JP7754735B2 - Dialysis effluent component measuring device and method - Google Patents

Description

The present invention relates to a device and method for measuring components in dialysis effluent.

In blood purification devices, the blood is purified by bringing the blood into contact with the dialysate via a blood purification membrane in a blood purifier (also called a dialyzer). If excessive leakage of certain components from the blood into the dialysate occurs, complications and other problems may occur. Therefore, to avoid such problems, it is desirable to monitor the concentrations of certain components in the dialysis effluent discharged from the blood purifier.

One example of a component (referred to as a measured component) that may be desired to be monitored in dialysis effluent is albumin. Patent Document 1 discloses a method for measuring albumin concentration by optically exciting albumin in the fluid and measuring the resulting fluorescence.

Special Publication No. 2014-518517

However, fluorescence has a low light intensity, and measurement accuracy may decrease, especially when the concentration of the component being measured is low. For example, if the component being measured is albumin, this is a component that should not leak too much from the blood, so it is thought that the concentration of albumin would not normally be very high. For this reason, it is desirable to be able to measure the concentration of the component being measured accurately even when its concentration is low.

The present invention aims to provide a dialysis effluent component measuring device and method that can accurately measure the concentration of a target component in dialysis effluent.

A dialysis effluent component measuring device according to one embodiment of the present invention is a device for measuring the concentration of a metered component contained in dialysis effluent discharged from a blood purifier, wherein the metered component is a component that absorbs light of a first wavelength and is excited by light of the first wavelength to emit fluorescence at a second wavelength different from the first wavelength, and the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and is excited by light of the first wavelength to emit fluorescence at a third wavelength different from the first and second wavelengths, and the device includes a light source that irradiates the dialysis effluent with light of the first wavelength, and measures the light intensity of the transmitted light from the light source that has passed through the dialysis effluent, and determines the concentration of the metered component contained in the dialysis effluent discharged from a blood purifier. a first fluorescence measurement unit that measures the intensity of fluorescence at the second wavelength emitted by the analyte component upon excitation by light from the light source; a second fluorescence measurement unit that measures the intensity of fluorescence at the third wavelength emitted by the measurement-inhibiting component upon excitation by light from the light source; a ratio calculation unit that calculates the ratio of the concentration of the analyte component to the concentration of the measurement-inhibiting component contained in the dialysis effluent based on the measurement results of the first and second fluorescence measurement units; and a analyte component concentration calculation unit that calculates the concentration of the analyte component in the dialysis effluent based on the ratio of the concentrations calculated by the ratio calculation unit and the absorbance at the first wavelength measured by the absorbance measurement unit.

A dialysis effluent component measurement method according to one embodiment of the present invention is a method for measuring the concentration of a metered component contained in dialysis effluent discharged from a blood purifier, wherein the metered component is a component that absorbs light of a first wavelength and is excited by light of the first wavelength to emit fluorescence of a second wavelength different from the first wavelength, and the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and is excited by the first light to emit fluorescence of a third wavelength different from the first and second wavelengths, and the dialysis effluent is irradiated with light of the first wavelength from a light source, and the intensity of the transmitted light from the light source that has passed through the dialysis effluent is measured. The intensity of the fluorescence at the second wavelength emitted by the component to be measured upon excitation with light from the light source is measured, the intensity of the fluorescence at the third wavelength emitted by the component to be measured upon excitation with light from the light source is measured, and the ratio of the concentration of the component to be measured to the concentration of the component to be measured contained in the dialysis effluent is calculated based on the measurement results of the fluorescence at the second and third wavelengths, and the concentration of the component to be measured in the dialysis effluent is calculated based on the calculated concentration ratio and the measured absorbance at the first wavelength.

The present invention provides a dialysis effluent component measuring device and method that can accurately measure the concentration of a target component in dialysis effluent.

1 is a schematic diagram illustrating the configuration of a blood purification device using a dialysis effluent component measuring device according to one embodiment of the present invention. FIG. 1A is a diagram showing the absorption spectrum of the main filtered toxins contained in dialysis effluent, and FIG. 1B is a diagram showing the fluorescence spectrum thereof. 1 is a schematic diagram of a dialysis effluent component measuring device according to one embodiment of the present invention. FIG. FIG. 1 is a flow diagram of a method for measuring components in a dialysis effluent according to one embodiment of the present invention.

[Embodiment]
Hereinafter, an embodiment of the present invention will be described with reference to the accompanying drawings.

(blood purification device)
First, a blood purification apparatus using the dialysis effluent component measuring device according to the present embodiment will be described. Fig. 1 is a schematic diagram of a blood purification apparatus using the dialysis effluent component measuring device according to the present embodiment.

