JP7443934B2 - Blood component measuring device and blood purification device - Google Patents

Description

The present invention relates to a blood component measuring device and a blood purification device that are capable of continuously measuring changes in the concentration of blood components in extracorporeally circulating blood.

In blood purification therapy such as dialysis treatment, the concentration of blood components contained in a patient's blood is an important index for determining the effectiveness and efficiency of treatment. Since the concentration of blood components changes during treatment, it is necessary to continuously measure changes in the concentration of blood components circulating extracorporeally. As a method for continuously measuring the concentration of blood components, light of a predetermined wavelength is irradiated from a light emitting part through a tube or the like without contacting the blood, and the intensity of the transmitted light and reflected light is converted into voltage by a light receiving part. 2. Description of the Related Art A method of measuring concentration based on the output voltage of a light receiving section is known.

In such measurements using light, an error occurs in the output voltage of the light receiving section due to external light incident on the light receiving section. In order to reduce this error, for example, Patent Document 1 discloses that the light emitting section is repeatedly turned off and on, and the output voltage while the light is turned off is used as the output voltage of external light, and the output voltage is subtracted from the output voltage when the light is turned on for correction. A method for calculating the concentration is described. Since correction is performed every time the light emitting unit blinks, it is possible to continuously and accurately measure component concentrations.

Further, Patent Document 2 describes a blood purification device that can measure blood component concentrations such as hematocrit value and oxygen saturation in blood using a plurality of light emitting sections.
Generally, light in two wavelength bands of about 600 nm and about 800 nm is used to measure oxygen saturation, and light in a wavelength band of about 800 nm is used to measure hematocrit. Further, in order to accurately measure the hematocrit value, light in two wavelength bands of approximately 1300 nm in addition to approximately 800 nm may be used.

Japanese Patent Application Publication No. 2004-97782 Unexamined Japanese Patent Publication No. 2016-125

As described in Patent Document 2 mentioned above, in measurements using light in multiple wavelength bands, in order to accurately measure using the method described in Patent Document 1, each turn-off time must be set to a length that eliminates afterglow. It is sufficient to measure the output voltage of external light by increasing the length to . However, since light in a plurality of wavelength bands is emitted, if the turn-off time is lengthened, the period in which the light in each wavelength band is turned on becomes longer. Therefore, the time required for measurement becomes long.

Therefore, an object of the present invention is to provide a blood component measuring device that can accurately measure the concentration of blood components in a short time.

The present invention is a blood component measuring device that continuously measures changes in the concentration of blood components based on the intensity of transmitted light or reflected light of light irradiated toward blood, and the device is capable of measuring blood components at multiple wavelengths including visible light. a light emitting section that emits a strip of light; a light receiving section that converts transmitted light or reflected light emitted from the light emitting section into a voltage and outputs the voltage; and a light emission control section that controls turning on and off of the light emitting section. , a concentration calculation unit that calculates the concentration of blood components based on the output voltage of the light receiving unit, and the light emission control unit controls the light emission in a plurality of wavelength bands at a predetermined period so that lighting sections do not overlap. of the plurality of off sections, the length of one off section is longer than the fall time of the output voltage of the light receiving section, and the length of the other off sections is the same as the one off section. The concentration calculating section obtains the output voltage of the light receiving section in the one lights-out section as the output voltage of external light, and calculates the output voltage of the light receiving section in the lighting section from the output voltage of the light receiving section in the lighting section. The present invention relates to a blood component measuring device that calculates the concentration of blood components based on a value obtained by subtracting the output voltage of light.

Further, it is preferable that the light emission control section performs control such that the other light-off period is shorter than a falling time of the output voltage of the light receiving section.

Further, the light receiving unit includes a plurality of light receiving elements, each of the plurality of light receiving elements receives light in a different wavelength band, and the density calculation unit is configured to calculate the number of light receiving elements in the one light-off period. The output voltage of each light-receiving element is obtained as the output voltage of each external light, and blood is detected based on the value obtained by subtracting the output voltage of each of the external lights from each output voltage of the plurality of light-receiving elements in the lighting section of each wavelength band. Preferably, the concentrations of the components are calculated.

The present invention also provides the blood component measuring device, a blood purifier, a blood circuit, a blood pump provided in the blood circuit for sending blood to the blood purifier, and a blood pump that is provided in the blood circuit to send blood to the blood purifier. A blood purification device comprising a measuring section for measuring component concentration and a control device, wherein the light emitting section and the light receiving section are provided in the measuring section, and the light emitting control section and the concentration calculating section are provided in the measuring section. , relates to a blood purification device provided in the control device.

