JPS5896234A - Method and apparatus for leaked blood - Google Patents

Abstract

PURPOSE:To achieve an accurate detection of blood leaked in a sample liquid regardless of the concentration thereof by continuously measuring transmission lights and scattering lights of a convergence light with a specified wavelength together. CONSTITUTION:A leaked blood detector I is provided wih a shield plate 2 having a ring-shaped slip 9 facing a light source 1 vertical to the optical axis. In the order of advancing light, it is also equipped with a convergence lens 3, a measusing cell 4 to be fed with a sample liquid from a sample liquid feed tube at the focal length of the convergence lens 3, a projection plate 5 having a through hole 10 at the center, a condenser lens 6 and a photodetector 8 at the focal length of the condenser lens 6. A photodetector 7 is also provided at the proper position of the projection plate 5. Detection signals from the photodetectors 7 and 8 are amplified with an amplifier 12 and then, compared with set signals from a level setting circuit 17 by means of a comparator circuit 13 which provides an warning generation signal to an alarm 14 when the detection signals of the transmission light are smaller than the corresponding set signals or the detection signals of scattering light are larger than the corresponding set signals. The comparator circuit 13 sents the results of the comparison concerning these signals continuously to an indicator 15 and they are recorded on a recorder 16.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to a blood leakage detection method and apparatus for detecting blood leakage that occurs particularly when blood is circulated outside the body for treatment such as hemodialysis, blood plasma separation, etc. More specifically, the present invention irradiates a sample liquid with convergent light of a specific wavelength and monitors the transmitted light and scattered light together, thereby detecting blood leakage in the sample liquid depending on the concentration. The purpose of the present invention is to provide a method for detecting blood leakage that can accurately detect blood leakage, and an apparatus for specifically implementing this method.

First, if we explain the example of blood detection using artificial kidney treatment,
Blood taken from the human body passes through a semi-permeable membrane to remove waste matter and is returned to the human body, but since the treatment takes quite a long time, even small amounts of blood may leak into the waste reservoir. The end result is a significant amount of blood loss, which is dangerous. Therefore, the waste must be separated, that is, in the dialysate for dialysis, or in the F solution for filtration (hereinafter collectively referred to as "in liquid").
If blood leaks, it is necessary to thoroughly detect the blood and take measures such as discontinuing treatment.

In response to this demand, several blood leakage detection methods have been proposed. One is a method that takes advantage of the fact that the light transmittance of the liquid decreases due to the presence of blood in the wave body, but this method is based on the fact that the decrease in light transmittance is due to reasons other than blood contamination, such as This is not practical because it can also be caused by air bubbles, etc. This is because the light is scattered or absorbed by air bubbles, etc. and the apparent transmittance decreases, making it impossible to distinguish whether the decrease in transmittance is due to blood contamination or air bubbles, etc., which reduces reliability. That's why it's missing. Another method is to use light in two wavelength ranges (usually red and fringe) that have different absorption rates for blood (particularly hemoglobin in blood). In other words, it can be assumed that the decrease in transmittance due to causes other than blood is approximately the same for light in these two wavelength ranges, so the decrease in transmittance due to causes other than blood can be offset, and therefore the decrease in transmittance due to blood This method detects only the decline. However, this method is susceptible to changes due to the voltage of the light source, changes over time, and changes in the light-receiving element in order to obtain sufficient reliability. It had the disadvantage of requiring Furthermore, this method has the disadvantage that there is almost no difference in the absorption rate of light in the two wavelength ranges in normal blood that has not undergone hemolysis, and that it is unstable when it comes to low-concentration blood leakage. Ta. In addition, for drugs that have an absorption band in a short wavelength range mixed into a liquid, the light in the short wavelength range of the above two wavelength ranges is absorbed, and even if the effect of air bubbles can be distinguished, it is possible to distinguish between the effects of blood and the drug. The drawback was that it was difficult to distinguish between