As shown in FIG. 1, the blood purification device 10 includes a blood circuit 11 for extracorporeally circulating the patient's blood, a liquid supply flow path 13 for supplying supply liquid to a blood purifier 12 provided in the blood circuit 11, and a drainage flow path 14 for discharging drainage liquid from the blood purifier 12. In the example of FIG. 1, the liquid supply flow path 13 is shown as a dialysate flow path 13a for supplying dialysate to the blood purifier 12. However, this is not limited to this, and the liquid supply flow path 13 may be a replenishment flow path that directly supplies replenishment liquid to the blood circuit 11, or may have both a dialysate flow path 13a and a replenishment flow path.

The blood circuit 11 is composed of, for example, flexible tubing. The blood circuit 11 is sequentially equipped with a blood pump 111, a blood purifier 12, and an air trap chamber 112, arranged from upstream to downstream in the blood flow. The blood pump 111 is a pump that pumps blood. The air trap chamber 112 is used to remove air bubbles from the blood.

Dialysis water is supplied to the dialysate flow path 13a from an RO device (not shown), which produces clean dialysis water using a reverse osmosis (RO) membrane. Two types of dialysis solution stock solutions, stock solution A and stock solution B, are also supplied to the dialysate flow path 13a. Both stock solutions are stored in stock solution storage tanks 151, and stock solution A and stock solution B are supplied from the stock solution storage tanks 151 to the dialysate flow path 13a via stock solution flow paths 152. Each stock solution flow path 152 is provided with a stock solution injection pump 153, which is a liquid delivery pump that delivers stock solution A or stock solution B. Dialysis water is prepared by mixing stock solution A and stock solution B with the dialysis water in the dialysate flow path 13a. The prepared dialysis solution is introduced into the blood purifier 12 via the duplex pump 16. However, the present invention is not limited to this, and may be configured to supply a prepared dialysis solution stock solution prepared by mixing stock solutions A and B. Alternatively, the mechanism for preparing dialysis solution from dialysis water and dialysis solution stock solution may be omitted, and dialysis solution may be supplied from an external source. In other words, the blood purification device 10 may be a personal dialysis device having a mechanism for preparing dialysis solution from dialysis water and dialysis solution stock solution, or a dialysis monitoring device supplied with dialysis solution from a multi-person dialysis solution supply device.

The dialysis effluent discharged from the blood purifier 12 is discharged through the drainage flow path 14. The duplex pump 16 is provided across the dialysate flow path 13a and the drainage flow path 14, and performs pumping operation so that the amount of dialysate introduced into the blood purifier 12 is equal to the amount of effluent discharged from the blood purifier 12. The drainage flow path 14 is also provided with a water removal flow path 14a that bypasses the duplex pump 16, and this water removal flow path 14a is provided with a water removal pump 17. When the water removal pump 17 is driven, the amount of effluent discharged from the blood purifier 12 becomes greater than the amount of dialysate introduced into the blood purifier 12, thereby removing water from the blood. The amount of water removed from the blood can be adjusted by adjusting the amount of fluid delivered by the water removal pump 17.

A dialysis effluent component measuring device 1 according to this embodiment is provided in the drainage flow path 14 of the blood purification device 10. The dialysis effluent component measuring device 1 is provided in the drainage flow path 14 downstream of the position where the water removal flow path 14a joins the drainage flow path 14. Note that the configuration in Figure 1 is merely an example, and the specific configuration of the blood purification device 10 can be modified as appropriate.

(Dialysis effluent component measuring device 1)
The dialysis effluent component measuring device 1 is a device that measures the concentration of a specific analyte component contained in the dialysis effluent discharged from the blood purifier 12. The analyte component is a component that absorbs light of a first wavelength and, upon being excited by light of the first wavelength, emits fluorescence of a second wavelength different from the first wavelength. In this embodiment, a case will be described in which the analyte component is albumin. That is, the dialysis effluent component measuring device 1 is a device that measures the concentration of albumin in the dialysis effluent, for example. When the analyte component is albumin, the first wavelength, which is the wavelength of the excitation light, is 250 nm or more and 330 nm or less, more preferably 275 nm or more and 285 nm or less. The second wavelength, which is the wavelength of the fluorescence emitted by albumin, is 300 nm or more and 400 nm or less.

However, the light intensity of fluorescent light is low, and it can be difficult to ensure sufficient detection accuracy, especially when the concentration of the component to be measured is low. In response to this, the inventors considered using absorbance. When using absorbance, transmitted light is measured, making it possible to measure with sufficient light intensity even when the concentration of the component to be measured is low. However, with absorbance alone, sufficient measurement accuracy may not be achieved due to the influence of other components in the dialysis effluent.

