingertip. Representative blood vessels include blood vessels with a high blood flow, blood vessels with a large diameter, and blood vessels running shallow from the surface of the finger.

[0031] (Blood Circulation Determination Step S12) In the blood circulation determination step S12, it is determined whether or not the blood circulation in the fingers is poor based on the signal intensity of pixels representing blood vessels in the finger vascular image. The determination of whether or not the blood circulation in the fingers is poor can be performed by comparing a representative value, such as the average value of the signal intensity of pixels representing blood vessels in the finger vascular image, with a preset threshold and determining whether or not the representative value of the signal intensity is below the threshold. This determination makes it possible to stably detect a decrease in blood volume due to poor circulation.

[0032] As the signal intensity threshold, for example, data on the signal intensity of pixels representing blood vessels when blood circulation is good can be collected from multiple blood recipients, and any number between the maximum and minimum values ​​of the collected data can be set, taking into account data accuracy and error.

[0033] In the blood circulation determination step S12, when the representative value of the signal intensity of the pixels representing blood vessels in the finger vascular image is below a predetermined threshold, it can be determined that the blood circulation in the fingers is poor and that there is an obstacle to blood collection from the fingers.On the other hand, when the representative value of the signal intensity of the pixels representing blood vessels in the finger vascular image is equal to or greater than the predetermined threshold, it can be determined that the blood circulation in the fingers is good and that there is no obstacle to blood collection from the fingers.

[0034] (Blood Collection Steps S13 and S14) In the blood collection steps S13 and S14, blood is selectively collected from the subject's fingers according to the blood circulation assessment result. The blood collection device and the blood collection staff can select whether or not to collect blood from the subject's fingers according to preset conditions and the blood collection conditions according to the assessment result. The assessment result can also be notified to a control unit that controls the blood collection operation of the blood collection device that performs the blood collection, or to the blood collection staff who performs the blood collection. The blood collection device and the blood collection staff can select whether or not to collect blood from the subject's fingers and the blood collection conditions according to the notification.

[0035] For example, if the determination result shows that the blood circulation in the fingers is not poor (blood circulation determination step S12; NO), the user can select to draw blood from the target fingers under preset conditions (blood drawing step S13).On the other hand, if the determination result shows that the blood circulation in the fingers is poor (blood circulation determination step S12; YES), the user can select to stop drawing blood from the target fingers under preset conditions or to change the blood drawing conditions (blood drawing step S14).

[0036] Blood sampling conditions include the depth of insertion of the puncture needle into the finger, the amount of movement of the puncture needle from the initial position to the position where it punctures the blood vessel in the finger, the puncture position at the fingertip where the puncture needle is inserted, the type of finger from which blood is sampled, the type of body part from which blood is sampled, etc. Types of body parts from which blood is sampled include the fingers, the radial side of the antecubital fossa, the ulnar side of the antecubital fossa, the dorsum of the hand, the dorsum of the foot, etc.

[0037] This blood collection method assesses the state of blood circulation in the subject's fingers before collection, thereby avoiding the need to collect blood from fingers where it is difficult to ensure the required amount of blood, thereby enabling appropriate finger blood collection. Whether or not to collect blood from fingers and the blood collection conditions can be selected based on the assessment results, allowing the subject and collection conditions to be selected based on the state of blood circulation in the fingers. Furthermore, a low-cost near-infrared camera or similar device can be used to measure the state of blood circulation in the fingers. Images of the finger veins can be used to objectively and easily quantify the state of blood circulation in the fingers through image processing. Therefore, this blood collection method allows factors that may hinder blood collection to be identified in advance, allowing stable and low-cost blood collection from the subject and the appropriate blood collection conditions.

[0038] Fig. 2 is a flowchart showing an example of a blood sampling method according to an embodiment of the present invention. Fig. 2 shows the flow of the blood sampling method in which blood is sampled from a subject's finger by determining the puncture depth of a puncture needle into the subject's finger. As shown in Fig. 2, the blood sampling method according to this embodiment includes a stereo image capturing step S20, a distance calculation step S21, a puncture depth determination step S22, and blood sampling steps S23 and S24.

[0039] In the blood collection method shown in Figure 2, the determination of the puncture depth of the puncture needle into the finger and the blood collection from the finger can be performed by an automatic blood collection device or a blood collection worker. The determination result can be used to determine whether or not blood can be collected from the finger and to select blood collection conditions. The determination result can also be notified to a control unit that controls the blood collection operation of the blood collection device or to a blood collection worker.

[0040] (Stereo image capturing step S20) In the stereo image capturing step S20, stereo images of the blood vessels of the subject's fingers are captured with different parallaxes. The stereo image of the fingers can be captured by a stereo imaging device such as a stereo camera. In the stereo image capturing step S20, the fingertips of the subject's fingers are captured from two imaging positions located in the direction of the initial position of the puncture needle. The blood vessels running through the fingertips are captured from different angles so that parallax occurs between the imaging positions.

[0041] The stereo image of the fingers is a two-dimensional image of the fingertips of a blood sample recipient captured with different parallaxes, and contains information on two images in which the blood vessels on the fingertips look different at each imaging position. By processing the stereo image of the fingers, it is possible to determine the parallax between the objects captured from each of the two imaging positions, as well as distance and angle parameters that allow the parallax to be uniquely calculated.

[0042] Stereo images of fingers can be captured by detecting transmitted near-infrared light or reflected near-infrared light, with the blood vessels running through the fingers as the target. When capturing stereo images of fingers, it is preferable to irradiate the fingers with near-infrared light and capture images of the blood vessels running through the fingers as the target.

[0043] (Distance Calculation Step S21) In the distance calculation step S21, the distance between the imaging positions of the stereo image of the hand and the blood vessel from which blood is to be sampled is calculated based on one or more of the distance between the two imaging positions where the stereo image of the hand and the blood vessel is captured, the focal length specific to the imaging device, the parallax determined from the stereo image of the hand and the blood vessel, and distance and angle parameters that have a relationship that allows these to be uniquely calculated. By calculating the distance between the imaging positions and the blood vessel, the distance between the blood vessel and the initial position of the puncture needle fixed relative to the imaging positions can be found.

[0044] The distance between the two imaging positions where the stereo images of the finger are captured, the focal length specific to the imaging device, and distance and angle parameters that have a relationship that allows them to be uniquely calculated can be prepared in advance as known variables. As the blood vessel to be sampled as the object to be measured, a blood vessel with a large blood flow, a blood vessel with a large diameter, a blood vessel running shallow from the surface of the finger, etc. can be selected.

[0045] (Puncture Depth Determination Step S22) In the puncture depth determination step S22, it is determined whether the puncture depth of the puncture needle into the finger is appropriate based on the calculation result of the distance between the imaging position of the stereo image of the finger and the blood vessel. The determination of whether the puncture depth is appropriate can be made by determining whether the puncture depth of the puncture needle according to the current setting is within a predetermined target puncture depth range. This determination makes it possible to detect over-puncturing or under-puncturing of the subject's finger.

[0046] The puncture needle may be one built into a puncture device. Some puncture devices have a built-in puncture needle that resiliently protrudes when it comes into contact with the skin. When using such a puncture device, the amount of protrusion of the puncture needle from the puncture device is constant. Therefore, the puncture depth of the puncture needle into the finger's vein is affected by the amount of movement of the puncture needle from its initial position toward the finger's vein.

[0047] In a blood collection device that automatically collects blood, the amount of movement of the puncture needle from its initial position toward the blood vessel in the finger can be set according to the distance between the initial position of the puncture needle and the blood vessel in the recipient's finger. Therefore, determining whether the puncture depth is appropriate can be performed by determining whether the amount of movement of the puncture needle according to the current setting is within a predetermined range with respect to the target amount of movement. Under conditions where the distance between the initial position of the puncture needle and the recipient's finger is fixed, it can be determined whether the absolute value of the difference between the amount of movement of the puncture needle from the initial position according to the current setting toward the finger and the target amount of movement of the puncture needle is equal to or less than a preset threshold.

[0048] The target movement amount of the puncture needle can be set to approximately match the distance between the initial position of the puncture needle and the blood vessel of the blood collection target, based on the calculation result of the distance between the imaging position of the stereo image of the hand and fingers and the blood vessel of the blood collection target calculated in the distance calculation step S21. As the threshold value, for example, data on appropriate puncture depths and movement amounts of the puncture needle can be collected for multiple blood collection targets, and any numerical value between the maximum and minimum values ​​of the collected data can be set taking into consideration the data accuracy and error.