The present invention was developed in view of these circumstances, and its specific configuration is to continuously supply a sample liquid to a measurement cell, irradiate a light shielding plate with a slit with a light beam in the wavelength range of 400 to 900 nm, The slit light beam that has passed through the slit is converged by a converging lens into a measurement cell through which the sample liquid passes, and the intensity of transmitted light and the intensity of scattered light of the slit light beam that has passed through the measurement cell are recorded on a daily basis. This blood leakage detection method is characterized in that blood leakage in a sample liquid is detected by
A light source unit that emits light within the range of 0 nm, a light shielding plate with a slit, a measurement cell through which the supplied sample liquid passes and is equipped with means for removing bubbles in the sample liquid, and a measurement cell that measures the light beam that passes through the slit in the light shielding plate. Continuously compares the convergent lens that converges into the cell, the detector for transmitted light that has passed through the measurement cell, the detector for scattered light, and the detection signals from both of these detectors and each preset signal. The present invention is a blood detection device characterized by comprising a blood leak notification means for issuing an alarm or displaying a blood leakage notification means.

In other words, the blood leakage detection method of the present invention accurately detects blood leakage in a sample wave body without being affected by the concentration by performing continuous measurements of transmitted light and scattered light of a specific wavelength convergent light. can.

In other words, according to the present invention, the output voltage of transmitted light with respect to the blood leakage concentration in the limb shows a large change in areas where the blood leakage concentration is large, whereas there is almost no change in the output voltage in areas where the blood leakage concentration is low and it is difficult to detect the concentration. On the other hand, the output voltage of the scattered light shows a large change when the blood leakage concentration is small, but there is almost no change or an inverse change when the blood leakage concentration is large; in other words, at each concentration, If the transmitted light and the scattered light are continuously measured by taking advantage of the large change in output voltage of either light, blood leakage can be detected accurately regardless of the magnitude of the blood leakage concentration.

Next, the blood leakage detection device of the present invention enables the continuous measurement of the transmitted light and the scattered light by a specific means of continuously comparing the detection signals of both lights with each preset setting signal. It is.

In particular, according to the method and device of the present invention, it is possible to accurately detect blood leakage even if there is a slight leakage of blood in the sample liquid or a large amount of blood leakage. This has the effect that even if it is included, it will not be affected by it.

Normally, sample liquids often contain air bubbles, which often pose an obstacle when measuring transmitted light and scattered light. The device of the present invention is equipped with means for removing such bubbles.

The method and device of the present invention can be used in hemodialysis, hemofiltration, plasma separation, etc., and are particularly effective in detecting blood leakage from artificial kidneys. Note that these devices that come into contact with blood are discarded in order to prevent slow staining, but in the device of the present invention, the sample liquid conduit, measurement cell, and flow rate measurement that constitute the sample liquid supply section are The pot and these connecting pipes are made into a unit,
It can be manufactured separately from other device parts (filtration unit, optical system, control system unit, etc.). Accordingly, from my perspective, the present invention aims to separately provide a unit including a disposable visceral cell and a unit including an optical system and a 11111111 system.

The light beam used in the present invention has a wavelength of 400~
900 am is used. Among these, near-infrared,
In particular, a light beam with a wavelength of 776 nm is desirable. As a light source for these light beams, it is desirable to use a light emitting diode, which has a quick response, is small in size, and has a long latency.

The adjustment cell used in the present invention is made of a transparent material so that the sample liquid supplied by the sample liquid supply section can receive light irradiation while passing through the cell. Of course, it is necessary to have a configuration that does not cause leakage of light rays from the outside. In addition, as mentioned above, it is desirable that this measurement cell is equipped with a bubble removing means, and specifically, as in the embodiment, the bubble removing means is attached to the main ascending path and the air bubble removing channel that detours smoothly to the side of the main ascending path. It is desirable that the measurement cell flow path is formed by the measurement cell flow path. Further, the main upward passage may be replaced with a main horizontal passage or a main inclined passage, and a bubble removal passage that smoothly detours downward (9) may be provided in these passages. Alternatively, a mesh may be interposed between the main channel and the detour channel, if necessary, to prevent air bubbles from flowing into the detour channel through which the light beam passes.

By the way, the above-mentioned sample liquid supply section is specifically composed of, for example, a simple pipe line, but this electric line is connected to the second side of a circulating blood vessel such as an artificial kidney. Normally, on the discharge side of the adjustment cell, the above-mentioned pot for collecting blood pressure gauges is interposed in the discharge pipe, so that a replacement fluid corresponding to the flow rate can be separately supplied to the circulating blood.