Figure 2(a) shows the absorption spectra of the main filtered toxins contained in dialysis effluent, and Figure 2(b) shows their fluorescence spectra. As shown in Figure 2(a), the absorption spectrum of the measured component, albumin, does not overlap with that of creatinine or urea, but does overlap with that of uric acid. Because uric acid absorbs light of the first wavelength (wavelength 250 nm or greater and 330 nm or less), it can be said that the concentration of the measured component, albumin, cannot be accurately measured simply by measuring the absorbance of light of the first wavelength due to the influence of uric acid.

On the other hand, as shown in Figure 2(b), the wavelength of fluorescence (second wavelength) due to albumin is different from the wavelength of fluorescence due to uric acid. Thus, the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and, upon being excited by light of the first wavelength, emits fluorescence of a third wavelength different from the first and second wavelengths. When the component to be measured is albumin, uric acid corresponds to the measurement-inhibiting component. In this case, the third wavelength, which is the wavelength of the fluorescence of uric acid, is 380 nm or more and 480 nm or less. Here, we will explain the case where the measurement-inhibiting component is uric acid as an example, but the measurement-inhibiting component may be any component that corresponds to the component to be measured and is not limited to uric acid. Furthermore, two or more measurement-inhibiting components may be contained in the dialysis effluent.

As such, when measuring the concentration of a component to be measured, if only fluorescence is used, there is a risk of measurement accuracy being reduced due to the low light intensity of the fluorescence, and if only absorbance is used, there is a risk of measurement accuracy being reduced due to the influence of components that inhibit measurement. Based on these findings, the inventors conducted extensive research and arrived at the present invention.

Figure 3 is a schematic diagram of a dialysis effluent component measuring device 1 according to this embodiment. As shown in Figure 3, the dialysis effluent component measuring device 1 mainly comprises a light source 2, an absorbance measurement unit 3, a first fluorescence measurement unit 4, a second fluorescence measurement unit 6, and a calculation unit 5. The light source 2 irradiates the dialysis effluent with light of a first wavelength capable of exciting albumin, the component to be measured. In this example, a light-emitting diode that irradiates ultraviolet light with a wavelength of 280 nm is used as the light source 2. In this embodiment, the light source 2 is pulse-driven so that light emission and non-emission are repeated at a predetermined cycle. This reduces power consumption and extends the life of the light-emitting diode used as the light source 2, and also makes it possible to suppress the effects of noise (the suppression of noise effects will be described later).

The drainage flow path 14 is provided with a thin, flat measuring section 14b that is formed to ensure that the flow path has a substantially uniform thickness. Here, the measuring section 14b is formed to have a substantially elliptical shape when viewed from the light source 2 side. The light source 2 is provided facing the center of the measuring section 14b in the thickness direction. The measuring section 14b is made of a material that transmits light of at least the first and second wavelengths (having sufficiently high transmittance for the first and second wavelengths). A lens 7 is provided between the light source 2 and the measuring section 14b. Light emitted from the light source 2 is focused by the lens 7 and enters the measuring section 14b. Here, the light from the light source 2 is converted by the lens 7 into parallel light that enters the measuring section 14b.

The absorbance measurement unit 3 measures the light intensity of transmitted light from the light source 2 that has passed through the dialysis effluent, and calculates the absorbance at the first wavelength from the light intensity of the transmitted light and the light intensity of the light source 2. The absorbance measurement unit 3 includes a transmitted light receiving element (PD) 31 that receives the transmitted light, and a lens 32 that focuses the transmitted light and directs it to the transmitted light receiving element 31. Furthermore, although not shown, the absorbance measurement unit 3 includes an absorbance calculation unit that calculates absorbance based on the light intensity of the transmitted light received by the transmitted light receiving element 31 and the light intensity of the light source 2. The absorbance calculation unit may be mounted on the calculation unit 5, for example, or on a control board or the like separate from the calculation unit 5, and is realized by an appropriate combination of calculation elements, memory, software, interfaces, etc. Regarding the light intensity of the light source 2, for example, a light source measurement unit for measuring the light intensity of the light source 2 may be provided, and the measurement results of the light source measurement unit may be used, or a preset value (previously measured light intensity of the light source 2) may be used.

The transmitted light receiving element 31 is preferably a photodiode that can detect even weak optical signals and has a fast response speed to incident light, and more preferably an avalanche photodiode. This allows it to capture changes in transmitted light over time and improves light receiving sensitivity due to its high multiplication factor even for small amounts of light. The transmitted light receiving element 31 is positioned opposite the light source 2, with the measuring unit 14b in between.

