Multifunctional vein visualization device and blood collection site management system

Abstract

This invention provides a multi-functional vein visualization device and blood collection site management system that simplifies and reduces the cost of the device configuration while simultaneously performing screening for biological risks such as dehydration and anemia. [Solution] The system comprises a single imaging unit 22 that does not have a spectral filter on the light receiving path that receives reflected light from the target area, a light source unit 21 that sequentially switches and time-division irradiates the target area with four specific wavelengths of light: 660nm, 760nm, 850nm, and 940nm, an information processing unit 23 that extracts the spatial position of the veins in the target area and calculates an estimated index of the internal biological state from the absorbance at the target pixel based on the reflected images of each of the four specific wavelengths of light acquired by the imaging unit 22 in synchronization with the time-division irradiation by the light source unit 21, and an output unit 24 that outputs the spatial position of the veins and the estimated index extracted by the information processing unit 23.

Description

Technical Field

[0001] The present invention relates to a medical assistance device for visualizing subcutaneous veins using near-infrared light. In particular, it relates to a technique for non-invasively screening blood and tissue conditions while identifying vein positions for puncture support during blood collection.

Background Art

[0002] Conventional vein visualization devices irradiate specific near-infrared light and project the light absorption pattern of veins as visible light onto the skin surface (see, for example, Patent Document 1). On the other hand, as a technique for non-invasively discriminating tissue conditions (such as blood components), there are spectroscopic imaging devices such as hyperspectral cameras.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] However, existing spectroscopic imaging devices require optical mechanisms such as diffraction gratings and special spectroscopic filters on the light receiving side, leading to an increase in the size of the device and the manufacturing cost. In addition, in a medical setting (especially blood collection from the elderly), "dehydration" and "vein depth" are major factors contributing to difficult punctures, but an integrated device that can provide low-cost and non-invasive immediate presentation of these factors immediately before blood collection has not been provided.

[0005] The present invention has been made in view of the above problems, and its objective is to provide a multi-functional vein visualization device and blood collection site management system that can simultaneously perform three-dimensional localization of veins (including depth) and screening for biological risks such as dehydration and anemia, while greatly simplifying and reducing the device configuration by eliminating the existing spectroscopic measurement configuration that relies on spectral filters on the light-receiving side and adopting wavelength selection on the light source side (subtraction configuration). [Means for solving the problem]

[0006] To achieve the above objective, the multifunctional vein visualization device according to the present invention is characterized by comprising: an imaging unit that receives reflected light from a target area and has no spectral filter on the light receiving path; a light source unit that sequentially switches and time-division irradiates the target area with only four specific wavelengths of light: 660 nm, 760 nm, 850 nm, and 940 nm; an information processing unit that extracts the spatial position of the veins in the target area and calculates an estimation index of the internal biological state from the absorbance at the target pixel, based on the reflected images of each of the four specific wavelengths of light acquired by the imaging unit in synchronization with the time-division irradiation by the light source unit; and an output unit that outputs the spatial position of the veins extracted by the information processing unit and a determination result based on the estimation index.

[0007] Furthermore, the present invention comprises the following configuration as a preferred embodiment. (1) The information processing unit described above acquires planar position information of the vein based on the 760nm band reflection image, and estimates the depth of the vein by comparing the planar position information with the contrast intensity of the vein in the 850nm band reflection image.

[0008] (2) The information processing unit is characterized by calculating an estimated index of dehydration or edema related to the water content of the tissue based on the absorbance in the 940 nm band reflection image.

[0009] (3) The information processing unit is characterized by calculating an estimated index related to anemia or blood flow status based on the absorbance ratio of the 660nm band reflection image and the 760nm band reflection image.

[0010] Furthermore, the blood collection site management system according to the present invention comprises the multi-functional vein visualization device described above and a blood collection site management device for recording the patient's blood collection site. The output unit includes a communication interface and transmits alert information when the calculated estimated index exceeds a predetermined threshold, and spatial location information of the vein, to an external blood collection site management device via a communication network, where it is stored in association with the patient's puncture record data. [Effects of the Invention]

[0011] According to the present invention, multi-wavelength analysis is possible with only a combination of a light source unit for four specific wavelengths of light (e.g., a general-purpose light-emitting element (LED, etc.)) and a single imaging unit (e.g., a general-purpose image sensor), thus significantly reducing the manufacturing cost of the device.