Below, specific examples of the blood leakage detection method and device of the present invention will be explained based on the drawings.

FIG. 111 is an explanatory diagram of a blood leakage detection device used to implement the method and device of the present invention. First, the blood leakage detection device (
1) is a ring-shaped slit (9) facing the light m (1).
A light-shielding plate (2) is provided perpendicularly to the optical axis, and a converging lens (3) and a sample liquid supply pipe ( A measurement cell (4) that receives a sample wave body from the center, a projection plate (5) with a through hole in the center, a condenser lens (6), and a light receiving device at a position at the focal length of the condenser lens (6). II (Shun is provided.Furthermore, a light receiver (7) is placed at an appropriate position on the projection plate (5).
is the provision. And each detection signal obtained by the photoreceiver (7 bar 8) is amplified! It is amplified in 1 (b) and then compared with each setting signal from the level setting circuit side in 1 (b) and compared with each setting signal from the level setting circuit side, and it is determined whether the detected signal of transmitted light is smaller than the corresponding setting signal or the detected signal of scattered light corresponds. When the signal becomes larger than the set signal, the comparator circuit issues an alarm signal to the alarm (b). In addition, the comparison circuit displays the comparison results of the above-mentioned signals every moment on the display (
The display will be recorded on the recorder.

FIG. 2 shows the specific configuration of the measurement cell. This measuring cell (
4) consists of a main ascending path for the sample liquid and a detour side path.
This detour is constructed by bulging out in an arc shape from the main ascending passage, and the liquid enters from the entrance of the main ascending passage, fills the detour, and exits from the exit, but no liquid gets mixed into the liquid. The bubbles rise almost straight up the main ascending path from the inlet to the outlet, and there are almost no bubbles in the passage of the slit light.

Therefore, the light passing through the above-mentioned passage *5- is not affected by the air bubbles but is affected only by the blood. In addition, - is the main ascending road - and the detour side M! By installing a net as necessary to partition the area from @4, it is possible to more reliably prevent air bubbles from entering the detour side road.

Blood detection is performed in the following manner using the IIi blood sample ratio detection device configured as described above in the hypermorphic artificial kidney. .

First, the light having a predetermined wavelength emitted from the light source (1) is blocked by a light shielding plate (2), and the light that has passed through the slit (9) is fed into a continuous line through a converging lens (3) through a supply pipe. The dialysate of the artificial kidney to be treated is focused in a measuring cell (4) through which it passes. If there is no blood mixed in the liquid flowing in the direction of the arrow (6) in the measurement cell (4), the measurement cell (4)
It passes through the inside and creates an image of the slit (9) on the projection plate (5). The light receiving device is installed at the position where the above image can be seen on the projection plate (5)! The amount of transmitted light is measured based on (7).

On the other hand, when blood is mixed into the liquid, the blood causes scattering and the light is divided into transmitted light (A2) and scattered light (B1). Of the scattered light (B1), the scattered light (B2) that has passed through the through hole (2) is collected by a condenser lens (@) and its light amount is measured based on a light receiver (8).

Here, the output (signal) is based on blood concentration and scattered light and transmitted light.
The relationship with voltage is shown in FIG. That is, the scattered light (output voltage) is generated when the blood concentration is O~8000PP.
It increases as the blood concentration increases up to M11 degrees, but levels off when the blood concentration exceeds 8000 P or PM.
In the end, it decreases (not shown). Therefore, when detecting blood leakage using only scattered light, it is impossible to distinguish between a large amount of blood leakage and a very small amount of blood leakage. On the other hand, the transmitted light has an almost proportional relationship when the blood concentration is 1600 PPM or higher. Here, the blood leakage concentration limit is 80 PPM.
Then, the set output voltage of scattered light Xc = 18.45
(Ma), and if this value is stored in the level setting circuit @, the Xc between the measured output voltage of the scattered light and the comparison circuit (to)
If the measured output voltage is equal to or higher than Xc of B, an alarm is issued by the alarm α→. Furthermore, the set output voltage of the transmitted light is Yc corresponding to the blood leakage concentration of 2000 PPM.
=20.44! Level setting circuit Q using (ma) as the set value
2), the measured output voltage of transmitted light and this Yc
are compared in the same comparison circuit, and if the measured output voltage is less than this Yc, a large amount of blood has leaked, and an alarm 11M is issued. In this way, it is possible to accurately detect blood leakage directly regardless of its concentration (blood concentration 1600~
2000 PPM can be detected accurately in duplicate).