The lens 32 is disposed between the transmitted light receiving element 31 and the measurement unit 14b. Although not shown, the absorbance measurement unit 3 may be configured to direct the light focused by the lens 32 to the transmitted light receiving element 31 through a filter that blocks light of the second and third wavelengths and passes light of the first wavelength. In this case, the filter may be a bandpass filter that passes light of the emission wavelength of the light source 2, and is preferably configured to pass light with a wavelength of 250 nm to 330 nm, more preferably 275 nm to 285 nm. This makes it possible to remove fluorescence (and light that becomes noise) due to albumin and uric acid from the light focused by the lens 32, enabling more accurate measurements.

In addition, in this embodiment, the light source 2 is pulse-driven, repeatedly emitting and not emitting light at a predetermined cycle. The absorbance measurement unit 3 is preferably configured to measure the difference in the light intensity received when the light source 2 is emitting and not emitting light as the light intensity of transmitted light. By extracting only the light-receiving component at a predetermined cycle in the signal processing unit (arithmetic unit 5), the effects of noise can be suppressed, enabling more accurate measurements.

The first fluorescence measurement unit 4 measures the intensity of fluorescence emitted by albumin, the component to be measured, by measuring the intensity of fluorescence at a second wavelength emitted by albumin upon excitation by light from the light source 2. The first fluorescence measurement unit 4 includes a first fluorescence photodetector (PD) 41, a first filter 42, and a first lens 43 as a first light-guiding member that guides fluorescence generated in the dialysis effluent (i.e., generated in the measurement unit 14b) to the first fluorescence photodetector 41. The first filter 42 is disposed between the measurement unit 14b and the first fluorescence photodetector 41, and blocks light of the first wavelength (transmitted light and scattered light) and light of the third wavelength (fluorescence due to uric acid) from entering the first fluorescence photodetector 41, while allowing only light of the second wavelength due to the fluorescence of albumin to pass through. The first filter 42 may be a bandpass filter that passes light with a wavelength of 300 nm or more and 400 nm or less, the same as the second wavelength, and more preferably a bandpass filter that passes light with a wavelength in the wavelength range around 340 nm, the fluorescence wavelength of albumin (e.g., 330 nm or more and 350 nm or less). Because the light intensity of fluorescence is relatively low, in this embodiment, the light collected by the first lens 43 is received by the first fluorescence light receiving element 41. The first lens 43 is disposed between the measurement unit 14b and the first filter 42.

The second fluorescence measurement unit 6 measures the light intensity of fluorescence due to uric acid, a measurement-inhibiting component, and measures the light intensity of fluorescence at a third wavelength emitted by uric acid upon excitation by light from the light source 2. The second fluorescence measurement unit 6 includes a second fluorescence photodetector (PD) 61, a second filter 62, and a second lens 63 as a second light-guiding member that guides fluorescence generated in the dialysis effluent (i.e., generated in the measurement unit 14b) to the second fluorescence photodetector 61. The second filter 62 is disposed between the measurement unit 14b and the second fluorescence photodetector 61 and blocks light of the first wavelength (transmitted light and scattered light) and light of the second wavelength (fluorescence due to albumin) from entering the second fluorescence photodetector 61, allowing only light of the third wavelength due to the fluorescence of uric acid to pass through. The second filter 62 may be a bandpass filter that passes light with a wavelength of 380 nm or more and 480 nm or less, the same as the third wavelength, and more preferably a bandpass filter that passes light with a wavelength in the wavelength range around 430 nm, the fluorescent wavelength of uric acid (e.g., 420 nm or more and 440 nm or less). Because fluorescent light has a relatively low light intensity, in this embodiment, the light collected by the second lens 63 is received by the second fluorescent light receiving element 61. The second lens 63 is disposed between the measurement unit 14b and the second filter 62.

As with the transmitted light light receiving element 31 described above, the first fluorescent light receiving element 41 and the second fluorescent light receiving element 61 should preferably be photodiodes that can detect weak optical signals and have a fast response speed to incident light, and more preferably, avalanche photodiodes. This makes it possible to capture changes in the fluorescent light over time, and the high multiplication factor even for small amounts of light improves light receiving sensitivity.

In addition, in this embodiment, the light source 2 is pulse-driven, repeatedly emitting and not emitting light at a predetermined cycle, but the first fluorescence measurement unit 4 and second fluorescence measurement unit 6 can be configured to measure the difference in light intensity received when the light source 2 is emitting and not emitting light as the light intensity due to fluorescence. By extracting only the light-receiving component at a predetermined cycle in the signal processing unit (arithmetic device 5), the effects of noise can be suppressed, enabling more accurate measurements.

