JPH0889571A - Apparatus and method for monitoring turbidity of waste liquid of peritoneal dialysis - Google Patents

Abstract

PURPOSE: To qualitatively and quantitatively measure clouding by eliminating the influence of the clouding causes, exclusive of perotonisis and the coloration by urea, etc., and to prevent the occurrence of an erroneous alarm by these causes by measuring the clouded colors of the waste liquid of a peritoneal dialysis with scattered light. CONSTITUTION: The waste liquid of the peritoneal dialysis is usually discharged into a flexible bag 10 made of plastics, etc. This waste liquid bag 10 is provided with a recessed part 1 for fixing and positioning at least part thereof. A light source 2 of a light emitting element and at least two light receiving elements 4, 5 at different angles with its optical axis and, if necessary, a light receiving element 3 for detecting transmitted light existing on the optical axis of the light source of the light emitting element 2 are arranged on the inside surface of the recessed part 1. The space distribution of the scattered light intensity of the light past the waste liquid is varied by the size of the particles therein. The ways of the scattering thereof are measurable if the measurement is made at the different angle and, therefore, the measurement of the kinds and quantities of the particles is made possible.

Description

Detailed Description of the Invention

[0001]

[Industrial application] Peritoneal dialysis, especially continuous ambulatory peritoneal dialysis, continuous ambulatory dialysis
The present invention relates to a turbidity monitor system (monitoring device) for determining the presence or absence of peritonitis by detecting the cloudiness of drainage during ritoneal dialysis (CAPD).

[0002]

2. Description of the Related Art In CAPD, peritoneal perfusate is injected into the abdominal cavity,
After the injection, the plastic bag used for the injection is wrapped and placed in the abdomen, etc., the liquid is retained in the abdominal cavity for a relatively long time of 4 to 8 hours, and the peritoneum is circulated using the semipermeability of the peritoneum. This is a method of dialysis of existing blood or lymph, draining it after a predetermined time, replacing the bag, injecting new liquid again, and repeating this. This method is preferable because it does not limit the activity of patients and facilitates reintegration into society, but it is necessary to constantly monitor the complication of peritonitis.

[0003] CAPD effluent becomes cloudy when lipids and white blood cells are mixed. Generally, if leukocytes having a concentration of 100 cells / μl or more are present in the drainage, it is suspected that peritonitis has developed, so it is necessary to reliably judge the cloudiness of the drainage. At present, patients and the like visually check the presence or absence of white turbidity in the drained liquid after the end of CAPD, and if white turbidity should occur, go to a hospital for a detailed examination. However, since there are elderly people and persons whose visual acuity has deteriorated due to diabetes among patients undergoing CAPD, it is difficult to determine the cloudiness state, and the determination of quality is ambiguous.

[0004] White turbidity is not always caused by white blood cells, but it is also necessary to determine the cause of white turbidity because it is caused by the mixing of lipids such as triglyceride, but this determination is difficult for the patient himself. Japanese Patent Publication No. 4-25819 has been proposed as a device for monitoring peritonitis during peritoneal dialysis. This is a drainage tube from the peritoneum with a transmission type turbidity detector attached. As a general principle of liquid turbidity detection, a transmission type using light and a scattering type are described in the sensor handbook (Baifukan), and Japanese Patent Publication No. 4-25819 uses the transmission type principle. It was done.

[0005]

However, in this transmission type, the influence of the change in the transmitted light amount due to the coloring of the waste liquid with urea or the like and the influence of solutes, precipitates, and metabolites other than white blood cells on the cloudiness are avoided. False alarms are likely to occur because it is not possible. Therefore, even if white turbidity occurs, it is not always pathological. Therefore, there is a demand for an inspection apparatus that determines the cause of the cloudiness and reliably determines the necessity / unnecessity of treatment.

[0006]

The object of the present invention is to substitute for the eyes of the human and at the same time, whether the cause of the cloudiness is due to a pathological condition requiring treatment or not requiring immediate treatment. In order to surely determine whether or not the turbidity, a turbidity monitoring device using scattered light is provided.