According to the blood component measuring device of the present invention, by lengthening one of the plurality of light-off sections, it is possible to accurately obtain the output voltage of external light and measure the concentration of blood components with high precision. By shortening the other light-off periods, the concentration of blood components can be measured in a short time.

FIG. 1 is a block diagram showing a blood component measuring device according to a first embodiment of the present invention. FIG. 3 is a schematic diagram for explaining the configuration of a measuring section in the first embodiment. It is a graph which shows the output voltage of the light receiving part in 1st Embodiment. FIG. 2 is a diagram showing a schematic configuration of a blood purification device including a blood component measuring device according to a second embodiment of the present invention. It is a block diagram of the blood purification apparatus in 2nd Embodiment. FIG. 7 is a schematic diagram for explaining the configuration of a measuring section in a second embodiment. It is a graph which shows the output voltage of the light receiving part in 2nd Embodiment.

Hereinafter, preferred embodiments of the blood component measuring device of the present invention will be described with reference to the drawings.
The blood component measuring device of the present invention continuously measures the concentration of blood components without contacting the blood during treatment in which a patient's blood is circulated extracorporeally using a blood purification device, an artificial heart-lung machine, etc. for dialysis therapy, etc. This makes it measurable. The first embodiment describes a blood component measuring device capable of measuring oxygen saturation as a blood component, and the second embodiment includes a blood component measuring device capable of measuring oxygen saturation and hematocrit value as blood components. The blood purification device will be explained.

<First embodiment>
The first embodiment will be described in detail with reference to FIGS. 1 to 3. FIG. 1 is a block diagram showing a blood component measuring device 1 according to a first embodiment of the present invention.
As shown in FIG. 1, the blood component measurement device 1 includes a measurement section 10, a control section 20, and a display section 30.

The measurement unit 10 includes a light emitting unit 11 that emits light in two wavelength bands, and a light receiving unit 12 that receives transmitted light or reflected light emitted from the light emitting unit 11, converts it into a voltage, and outputs it, It is attached to a flow path such as a tube or blood chamber through which blood flows.

The light emitting section 11 includes two light emitting elements L1 and L2 and a light emitting circuit LC. In this embodiment, since oxygen saturation is measured as an example of blood components, a light emitting diode that emits visible light in a wavelength band of about 600 nm is used as the light emitting element L1, and a light emitting diode that emits light in a wavelength band of about 600 nm, which is visible light, is used as the light emitting element L2. A light emitting diode that emits light in the wavelength range is used. The light emitting circuit LC turns on or off the light emitting elements L1 and L2 based on a signal sent from a light emitting control circuit 21, which will be described later. Light in a wavelength band of about 600 nm is mainly absorbed by deoxyhemoglobin, and light in a wavelength band of about 800 nm is mainly absorbed by deoxyhemoglobin and oxyhemoglobin. When blood is irradiated with light in these two wavelength bands, some of it is absorbed, some of it is transmitted, and some of it is reflected.

The light receiving section 12 includes one light receiving element F1 and a light receiving circuit RC. Since the two wavelength bands used in this embodiment are close, approximately 600 nm and approximately 800 nm, the light receiving element F1 uses a photodiode that can receive light in both wavelength bands. Separate photodiodes may be used for the two wavelength bands. The light receiving circuit RC is a circuit that converts a weak current flowing in accordance with the intensity of light incident on the light receiving element F1 into a voltage, amplifies the voltage, and outputs the voltage.
In this embodiment, as shown in FIG. 2, the light emitting section 11 and the light receiving section 12 are arranged in parallel, and light is emitted from the light emitting section 11 toward the blood B flowing through the tube, and is reflected at the surface of the blood. The reflected light enters the light receiving section 12 and is converted into voltage.

The control section 20 includes a light emission control section 21 and a concentration calculation section 22.
The light emission control section 21 sends a signal to the light emitting circuit LC for blinking each of the light emitting elements L1 and L2 in the light emitting section 11 at a predetermined period, and controls lighting and extinguishing of the light emitting section 11.
The concentration calculation unit 22 calculates the oxygen saturation level as a blood component based on the voltage output from the light receiving circuit RC. A specific calculation method will be explained in detail later.

The display unit 30 is configured with a liquid crystal panel or the like that displays the concentration of blood components calculated by the concentration calculation unit 22, changes in blood components over time, and the like.