The calculation device 5 is equipped with a ratio calculation unit 51, a measured component concentration calculation unit 52, a measured component leakage amount calculation unit 53, an alarm unit 54, and a memory unit 55. The ratio calculation unit 51, the measured component concentration calculation unit 52, the measured component leakage amount calculation unit 53, and the alarm unit 54 are realized by appropriately combining calculation elements, memory, software, interfaces, storage devices such as hard disks, etc. The memory unit 55 is realized using a specified storage area in a memory or storage device such as a hard disk. The calculation device 5 may be, for example, a control device for the blood purification device 10.

The ratio calculation unit 51 calculates the ratio between the concentration of the measurement target component (here, albumin) contained in the dialysis effluent and the concentration of the measurement-inhibiting component (here, uric acid) based on the measurement results of the first fluorescence measurement unit 4 and the second fluorescence measurement unit 6. In other words, the ratio calculation unit 51 calculates the ratio between the concentrations of albumin and uric acid by comparing the light intensity of the fluorescence due to albumin with the light intensity of the fluorescence due to uric acid (for example, by calculating the ratio of the light intensities).

The analyte concentration calculation unit 52 calculates the concentration of the analyte (here, albumin) in the dialysis effluent based on the ratio of albumin to uric acid concentrations calculated by the ratio calculation unit 51 and the absorbance at the first wavelength measured by the absorbance measurement unit 3. The absorbance measured by the absorbance measurement unit 3 is affected by both albumin and uric acid (see Figure 2(a)). Therefore, by taking into account the ratio of albumin to uric acid concentrations, it is possible to calculate the albumin concentration while isolating only the effect of albumin.

The analyte leakage amount calculation unit 53 calculates the leakage amount of the analyte component since the start of treatment based on the concentration of the analyte component (here, albumin) calculated by the analyte concentration calculation unit 52 and the flow rate of the dialysis effluent. The flow rate of the dialysis effluent may be calculated from the drive amount of the duplex pump 16 and the ultrafiltration pump 17, or may be measured by installing a flow sensor in the drainage flow path 14.

More specifically, the measurement component leakage calculation unit 53 calculates the average albumin concentration for one minute, and multiplies this average albumin concentration by the flow rate of the dialysis effluent to calculate the albumin leakage per minute, which is stored in the memory unit 55 for each minute. The albumin leakage per minute stored in the memory unit 55 is then added together over the entire elapsed treatment time to calculate the leakage amount of the measurement component since the start of treatment.

The alarm unit 54 issues an alarm by appropriate means such as light, sound, or display when the albumin concentration calculated by the analyte concentration calculation unit 52 is equal to or greater than a preset threshold. In this embodiment, the alarm unit 54 also issues an alarm by appropriate means such as light, sound, or display when the amount of albumin leakage calculated by the analyte leakage amount calculation unit 53 is equal to or greater than a preset threshold.

(Method for measuring components in dialysis effluent)
4 is a flow diagram of the method for measuring components in a dialysis effluent according to the present embodiment. For example, the flow of FIG. 4 starts at the start of blood purification treatment.

As shown in FIG. 4, in this embodiment of the dialysis effluent component measurement method, first, in step S1, light of a first wavelength (here, 280 nm) is irradiated onto the dialysis effluent from the light source 2. In step S2, the transmitted light is received by the transmitted light receiving element 31 of the absorbance measurement unit 3, and the light intensity is measured to determine the absorbance at the first wavelength. Furthermore, the first fluorescent light receiving element 41 of the first fluorescent measurement unit 4 measures the light intensity of fluorescence at a second wavelength due to the component to be measured (here, albumin), and the second fluorescent light receiving element 61 of the second fluorescent measurement unit 6 measures the light intensity of fluorescence at a third wavelength due to a measurement-inhibiting component (here, uric acid).

Then, in step S3, the ratio calculation unit 51 calculates the ratio between the concentration of the measured component (here, albumin) contained in the dialysis effluent and the concentration of the measurement-inhibiting component (here, uric acid) based on the measurement results of the first and second fluorescence measurement units 4 and 6. In this embodiment, the ratio between the concentrations of albumin and uric acid is calculated by comparing the light intensity of the fluorescence at the second wavelength (340 nm) due to albumin with the light intensity of the fluorescence at the third wavelength (430 nm) due to uric acid.

Then, in step S4, the analyte concentration calculation unit 52 calculates the concentration of the analyte (here, albumin) in the dialysis effluent based on the ratio of the concentrations calculated in step S3 and the absorbance measured by the absorbance measurement unit 3 in step S2. The calculated albumin concentration is stored in the memory unit 55.

