Blood component measuring device and blood purification device

Abstract

A blood component measuring device is provided that can accurately measure the concentration of blood components in a short time. The blood component measuring device (1) controls the light emission control unit (21) to flash the light emission unit (11) in multiple wavelength regions in a manner that the lighting intervals do not overlap in a specified period T, and makes the length of one of the multiple light-off intervals Toff1 and Toff2 longer than the drop time of the output voltage of the light receiving unit (12), and the length of the other light-off intervals Toff2 shorter than one light-off interval Toff1, so that the concentration calculation unit (22) obtains the output voltage Vn of the external light in one light-off interval Toff1, and calculates the concentration of the blood component based on the values ​​Vc1 and Vc2 obtained by subtracting the output voltage Vn of the external light from the output voltage V1 and V2 of the light receiving unit (12) in the lighting intervals Ton1 and Ton2.

Description

Technical Field

[0001] This invention relates to a blood component measuring device and a blood purification device for continuously measuring changes in the concentration of blood components in blood during extracorporeal circulation. Background Technology

[0002] In blood purification therapies such as dialysis, the concentration of blood components in the patient's blood is a crucial indicator for assessing the treatment's effectiveness and efficiency. The concentration of blood components changes during treatment, necessitating continuous monitoring of these concentrations in the extracorporeal circulation. One known method for continuously measuring blood component concentration involves irradiating the blood with light of a predetermined wavelength through a tube or similar means in a non-contact manner. The intensity of the transmitted and reflected light is converted into a voltage at a receiving section, and the concentration is measured based on the output voltage of the receiving section.

[0003] In measurements using light in this manner, the output voltage of the light-receiving part is affected by external light incident on it. To reduce this error, for example, Patent Document 1 describes a method that involves repeatedly turning the light-emitting part on and off, using the output voltage during the off-lighting phase as the output voltage of the external light, subtracting the output voltage of the external light from the output voltage during the on-lighting phase, and then calculating the concentration. By correcting for each flicker of the light-emitting part, the component concentration can be measured continuously and with high accuracy.

[0004] In addition, Patent Document 2 describes a blood purification device that can use multiple light-emitting units to measure the concentration of blood components such as hematocrit and oxygen saturation.

[0005] Generally, oxygen saturation is measured using light in two wavelength regions: approximately 600 nm and approximately 800 nm. Hematocrit is measured using light in the approximately 800 nm wavelength region. However, for high-precision measurement of hematocrit, there are cases where light in two wavelength regions—approximately 800 nm and approximately 1300 nm—is used.

[0006] Prior art literature

[0007] Patent documents

[0008] Patent Document 1: Japanese Patent Application Publication No. 2004-97782

[0009] Patent Document 2: Japanese Patent Application Publication No. 2016-125 Summary of the Invention

[0010] The problem that the invention aims to solve

[0011] As described in Patent Document 2 above, in the measurement of light using multiple wavelength regions, in order to perform high-precision measurement using the method described in Patent Document 1, it is sufficient to extend the time for each lamp to be extinguished until the residual light disappears to measure the output voltage of the external light. However, since light from multiple wavelength regions is emitted, the lighting period of light in each wavelength region becomes longer when the extinguishing time is extended. Therefore, the measurement time required becomes longer.

[0012] Therefore, the present invention aims to provide a blood component measuring device that can accurately measure the concentration of blood components in a short time.

[0013] Methods for solving problems

[0014] This invention relates to a blood component measuring device, which continuously measures changes in the concentration of blood components based on the intensity of transmitted or reflected light irradiated onto blood. The device comprises: a light-emitting unit that emits light covering multiple wavelength regions of visible light; a light-receiving unit that receives transmitted or reflected light irradiated from the light-emitting unit and converts it into a voltage for output; a light-emitting control unit that controls the lighting and extinguishing of the light-emitting unit; and a concentration calculation unit that calculates the concentration of blood components based on the output voltage of the light-receiving unit. The control unit operates as follows: the light-emitting part flashes in multiple wavelength regions in a manner that the lighting intervals do not overlap within a specified period, and the length of one of the multiple light-off intervals is longer than the drop time of the output voltage of the light-receiving part, while the lengths of the other light-off intervals are shorter than the one light-off interval. The concentration calculation unit obtains the output voltage of the light-receiving part in the one light-off interval as the output voltage of the external light, and calculates the concentration of the blood component based on the value obtained by subtracting the output voltage of the external light from the output voltage of the light-receiving part in the lighting interval.

[0015] Furthermore, it is preferable that the light-emitting control unit controls the other light-off intervals in a manner that makes the drop time of the output voltage of the light-receiving unit shorter than that of the light-receiving unit.