Next, a specific method for measuring the concentration of blood components will be described with reference to FIG. 3.
The light emission control section 21 controls the light emission section 11 so as to cause the light emitting elements L1 and L2 to blink at a predetermined period T, respectively. When the light emitting section 11 is blinked at the predetermined period T in this manner, the output voltage of the light receiving section 12 has a waveform as shown in FIG.

In FIG. 3, the section from the start of lighting of the light emitting element L1 to the start of turning off the light is defined as a lighting section Ton1, and the section from the start of lighting of the light emitting element L2 to the start of turning off the light is set as a lighting section Ton2. Further, the section from the start of turning off the light emitting element L2 to the start of lighting of the light emitting element L1 is defined as a lights out section Toff1, and the section from the start of turning off the light emitting element L1 to the start of lighting of the light emitting element L2 is set as a lights out section Toff2.

In this case, the predetermined period T=Toff1+Ton1+Toff2+Ton2 holds true. Here, the light emission control unit 21 controls the light-off period Toff2 to be shorter than the light-off period Toff1 among the two light-off periods Toff1 and Toff2. Further, the length of the light-off section Toff1 is set so that it continues even after the influence of afterglow caused by the lighting of the light emitting element L2 disappears.

That is, the output voltage that has increased to a predetermined value in the lighting period Ton2 falls and converges with a predetermined fall time in the non-lighting period Toff1. That is, in the lights-off period Toff1, after the predetermined fall time has passed, the output voltage of the light receiving section 12 can be considered to be the output voltage Vn due to the incidence of external light.

In this embodiment, as an example, Ton1=Ton2=Toff1=8 ms, and Toff2=4 ms. In this way, by setting the light-off period Toff2 other than the light-off period Toff1 for obtaining the output voltage Vn of external light to be short, the period T can be shortened. This allows blood concentration to be measured in a short time. For example, in the case of this embodiment, the period T=28 ms, and the number of blinks per second of the light emitting element L1 that emits visible light is 35.7 times. Generally, blinking of 35 times or more per second is not visible as flickering, so the above settings can also reduce flickering.

The concentration calculation unit 22 obtains the output voltage of the light receiving unit 12 as the external light output voltage Vn in the lights-off period Toff1. Next, in the lighting period Ton1 of the light emitting element L1, a value obtained by subtracting the output voltage Vn of external light from the output voltage V1 is obtained as the correction voltage Vc1. Finally, in the lighting period Ton2 of the light emitting element L2, a value obtained by subtracting the output voltage Vn of external light from the output voltage V2 is obtained as the correction voltage Vc2. The concentration calculating unit 22 calculates the oxygen saturation by calculating the ratio of deoxyhemoglobin and oxyhemoglobin from a correction voltage Vc1 that depends on the concentration of deoxyhemoglobin and a correction voltage Vc2 that depends on the concentration of deoxyhemoglobin and the concentration of oxyhemoglobin. calculate. Thereafter, this is repeated to continuously calculate the concentration.

According to the blood component measuring device 1 of the first embodiment described above, the following effects are achieved.

(1) The blood component measuring device 1 causes the light emission control unit 21 to blink the light emission unit 11 in a plurality of wavelength bands at a predetermined cycle T so that the lighting sections do not overlap, and one of the plurality of light-off sections Toff1 and Toff2. , the length of one lights-off section Toff1 is longer than the fall time of the output voltage of the light receiving section 12, and the length of the other lights-off section Toff2 is controlled to be shorter than one lights-off section Toff1. , the density calculation unit 22 obtains the output voltage Vn of external light in one lights-off period Toff1, and the value Vc1 is obtained by subtracting the output voltage Vn of external light from the output voltages V1 and V2 of the light receiving unit 12 in the lighting periods Ton1 and Ton2. , the concentration of blood components was calculated based on Vc2. As a result, it is not necessary to lengthen all the light-off sections to the extent that there is no afterglow, so blood concentration can be measured in a short time and the concentration can be calculated with high accuracy. Furthermore, flickering can be reduced by shortening the period T.

<Second embodiment>
Next, a blood component measuring device 1A according to a second embodiment will be described with reference to FIGS. 4 to 7. In the second embodiment, a configuration in which an extracorporeal circulation apparatus includes a blood component measuring device 1A will be described. As an example of an extracorporeal circulation device, a blood purification device 100A that can perform dialysis therapy will be described. The blood purification device 100A described in this embodiment purifies the blood of patients with renal failure or drug addiction, as well as a priming step in which the constituent members of the device are cleaned, a blood removal step in which blood is removed from the patient, and a blood purification step in which blood is removed from the patient. This is an automatic blood purification device that continuously and automatically performs each process, such as the dialysis process to remove excess water from the blood, and the blood return process to return blood to the patient, by controlling the flow of dialysate in the blood circuit. .