Then, in step S5, the alarm unit 54 determines whether the albumin concentration determined in step S4 is equal to or greater than a preset threshold. If step S5 returns YES (Y), an alarm is issued using light, sound, etc. in step S6, and the process proceeds to step S7. If step S5 returns NO (N), the process proceeds to step S7 without issuing an alarm.

In step S7, the measurement component leakage calculation unit 53 calculates the leakage amount of the measurement component since the start of treatment based on the albumin concentration determined in step S4 and the flow rate of the dialysis effluent. More specifically, as described above, the measurement component leakage calculation unit 53 calculates the average albumin concentration for one minute, and multiplies this average albumin concentration by the flow rate of the dialysis effluent to calculate the albumin leakage amount per minute, which is stored in the memory unit 55 for each minute. The albumin leakage amount per minute stored in the memory unit 55 is then added together over the entire elapsed treatment time to calculate the albumin leakage amount since the start of treatment.

Then, in step S8, the alarm unit 54 determines whether the amount of albumin leakage determined in step S7 is equal to or greater than a preset threshold. If step S8 returns YES (Y), an alarm is issued using light, sound, etc. in step S9, and the process proceeds to step S10. If step S8 returns NO (N), the process proceeds to step S10 without issuing an alarm.

In step S10, the calculation device 5 determines whether the treatment has ended. Whether the treatment has ended can be determined, for example, by a signal from the dialysis control device. If the determination in step S10 is NO (N), the process returns to step S1 and continues monitoring the albumin concentration in the dialysis effluent. If the determination in step S10 is YES (Y), the process ends.

(Functions and Effects of the Embodiments)
As described above, in the dialysis effluent component measuring device 1 according to this embodiment, the component to be measured is a component that absorbs light of a first wavelength and is excited by light of the first wavelength to emit fluorescence of a second wavelength different from the first wavelength, and the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and is excited by light of the first wavelength to emit fluorescence of a third wavelength different from the first and second wavelengths, and the device comprises a light source 2 that irradiates the dialysis effluent with light of the first wavelength, an absorbance measuring unit 3 that measures the light intensity of transmitted light from the light source 2 that has passed through the dialysis effluent and determines the absorbance at the first wavelength from the light intensity of the transmitted light and the light intensity of the light source 2, and a light source 4 that measures the light intensity of the transmitted light and the light intensity of the light source 2. The device is equipped with a first fluorescence measurement unit 4 that measures the light intensity of fluorescence at a second wavelength emitted by a measurement component excited by light from the light source 2; a second fluorescence measurement unit 6 that measures the light intensity of fluorescence at a third wavelength emitted by a measurement-inhibiting component excited by light from the light source 2; a ratio calculation unit 51 that calculates the ratio of the concentration of the measurement component to the concentration of the measurement-inhibiting component contained in the dialysis effluent based on the measurement results of the first and second fluorescence measurement units 4 and 6; and a measurement component concentration calculation unit 52 that calculates the concentration of the measurement component in the dialysis effluent based on the concentration ratio calculated by the ratio calculation unit 51 and the absorbance at the first wavelength measured by the absorbance measurement unit 3.

As a result, even when the concentration of the component to be measured is low and the intensity of the fluorescence is low, the concentration of the component to be measured can be measured based on the intensity of the transmitted light that ensures sufficient light intensity (more specifically, based on the absorbance calculated from the intensity of the transmitted light), thereby improving the accuracy of measuring the concentration of the component to be measured. Furthermore, by calculating the concentration ratio of the component to be measured and measurement-inhibiting components using fluorescence, which makes it easy to distinguish between them, and then taking this ratio into consideration, the concentration of the component to be measured can be calculated based on absorbance, eliminating the influence of measurement-inhibiting components and allowing for accurate measurement of the concentration of the component to be measured.

(Summary of the embodiment)
Next, the technical ideas grasped from the above-described embodiments will be described by using the reference numerals and the like in the embodiments. However, the reference numerals and the like in the following description do not limit the components in the claims to the members and the like specifically shown in the embodiments.