Incidentally, the above-mentioned constant output voltage values of both membranes can be changed as appropriate.

Further, unlike the above example, the projection plate may be a transparent (glass) plate, but in that case, almost all of the scattered light that hits the condenser lens is condensed onto the light receiver. Of course, instead of the condensing lens (6) in FIG. 1, a scattered light receiver may be installed at that position.

The measuring cell can also be set horizontally for liquid flow, unlike in FIGS. 1-2. In this case, the measurement cell consists of a main horizontal path corresponding to the main ascending path, and a detour side path that detours downward from the main horizontal path so that almost no air bubbles enter. Of course, the light convergence section is set within the detour. By the way, the sl constant cell (4) in Fig. 1 is manufactured as one unit, with the inlet side connected to the sample liquid supply pipe, and the -force ratio port side connected to the PM flow rate measuring pot 4 through a pipe line. Ru. @■ is a connecting column at both ends. In addition, the measurement cell (4) can be detachably attached to the case (foundation) that is equipped with the optical system and control system 22 HE of this device (I), and when the attachment door is closed, the limit switch 4 is activated. The automatic operation of the control system and optical system becomes an OJ function. On the other hand, the limit switch (2
) is not operating, manual operation is possible. Of course, when the V-filtration of the artificial kidney is completed, the unit containing the measuring cell (4) and the filter (tg, 19) are discarded. If the artificial kidney is not a filtration type but a dialysis type, the dialyzers (18a, 19a) shown in Fig. 2 are used.

[Brief explanation of the drawing]

Fig. 1 is an explanatory diagram showing one embodiment of the blood leakage detection device of the present invention, Fig. 112 is a partial explanatory diagram showing another embodiment, and Fig. 118 (a) is an enlarged view of the adjustment cell in Fig. 1. Cross-sectional view, (b
) is a 2-2B box diagram of (a), and FIG. 4 is a graph showing blood concentration versus light output. (1)...light source, light source, light shielding plate, (3
)...Convergent lens, 0)...Measuring cell, (7c~...-Receiver, (B)...Comparison circuit, -...
Alarm, (to)...Display, Ring...Level setting - path, ■...Sample liquid supply pipe. Figure 3 (Zhang) (b)

Claims (1)

[Claims] 1. Continuously supply the sample liquid to the measurement cell, and
A light beam within the range of ~90 G am is emitted through a light shielding plate having a slit, and the slit beam that has passed through the slit is converged by a converging lens onto a measurement cell circle through which the sample liquid passes, and the slit that has passed through the measurement cell is converged by a converging lens. Blood leakage detection method 1 characterized in that a single blood in a sample liquid is detected by simultaneously and constantly measuring the intensity of transmitted light and the intensity of scattered light of a light beam. The method described in Scope No. 1. 8. The method according to claim 2, wherein the wavelength of the near-infrared rays is 776 nm. L. The method according to any one of claims s1 to 8, wherein the sample liquid is a dialysate or F solution in an artificial kidney. 5. Sample liquid supply unit, light IIT* that emits light within the wavelength range of 400 to 900 nm, light shielding plate with slits,
A measurement cell through which the supplied sample wave body passes and is equipped with means for removing bubbles in the sample liquid, a converging lens that converges the light beam that has passed through the slit of the light shielding plate into the measurement cell, and a convergence lens that focuses the light beam that has passed through the measurement cell. The present invention is characterized by comprising a detection section, a scattered light detection section, and a blood leak notification means that continuously compares the detection signals from both of these detection sections and each preset setting signal and issues an alarm or display. Blood leak detection device. 6. The measurement cell equipped with a means for removing air bubbles in the sample liquid is composed of a main path for the sample liquid and a detour flow path for removing air bubbles that detours smoothly below or to the side of this main path, and this Claim I in which the light beam passing through the slit is set to pass only through the detour flow path! Apparatus according to paragraph I6. 7. Claim 5, wherein the light source section is a light emitting diode
The apparatus according to paragraph 6 or paragraph 6.