FIG. 4 is a diagram showing a schematic configuration of a blood purification device 100A including a blood component measuring device 1A according to a second embodiment of the present invention, and shows a state in a dialysis process, and FIG. FIG.

As shown in FIG. 4, the blood purification device 100A includes a blood circuit 110 for flowing blood, a blood purifier 120, a measuring section 10A, a dialysate circuit 130, and a control device 140.

Blood circuit 110 includes an arterial line 111, a venous line 112, a drug line 113, a drainage line 114, and a blood chamber 115. The arterial line 111, the venous line 112, the drug line 113, and the drainage line 114 are all mainly composed of flexible, flexible tubes through which liquid can flow.

One end of the arterial line 111 is connected to a blood inlet 122a of a blood purifier 120, which will be described later. The artery side line 111 is provided with an artery side connection part 111a, an artery side air bubble detector 111b, a blood pump 111c, and an artery side clamp 111d.
The artery side connection part 111a is arranged at the other end side of the artery side line 111. A needle to be punctured into a patient's blood vessel is connected to the artery side connection portion 111a.
The arterial air bubble detector 111b detects the presence or absence of air bubbles within the tube.
The blood pump 111c is arranged downstream of the arterial air bubble detector 111b in the arterial line 111. The blood pump 111c pumps out liquid such as blood and priming liquid inside the arterial line 111 by squeezing the tube constituting the arterial line 111 with a roller.
The artery side clamp 111d is arranged upstream of the artery side bubble detector 111b. For example, when blood is returned through the arterial line 111, the arterial clamp 111d is controlled according to the result of air bubble detection by the arterial air bubble detector 111b, and opens and closes the flow path of the arterial line 111.

One end of the venous line 112 is connected to a blood outlet 122b of a blood purifier 120, which will be described later. The venous line 112 is provided with a venous connection part 112a, a venous bubble detector 112b, a drip chamber 112c, and a venous clamp 112d.
The venous connection part 112a is arranged at the other end of the venous line. A needle to be punctured into a patient's blood vessel is connected to the venous connection portion 112a.
The venous air bubble detector 112b detects the presence or absence of air bubbles within the tube.
The drip chamber 112c is arranged upstream of the venous bubble detector 112b. The drip chamber 112c stores a certain amount of blood in order to remove air bubbles, coagulated blood, etc. that have entered the venous line 112, and to measure venous pressure.
The venous clamp 112d is arranged downstream of the venous bubble detector 112b. The venous clamp 112d is controlled according to the result of bubble detection by the venous bubble detector 112b, and opens and closes the flow path of the venous line 112.

The drug line 113 supplies necessary drugs to the arterial line 111 during hemodialysis. The drug line 113 has one end connected to a drug liquid pump 113a that pumps out a drug, and the other end connected to the arterial line 111. Further, the drug line 113 is provided with a clamping means (not shown), and the flow path is closed by the clamping means except when injecting the drug. In the second embodiment, the other end of the drug line 113 is connected to the arterial line 111 downstream of the blood pump 111c.

Drain line 114 is connected to drip chamber 112c. A drain line clamp 114a is arranged on the drain line 114. The drain line 114 is a line for draining a priming liquid during a priming process for washing and cleaning the blood circuit 110 and the blood purifier 120.

The blood chamber 115 is provided at a location in the blood circuit 110 where the measuring section 10A is attached. The blood chamber 115 is made of a transparent and hard resin such as polycarbonate, and is configured in a flat shape so that the area irradiated by the light emitting part 11A is larger than that of the tube constituting the blood circuit 110. In this embodiment, a blood chamber 115 is provided in the arterial line 111 in order to measure the condition of blood taken out from a patient. Although the blood chamber 115 may be attached anywhere on the arterial line 111, it is attached to the connection part with the blood inlet 122a of the blood purifier 120, which is one end side of the artery line 111.

The blood purifier 120 includes a cylindrical container body 121 and a dialysis membrane (not shown) housed inside the container body 121. It is divided into a side channel and a dialysate side channel (both not shown). The container body 121 is formed with a blood inlet 122a and a blood outlet 122b that communicate with the blood circuit 110, and a dialysate inlet 123a and a dialysate outlet 123b that communicate with the dialysate circuit 130.