[0012] Furthermore, since the detection of bio-risk alerts is completed simultaneously with the search for the puncture site and the system is automatically linked to an external system, medical safety can be improved without reducing the efficiency of blood collection operations. [Brief explanation of the drawing]

[0013] [Figure 1] This is a functional block diagram showing the schematic configuration of the blood collection site management system according to the present invention. [Figure 2] This is a schematic diagram illustrating how the location of veins is projected onto a subject's forearm using the multi-functional vein visualization device in the blood collection site management system. [Modes for carrying out the invention]

[0014] Embodiments of the present invention will be described below with reference to Figures 1 and 2. The blood collection site management system 1 according to the present invention is a system for measuring persons D, such as doctors and nurses, to measure and record the condition of the veins of persons P, such as patients, and as shown in Figure 1, it is mainly composed of a multi-functional vein visualization device 2 and a blood collection site management device 3.

[0015] The multi-functional vein visualization device 2 is a device that identifies the location of veins by utilizing the fact that venous blood (deoxyhemoglobin) that has finished transporting oxygen absorbs near-infrared light (NIR) more strongly than other tissues. The multi-functional vein visualization device 2 according to this embodiment is a vein visualization device that can screen for biological risks such as dehydration and anemia in addition to identifying the three-dimensional location of veins, and has a functional configuration of a light source unit 21, an imaging unit 22, an information processing unit 23, and an output unit 24.

[0016] The light source unit 21 is a light source that outputs near-infrared (NIR) light and does not have an element that emits broadband light (white light). It consists only of four types of LEDs with central wavelengths of 660 nm, 760 nm, 850 nm, and 940 nm. These LED light sources are configured to be switched on sequentially in microsecond to millisecond intervals (time-division illumination).

[0017] The imaging unit 22 is an imaging unit that receives reflected light from a target area (e.g., the forearm) of the subject P that has been irradiated with near-infrared light, and is composed of a single imaging unit that does not have a spectral optical filter on the light receiving path. For example, an infrared camera using a CMOS image sensor is preferably used as the imaging unit 22. When near-infrared light is irradiated from the light source unit 21 to the target area of ​​the subject P, the vein areas absorb the near-infrared light, and the surrounding tissues reflect it, and this state is captured by the imaging unit 22.

[0018] Furthermore, as described above, the light source unit 21 in this embodiment irradiates near-infrared light with different central wavelengths in a time-division manner, so the imaging unit 22 continuously acquires reflected images of each wavelength in synchronization with the time-division lighting timing of the light source unit 21.

[0019] The information processing unit 23 is an image analysis means that extracts the spatial position of the vein in the target site and calculates an estimation index of the internal state of the living body from the absorbance at the target pixel based on the reflection images of the four specific wavelength lights acquired by the imaging unit 22 in synchronization with the time-division irradiation by the light source unit 21. In the information processing unit 23 shown in this embodiment, the following operations are executed from the reflection image captured by the imaging unit 22.

[0020] That is, the information processing unit 23 utilizes the absorbance characteristics of each wavelength (760 nm = reduced Hb peak, 850 nm = deep penetration, 940 nm = water absorption, 660 nm = oxidation / reduction Hb difference) to calculate the vein position, depth, dehydration index, anemia index, etc. as follows.

[0021] (1) Vein extraction: Generate a two-dimensional map of the vein from the reflection image in the 760 nm band (image when irradiating near-infrared light with a center wavelength in the 760 nm band). That is, the information processing unit 23 generates and acquires the planar position information of the vein based on the reflection image in the 760 nm band.

[0022] (2) Depth estimation: Compare the contrast of the reflection image in the 850 nm band (image when irradiating near-infrared light with a center wavelength in the 850 nm band) at the same position pixel, and estimate the depth of the vein from the scattering attenuation rate. That is, the information processing unit 23 estimates the vein depth by comparing the planar position information of the vein acquired based on the reflection image in the 760 nm band with the contrast intensity of the vein in the reflection image in the 850 nm band.

[0023] Regarding this vein depth estimation, the information processing unit 23 compares the calculated vein depth (estimation index) with a predetermined threshold value to perform an abnormality determination as to whether there is an abnormality in the vein depth, and generates a predetermined abnormality flag (vein depth warning) when it is determined that there is an abnormality.