[0049] In the puncture depth determination step S22, when the currently set puncture depth is within the target range, i.e., when the absolute value of the difference between the set puncture needle movement amount and the target movement amount is equal to or less than a preset threshold, it can be determined that puncture with just the right amount is possible and that there is no problem with blood collection from the finger.On the other hand, when the currently set puncture depth is not within the target range, i.e., when the absolute value of the difference between the set puncture needle movement amount and the target movement amount exceeds the preset threshold, it can be determined that puncture with just the right amount is impossible and that there is a problem with blood collection from the finger.

[0050] (Blood Collection Steps S23, S24) In the blood collection steps S23, S24, blood is selectively collected from the subject's finger according to the result of the puncture depth determination. The blood collection device or the blood collection staff can select whether or not to collect blood from the subject's finger according to preset conditions and the blood collection conditions according to the determination result. The determination result can also be notified to a control unit that controls the blood collection operation of the blood collection device that performs the blood collection, or to the blood collection staff who performs the blood collection. The blood collection device or the blood collection staff can select whether or not to collect blood from the subject's finger and the blood collection conditions according to the notification.

[0051] For example, if the determination result shows that the puncture depth according to the current settings is within the target range (puncture depth determination step S22; YES), the user can select to draw blood from the target finger according to the preset conditions (blood drawing step S23).On the other hand, if the determination result shows that the puncture depth according to the current settings is not within the target range (puncture depth determination step S22; NO), the user can select to stop drawing blood from the target finger according to the preset conditions or to change the blood drawing conditions (blood drawing step S24).

[0052] Blood sampling conditions include the depth of insertion of the puncture needle into the finger, the amount of movement of the puncture needle from the initial position to the position where it punctures the blood vessel in the finger, the puncture position at the fingertip where the puncture needle is inserted, the type of finger from which blood is sampled, the type of body part from which blood is sampled, etc. Types of body parts from which blood is sampled include the fingers, the radial side of the antecubital fossa, the ulnar side of the antecubital fossa, the dorsum of the hand, the dorsum of the foot, etc.

[0053] This blood collection method determines the puncture depth of the puncture needle into the subject's finger before blood collection, thereby avoiding the need to collect blood from fingers where it is difficult to ensure the required amount of blood, thereby enabling appropriate finger blood collection. Depending on the determination result, the feasibility of blood collection from the finger and the blood collection conditions can be selected, allowing the subject and blood collection conditions for finger blood collection to be selected based on the possibility of properly puncturing the target blood vessel. Furthermore, a low-cost stereo camera or the like can be used to measure the distance to the blood vessel. Stereo images of the hand and fingers allow the distance between the imaging position and the blood vessel to be objectively and easily quantified. Therefore, this blood collection method allows factors that may hinder blood collection to be identified in advance, allowing stable and low-cost blood collection from the subject and blood collection conditions.

[0054] Fig. 3 is a flowchart showing an example of a blood sampling method according to an embodiment of the present invention. Fig. 3 shows the flow of the blood sampling method, which involves determining both the state of blood circulation in the subject's finger and the puncture depth of the puncture needle into the subject's finger, and then performing a blood circulation promoting treatment for poor blood circulation. As shown in Fig. 3, the blood sampling method according to this embodiment includes a temperature measurement step S30, a blood vessel image capturing step S31, a pixel intensity quantification step S32, a blood circulation determination step S33, a stereo image capturing step S34, a distance calculation step S35, a puncture depth determination step S36, a treatment completion determination step S37, a treatment step S38, and blood sampling steps S39 and S40.

[0055] In the blood collection method shown in Figure 3, the determination of the state of blood circulation in the finger, the determination of the puncture depth of the puncture needle into the finger, and the blood collection from the finger can be performed by a blood collection device that automatically collects blood or by a blood collection technician. The determination results can be used to decide whether to perform a blood circulation promoting treatment, whether to collect blood from the finger, and to select blood collection conditions. The determination results can also be notified to a control unit that controls the blood collection operation of the blood collection device or to a blood collection technician.

[0056] (Temperature measurement step S30) In the temperature measurement step S30, the temperature of the fingers and body temperature of the subject from whom blood is to be collected are measured. The skin temperature of the fingers correlates with blood circulation in the fingers. The lower the skin temperature of the fingertips, the poorer the blood circulation in the fingers tends to be. Therefore, by measuring the temperature of the fingers and body temperature, the state of blood circulation in the fingers can be evaluated based on the temperature difference between the body temperature and the temperature of the fingers.

[0057] (Blood Vessel Image Capturing Step S31, Pixel Intensity Quantification Step S32, Blood Circulation Determination Step S33) In the blood vessel image capturing step S31, similar to the blood vessel image capturing step S10, a finger blood vessel image is captured, which represents the course of blood vessels in the finger using pixel contrast. In the pixel intensity quantification step S32, similar to the pixel intensity quantification step S11, the signal intensity of pixels representing blood vessels in the finger blood vessel image is quantified. In the blood circulation determination step S33, it is determined whether or not the blood circulation in the finger is poor based on the results of the temperature measurement step S30 and the pixel intensity quantification step S32.

[0058] If the determination result shows that the blood circulation in the fingers is not poor (blood circulation determination step S33; NO), the process proceeds to a stereo image capturing step S34. On the other hand, if the determination result shows that the blood circulation in the fingers is poor (blood circulation determination step S33; YES), the process proceeds to a treatment end determination step S37.

[0059] (Stereo image capturing step S34, distance calculation step S35, puncturing depth determination step S36) In the stereo image capturing step S34, similar to the stereo image capturing step S20, stereo images of the blood vessels of the subject's fingers are captured with different parallaxes. In the distance calculation step S35, similar to the distance calculation step S21, the distance between the capturing position of the stereo image of the fingers and the blood vessels of the subject's blood collection is calculated. In the puncturing depth determination step S36, similar to the puncturing depth determination step S22, it is determined whether the puncturing depth of the puncture needle into the finger is appropriate.

[0060] If the result of the determination is that the puncturing depth according to the current settings is within the target range (puncturing depth determination step S36; YES), the user can select to draw blood from the target finger according to the preset conditions (blood drawing step S39).On the other hand, if the result of the determination is that the puncturing depth according to the current settings is not within the target range (puncturing depth determination step S36; NO), the user can select to stop drawing blood from the target finger according to the preset conditions or to change the blood drawing conditions (blood drawing step S40).

[0061] (Treatment End Determination Step S37) In the treatment end determination step S37, it is determined whether the predetermined blood circulation-promoting treatment has been completed. Whether the blood circulation-promoting treatment has been completed can be determined, for example, by comparing the number of times and duration of the blood circulation-promoting treatments performed up to now with a preset target number of times and duration. The target number of times and duration can be set, for example, by collecting data on the number of times and duration for which the blood circulation-promoting treatment is recognized to be effective for multiple treatment recipients, and any numerical value between the maximum and minimum values ​​of the collected data.

[0062] If the result of the determination is that the predetermined blood circulation promoting treatment has been completed (determination step S37; YES), the process proceeds to blood collection step S40. In blood collection step S40, the user selects whether to stop blood collection from the target finger under preset conditions or change the blood collection conditions. On the other hand, if the result of the determination is that the predetermined blood circulation promoting treatment has not been completed (determination step S37; NO), the process proceeds to treatment step S38, in which the blood circulation promoting treatment is performed.

[0063] (Treatment step S38) In the treatment step S38, a blood circulation promoting treatment is performed on the subject's fingers to promote blood circulation. The blood circulation promoting treatment is a treatment that promotes blood circulation by expanding the blood vessels in the fingers, and examples of the treatment include warming the fingers with a hot water bath, a heater, a heating pad, etc., and massaging the fingers. The blood circulation promoting treatment may be performed by a blood collection worker or by a blood collection device that automatically collects blood. The blood collection device may also be provided with a function to warm the fingers and a function to massage the fingers.

[0064] After the blood circulation promoting treatment is performed, the process returns to the temperature measurement step S30. Thereafter, if the blood circulation in the fingers is not poor (blood circulation determination step S33; NO), the process proceeds to the stereo image capturing step S34. On the other hand, if the blood circulation in the fingers is poor (blood circulation determination step S33; YES), the process proceeds to the treatment termination determination step S37. In the treatment termination determination step S37, if the blood circulation does not improve after the blood circulation promoting treatment for the predetermined number of times or for the predetermined time, the process proceeds to the blood sampling step S40, where the user can choose to stop blood sampling or change the blood sampling conditions.