According to the above-described blood circuit 110 and blood purifier 120, the blood taken out from the artery of the subject (dialysis patient) flows through the artery side line 111 by the blood pump 111c and flows through the blood side flow path of the blood purifier 120. will be introduced in Blood introduced into the blood purifier 120 is purified by a dialysate flowing through a dialysate circuit 130 (described later) via a dialysis membrane. The blood purified in the blood purifier 120 flows through the venous line 112 and is returned to the vein of the subject.

As shown in FIG. 5, the measuring section 10A includes a light emitting section 11A that emits light in three wavelength bands, and a light receiving section 12A that converts transmitted light or reflected light emitted from the light emitting section 11A into a voltage and outputs the voltage. , attached to the blood chamber 115.
The light emitting section 11A includes three light emitting elements L1, L2, L3 and a light emitting circuit LCA. In this embodiment, oxygen saturation and hematocrit value are measured as examples of blood components. As the light emitting elements L1 and L2 for measuring oxygen saturation, the same light emitting diodes as those described in the first embodiment are used, so a description thereof will be omitted. The light emitting element L3 uses a light emitting diode that emits light in a wavelength band of about 1300 nm. The light emitting circuit LCA turns on or off the light emitting elements L1, L2, and L3 based on a signal sent from a light emitting control circuit 21A, which will be described later. Light in a wavelength band of about 1300 nm is mainly absorbed by water, and light in a wavelength band of about 800 nm is mainly absorbed by hemoglobin. The hematocrit value is measured using light in these two wavelength bands.

The light receiving section 12A includes two light receiving elements F1 and F2 and a light receiving circuit RCA. Of the three wavelength bands used in this embodiment, approximately 600 nm and approximately 800 nm are close to each other, so as described in the first embodiment, the light receiving element F1 includes a photodiode that can receive light in both wavelength bands. use The light receiving element F2 uses a photodiode capable of receiving light in a wavelength band of about 1300 nm. The light-receiving circuit RCA is a circuit that converts weak currents flowing into voltages according to the intensity of light incident on the light-receiving elements F1 and F2, amplifies the voltages, and outputs the respective voltages.

In this embodiment, as shown in FIG. 6, the light emitting section 11A and the light receiving section 12A are arranged to face each other with the blood chamber 115 in between. Light is emitted from the light emitting section 11 toward the blood B flowing in the blood chamber 115, and the light that has passed through the blood enters the light receiving section 12A and is converted into voltage.

In the second embodiment, the dialysate circuit 130 is configured by a so-called sealed volume control type dialysate circuit 130. The dialysate circuit 130 includes a dialysate supply line 131a, a dialysate drain line 131b, a dialysate introduction line 132a, a dialysate outlet line 132b, and a dialysate feed section 133.

The dialysate feeding unit 133 includes a dialysate chamber 1331, a bypass line 1332, and a water removal/reverse filtration pump 1333.
The dialysate chamber 1331 is composed of a hard container that can contain a fixed volume (for example, 300 mL to 500 mL) of dialysate, and the interior of this container is separated by a soft diaphragm from the fluid supply storage section 1331a and the drain fluid. It is divided into a housing section 1331b.
Bypass line 1332 connects dialysate lead-out line 132b and dialysate drain line 131b.

A water removal/reverse filtration pump 1333 is located in the bypass line 1332. The water removal/reverse filtration pump 1333 is configured to flow the dialysate inside the bypass line 1332 toward the dialysate drainage line 131b side (water removal direction) and to flow the dialysate fluid through the dialysate outlet line 132b side (reverse filtration direction). It is composed of a pump that can be driven to send liquid to.

The dialysate supply line 131a is connected to a dialysate supply device (not shown) at its proximal end and to the dialysate chamber 1331 at its distal end. The dialysate supply line 131a supplies dialysate to the liquid supply storage section 1331a of the dialysate chamber 1331.

The dialysate introduction line 132 a connects the dialysate chamber 1331 and the dialysate inlet 123 a of the blood purifier 120 , and transfers the dialysate contained in the liquid supply storage section 1331 a of the dialysate chamber 1331 to the blood purifier 120 for dialysis. Introduced into the liquid side channel.

The dialysate lead-out line 132b connects the dialysate outlet 123b of the blood purifier 120 and the dialysate chamber 1331, and leads the dialysate discharged from the blood purifier 120 to the drain fluid storage section 1331b of the dialysate chamber 1331. do.

The dialysate drain line 131b is connected at its proximal end to the dialysate chamber 1331, and discharges the dialysate contained in the drain fluid storage section 1331b.