[0016] In addition, preferably, the light-receiving unit has multiple light-receiving elements, each of which receives light from different wavelength regions. The concentration calculation unit obtains the output voltage of each of the multiple light-receiving elements in the one lamp-off interval as the output voltage of each external light, and calculates the concentration of blood components based on the value obtained by subtracting the output voltage of each external light from the output voltage of each of the multiple light-receiving elements in the lamp-on interval of each wavelength region.

[0017] In addition, the present invention relates to a blood purification apparatus, which includes: the aforementioned blood component measuring device; a blood purifier; a blood circuit; a blood pump disposed in the aforementioned blood circuit for delivering blood to the aforementioned blood purifier; a measuring unit for measuring the concentration of blood components flowing through the aforementioned blood circuit; and a control device, wherein the aforementioned light-emitting unit and the aforementioned light-receiving unit are disposed in the aforementioned measuring unit, and the aforementioned light-emitting control unit and the aforementioned concentration calculation unit are disposed in the aforementioned control device.

[0018] The effects of the invention

[0019] According to the blood component measuring device of the present invention, the output voltage of external light can be accurately obtained by lengthening one of the multiple light-off intervals, thereby measuring the concentration of blood components with high precision, and the concentration of blood components can be measured in a short time by shortening the other light-off intervals. Attached Figure Description

[0020] [ Figure 1 [This is a block diagram of a blood component measuring device according to the first embodiment of the present invention.]

[0021] [ Figure 2 [A schematic diagram illustrating the structure of the measuring unit in the first embodiment.]

[0022] [ Figure 3 A graph showing the output voltage of the light-receiving section in the first embodiment is provided.

[0023] [ Figure 4 [A diagram showing a simplified configuration of a blood purification apparatus equipped with the blood component measuring device according to the second embodiment of the present invention.]

[0024] [ Figure 5 Block diagram of the blood purification device in the second embodiment.

[0025] [ Figure 6 [A schematic diagram illustrating the structure of the measuring unit in the second embodiment.]

[0026] [ Figure 7 The graph shows the output voltage of the light-receiving section in the second embodiment. Detailed Implementation

[0027] The preferred embodiments of the blood component measuring device of the present invention will be described below with reference to the accompanying drawings.

[0028] In treatments involving extracorporeal circulation of a patient's blood, such as in dialysis or cardiopulmonary bypass, the blood component concentration of the blood can be continuously measured in a non-contact manner. In the first embodiment, a blood component measuring device capable of measuring oxygen saturation as a blood component will be described. In the second embodiment, a blood purification device will be described, which includes a blood component measuring device capable of measuring oxygen saturation and hematocrit as blood components.

[0029] <First Embodiment>

[0030] Reference Figures 1-3 The first embodiment will be described in detail. Figure 1 This is a block diagram illustrating the blood component measuring device 1 according to the first embodiment of the present invention.

[0031] like Figure 1 As shown, the blood component measuring device 1 includes a measuring unit 10, a control unit 20, and a display unit 30.

[0032] The measuring unit 10 has a light-emitting unit 11 that emits light in two wavelength regions, and a light-receiving unit 12 that receives transmitted or reflected light irradiated from the light-emitting unit 11 and converts it into voltage for output. It is installed in the flow path of blood, such as in a tube or blood chamber.

[0033] The light-emitting unit 11 consists of two light-emitting elements L1 and L2 and a light-emitting circuit LC. In this embodiment, oxygen saturation is measured as an example of blood components; therefore, a light-emitting diode emitting visible light (approximately 600 nm wavelength) is used as light-emitting element L1, and a light-emitting diode emitting light (approximately 800 nm wavelength) is used as light-emitting element L2. The light-emitting circuit LC illuminates or de-illuminates light-emitting elements L1 and L2 based on a signal transmitted from the light-emitting control circuit 21 (described later). Light in the approximately 600 nm wavelength region is mainly absorbed by deoxyhemoglobin, and light in the approximately 800 nm wavelength region is mainly absorbed by both deoxyhemoglobin and oxyhemoglobin. When light in these two wavelength regions irradiates blood, some is absorbed, some is transmitted, and some is reflected.

[0034] The light-receiving section 12 comprises a light-receiving element F1 and a light-receiving circuit RC. In this embodiment, the two wavelength regions used are approximately 600 nm and approximately 800 nm, which are close in wavelength; therefore, the light-receiving element F1 uses a photodiode capable of accepting light from both wavelength regions. Different photodiodes can also be used for the two wavelength regions. The light-receiving circuit RC is a circuit that converts the weak current flowing through the light-receiving element F1 into a voltage based on the intensity of the light incident on it, amplifies it, and outputs it.

[0035] In this embodiment, if Figure 2As shown, the light-emitting part 11 and the light-receiving part 12 are arranged side by side. Light is irradiated from the light-emitting part 11 onto the blood B flowing through the tube. The reflected light reflected from the surface of the blood is incident on the light-receiving part 12 and converted into voltage.

[0036] The control unit 20 includes a light emission control unit 21 and a concentration calculation unit 22.

