JPS58102164A - Blood collecting method for blood continuous analyzer - Google Patents

Abstract

PURPOSE:To obtain an appropriate amount of a blood collected with which a patient is prevented from being burdened and to prevent coagulation of a blood at a non-blood collecting time, by a method wherein a blood collection is intermittently performed without interrupting the flow of a dilute solution in a cannula. CONSTITUTION:A dilute solution is fed to a cannula 1 from a dilute solution receptacle 7 by a feed pump 6. The dilute solution or a mixture liquid of the dilute solution and a blood is sucked to a measuring part by a suction pump. A controller 9 controls the feed pump 6 and a suction pump 8 so that a blood collection is intermittently without interrupting the flow of the dilute solution in the cannula 1.

Description

DETAILED DESCRIPTION OF THE INVENTION The present invention relates to an am method of an apparatus for continuously measuring substances directly in the air. A device has been developed and has been put into clinical use that continuously monitors substances in the blood from a cannula punctured into a peripheral vein of a patient, using the collected blood as a sample. The general configuration of the *m section of those devices is shown in Figure 181. Double lumen cannula punctured and indwelled in the patient's peripheral vein/Volume of diluent containing anticoagulant II7, Feeding pump for feeding the diluent to the cannula ≦1 Diluent from inside the cannula I Alternatively, it consists of a suction pump 11 which sucks a mixed liquid of diluted liquid and blood directly into a measurement system 10 for measuring the concentration of a substance; and a control device for both pumps.

The double lumen cannula has an outer barrel and two small diameter tubes 3.
It consists of a stopper j that fixes the small-diameter tube and inserts it into the cannula. The S diameter tube is a flow path 111 through which the diluent flows from the container 7 into the outer cylinder by the feed pump 6.
! The tube 3 is a flow path through which a diluted liquid or a mixed liquid of a diluted liquid and blood is sucked from the tip of the outer cylinder using a suction pump and flows out to the measuring section 10 .

The diluent contains an anticoagulant to prevent blood taken out of the body from coagulating. As anticoagulants, heparin, urokinase, streptokinase, AOD solution, etc. are used.

In the conventional blood continuous analyzer configured in this way, when collecting the blood, a diluent containing an anticoagulant is continuously sent to the double lumen cannula, and the blood is not serially diluted. **do.

Specifically, by setting the suction amount of suction pump j to be greater than the amount of diluted liquid fed by feed pump B, a trace amount equivalent to the amount obtained by subtracting the amount of diluted liquid transported from the suction amount is Blood can be drawn continuously.

! Although it depends on the required sample amount of the physical quantity measurement unit, that is, the measurement range of the sensor, in general, /, j d /
It is hr.

The following points can be cited as problems with the conventional blood continuous analyzer. ■A large amount of blood is collected. If the device is used continuously for 7 days, the amount of blood collected will be about 3 tons to 72 tons, which will be a heavy burden on patients whose condition has worsened. 0
Since the whole sample is used as a sample, if the measurement is carried out for a long time, the sump circuit tube, measuring part Senna, etc. will become dirty due to adhesion of self-balls and proteins, reducing the measurement accuracy.

The inventor has arrived at the present invention as a result of intensive research aimed at solving the blood sampling problems of conventional blood continuous analyzers.

SUMMARY OF THE INVENTION Accordingly, it is a general object of the present invention to provide a blood sampling method for a continuous blood analyzer that reduces the amount of blood sampled, reduces system contamination, and the like.

Further, the main object of the present invention is to provide a double lumen cannula, a diluent container, a feeding pump for feeding the diluent to the cannula, and a suction of the diluent or a mixture of the diluent and blood from within the cannula to the measuring section. In the automatic tIl collection method of a blood continuous analyzer consisting of a suction pump, a control device for both pumps, and a measuring section, blood collection is performed intermittently without interrupting the flow of the diluent in the cannula. The purpose is to provide a blood sampling method.

In the blood sampling method described above, it is preferable to perform blood sampling intermittently without interrupting the flow of the diluent in the cannula by appropriately changing the ratio of the feeding volume of the transport pump to the suction volume of the suction pump. It is.

Adjustment of the flow rate of the suction pump and feeding pump can be done manually as appropriate, but blood sampling and non-Il! It is also possible to automatically perform intermittent blood sampling by using a control device that can repeat the cycle at regular time intervals.