According to the dialysate circuit 130 described above, by dividing the inside of the hard container constituting the dialysate chamber 1331 with a soft diaphragm, the amount of dialysate drawn out from the dialysate chamber 1331 (liquid supply capacity The amount of dialysate supplied to the dialysate chamber 1331a (the amount of dialysate supplied to the dialysate chamber 1331a) and the amount of drainage fluid collected in the dialysate chamber 1331 (drainage fluid storage section 1331b) can be made equal.
As a result, when the water removal/reverse filtration pump 1333 is stopped, the flow rate of the dialysate introduced into the blood purifier 120 and the amount of dialysate (effluent) drawn out from the blood purifier 120 are made equal to each other. Can be done. Furthermore, when the water removal/reverse filtration pump 1333 is driven to send liquid in the water removal direction, a predetermined amount of water is removed from the blood at a predetermined speed in the blood purifier 120. Further, when the water removal/back filtration pump 1333 is driven to send liquid in the back filtration direction, a predetermined amount of dialysate is injected into the blood circuit 110 in the blood purifier 120 (back filtration).

The control device 140 is constituted by an information processing device (computer), and controls the operation of the blood purification device 100A by executing a control program. As shown in FIG. 5, specifically, the control device 140 controls the operations of various pumps, clamps, etc. arranged in the blood circuit 110 and the dialysate circuit 130, and controls various operations performed by the blood purification device 100. Steps such as a priming step, a blood removal step, a dialysis step, a fluid replacement step, a blood return step, etc. are executed.

Further, the control device 140 includes a control section 20A that constitutes the blood component measuring device 1A. The control section 20A includes a light emission control section 21A and a concentration calculation section 22A.
The light emission control section 21A sends a signal to the light emitting circuit LCA to cause the light emitting elements L1, L2, and L3 in the light emitting section 11A to blink at a predetermined period, and controls lighting and extinguishing of the light emitting section 11A.
The concentration calculation unit 22A calculates the oxygen saturation level and hematocrit value as blood components based on the voltage output from the light receiving circuit RCA. A specific calculation method will be explained in detail later.

Among the various processes performed in the blood purification apparatus 100A described above, the dialysis process shown in FIG. 4 will be briefly described.

In the dialysis process, excess water from the patient is removed and waste products are removed.
In the dialysis process, the patient's blood introduced from the arterial connection 111a passes through the arterial line 111, is purified by the blood purifier 120, and is returned to the patient through the venous line 112 from the venous connection 112a. .

In the dialysis process, as shown in FIG. 4, the arterial side connection part 111a and the venous side connection part 112a are each connected to a needle puncturing the patient's blood vessel, and the drain line clamp 114a is in a closed state. The venous clamp 112d is in an open state.

A dialysate supply device (not shown) supplies and discharges dialysate to and from the dialysate chamber 1331 at an average flow rate of 500 mL/min, and operates a water removal/reverse filtration pump 1333 in the water removal direction at an average rate of 10 mL/min. The blood purifier 120 is operated to feed liquid, and water is removed at a rate of 10 mL/min.
The blood pump 111c sends blood from the artery side connection part 111a side to the blood purifier 120 side at a flow rate of, for example, 200 mL/min.
Blood flows into the blood purifier 120 from the blood inlet 122a at a flow rate of 200 mL/min, is removed at a flow rate of 10 mL/min, and is led out from the blood outlet 122b at a flow rate of 190 mL/min. Further, the dialysis fluid is led out from the dialysate outlet 123b.
In this way, water removal is performed at a flow rate of 10 mL/min in the dialysis step.

In this way, in the dialysis process, water is gradually removed and the patient's blood becomes concentrated, so by measuring the hematocrit value as a blood component, it is possible to adjust the water removal rate and measure recirculation, etc. becomes possible. It is also possible to calculate changes in the patient's circulating blood volume based on the hematocrit value. Additionally, by measuring oxygen saturation during the dialysis process, it is possible to detect sleep apnea syndrome and the like.