[0037] The light-emitting control unit 21 sends a signal to the light-emitting circuit LC to control the lighting and extinguishing of the light-emitting unit 11 so that each light-emitting element L1, L2 in the light-emitting unit 11 flashes at a predetermined period.

[0038] The concentration calculation unit 22 calculates the oxygen saturation of blood components based on the voltage output from the light-receiving circuit RC. The specific calculation method is explained in detail below.

[0039] The display unit 30 consists of an LCD panel that displays the concentration of blood components and changes in blood components over time, as calculated by the concentration calculation unit 22.

[0040] Next, regarding the methods for measuring the concentration of specific blood components, refer to... Figure 3 Please provide an explanation.

[0041] The light-emitting control unit 21 controls the light-emitting unit 11 to blink the light-emitting elements L1 and L2 at a predetermined period T. When the light-emitting unit 11 blinks at the predetermined period T in this manner, the output voltage of the light-receiving unit 12 is as follows: Figure 3 The waveform shown.

[0042] Figure 3 In this diagram, the interval from the start of lighting up to the start of lighting down for the light-emitting element L1 is designated as the lighting interval Ton1, and the interval from the start of lighting up to the start of lighting down for the light-emitting element L2 is designated as the lighting interval Ton2. Furthermore, the interval from the start of lighting down for the light-emitting element L2 to the start of lighting up for the light-emitting element L1 is designated as the lighting interval Toff1, and the interval from the start of lighting down for the light-emitting element L1 to the start of lighting up for the light-emitting element L2 is designated as the lighting interval Toff2.

[0043] In this case, the prescribed period T = Toff1 + Ton1 + Toff2 + Ton2 holds true. Here, the light emission control unit 21 controls the light emission in such a way that the light emission interval Toff2 is shorter than the light emission interval Toff1. In addition, the length of the light emission interval Toff1 is set so that it continues even after the residual light caused by the illumination of the light emission element L2 has disappeared.

[0044] In other words, during the lighting interval Ton2, the output voltage that rises to a predetermined value converges during the lighting-off interval Toff1 after a predetermined fall time. That is, during the lighting-off interval Toff1, after the predetermined fall time has elapsed, the output voltage of the light-receiving unit 12 can be considered as the output voltage Vn generated due to the incidence of external light.

[0045] In this embodiment, as an example, let Ton1 = Ton2 = Toff1 = 8ms and Toff2 = 4ms. When the lamp-off interval Toff2 is shortened in this way, the period T can be shortened. Here, the aforementioned lamp-off interval Toff2 is the lamp-off interval other than the lamp-off interval Toff1 used to obtain the output voltage Vn of the external light. Therefore, blood concentration can be measured in a short time. For example, in this embodiment, the period T = 28ms, and the number of flashes per second of the visible light emitting element L1 is 35.7. Generally, flashes of more than 35 times per second are considered flickering and cannot be seen; therefore, the flickering can be reduced by the above settings.

[0046] The concentration calculation unit 22 obtains the output voltage of the light-receiving unit 12 as the output voltage Vn of the external light during the lamp-off interval Toff1. Next, during the lamp-on interval Ton1 of the light-emitting element L1, it obtains the value obtained by subtracting the output voltage Vn of the external light from the output voltage V1 as the correction voltage Vc1. Finally, during the lamp-on interval Ton2 of the light-emitting element L2, it obtains the value obtained by subtracting the output voltage Vn of the external light from the output voltage V2 as the correction voltage Vc2. The concentration calculation unit 22 calculates the ratio of reduced hemoglobin to oxidized hemoglobin from the correction voltage Vc1, which depends on the concentration of reduced hemoglobin, and the correction voltage Vc2, which depends on the concentrations of reduced hemoglobin and oxidized hemoglobin, thereby calculating the oxygen saturation. This process is repeated thereafter to continuously calculate the concentration.

[0047] The blood component measuring device 1 according to the first embodiment described above can achieve the following effects.

[0048] (1) In the blood component measuring device 1, the light emission control unit 21 is controlled as follows: the light emission unit 11 flashes in multiple wavelength regions in a manner that the lighting intervals do not overlap within a predetermined period T; and the length of one of the multiple extinguishing intervals Toff1 and Toff2 is longer than the drop time of the output voltage of the light receiving unit 12, while the lengths of the other extinguishing intervals Toff2 are shorter than one extinguishing interval Toff1. The concentration calculation unit 22 obtains the output voltage Vn of the external light in one extinguishing interval Toff1, and calculates the concentration of the blood component based on the values ​​Vc1 and Vc2 obtained by subtracting the output voltage Vn of the external light from the output voltage V1 and V2 of the light receiving unit 12 in the lighting intervals Ton1 and Ton2. Therefore, it is not necessary for all extinguishing intervals to be long enough to completely eliminate residual light, so the blood concentration can be measured in a short time and the concentration can be calculated with high accuracy. In addition, the period T can be shortened and the flickering can be reduced.