[0065] According to this blood collection method, the state of blood circulation in the subject's fingers is determined before blood collection, and the puncture depth of the puncture needle into the subject's fingers is determined before blood collection, thereby avoiding insufficient puncturing due to poor circulation. Depending on the determination result, it is possible to select whether or not to perform a blood circulation promotion treatment, so that if the poor circulation is temporary, appropriate blood collection can be performed by performing the blood circulation promotion treatment. Therefore, blood can be stably collected from the subject's fingers under appropriate blood collection conditions without being limited by temporary poor circulation.

[0066] Fig. 4 is a diagram illustrating a method for determining circulatory disorders based on the temperature of the fingers and body temperature. Fig. 4 shows data used in determining whether or not the blood circulation in the fingers is poor, such as the temperature of the fingers and body temperature measured in the temperature measurement step S30. As shown in Fig. 4, whether or not the blood circulation in the fingers is poor can also be determined based on the temperature difference between the body temperature and the temperature of the fingers.

[0067] In Figure 4, ID indicates a code assigned to each blood recipient to identify them. Gender and age indicate the gender and age category of the blood recipient. Body temperature indicates the deep body temperature measured under the armpit of the blood recipient. Finger temperature indicates the skin temperature of the fingertips measured on the blood recipient's fingers. Temperature difference indicates the difference between body temperature and finger temperature. The judgment result indicates whether or not the blood circulation in the fingers is poor. A judgment result of "○" indicates that the blood circulation in the fingers is poor.

[0068] In the blood circulation determination step S33, whether or not the blood circulation in the fingers is poor can be determined using the temperature measurement results measured in the temperature measurement step S30. The determination using the temperature measurement results can be made by comparing the temperature difference between the measured body temperature and the finger temperature with a preset threshold. The temperature difference threshold can be set, for example, by collecting data on temperature differences that are deemed to indicate good blood circulation from multiple blood collection subjects and selecting any value between the maximum and minimum values ​​of the collected data.

[0069] In the blood circulation determination step S33, when the representative value of the signal intensity of the pixels representing blood vessels in the finger vascular image is equal to or less than a predetermined threshold, or when the temperature difference between the body temperature and the finger temperature exceeds a predetermined threshold, it can be determined that the blood circulation in the fingers is poor and that there is an obstacle to blood collection from the fingers.On the other hand, when the representative value of the signal intensity of the pixels representing blood vessels in the finger vascular image exceeds a predetermined threshold and the temperature difference between the body temperature and the finger temperature is equal to or less than a predetermined threshold, it can be determined that the blood circulation in the fingers is good and that there is no obstacle to blood collection from the fingers.

[0070] The data shown in Figure 4 can be stored in advance in the memory of a blood collection device that automatically collects blood before determining the state of blood circulation in the fingers. Data such as finger temperature and body temperature can be measured by a blood collection technician or by the blood collection device. Temperature measurement can be performed using a contact or non-contact device. Temperature measurement can be performed using a thermistor, thermocouple, infrared temperature sensor, or other appropriate device such as a thermograph.

[0071] Making a judgment using such temperature measurement results can improve the accuracy of judging whether or not the blood circulation in the fingers is poor. Depending on the constitution of the person receiving blood sampling, it may be difficult to make a judgment using only the finger vascular image. In such cases, using the temperature measurement results can accurately detect poor blood circulation in the fingers due to changes in physical condition, etc. Furthermore, it becomes possible to select in advance the subjects for which finger vascular images will be taken based on the temperature measurement results.

[0072] Fig. 5 is an external view of a blood collection device according to an embodiment of the present invention. Fig. 5 shows a finger blood collection device that automatically collects blood from the fingers of a subject. The symbol P in Fig. 5 is an enlarged partial view of the area around the finger rest of the blood collection device as viewed from below. The blood collection methods shown in Figs. 1, 2, and 3 can be automatically performed by providing functions to the blood collection device shown in Fig. 5.

[0073] As shown in Figure 5, the blood collection device 1 of this embodiment includes a housing 10, a turntable 11, multiple holders 110 where blood collection tubes are placed, multiple modules 120 to which puncture devices, hemostatic materials, etc. are attached, a rotation drive mechanism (not shown) that rotates the turntable 11, a lift drive mechanism (not shown) that raises and lowers the holders 110 and modules 120, and a pressure adjustment mechanism (not shown) that drives a cuff mechanism that tightens the fingers of the person to be blood-collected.

[0074] The housing 10 is formed from a plurality of structural materials, decorative panels, etc. Inside the housing 10, a turntable 11, a rotation drive mechanism, an elevation drive mechanism, a pressure adjustment mechanism, etc. are built in. A hand rest area where the subject's hand is placed is provided on the top surface of the housing 10. Also, adjacent to the hand rest area, there are a finger insertion section 130 where the subject's finger is inserted, and a circular opening. The turntable 11 is located below the opening.

[0075] A finger insertion section 130 and a finger rest 131 are provided on the opening side of the hand rest area. The finger insertion section 130 is provided above the finger rest 131 so as to surround a finger 134 of the subject placed on the finger rest 131. As shown in partial view P, a disposable finger rest component 132 is attached to the finger rest 131. A blood collection window 133, which is a through-hole, opens in the center of the finger rest component 132. The subject's finger 134 is placed on the blood collection window 133 of the finger rest component 132.

[0076] The finger insertion section 130 is equipped with a cuff mechanism that tightens the periphery of the finger 134 of the blood collection recipient (the finger of the blood collection recipient). A cuff is installed inside the finger insertion section 130 so as to surround the periphery of the finger 134 of the blood collection recipient placed in the finger holder 131. The cuff is, for example, in the shape of a flexible bag. The cuff is connected to a valve and a pump via a tube. The valve and the pump constitute a pressure adjustment mechanism that drives the cuff mechanism. The tightening pressure on the finger 134 of the blood collection recipient is adjusted by controlling the internal pressure of the cuff.

[0077] The turntable 11 is generally disk-shaped and is supported inside the housing 10 with its main surfaces facing up and down. The turntable 11 is provided with a plurality of portions for holding holders 110 and various modules 120. For example, the turntable 11 is provided with a plurality of holders 110 that rotate integrally with the turntable 11 and a plurality of holding holes that penetrate the turntable 11 from top to bottom. The modules 120 are held by being inserted into the holding holes from top to bottom. The holders 110 and modules 120 are regularly arranged at intervals from one another along the circumferential direction of the turntable 11.

[0078] The holder 110 is a location where blood collection tubes are placed, and various types of blood collection tubes, such as blood collection tubes for blood count tests and blood collection tubes for biochemistry and immunological tests, are placed therein. Blood collection tubes of a predetermined size or outer tubes containing blood collection tubes can be placed in the holder 110. The outer tube is used, for example, to adjust the size of the object to the location where the blood collection tube is placed, when using small micro blood collection tubes as the blood collection tubes.

[0079] The object to be installed on the holder 110 and the module 120 are detachable from the turntable 11. The module 120 is formed with, for example, a flange-like portion having a diameter larger than the inner diameter of the holding hole of the turntable 11. The module 120 is inserted into the holding hole, and the flange-like portion is supported from below. The object to be installed on the holder 110 and the module 120 can be raised and lowered by pushing up from below and releasing the pushing-up action.

[0080] As the module 120, different types of modules can be attached, such as a module for puncturing, a module for hemostasis, etc. A puncture device is attached to the module for puncturing. The puncture device has a built-in puncture needle (lancet). A hemostatic material such as gauze or a protective material such as a bandage is attached to the module for hemostasis. The bandage is attached to the module 120 with the adhesive side facing upward.

[0081] When the lancing device is pressed against the subject's finger, the puncture needle is extended and punctures the subject's finger. A hemostatic material such as gauze is pressed against the puncture site on the subject to absorb blood that has bled from the puncture site and stop the bleeding. A protective material such as a bandage is pressed against the puncture site on the subject and attached to cover the puncture site to stop the bleeding and protect the puncture site.

[0082] 6 and 7 are cross-sectional views showing typical examples of the placement of an imaging device in a blood collection device. In these views, the structure around the turntable 11 of the blood collection device 1 is shown, with some components omitted, to show a structure that has the function of determining the state of blood circulation in the fingers of a person to be blood-collected. Fig. 6 is a cross-sectional view of the area around the turntable 11. Fig. 7 is a plan view of the area around the turntable 11.

