JPH0733986B2 - Blood biochemical substance continuous measuring device - Google Patents

Description

Description: TECHNICAL FIELD The present invention relates to a continuous blood biochemical substance measuring device for measuring a biochemical substance in blood while continuously collecting blood.

<Prior art> As a continuous biochemical substance measuring device in this type,
A glucose measuring device having the following configuration is known.

Blood is continuously collected while being diluted with a heparin solution by a double-tube catheter placed in a blood vessel and a blood collection pump connected thereto. The blood sample is mixed with the buffer solution, passes through the sensitive part of the glucose electrode, and is pumped to the drain bottle by another pump. The glucose concentration in the sample solution is detected by the glucose electrode. Further, a standard solution having a known glucose concentration is also measured by the glucose electrode, and the measurement system is calibrated.

<Problems to be solved by the invention> Since this device is used while collecting blood from a patient, it is necessary to minimize the occurrence of abnormalities that obstruct correct measurement, and to investigate the cause even if abnormalities occur. It is very important that the recovery procedure is easy. Conventional devices are deficient in this respect.

One of the typical abnormalities is a situation where the output level of the enzyme electrode (glucose electrode) is abnormally low. If this abnormality is analyzed, the substance to be measured (glucose) above a certain concentration
There are cases in which the sample liquid containing the element is passing through the electrode sensitive section but the electrode output level is abnormally low, and cases in which the sample solution passing through the electrode sensitive section has an abnormally low concentration of the substance to be measured.

In the former case, the electrode itself or the processing system of the electrode output is the cause of abnormality, and countermeasures such as replacement of the enzyme membrane and checking of circuit operation will be taken.

In the latter case, it may be considered that blood collection is not performed properly. For example, when the catheter is worn properly,
The patient may move after wearing the device, blood may not be collected rapidly, or the amount of blood collected may not reach the specified amount, the dilution rate of the sample solution may increase, and the concentration of the measured substance in the sample solution reaching the electrode may abnormally decrease. . Further, since the sample tube of the blood collection system is very thin, the blood sample coagulates and becomes clogged even though the anticoagulant is used, and the same as above occurs.

The latter abnormality is not a device abnormality but is caused by inadequate handling of the blood collection system, and the abnormality recovery procedure is also different from the former case.

In the above-mentioned conventional apparatus, an alarm is issued when the electrode output level is abnormally low in the calibration mode in which the standard solution is supplied to the electrode sensitive section. This abnormality diagnosis function is effective for finding the former abnormality, but is not useful for the latter abnormality that occurs in the blood sample measurement mode.

Therefore, the conventional device takes a very long time to detect an abnormality such as a blood sampling error or blood clogging, and is not easy to use in actual use.

The present invention has been made in view of the above-mentioned conventional problems, and an object thereof is to provide a blood biochemical continuous measurement device capable of promptly discovering an abnormality caused by a blood sampling error or blood clogging. To do.

<< Means for Solving Problems >> Accordingly, in the present invention, a blood collecting means for continuously collecting blood while mixing an anticoagulant, a sending means for diluting and sending the collected blood, and a diluting means. The blood collecting means or the flow means, which comprises a measuring means for continuously measuring the biochemical substance by continuous contact with the collected blood and a calibrating means for supplying a standard solution to the measuring means instead of the blood sample. A blood sensor for detecting whether or not the blood in the flow passage has a predetermined concentration or more is provided in the middle of the flow path of the blood sample in the sending means, and a display means for displaying the detection result of the blood sensor is provided.

<Operation> If the catheter is not properly attached or blood is clogged with a thin tube near the blood collection port, the blood concentration in the sample liquid flowing through the flow channel will suddenly decrease or become zero. Quickly detected by blood sensor.

<< Embodiment >> FIG. 1 shows an outline of a flow system of an embodiment of the present invention. In the figure, 11 is a catheter as a blood sampling port, 12 is a container of physiological saline containing heparin (hereinafter referred to as heparin saline) as an anticoagulant, 13 and 16 are blood sampling pumps, 14 is blood and heparin. Mixer with raw water,
These constitute blood collecting means, and a blood sensor 15 which is an essential part of the present invention is provided in the blood sample flow path of the blood collecting means. Correctly attach the catheter 11 to the patient and pump 1
By operating 3, 16 and 16 at a predetermined speed (flow rate), a predetermined flow rate of blood is sucked from the catheter 11 and a predetermined flow rate of heparin saline is suctioned from the container 12, and these are mixed in the mixer 14, Switching valve 18 through blood sensor 15
Sent to the side.

The switching valve 18 selectively guides the blood sample (blood diluted with heparin saline) and the standard solution in the container 17 to the pump 20 side by the blood collecting means. This pump 20 and another pump
Reference numeral 23 is a main part of the sending means, and the blood sample or the standard solution is diluted with a buffer solution, passed through the measuring means by the enzyme electrode 27, and discharged into a drain container (not shown).