The principle of the present invention is based on the fact that the distribution of the angle of light scattering depending on the particle size of the substance causing white turbidity changes depending on the particle size. Leukocytes, which are one of the causes of cloudiness and appear in CAPD drainage fluid when peritonitis occurs, have a diameter of around 20 μm, while TG, which is a lipid,
(Triglyceride) is as small as 0.2 μm. Therefore,
The difference in the distribution of scattered light intensity due to the difference in particle size due to the angle is detected, and the cause of the turbidity is specified by performing qualitative and quantitative measurement of the cloudiness.

That is, the present invention relates to peritoneal dialysis (CAPD).
A turbidity monitoring device for peritoneal dialysis effluent, characterized in that the turbidity of the effluent is measured by scattered light.

In particular, a device for monitoring the turbidity of the peritoneal dialysis (CAPD) drainage discharged into a flexible light-transmitting container after being stored in the abdominal cavity, wherein at least the drainage container is provided. A recess for fixing and positioning a part, and a light-emitting element fixed to the inner surface of the recess and having its surface in contact with the surface of the drainage container,
A turbidity monitoring device for peritoneal dialysis effluent characterized by comprising at least two light-receiving elements provided so as to receive light from the light-emitting element at different angles facing the optical axis of the light-emitting element.

Here, the light receiving element is further provided on the optical axis of the light emitting element, and the surfaces of the light emitting element and the light receiving element are convex surfaces, and the convex surface is the surface of the drainage container. It may be provided so as to be deformed into a concave surface and contact the container.

[0011] A method for monitoring the turbidity of the peritoneal dialysis (CAPD) drainage discharged after being stored in the abdominal cavity, wherein the drainage is exposed to a light beam, and the light beam is emitted according to the particle size of particles in the drainage liquid. Provided is a method for monitoring the turbidity of peritoneal dialysis effluent, which measures the degree of scatter and qualitatively and / or quantifies the turbidity of the effluent from the relationship of at least two measurements.

[0012]

By using the apparatus of the present invention, it is possible to qualitatively and quantitatively detect the causative substance of the cloudiness of the peritoneal dialysis effluent, and to discriminate the substance, and the occurrence of peritonitis during peritoneal dialysis (CAPD) can be reliably detected without any false alarm. You can do it. The present invention will be described in detail below with reference to the preferred embodiments shown in the drawings, but the present invention is not limited to these exemplifications.

[0013]

1 and 2 show a preferred embodiment of the present invention. Peritoneal dialysis (CAPD) drainage is typically drained into a flexible bag 10 (FIG. 2), such as plastic. However, the present invention may measure not only the drainage drained in such a flexible bag, but also the drainage drained in a container having a fixed shape. The drainage in the tube that connects to the bag may be measured. In such a case, the light emitting element and the light receiving element may be arranged so as to sandwich the drainage tube.

The flexible bag is usually made of polyvinyl chloride or polypropylene as a main material and has a thickness of 2 m.
A transparent bag of m or less is used. When the drainage is discharged into the flexible drainage bag 10, the recess 1 is provided to fix and position at least a part of the drainage bag 10. The recess 1 is usually a hemisphere having a radius of 5 to 50 mm. On the inner surface 11 of the recess 1, a light source which is the light emitting element 2 and at least two light receiving elements 4.5 are provided at different angles with respect to the optical axis thereof. One of the light receiving elements for detecting scattered light is arranged so that, for example, the angle is 20 degrees with respect to the optical axis and the other is 40 degrees. If necessary, the light receiving element 3 for detecting transmitted light may be arranged at a position opposite to the optical axis of the light source of the light emitting element 2.

Both the light emitting element and the light receiving element are preferably arranged so as to project from the inner surface of the base of the recess 1. When the light emitting element and the light receiving element are arranged in this way, the outer surface of the flexible bag 10 is dented by the convex portion of the surface of the element and dented, and the element and the back are in contact with each other so as not to cause an optical error. Because you can If a standard solution and a calibration curve are used, one light-receiving element may be provided on the opposite side to the optical axis of the light-emitting element at an angle different from the optical axis, but preferably at least two different angles. Once arranged, the influence of ambient light and other errors can be eliminated by performing arithmetic processing using a differential amplifier circuit, which will be described later. In this embodiment, the light receiving elements for detecting scattered light are arranged at 20 degrees and 40 degrees with respect to the optical axis.
It can be set arbitrarily according to the light amount. The different angles are preferably one place within the range of 5 to 30 degrees from the optical axis, 30 to 30
Place the second part within the range of 50 degrees. In the case of arranging in three places, it is preferable to arrange them on the optical axis or in the range of 20 to 40 degrees.