Next, a specific method for measuring the concentration of blood components in this embodiment will be described with reference to FIG.
The light emission control unit 21A controls the light emission unit 11A to cause the light emitting elements L1, L2, and L3 to blink at a predetermined period _TA . In this way, when the light emitting section 11A is blinked at a predetermined period _TA , the output voltages of the light receiving section 12A are output voltage 1 from the light receiving element F1 and output voltage 2 from the light receiving element F2. . The respective output voltages 1 and 2 have waveforms as shown in FIG.
In FIG. 7, the section from the start of lighting of the light emitting element L1 to the start of turning off the light is defined as a lighting section T _A on1, the section from the start of lighting of the light emitting element L2 to the start of turning off the light is defined as a lighting section T A on2, and the section from the start of lighting of the light emitting element L2 to the start of turning off the light is set as a lighting section T A on2, and the section from the start of lighting of the light emitting element L2 to the start of turning off the light is set as a lighting section T _A on1, and the section from the start of lighting of the light emitting element L2 to the start of turning off the light is a lighting section T A on1 The section from the start to the start of turning off the light is defined as a lighting section T _A on3. Further, the section from the start of turning off the light emitting element L3 to the start of lighting of the light emitting element L1 is defined as a light-off section T _A off1, and the section from the start of turning off the light emitting element L1 to the start of lighting of the light emitting element L2 is set as a light-off section T _A off2, The section from the start of turning off the light emitting element L2 to the start of turning on the light emitting element L3 is defined as a turning off section T _A off3. A relationship of predetermined period _TA = _TA off1 + _TA on1 + _TA off2 + _TA on2 + _TA off3 + _TA on3 is established. The light emission control unit 21A determines that among the three light- _off sections TA _off1 , _TA off2, and _TA off3, the other light-off sections TA _off1 and _TA off2 are shorter than one light-off section TA off3. Control as follows. Further, the length of the light-off section T _A off3 is set so that it continues even after the influence of afterglow caused by the lighting of the light emitting element L2 disappears. That is, the output voltage that has increased to a predetermined value in the lighting section T _A on2 falls and converges with a predetermined fall time in the light-off section T _A off3. That is, in the light-off period T _A off3, after a predetermined falling time, the output voltages of the light receiving elements F1 and F2 of the light receiving section 12A are the respective output voltages V _A n1 and V _A n2 due to the incidence of external light. It can be considered as In addition, in the light-off sections T _A off1 and T _A off2, lighting of the next light emitting element L1 and light emitting element L2 is started without the afterglow of the light emitting element L3 and the afterglow of the light emitting element L1 converging, respectively. That is, the light-off periods T _A off1 and T _A off2 are set so that the time is shorter than the fall time of the output voltage that has risen to a predetermined value due to the lighting of the light emitting element that emitted light immediately before.

In this embodiment, as an example, T _A on1 = T _A on2 = T _A on3 = 5 ms, T _A off3 = 7 ms, and T _A off1 = T _A off2 = 3 ms. In this way, by setting the light-off periods T A off1 and T _A off2 other than the light-off period T _A off3 for obtaining the output voltage _{V A} n of external light to short times such that the afterglow does not converge, the period T _A can be made even shorter. This makes it possible to measure blood concentration in an even shorter time. For example, in the case of this embodiment, the period T=28 ms, and the number of blinks per second of the light emitting element L1 that emits visible light is 35.7 times. Generally, blinking of 35 times or more per second is not visible as flickering, so the above settings can also reduce flickering.

The concentration calculation unit 22A obtains the output voltages from the respective light receiving elements F1 and F2 in the light receiving unit 12A as external light output voltages V _A n1 and V _A n2 in the lights-off period T _A off3. Next, in the lighting period T _A on3 of the light emitting element L3, a value obtained by subtracting the output voltage V _A n2 of external light from the output voltage V _A 3 is obtained as a correction voltage V _A c3. Subsequently, in the lighting period T _A on1 of the light emitting element L1, a value obtained by subtracting the output voltage V _A n1 of external light from the output voltage V _A 1 is obtained as the correction voltage V _A c1. Finally, in the lighting period T _A on2 of the light emitting element L2, the value obtained by subtracting the output voltage V _A n1 of external light from the output voltage V _A 2 is obtained as the correction voltage V _A c2. The concentration calculation unit 22A calculates the ratio of deoxyhemoglobin and oxyhemoglobin from a correction voltage V _A c1 that depends on the concentration of deoxyhemoglobin and a correction voltage V _A c2 that depends on the concentration of deoxyhemoglobin and the concentration of oxyhemoglobin. Calculate oxygen saturation. Further, the concentration calculation unit 22A calculates the hematocrit value from the correction voltage V _A c2 that depends on the concentration of hemoglobin and the correction voltage V _A c3 that depends on the proportion of water. Thereafter, this is repeated to continuously calculate the oxygen saturation and hematocrit values.

According to the blood component measuring device 1A of the second embodiment described above, in addition to the above-mentioned effect (1), the following effects are achieved.

(2) The light emission control unit 21A of the blood component measuring device 1A controls the light-off periods T _A off1 and T _A off2 to be shorter than the falling time of the output voltage from the light receiving elements F3 and F1 of the light receiving unit 12A. I took it as a thing. This allows the cycle to be further shortened, and therefore the blood concentration can be measured in a shorter period of time. Furthermore, flickering can be further reduced.