[1] An apparatus for measuring the concentration of a component to be measured contained in a dialysis effluent discharged from a blood purifier (12), wherein the component to be measured is a component that absorbs light of a first wavelength and, upon being excited by light of the first wavelength, emits fluorescence at a second wavelength different from the first wavelength; the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and, upon being excited by light of the first wavelength, emits fluorescence at a third wavelength different from the first and second wavelengths; the apparatus comprises: a light source (2) that irradiates the dialysis effluent with light of the first wavelength; an absorbance measurement unit (3) that measures the light intensity of the transmitted light from the light source (2) that has passed through the dialysis effluent and determines the absorbance at the first wavelength from the light intensity of the transmitted light and the light intensity of the light source; a first fluorescence measurement unit (4) that measures the light intensity of the fluorescence of the second wavelength emitted by the analyte component when excited by light from the light source (2); a second fluorescence measurement unit (6) that measures the light intensity of the fluorescence of the third wavelength emitted by the measurement-inhibiting component when excited by light from the light source (2); a ratio calculation unit (51) that calculates the ratio of the concentration of the analyte component to the concentration of the measurement-inhibiting component contained in the dialysis effluent based on the measurement results of the first and second fluorescence measurement units (4, 6); and a analyte component concentration calculation unit (52) that calculates the concentration of the analyte component in the dialysis effluent based on the concentration ratio calculated by the ratio calculation unit (51) and the absorbance at the first wavelength measured by the absorbance measurement unit (3).

[2] The dialysis effluent component measuring device (1) described in [1], wherein the component to be measured is albumin and the measurement-inhibiting component is uric acid.

[3] The dialysis effluent component measuring device (1) described in [2], wherein the first wavelength is 250 nm or more and 330 nm or less, the second wavelength is 300 nm or more and 400 nm or less, and the third wavelength is 380 nm or more and 480 nm or less.

[4] The dialysis effluent component measuring device (1) described in any one of [1] to [3], wherein the first fluorescence measurement unit (4) has a first fluorescence light receiving element (41) and a first filter (42) that blocks light of the first wavelength and the third wavelength from entering the first fluorescence light receiving element (41) and transmits light of the second wavelength, and the second fluorescence measurement unit (6) has a second fluorescence light receiving element (61) and a second filter (62) that blocks light of the first wavelength and the second wavelength from entering the second fluorescence light receiving element (61) and transmits light of the third wavelength.

[5] The dialysis effluent component measuring device (1) described in [4], wherein the first fluorescence measurement unit (4) has a first light-guiding member (43) that guides the fluorescence generated in the dialysis effluent to the first fluorescence light-receiving element (41), and the second fluorescence measurement unit (6) has a second light-guiding member (63) that guides the fluorescence generated in the dialysis effluent to the second fluorescence light-receiving element (61).

[6] The dialysis effluent component measuring device (1) described in any one of [1] to [5], wherein the light source (2) repeatedly emits and does not emit light at a predetermined cycle, the absorbance measuring unit (3) measures the difference in the intensity of light received when the light source emits and does not emit light as the light intensity of the transmitted light, and the first and second fluorescence measuring units (4, 6) measure the difference in the intensity of light received when the light source emits and does not emit light as the light intensity of the fluorescent light.

[7] A method for measuring the concentration of a component to be measured contained in a dialysis effluent discharged from a blood purifier (12), wherein the component to be measured is a component that absorbs light of a first wavelength and is excited by light of the first wavelength to emit fluorescence of a second wavelength different from the first wavelength, and the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and is excited by the first light to emit fluorescence of a third wavelength different from the first and second wavelengths, and wherein the dialysis effluent is irradiated with light of the first wavelength from a light source (2), the light intensity of the transmitted light from the light source (2) that has passed through the dialysis effluent is measured, and the light intensity of the transmitted light is compared with the light intensity of the previous measurement. A dialysis effluent component measurement method comprising: determining the absorbance at the first wavelength from the light intensity of the light source (2); measuring the light intensity of the fluorescence at the second wavelength emitted by the analyte component excited by the light from the light source (2); measuring the light intensity of the fluorescence at the third wavelength emitted by the measurement-inhibiting component excited by the light from the light source (2); calculating the ratio of the concentration of the analyte component to the concentration of the measurement-inhibiting component contained in the dialysis effluent based on the measurement results of the fluorescence at the second and third wavelengths; and calculating the concentration of the analyte component in the dialysis effluent based on the calculated concentration ratio and the measured absorbance at the first wavelength.

The above describes embodiments of the present invention, but the above-described embodiments do not limit the scope of the invention as claimed. It should also be noted that not all of the combinations of features described in the embodiments are necessarily essential to solving the problems of the invention. Furthermore, the present invention can be modified and implemented as appropriate within the scope of its spirit.