[0049] <Second Implementation>

[0050] Next, regarding the blood component measuring device 1A of the second embodiment, refer to... Figures 4-7 The following description will be provided. In the second embodiment, the configuration of the extracorporeal circulation device including the blood component measuring device 1A will be described. As an example of the extracorporeal circulation device, a blood purification device 100A capable of performing dialysis therapy will be described. The blood purification device 100A described in this embodiment is an automatic blood purification device that purifies the blood of patients with renal failure or drug poisoning, and continuously and automatically performs the following processes by controlling the dialysate flowing through the blood circuit. The aforementioned processes include: a pre-rinsing process for cleaning the components of the device; a de-blooding process for removing blood from the patient; a dialysis process for removing excess water from the blood; and a return process for returning blood to the patient, etc.

[0051] Figure 4 This diagram, illustrating a simplified configuration of a blood purification apparatus 100A including the blood component measuring device 1A according to the second embodiment of the present invention, shows the state during the dialysis process. Figure 5 This is a block diagram of the blood purification device 100A.

[0052] like Figure 4 As shown, the blood purification device 100A includes a blood circuit 110 for blood flow, a blood purifier 120, a measuring unit 10A, a dialysate circuit 130, and a control device 140.

[0053] The blood circuit 110 includes an arterial side conduit 111, a venous side conduit 112, a drug conduit 113, a drainage conduit 114, and a blood chamber 115. The arterial side conduit 111, the venous side conduit 112, the drug conduit 113, and the drainage conduit 114 are all mainly composed of flexible soft tubes that allow fluid to flow.

[0054] One end of the arterial side tubing 111 is connected to the blood inlet 122a of the blood purifier 120, which will be described later. The arterial side tubing 111 is equipped with an arterial side connector 111, an arterial side bubble detector 111b, a blood pump 111c, and an arterial side clamp 111d.

[0055] An arterial side connector 111a is disposed at the other end of the arterial side conduit 111. A needle for puncturing a patient's blood vessel is connected to the arterial side connector 111a.

[0056] The arterial side bubble detector 111b detects whether there are bubbles in the tube.

[0057] The blood pump 111c is positioned downstream of the arterial side bubble detector 111b in the arterial side conduit 111. The blood pump 111c uses rollers to agitate the tubes constituting the arterial side conduit 111, thereby delivering blood, pre-fluid, and other liquids from inside the arterial side conduit 111.

[0058] The arterial side clamp 111d is disposed upstream of the arterial side bubble detector 111b. For example, in the case of blood return via the arterial side conduit 111, the arterial side clamp 111d is controlled to open or close the flow path of the arterial side conduit 111 based on the bubble detection result of the arterial side bubble detector 111b.

[0059] One end of the venous side tubing 112 is connected to the blood outlet 122b of the blood purifier 120, which will be described later. The venous side tubing 112 is provided with a venous side connector 112a, a venous side bubble detector 112b, an infusion device 112c, and a venous side clamp 112d.

[0060] A venous-side connector 112a is disposed at the other end of the venous-side tubing. A needle for puncturing the patient's blood vessel is connected to the venous-side connector 112a.

[0061] The 112b venous bubble detector detects whether there are air bubbles in the tube.

[0062] The drip device 112c is positioned upstream of the venous air bubble detector 112b. The drip device 112c stores a certain amount of blood to remove air bubbles, coagulated blood, etc., mixed into the venous tubing 112, and to measure venous pressure.

[0063] The vein-side clamp 112d is positioned downstream of the vein-side bubble detector 112b. The vein-side clamp 112d is controlled to open or close the flow path of the vein-side conduit 112 based on the bubble detection results of the vein-side bubble detector 112b.

[0064] The medication line 113 supplies the medications required for hemodialysis to the arterial side line 111. One end of the medication line 113 is connected to the medication pump 113a, which delivers the medication, and the other end is connected to the arterial side line 111. Additionally, a clamping mechanism (not shown) is provided on the medication line 113, which keeps the flow path closed except during medication injection. In the second embodiment, the other end of the medication line 113 is connected downstream of the blood pump 111c in the arterial side line 111.

[0065] The drain line 114 is connected to the drip infusion unit 112c. A drain line clamp 114a is provided on the drain line 114. The drain line 114 is used to drain the pre-flushing fluid during the pre-flushing process of the blood cleaning and purification circuit 110 and the blood purifier 120.

[0066] The blood chamber 115 is located within the blood circuit 110 at the position where the measuring unit 10A is installed. The blood chamber 115 is formed of a transparent and rigid resin such as polycarbonate, and is flattened in such a way that the irradiation area from the light-emitting unit 11A is larger compared to the tube constituting the blood circuit 110. In this embodiment, the blood chamber 115 is located in the arterial side conduit 111 to measure the state of blood taken from the patient. The blood chamber 115 can be installed at any position in the arterial side conduit 111, but in this embodiment, it is installed at one end of the arterial side conduit 111, specifically at the connection point with the blood inlet 122a of the blood purifier 120.