When collecting blood, as in the conventional blood sampling method, by setting the suction volume of the suction pump to be slightly larger than the transport volume of the diluent, it is possible to collect blood in an amount equal to the amount obtained by subtracting the supply volume of the diluent from the suction volume. On the other hand, II! When stopping the pump, set the feeding amount of the feed pump and the suction amount of the suction pump to be the same amount, or set the diluent feeding amount to be slightly larger than the suction amount.
No blood is aspirated from the tip of the cannula; only the diluted fluid returns. Therefore, by appropriately changing and controlling the flow rates of both pumps as in the present invention, intermittent blood collection can be performed without interrupting the flow of the diluent in the cannula.

The amount of blood collected depends on the time interval between blood collection and non-collection. The time interval setting varies depending on the purpose of use of the device, the patient's condition, the amount of data required, etc.

If rapid changes in the concentration of substances in the blood are expected,! 1
111 hours, that is, the measurement time, is set long, and the non-** time, that is, the non-measurement time, is set short, or blood collection and non-blood collection are repeated frequently for a short period of time. On the other hand, if rapid fluctuations are not expected, the blood sampling time is set short and the non-blood sampling time is set long. The longer the non-blood sampling time, the more Is
Blood volume decreases.

! In the case where non-blood sampling is repeated in a short period of time, the response speed of the sensor in the measuring section is the same. In recent years, as sensor technology has advanced to a high level, sensors with response times ranging from several seconds to several io seconds have been developed. Therefore, it is possible to obtain a sensor that can sufficiently follow and measure even sudden changes in concentration, so it is possible to make sufficient measurements even when repeated interruptions occur at intervals of several seconds.

Furthermore, since intermittent blood sampling naturally results in intermittent measurement of the concentration of the substance, it is necessary to display and record the measured values at a time interval that makes it clear the movement of the measured values due to blood sampling and non-tIA blood. be.

Next, examples of the flow rate patterns of each pump for carrying out the sampling method according to the present invention will be shown with reference to the accompanying drawings.

112 and Ij&I are graphs showing the flow rate pattern of each pump when the flow rate of the feed pump is kept constant and the flow rate of the suction pump is changed as appropriate. In this case, the flow rate of the transport pump is constant at 10 m, and the suction amount of the suction pump during blood collection is lλθ l/-, so the blood sampling amount is 20 l/-. When not sampling, the suction amount is / 00P
4/m, and only the diluted liquid is aspirated. When performing intermittent blood sampling using this method, the amount of blood collected is 1/7th compared to continuous blood sampling.
decreases to

FIG. 111 and FIG. 3 are graphs showing flow patterns in the case where, on the contrary, the reduction of the amount of the feed pump is changed and the flow rate of the suction pump is kept constant, and intermittent feeding is performed. Note that the flow rate and flow rate pattern of each pump can be changed as necessary, as described above.

According to the blood sampling method according to the present invention, an appropriate amount of blood can be obtained without putting a burden on the patient. In addition, since the diluent containing anticoagulant flows inside the cannula and the device even when blood is not being collected, there is no coagulation inside the cannula or the device, and only the diluted solution flows to the measurement section, so the sample flow path It has the effect of cleaning dirt caused by deer waves on sensors, etc., and has advantages such as being able to maintain good measurement accuracy for a long period of time.

[Brief explanation of the drawing]

FIG. 7 is a configuration diagram of a continuous blood analyzer. FIGS. 2 and 93 show flow patterns of the respective pumps when the flow rate of the feed pump is kept constant and the flow rate of the suction pump is appropriately changed in an embodiment of the liquid sampling method according to the present invention. Further, FIG. 1 and FIG. 1 show the weight loss patterns of the respective pumps when the flow rate of the feed pump is changed as appropriate and the flow rate of the suction pump is kept constant. 1. Double lumen cannula t. Feeding pump
Outer tube Z Diluent container Sample suction line @ Pull pump Diluent supply line De Control device stopper IO, If fixed part

Claims (1)

[Claims] (1) A double lumen cannula, a diluent container, a feeding pump for feeding the diluent to the cannula, and measuring the diluent or a mixed wave of the diluent and blood from within the cannula. In a blood sampling method in a blood continuous analyzer consisting of a suction pump that draws suction into the cannula, a control device for both pumps, and a measuring section, self-wave sampling is performed intermittently without interrupting the flow of the diluent in the cannula. A blood sampling method characterized by: 1) By appropriately changing the ratio of the feeding volume of the feeding pump to the suction volume of the suction pump, self-wave sampling can be performed intermittently without interrupting the flow of the diluent in the cannula. Claim 1 is characterized in that l Blood sampling method described in Section II(1).