REFERENCE SIGNS LIST 1...dialysis effluent component measuring device 2...light source 3...absorbance measuring unit 31...transmitted light receiving element 4...first fluorescence measuring unit 41...first fluorescence receiving element 42...first filter 43...first lens (first light guiding member)
5...Calculation device 51...Ratio calculation section 52...Measured component concentration calculation section 53...Measured component leakage amount calculation section 54...Alarm section 6...Second fluorescence measurement section 61...Second fluorescence light receiving element 62...Second filter 63...Second lens (second light guiding member)
10...blood purification device 12...blood purifier

Claims (7)

An apparatus for measuring the concentration of a target component contained in dialysis wastewater discharged from a blood purifier,
the component to be measured is a component that absorbs light of a first wavelength and is excited by the light of the first wavelength to emit fluorescence of a second wavelength different from the first wavelength,
the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and is excited by light of the first wavelength to emit fluorescence of a third wavelength different from the first and second wavelengths;
a light source that irradiates the dialysis effluent with light of the first wavelength;
an absorbance measurement unit that measures the light intensity of transmitted light from the light source that has passed through the dialysis effluent, and calculates the absorbance at the first wavelength from the light intensity of the transmitted light and the light intensity of the light source;
a first fluorescence measurement unit that measures the light intensity of the fluorescence of the second wavelength emitted by the component to be measured upon excitation by the light from the light source;
a second fluorescence measurement unit that measures the light intensity of the fluorescence of the third wavelength emitted by the measurement-inhibiting component upon excitation by light from the light source;
a ratio calculation unit that calculates a ratio between the concentration of the measurement target component and the concentration of the measurement inhibiting component contained in the dialysis effluent based on the measurement results of the first and second fluorescence measurement units;
and a measurement component concentration calculation unit that calculates the concentration of the measurement component in the dialysis effluent based on the concentration ratio calculated by the ratio calculation unit and the absorbance at the first wavelength measured by the absorbance measurement unit.
Dialysis effluent component measuring device. the component to be measured is albumin,
The measurement-inhibiting component is uric acid.
The dialysis effluent component measuring device according to claim 1. the first wavelength is equal to or greater than 250 nm and equal to or less than 330 nm,
the second wavelength is 300 nm or more and 400 nm or less,
the third wavelength is 380 nm or more and 480 nm or less;
The dialysis effluent component measuring device according to claim 2. the first fluorescence measurement unit includes a first fluorescence light-receiving element and a first filter that blocks light of the first wavelength and the third wavelength from being incident on the first fluorescence light-receiving element and transmits light of the second wavelength;
the second fluorescence measurement unit includes a second fluorescence light-receiving element and a second filter that blocks light of the first wavelength and the second wavelength from being incident on the second fluorescence light-receiving element and transmits light of the third wavelength.
The dialysis effluent component measuring device according to any one of claims 1 to 3. the first fluorescence measurement unit has a first light guiding member that guides the fluorescence generated in the dialysis effluent to the first fluorescence light receiving element,
the second fluorescence measurement unit has a second light guiding member that guides the fluorescence generated in the dialysis effluent to the second fluorescence light receiving element.
The dialysis effluent component measuring device according to claim 4. the light source repeats light emission and non-light emission at a predetermined cycle;
the absorbance measurement unit measures a difference between the received light intensity when the light source emits light and when it does not emit light as the light intensity of the transmitted light;
The first and second fluorescence measurement units measure a difference in received light intensity between when the light source emits light and when it does not emit light as the light intensity due to the fluorescence.
The dialysis effluent component measuring device according to any one of claims 1 to 5. A method for measuring the concentration of a target component contained in a dialysis effluent discharged from a blood purifier using a dialysis effluent component measuring device , comprising:
the component to be measured is a component that absorbs light of a first wavelength and is excited by the light of the first wavelength to emit fluorescence of a second wavelength different from the first wavelength,
the dialysis effluent contains a measurement-inhibiting component that absorbs light of the first wavelength and is excited by the first light to emit fluorescence of a third wavelength different from the first and second wavelengths;
The device,
irradiating the dialysis effluent with light of the first wavelength from a light source;
measuring the intensity of light transmitted from the light source through the dialysis effluent, and calculating the absorbance at the first wavelength from the intensity of the transmitted light and the intensity of the light source;
measuring the light intensity of the fluorescence of the second wavelength emitted by the component to be measured upon excitation by the light from the light source;
measuring the light intensity of the fluorescence of the third wavelength emitted by the measurement-inhibiting component upon excitation by the light from the light source;
calculating a ratio of the concentration of the measurement target component contained in the dialysis effluent to the concentration of the measurement inhibiting component based on the measurement results of the fluorescence of the second and third wavelengths;
calculating a concentration of the measured component in the dialysis effluent based on the ratio of the calculated concentrations and the measured absorbance at the first wavelength;
Method for measuring components in dialysis effluent.