22 is a container for buffer solution, 21 is a mixer for mixing the buffer solution and air bubbles from the open line 24 with a blood sample (or standard solution),
Reference numeral 25 is a mixing coil that promotes mixing of these, and 26 is a defoaming device that removes mixed air bubbles. A part of the solution passed through the defoamer 26 is sent to the sensitive part of the enzyme electrode 27, and the rest is discarded. The part consisting of 21, 25, 26, 27 is heated by a heating block 28.

The above-mentioned flow system is controlled by a microcomputer, and is normally in a measurement mode and a calibration mode with a relatively long constant period. In the measurement mode, the blood collecting means operates as described above, the blood sample passes through the enzyme electrode 27, and the concentration of the specific biochemical substance is detected. In the calibration mode, the switching valve 18 is switched to the container 17 side, the standard solution passes through the enzyme electrode 27, and the measurement system is calibrated with the detection value at this time.
In the calibration mode, the pump 16 is stopped and the pump 13 is driven at a low speed. Heparin saline is caused to flow into the catheter 11, the mixer 14, and the blood sensor 15 by the pump 13 to prevent coagulation of blood during non-blood sampling.

Next, the blood sensor 15, which is a main part of the present invention, will be described. An example of the structure of blood sensor 15 is shown in FIG.

In FIG. 2, 31 is a tube connected to the mixer 14, 32
Is a tube connected to the pump 16, and the blood sensor 15 is connected between them. The blood sensor 15 has a flat transparent tube 34 made of a transparent material (such as quartz) built in an opaque outer shell 33. This transparent tube 34 is a tube 3
In communication with 1, 32, a blood sample diluted with heparin saline is flowed through a transparent tube 34.

A light emitting device 35 and a light receiving device are provided outside the two opposite planes of the transparent tube 34.
36 is provided, and the light emitted from the light emitter 35 is a transparent tube.
It is positioned so that it crosses 34 and reaches the light receiver 36.
The wavelength of the light emitted from the light emitter 35 is preferably about 540 nm so that the amount of transmitted light greatly changes depending on the blood concentration. As the light emitter 35, for example, a combination of a halogen lamp and a filter is used, and as the light receiver 36, for example, a photodiode is used.

The light emitter 35 receives the output of the light emission drive circuit 37 and emits light, and the output of the light receiver 36 is input to the level discrimination circuit 39 via the amplifier circuit 38. The higher the blood concentration of the solution flowing in the transparent tube 34,
The amount of light reaching the light receiver 36 from the light emitter 35 decreases, and the amount of light received increases when the blood concentration is low. The level discrimination circuit 39 receives the amplified received light output and determines whether the blood concentration is equal to or higher than a predetermined value. The determination result is displayed on the display circuit 40.

<< Effects of the Invention >> As described in detail above, in the blood biochemical substance continuous measuring apparatus according to the present invention, whether or not blood is correctly collected, or the collected sample is correctly sent to the measuring means. Whether or not the sample has been collected is constantly checked by the blood sensor provided in the sample flow path, so even if a blood sampling error or clogging occurs, appropriate recovery measures can be taken immediately and smooth measurement can be performed. become.

[Brief description of drawings]

FIG. 1 is a block diagram showing an outline of a flow system of an apparatus according to an embodiment of the present invention, and FIG. 2 is a diagram showing a configuration example of a blood sensor in the apparatus. 11 …… Catheter, 12 …… Heparin saline container, 13 ……
Pump, 14 ... Mixer, 15 ... Blood sensor, 16 ... Pump, 17 ... Standard solution container, 18 ... Switching valve, 20 ... Pump,
21 ... Mixer, 22 ... Buffer container, 23 ... Pump, 24 ...
… Open line, 25 …… Mixing coil, 26 …… Deaerator, 27 …… Enzyme electrode, 28 …… Heating block, 3
1,32 …… Chuube, 33 …… Outer shell, 34 …… Transparent tube, 35…
… Light emitter, 36 …… light receiver.

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Satoshi Nakajima Satoshi Nakajima, No. 3 Nakamimon-cho, Hanazono, Ukyo-ku, Kyoto Prefecture, Japan Tateishi Life Science Laboratory Co., Ltd. (56) Reference JP-A-58-38856 (JP, A) Actual Kai 60-79145 (JP, U) Actual Kai 57-101981 (JP, U) Japanese Patent Sho 58-11018 (JP, B2)

Claims (1)

[Claims] 1. A blood collecting means for continuously collecting blood while mixing an anticoagulant, a sending means for diluting and sending the collected blood, and a continuous contact with the diluted blood. A measuring means for measuring a biochemical substance and a calibrating means for supplying a standard solution to the measuring means instead of the blood sample, wherein the blood collecting means or the sending means has a blood sample in the middle of the flow path. An apparatus for continuously measuring chemical substances in blood, comprising: a blood sensor for detecting whether or not blood in the flow channel has a predetermined concentration or more, and display means for displaying a detection result of the blood sensor.