[0083] 6 and 7 , in blood collection device 1, turntable 11 and the like are built in below the opening of housing 10. When determining the state of blood circulation in the fingers of a person to be blood-collected, near-infrared light imaging device 20 that captures images of the blood vessels in the fingers can be installed below finger rest area 131 inside housing 10 and to the side of turntable 11. In addition, near-infrared light source 40 can be installed above finger rest area 131.

[0084] A shaft 12 is connected to the center of the turntable 11. The other end of the shaft 12 is connected to the output shaft of a motor via a power transmission mechanism. The power transmission mechanism transmits the rotational motion of the motor to the shaft 12 using a predetermined mechanical mechanism. When the motor rotates the shaft 12, the turntable 11 can rotate in both clockwise and counterclockwise directions around the shaft as the rotation axis.

[0085] The turntable 11 is controlled to rotate by a predetermined step angle around the shaft 12 as a rotation axis in accordance with the blood collection operation or treatment operation. The holder 110 and the module 120 are sequentially transported by the rotation of the turntable 11 to the blood collection position where the finger rest area 131 is formed.

[0086] At the blood collection position, the following steps are performed in order: puncturing the finger 134 with the puncturing needle by the puncturing module 120, stopping the bleeding with gauze by the hemostasis module 120, and applying a bandage by the hemostasis module 120. The finger 134 of the person to be blood-collected is compressed by the cuff 136, and then punctured with the puncturing needle by the puncturing module 120. The blood that flows out from the puncture site is collected in a blood collection tube that has been moved to the blood collection position on the turntable 11.

[0087] The puncturing module 120, the hemostasis module 120, and the blood collection tubes installed in the holder 110 are driven by an elevation drive mechanism (not shown) to rise and fall relative to the subject's finger 134 placed in the finger rest area 131. The elevation drive mechanism is composed of a movable support member that pushes up the module 120 or the blood collection tube installed in the holder 110 from below, a motor that drives the vertical movement of the movable support member, and the like.

[0088] The near-infrared light imaging device 20 can be arranged to face the pad side of the fingertip of the subject's finger 134 placed in the finger holder 131. The near-infrared light source 40 can be arranged to face the nail side of the subject's finger 134 placed in the finger holder 131. The near-infrared light imaging device 20 and the near-infrared light source 40 are preferably arranged to face each other on the same optical axis, sandwiching the fingertip to be punctured by the puncture needle. The near-infrared light imaging device 20 is preferably arranged outside the turntable 11 so as not to interfere with the rotational operation.

[0089] The near-infrared light imaging device 20 detects near-infrared light that has passed through the subject's finger 134 placed in the finger holder 131, and captures a finger blood vessel image that shows, in contrast, the course of the blood vessels in the subject's finger 134. The near-infrared light imaging device 20 can be a near-infrared camera or the like in which photodetector elements capable of detecting near-infrared light are arranged in an array.

[0090] The near-infrared light source 40 is a light source that emits near-infrared light, and irradiates the finger 134 of the subject placed in the finger rest 131. An LED (Light Emitting Diode) or the like that is compatible with the near-infrared light range can be used as the near-infrared light source 40. Examples of near-infrared light include light with a wavelength of 700 nm or more and 2500 nm or less, for example, light of about 940 nm.

[0091] The image of the blood vessels of the finger can be captured after the blood sampling device 1 is started up, after the subject's finger 134 is placed in the finger holder 131, and before the subject's finger 134 is punctured with the puncture needle. The near-infrared light imaging device 20 and the near-infrared light source 40 can be controlled by a controller (not shown). The data of the image of the blood vessels of the finger acquired by the near-infrared light imaging device 20 is sent to the blood sampling control device, which performs processing to determine whether or not there is an obstacle to blood sampling.

[0092] 8 and 9 are cross-sectional views showing typical examples of the placement of an imaging device in a blood collection device. In these views, the structure around the turntable 11 of the blood collection device 1 is shown, with some components omitted, to show a structure that has the function of determining the puncture depth of the puncture needle into the subject's finger. Fig. 8 is a cross-sectional view of the area around the turntable 11. Fig. 9 is a plan view of the area around the turntable 11.

[0093] 8 and 9 , in blood collection device 1, turntable 11 and the like are built in below the opening of housing 10. When determining the puncture depth of the puncture needle into the subject's fingers, stereo imaging device 30 that captures stereo images of the fingers can be installed below finger placement area 131 inside housing 10 and to the side of turntable 11. In addition, near-infrared light source 40 can be installed above finger placement area 131.

[0094] The stereo image capture device 30 can be placed so as to face the pad side of the subject's finger 134 placed in the finger rest area 131. The stereo image capture device 30 includes two image capture units 31 that capture images of an object from different image capture positions. The image capture units 31 are placed at image capture positions that are angled differently relative to the object so as to generate parallax in the object. The stereo image capture device 30 is configured to capture stereo images of the fingers by detecting transmitted near-infrared light under illumination from a near-infrared light source 40.

[0095] The stereo imaging device 30 captures stereo images of the blood vessels of the subject's finger 134 placed in the finger rest area 131 with different parallaxes. A stereo camera or the like can be used as the stereo imaging device 30. The stereo imaging device 30 can be installed so that the two imaging units 31 are aligned in any direction. However, from the viewpoint of detecting parallax in a direction intersecting the trajectory of the puncture needle caused by the rotation of the turntable 11, it is preferable to install the two imaging units 31 so that they are aligned along the width direction of the subject's finger 134.

[0096] Stereo images of blood from the fingers can be captured after blood sampling device 1 is started up, after the subject's finger 134 is placed in finger holder 131, and before the subject's finger 134 is punctured with the lancing needle. Stereo image capturing device 30 can be controlled by a controller (not shown). Data on the stereo image of the fingers acquired by stereo image capturing device 30 is sent to a blood sampling control device that performs processing to determine whether or not there is an obstacle to blood sampling.

[0097] The stereo imaging device 30 may be installed in the blood collection device 1 together with the near-infrared light imaging device 20. The stereo imaging device 30 can be installed in parallel at a position where they do not interfere with each other, such as below or above the near-infrared light imaging device 20. By installing the stereo imaging device 30 and the near-infrared light imaging device 20, it is possible to quantify both the state of blood circulation in the subject's fingers and the puncture depth of the puncture needle into the subject's fingers.

[0098] Fig. 10 is a block diagram showing the functions of a blood collection control device that controls a blood collection device. Fig. 10 shows an example of the configuration of a blood collection control device 100 that controls a blood collection device 1 that has the function of determining the state of blood circulation in the subject's fingers and the function of determining the puncture depth of the puncture needle into the subject's fingers. As shown in Fig. 10, the blood collection control device 100 includes a CPU (Central Processing Unit) 101, memory 102, storage unit 103, input unit 104, output unit 105, blood collection control unit 106, near-infrared imaging control unit 107, stereo imaging control unit 108, etc.

[0099] The puncturing blood collection mechanism 109 of the blood collection device 1 is connected to the blood collection control unit 60 via signal lines and an interface. The near-infrared imaging control unit 107 is connected to the near-infrared light imaging device 20 and near-infrared light source 40 of the blood collection device 1 via signal lines and an interface. The stereo imaging control unit 108 is connected to the stereo imaging device 30 of the blood collection device 1 via signal lines and an interface.

[0100] The blood collection control device 100 controls the blood collection from the fingers of the person to be collected by the blood collection device 1. The blood collection control device 100 is formed by hardware such as a general-purpose computer. The blood collection control device 100 has functions to determine the state of blood circulation in the fingers of the person to be collected, to determine the puncture depth of the puncture needle into the finger of the person to be collected, and to control the blood collection operation by the blood collection device 1 based on the results of the determination.

[0101] The blood collection control device 100 can be connected to a blood collection device 1 that automatically collects blood via a USB (Universal Serial Bus) or the like. The blood collection control device 100 may be connected to a single blood collection device 1 to support that single blood collection device 1, or may be connected to multiple blood collection devices 1 to support multiple blood collection devices 1. Some or all of the functions of the blood collection control device 100 may be built into the blood collection device 1. The blood collection control device 100 may also have a function for authenticating a subject from whom blood is to be collected by the blood collection device 1.