[0024] (3) Dehydration estimation: The amount of tissue water is calculated from the absorbance of the 940nm band reflection image (image when near-infrared light is irradiated with a central wavelength of 940nm band), and a dehydration / edema flag is generated by threshold determination. In other words, the information processing unit 23 calculates an estimation index of the dehydration state or edema state related to the amount of tissue water based on the absorbance in the 940nm band reflection image.

[0025] In addition, in relation to the estimation of dehydration or edema, the information processing unit 23 compares the calculated dehydration or edema state (estimated index) with a predetermined threshold, similar to the estimation of venous depth described above, to determine if there is an abnormality in the dehydration or edema state. If an abnormality is determined, it generates a predetermined abnormality flag (dehydration warning / edema warning).

[0026] (4) Anemia estimation: A hemoglobin status flag is generated from the absorbance ratio of the 660nm band reflection image (image when near-infrared light is irradiated with a central wavelength of 660nm) and the 760nm band image (image when near-infrared light is irradiated with a central wavelength of 760nm). That is, the information processing unit 23 calculates an estimated index related to anemia or blood flow status based on the absorbance ratio of the 660nm band reflection image and the 760nm band reflection image.

[0027] In addition, in relation to the estimation of anemia or blood flow status, the information processing unit 23 compares the calculated anemia or blood flow status (estimated index) with a predetermined threshold, similar to the estimation of venous depth and dehydration status described above, to determine if there is an abnormality in the anemia or blood flow status. If an abnormality is determined, it generates a predetermined abnormality flag (anemia warning / blood flow status warning).

[0028] The output unit 24 is an output interface for outputting calculation results (vein position, estimated index) and judgment results (abnormal flag) from the information processing unit 23. In this embodiment, the output unit 24 includes a visible light projection unit 25 for projecting the calculation results onto the skin of the person being measured P, and a communication interface 26 for transmitting the calculation results to an external device (for example, a blood collection site management device 3).

[0029] The visible light projection unit 25 includes a projector mechanism (not shown). The projector mechanism has a visible light source (e.g., a visible light LED) that outputs visible light 27, and projects the calculation results of the information processing unit 23 onto the skin of the person being measured P using the visible light 27. Figure 2 shows the state in which the vein positions are projected onto the forearm of the person being measured P. As shown in this figure, the vein positions and other information are realistically projected onto the skin of the person being measured P based on the calculation results of the information processing unit 23.

[0030] In the illustrated example, only the vein location is shown projected onto the skin of the subject P. However, it is also possible to project estimated indicators calculated by the information processing unit 23 (such as depth indicators, dehydration / edema indicators, anemia / blood flow indicators, etc.) or judgment results (such as vein depth warnings, dehydration / edema warnings, anemia / blood flow warnings, etc.) along with, or instead of, the vein location.

[0031] The communication interface 26 is an interface for outputting calculation results from the information processing unit 23 to an external blood collection site management device 3, and includes, for example, an API (Application Programming Interface) to enable data sharing with the blood collection site management device 3. The communication interface 26 is also connected to the blood collection site management device 3 by wired or wireless connection, and can transmit calculation results from the information processing unit 23 to the blood collection site management device 3 via wired or wireless connection. Therefore, in the multi-functional vein visualization device 2 shown in this embodiment, for example, patient (subject P) pre-screening information can be integrated and managed on the screen of the blood collection site management device 3, along with records of puncture sites.

[0032] The blood collection site management device 3 is a device for supporting blood collection operations in medical institutions such as hospitals. It records the blood collection history for each patient (including information such as past puncture sites and difficult puncture sites) and displays the puncture sites on the screen using photographic images and illustrations. The configuration of the blood collection site management device 3 is publicly known, so a detailed explanation will be omitted, but as shown in Figure 1, the blood collection site management device 3 is equipped with a storage unit 31 that stores blood collection history such as puncture record data.