[0067] The blood purifier 120 includes a cylindrical container body 121 and a dialysis membrane (not shown) housed inside the container body 121. The interior of the container body 121 is divided into a blood-side flow path and a dialysate-side flow path (both not shown) by the dialysis membrane. A blood inlet 122a and a blood outlet 122b communicating with the blood circuit 110, and a dialysate inlet 123a and a dialysate outlet 123b communicating with the dialysate circuit 130 are formed on the container body 121.

[0068] Based on the blood circuit 110 and blood purifier 120 described above, blood drawn from the artery of the recipient (dialysis patient) flows through the arterial side tubing 111 via the blood pump 111c and is introduced into the blood side flow path of the blood purifier 120. The blood introduced into the blood purifier 120 is purified by dialysate flowing through the dialysate circuit 130 described later via the dialysis membrane. The purified blood in the blood purifier 120 flows through the venous side tubing 112 and is returned to the recipient's vein.

[0069] like Figure 5As shown, the measuring unit 10A has a light-emitting unit 11A that emits light in three wavelength regions and a light-receiving unit 12A that converts the transmitted or reflected light irradiated by the light-emitting unit 11A into voltage and outputs it, and is installed in the blood cavity 115.

[0070] The light-emitting unit 11A consists of three light-emitting elements L1, L2, and L3 and a light-emitting circuit LCA. In this embodiment, oxygen saturation and hematocrit are measured as an example of blood components. The light-emitting elements L1 and L2 used to measure oxygen saturation are the same light-emitting diodes described in the first embodiment, so their description is omitted. The light-emitting element L3 is a light-emitting diode that emits light in the wavelength region of approximately 1300 nm. The light-emitting circuit LCA turns the light-emitting elements L1, L2, and L3 on or off based on a signal transmitted by the light-emitting control circuit 21A described later. Light in the wavelength region of approximately 1300 nm is mainly absorbed by water, and light in the wavelength region of approximately 800 nm is mainly absorbed by hemoglobin. Hematocrit is measured using light in these two wavelength regions.

[0071] The light-receiving section 12A consists of two light-receiving elements F1 and F2 and a light-receiving circuit RCA. In this embodiment, the wavelength regions of approximately 600 nm and approximately 800 nm are close; therefore, the light-receiving element F1 uses the same photodiode as described in the first embodiment, capable of accepting light from both wavelength regions. The light-receiving element F2 uses a photodiode capable of accepting light from a wavelength region of approximately 1300 nm. The light-receiving circuit RCA is a circuit that converts the weak current flowing through the light-receiving elements F1 and F2 into voltage based on their respective light intensities, amplifies it, and outputs the voltage.

[0072] In this embodiment, if Figure 6 As shown, the light-emitting part 11A and the light-receiving part 12A are arranged opposite each other, sandwiching the blood cavity 115. Light is irradiated from the light-emitting part 11A onto the blood B flowing through the blood cavity 115, and the light that has passed through the blood is incident on the light-receiving part 12A and converted into voltage.

[0073] In the second embodiment, the dialysate circuit 130 is configured as a dialysate circuit 130 with a so-called closed-loop capacity control method. The dialysate circuit 130 includes a dialysate supply line 131a, a dialysate discharge line 131b, a dialysate inlet line 132a, a dialysate outlet line 132b, and a dialysate delivery section 133.

[0074] The dialysate delivery unit 133 includes a dialysate chamber 1331, a bypass line 1332, and a water removal / reverse filtration pump 1333.

[0075] The dialysate chamber 1331 is made of a rigid container that can hold a certain volume (e.g., 300 mL to 500 mL) of dialysate. The interior of the container is divided into a liquid delivery receiving section 1331a and a liquid discharge receiving section 1331b by a soft diaphragm.

[0076] The bypass line 1332 is connected to the dialysate outlet line 132b and the dialysate drain line 131b.

[0077] A water removal / reverse filtration pump 1333 is disposed in a bypass line 1332. The water removal / reverse filtration pump 1333 is a pump that can be driven to deliver liquid in the following directions: the direction in which the dialysate inside the bypass line 1332 flows to the dialysate discharge line 131b (water removal direction) and the direction in which the dialysate inside the bypass line 1332 flows to the dialysate outlet line 132b (reverse filtration direction).

[0078] The base end of the dialysate supply line 131a is connected to the dialysate supply device (not shown), and the front end is connected to the dialysate chamber 1331. The dialysate supply line 131a supplies dialysate to the liquid delivery and receiving section 1331a of the dialysate chamber 1331.