[0102] The CPU 101 executes processes according to programs, reads programs and data, and controls the operation of each device in the blood collection device 1 and the process of determining blood collection problems. The memory 102 is composed of main storage devices such as RAM (Random Access Memory) and ROM (Read Only Memory).

[0103] By executing a predetermined program, CPU 101 functionally embodies a pixel intensity quantification unit that quantifies the signal intensity of pixels representing blood vessels in a finger vascular image, a blood circulation determination unit that determines whether blood circulation in the finger is poor, a distance calculation unit that calculates the distance between the imaging position of the finger stereo image and the blood vessel from which blood is to be drawn, and a puncture depth determination unit that determines whether the puncture depth of the puncture needle into the finger is appropriate.

[0104] The storage unit 103 stores various data and programs. The storage unit 103 is configured by a storage device such as a semiconductor memory, a hard disk, etc. The storage unit 103 pre-stores data necessary for determining the state of blood circulation in the subject's fingers and data necessary for determining the puncture depth of the puncture needle into the subject's fingers.

[0105] The input unit 104 is configured by a device or controller that accepts input from the operator of the blood collection control device 100. The input unit 104 can be connected to, for example, a touch panel, a keyboard, a mouse, or the like.

[0106] The output unit 105 is composed of a device or controller that displays information related to blood collection, information related to the operation of the blood collection device 1, information related to the results of the determination, etc. The information related to blood collection includes the blood collection subject, blood collection conditions, blood collection progress, blood collection results, warnings, etc. The output unit 105 can be connected to, for example, a touch panel, a liquid crystal display, an organic EL display, etc.

[0107] Blood collection control unit 106 is composed of a controller that controls the conditions for the puncturing operation, blood collection operation, and treatment operation by blood collection device 1. Blood collection control unit 106 sends control signals to puncturing blood collection mechanism 109 to control the puncturing position and puncturing depth of the puncture needle relative to the finger. Lancing blood collection mechanism 109 is composed of a rotation drive mechanism that rotates turntable 11, an elevation drive mechanism that raises and lowers holder 110 and module 120, a pressure adjustment mechanism that drives the cuff mechanism, etc.

[0108] The near-infrared imaging control unit 107 is configured by a controller that controls the conditions of the near-infrared imaging operation for capturing an image of blood vessels in a finger. The near-infrared imaging control unit 107 sends control signals for controlling the irradiation of near-infrared light and the detection of transmitted light to the near-infrared light imaging device 20 and the near-infrared light source 40. The near-infrared imaging control unit 107 also receives data of the image of blood vessels in a finger captured by the near-infrared light imaging device 20.

[0109] The stereo imaging control unit 108 is configured by a controller that controls the conditions of the stereo imaging operation for capturing stereo images of fingers. The stereo imaging control unit 108 sends control signals for irradiating near-infrared light and capturing stereo images of fingers to the stereo imaging device 30 and the near-infrared light source 40. The stereo imaging control unit 108 also receives data of the stereo images of fingers captured by the stereo imaging device 30.

[0110] Fig. 11 is a flowchart showing an example of the operation of the blood collection device. Fig. 11 shows the flow of operation of the blood collection device 1, which collects blood from a finger by determining both the state of blood circulation in the finger of a blood collection recipient and the puncture depth of the puncture needle into the finger of the blood collection recipient. As shown in Fig. 11, the blood collection device 1 determines the state of blood circulation in the finger, determines the puncture position of the puncture needle, and then determines the puncture depth of the puncture needle for the determined puncture position.

[0111] (Light source luminance adjustment step S40) In the light source luminance adjustment step S40, the luminance of the near-infrared light emitted by the near-infrared light source 40 is adjusted. By adjusting the luminance of the near-infrared light source 40 within a predetermined range, it is possible to obtain brightness suitable for capturing an image of blood vessels in a finger, brightness suitable for capturing a stereo image of a finger, and contrast suitable for extracting pixels representing blood vessels.

[0112] The brightness of the near-infrared light source 40 can be adjusted, for example, for a two-dimensional processing region including pixels representing blood vessels in a finger blood vessel image. For multiple pixels constituting the processing region, an average brightness corresponding to the intensity of transmitted near-infrared light is calculated, and the brightness of the light source can be adjusted by a dimming amount based on the average brightness of the processing region. To adjust the contrast of the finger blood vessel image, a variable amount adjusted according to the average brightness of the processing region can be applied to each level of the average brightness.

[0113] (Blood Circulation Determination Step S41) In the blood circulation determination step S41, it is determined whether or not the blood circulation of the finger is poor based on the signal intensity of pixels representing blood vessels in the finger blood vessel image. The blood circulation determination step S41 can be performed in the same manner as the blood vessel image capturing step S10, the pixel intensity quantifying step S11, and the blood circulation determination step S12, after adjusting the luminance of the light source.

[0114] In the blood circulation determination step S41, the pixel intensity quantification unit quantifies the signal intensity of pixels representing blood vessels in the finger vascular image. The signal intensity of the pixels representing blood vessels is quantified as a representative value such as an average value for a processing region or the like. The data of the quantification result is stored in the memory unit 103.

[0115] The blood circulation determination unit determines whether the blood circulation in the finger is poor based on the intensities of pixels representing blood vessels in the finger blood vessel image quantified by the pixel intensity quantification unit. The blood circulation determination unit reads out the quantification result data stored in the memory unit 103 and determines whether the representative value of the pixel intensities is equal to or less than a predetermined first threshold. When the representative value of the pixel intensities is equal to or less than the first threshold, the blood circulation determination unit determines that the blood circulation in the finger is poor and instructs the user to stop blood sampling from the target finger according to predetermined conditions or to change the blood sampling conditions.

[0116] Furthermore, when the representative value of pixel intensity exceeds a first threshold, the blood sampling control unit 106 executes blood sampling from the target finger according to preset conditions. On the other hand, when the representative value of pixel intensity is equal to or less than the first threshold, the blood sampling control unit 106 selectively stops blood sampling from the target finger according to the preset conditions or changes the blood sampling conditions. For example, if the type of finger from which blood is to be sampled is changed or a blood circulation promoting treatment is performed, and blood circulation does not improve within a predetermined range, the blood sampling control unit 106 can select to stop the subsequent steps.

[0117] (Puncture Position Determining Step S42) In the puncture position determining step S42, the puncture position of the puncture needle relative to the subject's finger is determined based on the finger vascular image. The puncture position of the puncture needle can be specified, for example, as the intersection of the trajectory of the puncture needle caused by the rotation of the turntable and a representative blood vessel running through the fingertip on the finger vascular image. Representative blood vessels include blood vessels with a high blood flow, blood vessels with a large diameter, and blood vessels running shallow from the surface of the finger.

[0118] (Puncture depth determination step S43) In the puncture depth determination step S43, it is determined whether the puncture depth of the puncture needle into the finger is appropriate based on the calculation result of the distance between the imaging position of the stereo image of the finger and the blood vessel. The puncture depth determination step S43 can be executed in the same manner as the stereo image imaging step S20, distance calculation step S21, and puncture depth determination step S22. If the puncture depth based on the current setting is not within the target range, the puncture position and puncture depth settings can be changed.

[0119] In the puncture depth determination step S43, the distance calculation unit calculates the distance between the imaging positions of the stereo image of the hand and the blood vessel of the blood sample based on one or more of the distance between the imaging positions of the stereo image of the hand and the blood vessel of the blood sample, the focal length specific to the imaging device, the parallax determined from the stereo image of the hand and the blood vessel, and a distance or angle parameter that has a relationship that allows these parameters to be uniquely calculated. The data of the calculation result is stored in the memory unit 103.

[0120] The puncture depth determination unit determines whether the puncture depth of the puncture needle into the finger is within a predetermined target puncture depth range based on the calculation result calculated by the distance calculation unit. The puncture depth determination unit reads the calculation result data stored in memory unit 103 and determines whether the absolute value of the difference between the current setting's puncture needle movement amount and the target puncture needle movement amount is equal to or less than a predetermined second threshold. When the absolute value of the difference exceeds the second threshold, the puncture depth determination unit determines that proper puncturing with just enough depth is not possible and instructs the device to stop blood collection from the target finger according to the predetermined conditions or to change the blood collection conditions.