With such a structure, the light passing through the drainage liquid has a different spatial distribution of scattered light intensity depending on the size of the particles in the liquid, and when scattered light is measured at different angles, the scattering of the light will be different. It is possible to measure, and therefore the type and amount of particles in the drainage can be measured.

The light source of the light emitting element may be a visible light source or an ultraviolet light source, but an LED (light emitting diode) or a semiconductor laser can be used. Parallel light may be used, and it is better to reduce the spread of light rays by narrowing the light flux. As the light receiving element, a photoelectric tube, a photoconductive cell, a photodiode, a phototransistor, a photomultiplier or the like which converts these lights into electric signals corresponding to the light emitting element may be used.

FIG. 2 shows an enlarged view of a detection portion composed of a light emitting element, a transmitted light, and a light receiving element for detecting scattered light at two different angles. Here, the light emitting element is a semiconductor laser, the light receiving element is a photodiode or a phototransistor, and there are three locations on the optical axis (light receiving element 3), angle θ ₁ (light receiving element 4), and angle θ ₂ (light receiving element 5). Placed in. The principle is shown below. Although this is an example of arithmetic processing, any other known comparison arithmetic processing method may be used.

Intensity I _{s of} scattered light detected by the light receiving element 5
Is Ray's theoretical formula, I _s = I _OI · f (θ) {(aNV ² ) / (l ² λ ⁴ )} ・ ・ ・ 1) where a is a coefficient, N is a particle concentration, and V is a particle. Volume, l is the distance from the scattering point to the detector, λ is the measurement wavelength, and f (θ) is the intensity distribution function depending on the scattering angle. Further, considering the attenuation due to the light absorption / scattering by the material containing the drainage and the ambient light I _P , the intensity I _{s1 of the} scattered light detected by the light receiving element 4 is I _s1 = I _O e ^-at · f (θ ) {(ANV ² ) / (l ² λ ⁴ )} + I _P ... 2). Taking the difference between the light intensities at these two points assuming that the disturbance lights at the scattering angles θ ₁ and θ ₂ are almost the same, ΔI = I ₁ -I ₂ = I ₀ β ・ {(aNV ² ) / (l ² λ ⁴ )} {f (θ ₁ ) −f (θ ₂ )} = I ₀ β · {(a NV ² ) / (l ² λ ⁴ )} F (θ ₁ , θ ₂ ) ... 3) From this, By measuring the light intensity at two points with a fixed angle, it is possible to detect a difference in particle size, that is, a difference in volume V. Further, the transmitted light I detected by the light receiving element 3
_t is

Embedded image Where τ is the scattering coefficient and γ is the absorption coefficient ... 4). Therefore, from equations 3) and 4),

Embedded image Is obtained. Therefore, ΔI / I _t depends on the particle concentration N, and the particle volume V can be discriminated.

Although the transmitted light is used together with the scattered light in the above embodiment, a method of using only the scattered light may be used due to the influence of the backing material and the stability of the light source. FIG. 3 shows a block diagram of an example of the detection circuit. 1 of this detection circuit
In the example, the influence of the ambient light is removed by amplifying the output voltage of the light receiving elements arranged at different angles by using the differential amplifier circuit. Further, when the value obtained by dividing the differential output voltage by the output voltage of the transmitted light in the arithmetic circuit exceeds a preset threshold value, an alarm is issued. This circuit is an example, and other methods such as taking in the output voltage of each light receiving element for calculation can be used.