[0079] The dialysate inlet tubing 132a connects the dialysate chamber 1331 to the dialysate inlet 123a of the blood purifier 120, and introduces the dialysate contained in the liquid delivery receiving part 1331a of the dialysate chamber 1331 into the dialysate side flow path of the blood purifier 120.

[0080] The dialysate outlet 132b connects the dialysate outlet 123b of the blood purifier 120 to the dialysate chamber 1331, and discharges the dialysate discharged from the blood purifier 120 to the drain receiving part 1331b of the dialysate chamber 1331.

[0081] The base end of the dialysate drain line 131b is connected to the dialysate chamber 1331 to drain the dialysate contained in the drain receiving section 1331b.

[0082] Based on the dialysate circuit 130 described above, by dividing the interior of the rigid container that forms the dialysate chamber 1331 by a soft diaphragm, the amount of dialysate discharged from the dialysate chamber 1331 (the amount of dialysate supplied to the liquid delivery container 1331a) and the amount of liquid discharged back into the dialysate chamber 1331 (the amount of liquid discharged into the liquid discharge container 1331b) can be the same.

[0083] Therefore, when the dehydration / reverse filtration pump 1333 is stopped, the flow rate of dialysate introduced into the blood purifier 120 can be the same as the amount of dialysate (drainage) discharged from the blood purifier 120. Furthermore, when the dehydration / reverse filtration pump 1333 is driven to deliver fluid in the dehydration direction, a predetermined amount of water is removed from the blood at a predetermined rate in the blood purifier 120. Additionally, when the dehydration / reverse filtration pump 1333 is driven to deliver fluid in the reverse filtration direction, a predetermined amount of dialysate is injected (reverse filtered) into the blood circuit 110 in the blood purifier 120.

[0084] The control device 140 is composed of an information processing device (computer) and controls the operation of the blood purification device 100A by executing a control program. For example... Figure 5 As shown, specifically, the control device 140 controls the operation of various pumps, clamps, etc., configured in the blood circuit 110 and the dialysate circuit 130, and executes various processes performed by the blood purification device 100, such as pre-flushing process, blood removal process, dialysis process, fluid replenishment process, blood return process, etc.

[0085] In addition, the control device 140 includes a control unit 20A that constitutes the blood component measuring device 1A. The control unit 20A includes a light emission control unit 21A and a concentration calculation unit 22A.

[0086] The light-emitting control unit 21A sends a signal to the light-emitting circuit LCA to make each light-emitting element L1, L2, L3 in the light-emitting unit 11A flash at a predetermined period, thereby controlling the lighting and extinguishing of the light-emitting unit 11A.

[0087] The concentration calculation unit 22A calculates the oxygen saturation and hematocrit of blood components based on the voltage output from the light-receiving circuit RCA. The specific calculation method is explained in detail below.

[0088] Among the various processes performed by the blood purification device 100A described above, for Figure 4 The dialysis procedure shown is briefly explained.

[0089] During the dialysis process, excess water and metabolic waste are removed from the patient.

[0090] During the dialysis process, the patient's blood introduced from the arterial side connection 111a is purified in the blood purifier 120 through the arterial side tubing 111 and returned to the patient from the venous side connection 112a through the venous side tubing 112.

[0091] like Figure 4As shown, during the dialysis process, the arterial side connection 111a and the venous side connection 112a are respectively connected to the needle used to puncture the patient's blood vessels, the drain tubing clamp 114a is in the closed state, and the venous side clamp 112d is in the open state.

[0092] The dialysate supply device (not shown) supplies and discharges dialysate to the dialysate chamber 1331 at an average rate of 500 mL / min. As an example in the direction of water removal, the water removal / reverse filtration pump 1333 operates at a rate of 10 mL to remove water at a rate of 10 mL / min in the blood purifier 120.

[0093] The blood pump 111c delivers blood from the arterial side connection 111a to the blood purifier 120 at a flow rate of 200 mL / min, for example.

[0094] Within the blood purifier 120, blood flows in through the blood inlet 122a at a flow rate of 200 mL / min, is dehydrated at a flow rate of 10 mL / min, and is discharged through the blood outlet 122b at a flow rate of 190 mL / min. Additionally, dialysis fluid is discharged through the dialysate outlet 123b.

[0095] In this way, water is removed during the dialysis process at a flow rate of 10 mL / min.

[0096] In dialysis procedures like this, water is slowly removed to gradually concentrate the patient's blood. Therefore, by measuring hematocrit, a blood component, the rate of water removal can be adjusted, and recirculation can be monitored. Furthermore, changes in the patient's circulating blood volume can be calculated based on hematocrit. Additionally, by measuring oxygen saturation during dialysis, it may be possible to detect conditions such as sleep apnea.

[0097] Next, regarding the specific method for measuring the concentration of blood components in this embodiment, refer to... Figure 7 Please provide an explanation.