[0121] Furthermore, when the absolute value of the difference between the current puncture needle movement amount and the target movement amount is equal to or less than a second threshold, the blood sampling control unit 106 executes blood sampling from the target finger under preset conditions. On the other hand, when the absolute value of the difference between the current puncture needle movement amount and the target movement amount exceeds the second threshold, the blood sampling control unit 106 selectively stops blood sampling from the target finger under preset conditions or changes the blood sampling conditions. For example, if the puncture needle movement amount, puncture position, etc. are changed and the puncture depth does not improve within a predetermined range, the blood sampling control unit 106 can select to stop subsequent steps.

[0122] (Puncturing operation control step S44) In the puncturing operation control step S44, the puncturing operation by the puncturing and blood collection mechanism is controlled to puncture the finger of the person to be blood-collected with the puncture needle. A control signal for executing the puncturing operation under the set puncturing position and puncturing depth conditions is sent to the puncturing and blood-collecting mechanism.

[0123] (Blood collection operation control step S45) In the blood collection operation control step S45, the blood collection operation by the puncturing blood collection mechanism is controlled to collect blood from the subject's finger into a collection tube. The puncturing blood collection mechanism is sent a control signal for rotating a turntable to transport the collection tube to the blood collection position, and a control signal for driving an elevation drive mechanism to lift the collection tube toward the puncture site.

[0124] (Treatment Operation Control Step S46) In treatment operation control step S46, the treatment operation by the puncture and blood collection mechanism is controlled to stop bleeding and protect the puncture site of the subject's finger. The puncture and blood collection mechanism is sent a control signal for rotating a turntable for transporting a module with a hemostatic material attached and a module with a protective material attached to the blood collection position, and a control signal for driving an elevation drive mechanism for raising the module toward the puncture site.

[0125] (Blood collection completion notification step S47) In blood collection completion notification step S47, the completion of blood collection from the target finger is notified to the control unit that controls the blood collection operation of the blood collection device and the blood collection staff. By notifying the control unit that controls the blood collection operation of the blood collection device, the series of blood collection operations from the target finger can be completed. In addition, an image indicating the completion of blood collection can be displayed on the output unit 105 as a notification to the blood collection staff.

[0126] Figures 12, 13, and 14 are diagrams illustrating the absorption of near-infrared light according to blood circulation in a finger blood vessel image. Figures 12, 13, and 14 show examples of absorption signals obtained by irradiating near-infrared light onto the fingers of a blood sample recipient and detecting near-infrared light that has passed through the blood vessels of the fingers. Figure 12 shows a pulse wave caused by pulsation when blood circulation in the fingers is good. Figure 13 shows a pulse wave caused by pulsation when blood circulation in the fingers is poor. Figure 14 is an enlarged view of the absorption signals that constitute the pulse wave.

[0127] In Figures 12, 13, and 14, the vertical axis represents the intensity of the absorption signal of near-infrared light irradiated onto the blood vessels. The horizontal axis represents the time during which the near-infrared light absorption signal was continuously detected. The upper part of Figure 14 shows an enlarged schematic diagram of the blood vessels in the finger corresponding to the time when the absorption signal was detected. The enlarged schematic diagram displays the blood vessels running through the fingertip with a contrast different from the surrounding area.

[0128] As shown in Figures 12, 13, and 14, when finger blood vessel images are captured over time, a pulse wave is observed in which the intensity of the near-infrared light absorption signal changes in a pulse-like manner for pixels representing blood vessels. Such a pulse wave is caused by the pulsation of blood vessels due to heartbeats. The pulsation changes the amount of blood flowing through the blood vessels, causing an increase or decrease in the amount of hemoglobin that absorbs near-infrared light.

[0129] As shown in Figure 12, when blood circulation in the fingers is good, the peak height of the near-infrared light absorption signal is high. On the other hand, as shown in Figure 13, when blood circulation in the fingers is poor, the peak height of the near-infrared light absorption signal is low. The overall decrease in near-infrared light absorption intensity is caused by a decrease in the maximum hemoglobin amount. When sympathetic nerve excitation causes blood vessels to constrict and the amount of blood flowing through the vessels decreases, an overall decrease in hemoglobin amount occurs.

[0130] As shown in Figure 14, a state in which the blood volume is low and the peak height of the absorption signal is low corresponds to a state in which the contrast change between the pixels representing the blood vessels and the surrounding pixels is small. On the other hand, a state in which the blood volume is high and the peak height of the absorption signal is high corresponds to a state in which the contrast change between the pixels representing the blood vessels and the surrounding pixels is large. Therefore, by detecting a significant overall change in the signal intensity that constitutes the pulse wave for the pixels representing the blood vessels on the finger blood vessel image, it is possible to determine whether the blood circulation in the fingers is good or poor.

[0131] The process of detecting changes in the signal intensity of pixels representing blood vessels can be performed by, for example, performing an inter-frame averaging process that averages the brightness of pixels at the same position across multiple frames of the finger vascular image, a noise filtering process that removes noise from the finger vascular image using a Gaussian filter or the like, a minimum value filtering process that corrects the intensity of each pixel of the finger vascular image to match the minimum value, a tone adjustment process that adjusts the contrast of each pixel of the finger vascular image, and then performing a blood circulation determination process.

[0132] In the blood circulation assessment process, a representative value, such as the average value of the signal intensity of pixels representing blood vessels in a finger vascular image, is compared with a preset threshold value. The signal intensity of pixels representing blood vessels may be quantified for a two-dimensional processing region including the pixels representing blood vessels, or for a collection of pixels representing blood vessels. The pixel signal intensity may be quantified as peak height, but is preferably quantified as peak area. In the blood circulation assessment step S41, data such as threshold values ​​can be stored in the memory unit 103.

[0133] 15 and 16 are diagrams illustrating the process of determining the puncture position of the puncture needle. The upper part of Fig. 15 schematically shows an example of a finger vascular image obtained by capturing an image of the fingers of a blood sample recipient. The lower part of Fig. 15 shows an example of the distribution of the intensity of transmitted near-infrared light corresponding to the finger vascular image. Fig. 16 corresponds to an enlarged view of region A in Fig. 15.

[0134] 15 and 16, reference numeral 140 denotes a blood vessel from which blood is to be collected, reference numeral 150 denotes a processing area, reference numeral 151 denotes a trajectory of the puncture needle caused by the rotation of the turntable, and reference numeral 152 denotes an intersection between blood vessel 140 from which blood is to be collected and trajectory 151 of the puncture needle caused by the rotation of the turntable. Intersection 152 is a candidate for the puncture position of the puncture needle on the finger of the person to whom blood is to be collected.

[0135] As shown in Figure 15, the puncture needle moves along an arc-shaped trajectory 151 relative to the fingertip of the person to be sampled as the turntable rotates. The puncture position of the puncture needle on the finger of the person to be sampled can be selected from positions on this trajectory 151. The trajectory 151 of the puncture needle can be drawn on the fingertip by placing a pen at the position of the puncture needle on the turntable and moving the pen in the same way as the puncture needle. In the puncture position determination step S42, coordinate data of the drawn trajectory can be stored in advance in the memory unit 103.

[0136] The puncture position of the puncture needle on the subject's finger is preferably set to a position where a blood vessel with good blood circulation is punctured, from the viewpoint of ensuring the required amount of blood to be collected. Blood vessels with good blood circulation are represented in the finger vascular image by pixels with low intensity of transmitted near-infrared light. Therefore, blood vessels with good blood circulation can be detected by identifying pixel groups on the trajectory 151 of the puncture needle where the intensity of transmitted near-infrared light is greatly reduced.

[0137] 16, pixel groups with a large decrease in the intensity of transmitted near-infrared light can be identified by detecting valley-shaped signals whose interior angle is small relative to a given signal width. When the lowest point of the valley-shaped signal is P, the point on the signal that is a given distance W / 2 to the left of P is R, and the point on the signal that is a given distance W / 2 to the right of P is Q, ∠QPR is the interior angle of the valley-shaped signal.

[0138] When the decrease in the intensity of transmitted light is small, ∠QPR produces a large interior angle a, whereas when the decrease in the intensity of transmitted light is large, it produces a small interior angle b. Therefore, by calculating the interior angle from the signal intensity data for each coordinate, it is possible to identify pixel groups with a large decrease in the intensity of transmitted near-infrared light, and based on the results, it is possible to determine the appropriate puncturing position for blood collection.