[0033] In this embodiment, the blood collection site management device 3 is connected to the communication interface of the multifunctional vein visualization device 2 via wired or wireless communication. It is configured to receive calculation results and judgment results from the information processing unit 23 of the multifunctional vein visualization device 2, link them to the patient's puncture record data, and store them in the storage unit 31. In other words, the blood collection site management device 3 shown in this embodiment can display the vein position, various estimated indicators (vein depth indicator, dehydration / edema indicator, anemia / blood flow indicator, etc.), various judgment results (vein depth warning, dehydration / edema warning, anemia / blood flow warning, etc.) acquired by the multifunctional vein visualization device 2, along with the blood collection history (for example, past puncture sites), either side-by-side or overlaid, providing useful information for blood collection and intravenous infusion.

[0034] Thus, with the multi-functional vein visualization device 2 according to the present invention, multi-wavelength (4 wavelengths) analysis is possible with only a combination of a light source unit 21 of four specific wavelengths and a single imaging unit 22, making it possible to provide a vein visualization device at low cost.

[0035] Furthermore, since the vein location and depth are estimated, it is possible to simultaneously search for the puncture site and detect biological risks (abnormality detection). In addition, these results can be automatically linked to an external device (blood collection site management device 3), thereby improving medical safety without reducing the efficiency of blood collection operations.

[0036] The embodiments described above are merely preferred embodiments of the present invention, and the present invention is not limited to these, with various design modifications possible within its scope.

[0037] For example, in the embodiment described above, the multifunctional vein visualization device 2 was shown to use four types of light sources (LEDs) with central wavelengths of 660nm, 760nm, 850nm, and 940nm as the light source unit 21. However, the multifunctional vein visualization device 2 according to the present invention is only required to have at least a vein extraction function using a 760nm reflection image and a depth estimation function using reflection images of the 760nm and 850nm bands as basic functions, and to have at least one additional function (a function to estimate dehydration / edema using a 940nm reflection image or a function to estimate anemia or blood flow state using a 660nm reflection image). Therefore, it is also possible to omit either the 940nm or 660nm light source, or to configure the device so that either one can be turned off.

[0038] Furthermore, although the above-described embodiment showed a case where a single-color visible light, i.e., a single visible light source, is used as the visible light 27 output from the visible light projection unit 25, it is also possible to use multiple visible light sources to project the calculation results of the information processing unit 23, etc., into different colors onto the skin of the person being measured P. [Explanation of symbols]

[0039] 1. Blood collection site management system 2. Multifunctional vein visualization device 21 Light source section 22 Imaging Department 23 Information Processing Department 24 Output section 25 Visible light projection section 26 Communication Interfaces 27 Visible light 3 Blood sampling site management device 31 Storage section D. Measurers such as doctors and nurses P: Patients and other subjects being measured

Claims

1. An imaging unit that receives reflected light from a target area, comprising a single imaging unit without a spectral filter on the light receiving path, A light source unit that sequentially switches and time-divisions four specific wavelengths of light—660 nm, 760 nm, 850 nm, and 940 nm—onto the target area, An information processing unit extracts the spatial position of the veins in the target area based on the reflection images of each of the four specific wavelengths of light acquired by the imaging unit in synchronization with the time-resolved irradiation by the light source unit, and calculates an estimation index of the internal biological state from the absorbance at the target pixel. The system includes an output unit that outputs the spatial position of the vein extracted by the information processing unit and the estimated index. A multi-functional vein visualization device characterized by the following features.

2. The information processing unit acquires planar position information of the vein based on the 760 nm band reflection image, and estimates the depth of the vein by comparing the planar position information with the contrast intensity of the vein in the 850 nm band reflection image. The multi-functional vein visualization device according to claim 1.

3. The information processing unit calculates an estimated index of dehydration or edema related to the water content of the tissue based on the absorbance in the 940 nm band reflection image. The multi-functional vein visualization device according to claim 1.

4. The information processing unit calculates an estimated index related to anemia or blood flow status based on the absorbance ratio of the 660 nm band reflection image and the 760 nm band reflection image. The multi-functional vein visualization device according to claim 1.

5. The device comprises a multifunctional vein visualization device according to any one of claims 1 to 4, and a blood collection site management device for recording the blood collection site of a patient. The output unit includes a communication interface and transmits alert information when the calculated estimated index exceeds a predetermined threshold, as well as the spatial location information of the vein, to an external blood collection site management device via a communication network, where it is stored in conjunction with the patient's puncture record data. A blood collection site management system characterized by the following features.

Images