[Angle Dependence of Drainage Scattering Intensity] (Experiment 1) Using the apparatus shown in FIG.
The angle dependence of the scattered light intensity of the actual drainage (real drainage) after peritoneal dialysis in which white blood cells were turbid was measured at 0, 485 and 242 cells / ul. The drainage was measured by putting it in a transparent bag made of polyvinyl chloride resin having a thickness of 0.3 mm. Radius 30
mm hemisphere, the light-emitting element is arranged so that the light path passes through the diameter of the hemisphere, and the light-receiving element is 20, 30, 4 from the light path.
It was arranged at each position of 0, 50, 70, 90 °. Laser light with a wavelength of 640 nm was output from the light emitting element, and a lens was used to focus on the center of the sphere. A phototransistor (difference between measurement angles, Δθ = ± 10 °) was used for light reception. The angle from the optical axis of each light receiving position is plotted on the horizontal axis, and the output voltage received is plotted on the vertical axis, and the results are shown in FIG. From the result of FIG. 4, the output voltage changed significantly depending on the white blood cell concentration at the angle of 20 °, but the concentration dependency of the output voltage decreased as the angle approached 90 °.

(Experiment 2) Using the apparatus shown in FIG. 1, the angle dependence of the scattered light intensity of normal drainage, triglyceride turbidity, and triglyceride strong turbidity after peritoneal dialysis was measured in the same manner as in Experiment 1. did. The results are shown in Fig. 5. From the result of FIG. 5, the scattered light intensity of the normal drainage slightly depends on the angle at 20 to 40 °, but does not depend on the angle at 40 ° or more. On the other hand, when TG becomes turbid, angle dependence of scattered light intensity was observed over all angles, and it was found that the higher the turbidity of TG, the higher the output voltage, and the angular dependence of scattered light intensity of white blood cells and triglyceride. You can see that is different.

[0023]

Industrial Applicability According to the present invention, it becomes possible to qualitatively and quantitatively measure white turbidity by removing the influence of white turbidity due to causes other than peritonitis of CAPD drainage and coloring due to urea, etc. It is possible to monitor the turbidity of the peritoneal dialysis effluent by eliminating it.

[Brief description of drawings]

FIG. 1 is a perspective view illustrating a turbidity monitoring device for peritoneal dialysis effluent according to the present invention.

FIG. 2 is an enlarged sectional view of an essential part for explaining the turbidity monitoring device for peritoneal dialysis effluent according to the present invention.

FIG. 3 is a block diagram of the detection circuit side of the turbidity monitoring device for peritoneal dialysis effluent of the present invention.

FIG. 4 is a graph showing the angle dependence of the intensity of the actual scattered light scattered light.

FIG. 5 is a graph showing the scattered light intensity angle dependence of a TG (triglyceride) turbid solution.

[Explanation of symbols]

 1 recessed portion 2 light emitting element 3 light receiving element 4 light receiving element 5 light receiving element 6 light emitting element surface 7 light receiving element surface 9 drainage 10 drainage bag 11 recessed inner surface

Claims (5)

[Claims] 1. A turbidity monitoring device for peritoneal dialysis effluent, characterized by measuring the turbidity of the peritoneal dialysis (CAPD) effluent by scattered light. 2. A device for monitoring the turbidity of the peritoneal dialysis (CAPD) drainage discharged into a flexible light-permeable container after being stored in the abdominal cavity, the device comprising: A recess for fixing and positioning at least a part, a light-emitting element fixed to the inner surface of the recess and having its surface in contact with the surface of the drainage container, and a light-emitting element facing the optical axis of the light-emitting element at different angles. A turbidity monitoring device for peritoneal dialysis effluent, comprising at least two light-receiving elements provided to receive light. 3. The turbidity monitoring device for peritoneal dialysis effluent according to claim 2, wherein the light receiving element is further provided on the optical axis of the light emitting element. 4. The peritoneal dialysis according to claim 1, wherein the light emitting element and the light receiving element have convex surfaces, and the convex surfaces are provided so as to deform the surface of the drainage container into a concave surface and contact the container. Effluent turbidity monitoring device. 5. Peritoneal dialysis (CA) discharged after being stored in the abdominal cavity
PD) is a method for monitoring the turbidity of the drainage liquid, irradiating the drainage liquid with a light beam, measuring the degree of scattering of the light beam due to the particle size of the particles in the drainage liquid, and comparing the measured values at at least two locations. A method of qualifying and / or quantifying effluent turbidity, a method for monitoring effluent turbidity of peritoneal dialysis.