[0139] The process of determining the insertion position of the puncture needle can be performed by sequentially performing, for example, an inter-frame averaging process that averages the brightness of pixels at the same position across multiple frames of the finger vascular image, a noise filtering process that removes noise from the finger vascular image using a Gaussian filter or the like, a minimum value filtering process that corrects the intensity of each pixel of the finger vascular image to match the minimum value, a tone adjustment process that adjusts the contrast of each pixel of the finger vascular image, and a puncture position identification process that identifies a group of pixels on the trajectory 151 of the puncture needle where the intensity of transmitted near-infrared light is greatly reduced.

[0140] In the puncture position identification process, the puncture position of the puncture needle can be determined so as to coincide with the coordinates of the pixel group with the largest decrease in transmitted light intensity or the pixel group with the largest decrease in transmitted light intensity. Multiple candidates can be extracted as the pixel group with the largest decrease in transmitted light intensity. From these candidates, a position that was not punctured during the previous blood collection can be determined as the current puncture position. In the puncture position determination step S42, the coordinate data determined as the puncture position can be stored in the memory unit 103.

[0141] 17 and 18 are diagrams illustrating the puncture depth of the puncture needle in the finger of the person to be blood-collected. Fig. 17 shows a state in which the puncture depth of the puncture needle in the finger of the person to be blood-collected has reached the target puncture depth, and the puncture needle has just enough puncture depth in the target blood vessel. Fig. 18 shows a state in which the puncture depth of the puncture needle in the finger of the person to be blood-collected has not reached the target puncture depth, and the puncture needle has not yet reached the target blood vessel.

[0142] 17 and 18, reference numeral 121 denotes a puncture needle, and reference numeral 140 denotes a blood vessel from which blood is to be collected. The dotted line representing the puncture needle indicates the initial position of the puncture needle. ｔ is the target puncture depth for the blood vessel to be sampled, symbol A ｍ indicates the target movement distance of the puncture needle from the initial position toward the blood vessel from which blood is to be collected.

[0143] As shown in FIGS. 17 and 18, when the puncture needle 121 is inserted into the finger 134 of the subject, the actual puncture depth of the puncture needle 121 is set to a target puncture depth D ｔ It is preferable to drive the movement of the puncture needle 121 so that the target puncture depth D is within a predetermined range. ｔ can be set so as to approximately coincide with the distance between the surface of the subject's finger 134 and the blood vessel 140 from which blood is to be collected.

[0144] As shown in FIG. 17, when the blood vessel 140 from which blood is to be collected is close to the surface of the finger 134, the actual puncture depth of the puncture needle 121 is greater than the target puncture depth D ｔ On the other hand, as shown in FIG. 18, when the blood vessel 140 from which blood is to be collected is far from the surface of the finger 134, the actual puncture depth of the puncture needle 121 is closer to the target puncture depth D ｔThis makes it difficult to secure the amount of blood needed for blood tests, etc.

[0145] Therefore, in the blood collection device 1, the puncture needle 121 is set to the target puncture depth D ｔ In order to match this, the amount of movement of the puncture needle from the initial position toward the blood vessel of the blood collection target is set to a predetermined target movement amount A, taking into consideration the amount of protrusion of the puncture needle 121 from the puncture device. ｍ Target movement amount A ｍ The distance between the imaging position and the blood vessel 140 calculated based on the stereo image of the finger blood is used for setting the distance.

[0146] Fig. 19 is a diagram illustrating a finger stereo image. Fig. 19 schematically shows an example of a finger stereo image in which blood vessels in the fingers of a subject are captured with different parallaxes. The left side of Fig. 19 shows an image of the fingertips of the subject's fingers from which blood is to be collected, captured from one of the different imaging positions. The right side of Fig. 19 shows an image of the fingertips of the subject's fingers from which blood is to be collected, captured from the other of the different imaging positions.

[0147] 19, reference numeral 140 denotes a blood vessel from which blood is to be collected, reference numeral 150 denotes a processing area, reference numeral 151 denotes a trajectory of the puncture needle caused by the rotation of the turntable, and reference numeral 152 denotes an intersection between the blood vessel 140 from which blood is to be collected and the trajectory 151 of the puncture needle caused by the rotation of the turntable. The intersection 152 can function as a matching feature for matching between images.

[0148] 19 , when the tip of a finger 134 of a subject's finger is imaged from different imaging positions, two images with different parallaxes of a blood vessel 140 from which blood is to be collected are obtained. When these images are compared using the comparison feature as a reference, the parallax at an intersection 152 between the blood vessel 140 from which blood is to be collected and a trajectory 151 of the puncture needle caused by the rotation of the turntable, as well as the parallax angle relative to the intersection 152, can be determined.

[0149] Therefore, in the puncture depth determination process S43, the distance between the imaging position fixed with respect to the initial position of the puncture needle and intersection 152, which is a candidate for the puncture position of the puncture needle, can be determined using a triangulation method using similar figures based on the distance between the two imaging positions where the stereo image of the hand and fingers was captured, the focal length specific to the imaging device, the parallax determined from the stereo image of the hand and fingers, and distance and angle parameters that have a relationship that allows these to be uniquely calculated.

[0150] 20, 21, and 22 are diagrams illustrating a method for calculating distances based on stereo images of fingers. Fig. 20 shows the distances between each part when blood vessels in a subject's finger 134 are imaged using a stereo imaging device 30 equipped with two imaging units 31. Fig. 21 shows the distances between each part related to the right imaging unit 31. Fig. 22 shows the distances between each part related to the left imaging unit 31.

[0151] 20 , symbol P denotes a distance measurement target point corresponding to the blood vessel from which blood is to be collected, symbol H denotes a horizontal axis indicating the imaging position where the two imaging units 31 are arranged, and symbol θ denotes a partial parallax angle obtained by dividing the parallax angle by an orthogonal axis perpendicular to the horizontal axis. Symbol H(P) denotes the point where P is projected onto H, symbol O(L) denotes the center of the left imaging unit 31, and symbol O(R) denotes the center of the right imaging unit 31. Symbol H(L) denotes the distance between H(P) and O(L), symbol H(R) denotes the distance between H(P) and O(R), symbol H(D) denotes the distance between O(L) and O(R), and symbol X denotes the distance between H(P) and P.

[0152] 21 and 22 , reference numeral 32 denotes a set of imaging pixels that constitute the imaging unit 31, reference numeral 33 denotes a lens that constitutes the imaging unit 31, and reference numeral f denotes the focal length of the imaging unit 31. Reference numeral PO(R) denotes the center of the set of imaging pixels of the right imaging unit 31, reference numeral PI(R) denotes the imaging position of P relative to the imaging pixels of the right imaging unit 31, and reference numeral D(R) denotes the distance between PO(R) and PI(R). Reference numeral PO(L) denotes the center of the set of imaging pixels of the left imaging unit 31, reference numeral PI(L) denotes the imaging position of P relative to the imaging pixels of the left imaging unit 31, and reference numeral D(L) denotes the distance between PO(L) and PI(L).

[0153] 20, 21, and 22, the distance between the imaging positions of the stereo images of the hand and finger and the blood vessel from which blood is to be collected can be found as the distance X between H(P) and P. Distance X can be calculated based on the distance between the two imaging positions (H(D)), the focal length f specific to the imaging device, the parallax (D(L)+D(R)) caused by the two imaging units 31, and distance and angle parameters that can uniquely calculate these.

[0154] For example, the distance X between H(P) and P can be calculated using the following equations (1) and (2) with a known angle θ, a known H(D), a known D(R), and a known D(L): X = H(R) / tan θ (1) H(R) = H(D) × [D(R) / {D(R) + D(L)}] (2)

[0155] According to the formulas (1) and (2), the coordinate data of the imaged pixel can be used, so that the distance between the imaged position and the blood vessel can be easily quantified by image processing. In the puncture depth determination step S43, data corresponding to the known angles θ, H(D), D(R), and D(L) and data corresponding to the formulas (1) and (2) can be stored in advance in the storage unit 103.

[0156] This blood collection device determines the state of blood circulation in the recipient's fingers and the puncture depth of the needle before blood collection, thereby avoiding the need to collect blood from fingers where it is difficult to ensure the required amount of blood. This allows for proper blood collection. The recipient and blood collection conditions can be selected based on the state of blood circulation in the fingers and the possibility of proper puncture, reducing the burden on blood collection workers and the workload involved. Furthermore, a low-cost imaging device can be used to measure the state of blood circulation in the fingers and the distance from the blood vessels. By capturing images, the state of blood circulation in the fingers and the distance from the blood vessels can be objectively and easily quantified through image processing. Therefore, this blood collection device allows for prior identification of factors that may hinder blood collection, enabling stable and low-cost blood collection from the recipient and blood collection conditions.