(3) The light receiving unit 12A of the blood component measuring device 1A has a plurality of light receiving elements F1 and F2, and the plurality of light receiving elements F1 and F2 each receive light in different wavelength bands, and the concentration calculating unit 22A acquires each output voltage from the plurality of light-receiving elements F1 and F2 as output voltages V A n1 and V A n2 of each external light in one light-off period T _A off3, and obtains each output voltage from the plurality of light-receiving elements F1 and F2 as output voltages V _A n1 and V _A n2 of each wavelength band, and calculates the output voltages from each of the light receiving elements F1 and F2 as the output voltage V A n1 and V _{A n2} of each wavelength band. The value obtained by subtracting the output voltages VA _n1 and _VA n2 of each external light from the output voltages _VA 1, _VA 2, and _{VA 3} of the plurality of light receiving elements F1 and F2 in on1, TA on2, and _TA on3. The concentration of blood components was calculated based on V _A c1, V _A c2, and V _A c3. As a result, even if the number of light-receiving elements included in the light-receiving section increases, only one light-off period needs to be lengthened, so the period can be shortened.

Although preferred embodiments of the blood component measuring device of the present invention have been described above, the present invention is not limited to the embodiments described above, and can be modified as appropriate.

For example, in each of the embodiments described above, the light emitting unit has a configuration using a plurality of light emitting elements that emit light in different wavelength bands, but by applying a filter to one light emitting element, light in multiple wavelength bands can be emitted. It may be configured so that it is possible.
Further, in each of the above-described embodiments, a case has been shown in which the measurement unit is attached to a tube or a blood chamber of a blood circuit, but for example, a measurement unit may be attached to the casing of the main body of an extracorporeal circulation apparatus to configure a blood circuit. The tube may be configured to be attached to the measurement section.

1, 1A Blood component measuring device 10, 10A Measuring section 11, 11A Light emitting section 12, 12A Light receiving section 20, 20A Control section 21, 21A Luminescence control section 22, 22A Concentration calculation section 30 Display section 100A Dialysis device 110 Blood circuit 111 Artery Side line 111c Blood pump 112 Venous line 120 Blood purifier 130 Dialysate circuit 133 Dialysate feeding section 140 Control section

Claims (4)

A blood component measuring device that continuously measures changes in the concentration of blood components based on the intensity of transmitted light or reflected light of light irradiated toward the blood,
a light emitting part that emits light in multiple wavelength bands including visible light;
a light receiving section that receives transmitted light or reflected light of the light emitted from the light emitting section, converts it into a voltage, and outputs it;
a light emission control unit that controls lighting and extinguishment of the light emission unit;
a concentration calculation unit that calculates the concentration of blood components based on the output voltage of the light receiving unit;
Equipped with
The light emission control section causes each of the light emitting sections to blink in a plurality of wavelength bands at a predetermined period so that the lighting sections do not overlap, and the length of one of the plurality of non-lighting sections is the output of the light receiving section. Controlling the voltage so that it is longer than the fall time of the voltage and the length of the other non-lighting sections is shorter than the one non-lighting section;
The concentration calculation unit acquires the output voltage of the light receiving unit in the one lights-out period as the output voltage of external light, and calculates the output voltage of the light receiving unit in the one lighting period by subtracting the output voltage of the external light. A blood component measuring device that calculates the concentration of blood components based on the following information. The blood component measuring device according to claim 1, wherein the light emission control section controls the other light-off period to be shorter than a fall time of the output voltage of the light receiving section. The light receiving section has a plurality of light receiving elements,
The plurality of light receiving elements each receive light in different wavelength bands,
The concentration calculation unit acquires each output voltage of the plurality of light receiving elements as an output voltage of each external light in the one lights-out section, and obtains each output voltage of the plurality of light receiving elements in the lighting section of each wavelength band. The blood component measuring device according to claim 1 or 2, wherein the blood component concentration is calculated based on a value obtained by subtracting the output voltage of each of the external lights from the output voltage of each external light. The blood component measuring device according to any one of claims 1 to 3,
blood purifier,
blood circuit,
a blood pump provided in the blood circuit and configured to send blood to the blood purifier;
a measurement unit for measuring component concentration of blood flowing through the blood circuit;
a control device;
A blood purification device comprising:
The light emitting section and the light receiving section are provided in the measuring section,
The light emission control section and the concentration calculation section are a blood purification device provided in the control device.

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