[0098] The light-emitting control unit 21A causes the light-emitting elements L1, L2, and L3 to emit light at a predetermined period T. A The light-emitting unit 11A is controlled by flashing. The light-emitting unit 11A is thus controlled to flash at a predetermined period T. A In the event of flickering, the output voltage of the light-receiving unit 12A can be obtained as output voltage 1 from the light-receiving element F1 and output voltage 2 from the light-receiving element F2. Each output voltage 1 and output voltage 2 is as follows: Figure 7 The waveform shown.

[0099] Figure 7 In this context, the interval from the start of lighting up to the start of lighting down for the light-emitting element L1 is defined as the lighting interval T. Aon1, define the interval from the start of lighting up to the start of lighting down for the light-emitting element L2 as the lighting interval T. A on2, set the interval of the light-emitting element L3 from the start of lighting to the start of lighting off as the lighting interval T. A on3. Additionally, the interval from the start of the lamp being turned off by the light-emitting element L3 to the start of the lamp being turned on by the light-emitting element L1 is defined as the lamp-off interval T. A off1, the interval from when the light-emitting element L1 goes out to when the light-emitting element L2 goes on is defined as the light-out interval T. A off2, the interval from when the light-emitting element L2 turns off to when the light-emitting element L3 turns on is defined as the off interval T. A off3. The specified period T A =T A off1+T A on1+T A off2+T A on2+T A off3+T A The on3 relationship is established. The light emission control unit 21A uses three lamp-off intervals T. A off1、T A off2, and T A One of the light-off intervals T in Off3 A Off3 is different from other light-off zones T A off1、T A The light is controlled using a short off-2 method. Additionally, the light-off interval T... A The length of off3 is set so that the residual light caused by the illumination of the light-emitting element L2 continues even after the effect disappears. That is, during the illumination interval T... A In ON2, the output voltage rises to the specified value during the lamp-off interval T. A In off3, it converges after a specified descent time. That is, during the extinguishing interval T... A In off3, if the specified descent time is exceeded, the output voltages of the light-receiving elements F1 and F2 of the light-receiving section 12A can be considered as the output voltages V generated due to the incident external light. A n1, V A n2. Additionally, in the light-out zone T... A off1、T A In off2, while the residual light from light-emitting element L3 and the residual light from light-emitting element L1 are not converging, the next light-emitting element L1 and then light-emitting element L2 are immediately illuminated. In other words, the extinguishing interval T is set by immediately following the illumination of the previously illuminated light-emitting element. A off1、T Aoff2 makes it so that the fall time of the output voltage rising to the specified value is shorter.

[0100] In this embodiment, as an example, let T A on1 = T A on2=T A on3 = 5ms, T A off3 = 7ms, T A off1 = T A off2 = 3ms. The output voltage V used to obtain external light is set in this way. A The light-off interval T of n A The light-off zone T outside of off3 A off1、T A Setting off2 to a short time, representing the degree of peripheral vision non-convergence, can further shorten the period T. A Therefore, blood concentration can be measured in a shorter time. For example, in this embodiment, the light-emitting element L1, which emits visible light, flashes 35.7 times per second with a period T = 28 ms. Generally, flashes of more than 35 times per second are considered flickering and cannot be seen, so flickering can be reduced by the above setting.

[0101] Concentration calculation unit 22A in lamp-extinguishing interval T A off3 obtains the output voltages of each light-receiving element F1 and F2 in the light-receiving section 12A as the output voltage V of the external light. A n1, V A n2. Next, in the lighting zone T of the light-emitting element L3. A on3 obtains the output voltage V A 3 minus the output voltage V of external light A The value obtained from n2 is used as the correction voltage V. A c3. Next, in the lighting zone T of the light-emitting element L1. A on1 obtains the output voltage V A 1 minus the output voltage V of external light A The value obtained from n1 is used as the correction voltage V. A c1. Finally, in the lighting zone T of the light-emitting element L2. A on2 obtains the output voltage V A 2 minus the output voltage V of external light A The value obtained from n1 is used as the correction voltage V. A c2. The concentration calculation unit 22A calculates the concentration from the correction voltage V, which depends on the concentration of reduced hemoglobin. A c1, and the correction voltage V that depends on the concentrations of reduced hemoglobin and oxidized hemoglobin. Ac2 is used to calculate the ratio of reduced hemoglobin to oxidized hemoglobin, thereby calculating oxygen saturation. Additionally, the concentration calculation unit 22A uses a correction voltage V that depends on the hemoglobin concentration. A c2, and the correction voltage V that depends on the water ratio. A c3, calculate hematocrit. Then, repeat this process, continuously calculating oxygen saturation and hematocrit.

[0102] In addition to the effects described above (1), the blood component measuring device 1A according to the second embodiment of the above description can also achieve the following effects.