[0157] Although the embodiments of the present invention have been described above, the present invention is not limited to the above-described embodiments, and various modifications are possible within the scope of the present invention. For example, the present invention is not necessarily limited to those having all of the configurations of the above-described embodiments. It is possible to replace part of the configuration of an embodiment with another configuration, add part of the configuration of an embodiment to another form, or omit part of the configuration of an embodiment.

[0158] For example, in the blood collection method (see FIG. 3) that determines both the state of blood circulation and the puncture depth of the puncture needle, the state of blood circulation is determined first and then the puncture depth is determined, but the order of these determinations is not particularly limited. The state of blood circulation may be determined after the puncture depth is determined. Also, in the operation of the blood collection device (see FIG. 11) that determines both the state of blood circulation and the puncture depth of the puncture needle, the state of blood circulation is determined first and then the puncture depth is determined, but the order of these determinations is not particularly limited. The state of blood circulation may be determined after determining the puncture position or after determining the puncture depth.

[0159] REFERENCE SIGNS LIST 1 Blood collection device 10 Housing 11 Turntable 12 Shaft 20 Near-infrared light imaging device 30 Stereo imaging device 31 Imaging unit 32 Imaging pixel 33 Lens 40 Near-infrared light source 110 Holder 120 Module 121 Puncture needle 130 Finger insertion section 131 Finger rest 132 Finger rest part 133 Blood collection window 134 Finger of blood recipient 136 Cuff 140 Blood vessel to be collected 150 Processing area 151 Trajectory 152 Intersection

Claims

1. A blood sampling method for determining the puncture depth of a puncture needle into a subject's fingers and sampling blood from the fingers, comprising the steps of: capturing stereo images of the subject's fingers in which the blood vessels of the subject's fingers are captured with different parallaxes; calculating the distance between the imaging positions where the stereo images of the fingers were captured and the blood vessels based on one or more of the distance between the imaging positions, focal length, parallax, and parameters that enable these to be calculated; and determining based on the result of the calculation whether the puncture depth of the puncture needle into the finger is within a predetermined target puncture depth range, and selectively performing blood sampling from the finger, canceling blood sampling from the finger, or changing blood sampling conditions depending on the result of the determination.

2. A blood sampling method as described in claim 1, wherein the puncture depth of the puncture needle into the finger is determined by comparing the amount of movement of the puncture needle from an initial position toward the vein in the finger with a predetermined target amount of movement.

3. A blood sampling method according to claim 2, wherein the target movement amount is set to coincide with the distance between the initial position of the puncture needle based on the result of the calculation and the blood vessel.

4. A blood sampling method for determining the state of blood circulation in the fingers of a person to be sampled and sampling blood from the fingers, comprising the steps of: irradiating near-infrared light onto the fingers of the person to be sampled, detecting the near-infrared light that has passed through the blood vessels of the fingers, and capturing an image of the blood vessels of the fingers that shows the course of the blood vessels in the fingers as pixel contrast; and determining whether or not the blood circulation of the fingers is poor based on the intensity of the pixels that represent the blood vessels in the image of the blood vessels of the fingers, and selectively performing blood sampling from the fingers, canceling blood sampling from the fingers, or changing the blood sampling conditions depending on the result of the determination.

5. A blood sampling method according to claim 4, wherein the determination of blood circulation in the fingers is performed by comparing a representative value of the intensity of the pixels with a preset threshold value.

6. A blood sampling method according to claim 5, wherein the representative value of pixel intensity is an average value of the intensities of pixels constituting a processing area in the finger vascular image.

7. A blood sampling method for sampling blood from a subject's fingers by determining the state of blood circulation in the fingers and the depth of a puncture needle into the fingers, comprising the steps of: irradiating near-infrared light onto the subject's fingers, detecting near-infrared light that has passed through the blood vessels of the fingers, and capturing a finger vascular image that represents the course of the blood vessels in the fingers as pixel contrast; determining whether or not the blood circulation in the fingers is poor based on the intensity of the pixels representing the blood vessels in the finger vascular image; capturing finger stereo images in which the blood vessels of the subject's fingers are captured with different parallaxes; calculating the distance between the imaging positions where the finger stereo images were captured and the blood vessels based on one or more of the distance between the imaging positions, focal length, parallax, and parameters that are in a relationship that allows these to be calculated; and determining whether or not the puncture depth of the puncture needle into the fingers is within a range of a preset target puncture depth based on the distance calculation result. A blood sampling method, which selectively performs blood sampling from the finger, stops blood sampling from the finger, or changes blood sampling conditions depending on the result of the judgment.

8. A blood sampling method as described in claim 7, wherein, when it is determined that the blood circulation in the finger is not poor and when it is determined that the puncture depth of the puncture needle into the finger is within a range of a predetermined target puncture depth, blood is sampled from the finger by setting the puncture depth.

9. A blood sampling device for sampling blood from the fingers of a subject, comprising: a stereo imaging device for capturing stereo images of the subject's fingers with different parallaxes; a distance calculation unit for calculating the distance between the imaging positions where the stereo images of the fingers were captured and the blood vessels based on one or more of the distance between the imaging positions, the focal length, the parallax, and parameters that enable the calculation of these; a puncture depth determination unit for determining whether the puncture depth of the puncture needle into the finger is within a predetermined target puncture depth range based on the result of the calculation; and a control unit for controlling the blood sampling operation based on the result of the determination by the puncture depth determination unit.

10. A blood sampling device as described in claim 9, wherein the puncture depth determination unit determines whether the absolute value of the difference between the amount of movement of the puncture needle from an initial position toward a blood vessel in a finger and a target amount of movement of the puncture needle is equal to or less than a preset threshold value, and the control unit performs blood sampling from the finger under preset conditions when the absolute value of the difference is equal to or less than the threshold value.

11. A blood sampling device for sampling blood from the fingers of a person to be sampled, comprising: a light source for irradiating near-infrared light onto the fingers of the person to be sampled; a near-infrared light imaging device for detecting near-infrared light that has passed through the blood vessels of the fingers and capturing an image of the blood vessels of the fingers that represents the course of the blood vessels in the fingers as pixel contrast; a blood circulation determination unit for determining whether or not the blood circulation of the fingers is poor based on the intensity of the pixels representing the blood vessels in the image of the fingers; and a control unit for controlling the blood sampling operation based on the result of the determination by the blood circulation determination unit.

12. A blood sampling device as described in claim 11, wherein the blood circulation judgment unit judges whether a representative value of the pixel intensity is below a preset threshold value, and the control unit performs blood sampling from the finger under preset conditions when the representative value of the pixel intensity exceeds the threshold value.

13. A blood sampling device for sampling blood from the fingers of a person to be sampled, comprising: a light source for irradiating near-infrared light onto the fingers of the person to be sampled; a near-infrared light imaging device for detecting near-infrared light that has passed through the blood vessels of the fingers and capturing a finger vascular image showing the course of the blood vessels in the fingers as pixel contrast; a blood circulation determination unit for determining whether or not the blood circulation of the fingers is poor based on the intensity of pixels showing the blood vessels in the finger vascular image; a stereo imaging device for capturing finger stereo images in which the blood vessels of the person to be sampled are captured with different parallaxes; a distance calculation unit for calculating the distance between the imaging positions where the finger stereo images were captured and the blood vessels based on one or more of the distance between the imaging positions, focal length, parallax, and parameters that are in a calculable relationship between these; and a puncture depth determination unit for determining whether or not the puncture depth of the puncture needle into the finger is within a preset target puncture depth range based on the result of the calculation. a control unit that controls a blood sampling operation based on a result of the determination by the blood circulation determination unit and a result of the determination by the puncture depth determination unit.

14. A blood sampling device as described in claim 13, wherein the blood circulation determination unit determines whether a representative value of the pixel intensity is equal to or less than a predetermined first threshold value, the puncture depth determination unit determines whether an absolute value of a difference between an amount of movement of the puncture needle from an initial position toward a blood vessel in a finger and a target amount of movement of the puncture needle is equal to or less than a predetermined second threshold value, and the control unit performs blood sampling from the finger under predetermined conditions when the representative value of the pixel intensity exceeds the first threshold value and the absolute value of the difference is equal to or less than the second threshold value.

Images