[0103] (2) The light emission control unit 21A of the blood component measuring device 1A enables the lamp-off interval T to be turned off. A off1、T A Off2 is controlled in a manner that makes the drop time of the output voltage from the light-receiving elements F3 and F1 of the light-receiving section 12A shorter than that of the light-receiving element. This allows for a further shortening of the cycle, thus enabling shorter measurement times for blood concentration. Additionally, flicker may be further reduced.

[0104] (3) The light-receiving part 12A of the blood component measuring device 1A has multiple light-receiving elements F1 and F2, which respectively receive light from different wavelength regions. The concentration calculation part 22A is in one lamp-off interval T. A off3 obtains the output voltages from multiple light-receiving elements F1 and F2 as the output voltage V of each external light source. A n1, V A n2, based on the lighting interval T from each wavelength region A on1、T A on2、T A The output voltages V of the multiple light-receiving elements F1 and F2 in ON3 A 1. V A 2. V A 3 minus the output voltage V of each external light A n1, V A The value V obtained by n2 A c1, V A c2、V A c3 calculates the concentration of blood components. Therefore, even if the light-receiving section has more light-receiving elements, only one longer lamp-extinguishing interval is needed, thus shortening the cycle.

[0105] The preferred embodiments of the blood component measuring device of the present invention have been described above, but the present invention is not limited to the above embodiments and can be modified appropriately.

[0106] For example, in the embodiments described above, the light-emitting part is shown to be composed of multiple light-emitting elements that emit light in different wavelength regions, but it can also be composed by installing a filter on a single light-emitting element so that it can emit light in multiple wavelength regions.

[0107] Furthermore, in the above embodiments, the measuring unit is shown to be installed in the tube or blood chamber of the blood circuit. However, for example, the measuring unit may also be installed in the outer casing of the main body of the extracorporeal circulation device, and the tube constituting the blood circuit may be installed in the measuring unit.

[0108] Explanation of reference numerals in the attached figures

[0109] 1.1A Blood Component Analyzer

[0110] 10, 10A Measurement Section

[0111] 11, 11A Light-emitting part

[0112] 12, 12A Light-receiving section

[0113] 20, 20A Control Unit

[0114] 21, 21A Light Emitting Control Unit

[0115] 22, 22A Concentration Calculation Section

[0116] 30 Display Section

[0117] 100A dialysis device

[0118] 110 Blood Circuit

[0119] 111 Arterial side access

[0120] 111c Blood Pump

[0121] 112. Venous sideline catheter

[0122] 120 Blood Purifier

[0123] 130 Dialysis fluid circuit

[0124] 133 Dialysis Solution Delivery Section

[0125] 140 Control Department

Claims

1. A blood component measuring device, wherein the blood component measuring device continuously measures the concentration changes of blood components based on the intensity of transmitted or reflected light irradiated onto blood, and comprises: The light-emitting part emits light covering multiple wavelength regions of visible light; The light-receiving part receives transmitted or reflected light from the light-emitting part and converts it into voltage for output. A light-emitting control unit, which controls the lighting and extinguishing of the light-emitting unit; and The concentration calculation unit calculates the concentration of blood components based on the output voltage of the light-receiving unit. The light-emitting control unit controls the light-emitting unit to blink in multiple wavelength regions in a manner that ensures the illumination intervals do not overlap within a specified period. Furthermore, the length of one of the multiple extinguishing intervals is longer than the drop time of the output voltage of the light-receiving unit, while the lengths of the other extinguishing intervals are shorter than that single extinguishing interval. The concentration calculation unit obtains the output voltage of the light-receiving unit as the output voltage of the external light in the one light-off interval, and calculates the concentration of the blood component based on the value obtained by subtracting the output voltage of the external light from the output voltage of the light-receiving unit in the light-on interval.

2. The blood component measuring device as described in claim 1, wherein, The light-emitting control unit controls the light to make the other light-off intervals shorter than the drop time of the output voltage of the light-receiving unit.

3. The blood component measuring device as described in claim 1 or 2, wherein, The light-receiving part has multiple light-receiving elements. The multiple light-receiving elements each receive light from different wavelength regions. The concentration calculation unit obtains the output voltage of each of the plurality of light-receiving elements in the one lamp-off interval as the output voltage of each external light, and calculates the concentration of blood components based on the value obtained by subtracting the output voltage of each external light from the output voltage of each of the plurality of light-receiving elements in the lamp-on interval of each wavelength region.

4. A blood purification device, wherein the blood purification device comprises: The blood component measuring device according to any one of claims 1 to 3; Blood purifier; Blood circulation; A blood pump installed in the blood circuit for delivering blood to the blood purifier; A measuring unit for determining the concentration of blood components flowing through the blood circuit; and Control device, The light-emitting part and the light-receiving part are disposed in the measuring part. The light emission control unit and the concentration calculation unit are disposed in the control device.

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