JPS6145780B2 - - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an apparatus for automatically measuring the coagulation function of plasma.

[Conventional technology]

Conventionally, this type of test has been performed visually using a stopwatch or a constant temperature bath, which requires skill, and even though it is possible to measure the final point of solidification, the intermediate solidification process cannot be understood as a change over time. That was impossible.

[Problem that the invention seeks to solve]

In addition, in recent years, methods have been developed in which a probe is inserted into a test tube, the test tube is moved, and the force applied to the probe is measured, and a metal ball is inserted and an external magnetic field is applied to move the metal ball. Various detection methods and other devices have been devised, but the introduction of foreign substances may affect the coagulation function and cause errors in the measurement results, which is not desirable. There is also a device (US Patent No. 3307392) that measures the inflection point of the change in light transmittance of a sample during the coagulation reaction, but in reality it may show a gentle curve depending on the state of the sample and reagent, and the second change may occur. It was necessary to observe a considerable width at the coagulation measurement point, which is the curve point.

The present invention has been made in view of the above drawbacks,
To provide a device that automatically performs measurement more accurately without affecting the coagulation mechanism.

[Means for solving problems]

This will be explained below based on the drawings. Fig. 1 is a perspective view showing the structure of this device, Fig. 2 is a sectional view of the detection block, Fig. 3 is an explanatory diagram showing the operation of this device, and Fig. 4 is an electrical diagram of this device. 5 is a circuit diagram, and FIG. 5 is a graph showing an example of measurement results by this device.

The detection block 1 includes a hole 3 for inserting a sample test tube 2, a light source lamp 4, a light detection element 5,
and a constant temperature heater part 6 for keeping the entire detection block at 37°C, and is attached to a fixing base 7 for fixing one or more detection blocks.

On the other hand, in order to shake the plasma in the test tube and facilitate the detection of the coagulation reaction, the entire detection block is tilted at a predetermined angle as shown in FIG. This is done by fixing the upper part of the cylinder tube 8, fixing one end of the piston rod 9 as a fulcrum to a disc 11 with a crank pin 10, and rotating the disc 11 with a servo motor 12.

The electrical circuit is shown in FIG. The detection block 1 is supplied with a lamp voltage from a light source lamp control circuit 13, and the constant temperature heater is controlled by a heater control circuit 14. The detection signal is detected by detection circuit 1.
One enters the timer control circuit 17 that controls the timer 16, the other directly enters the recorder 18, and the third enters the recorder 18 via the differential amplifier circuit 19. The servo motor is controlled by a rotation control circuit 20.

[Effect]

The detection method by this device is an optical method,
The objective is to capture changes in light transmittance during the coagulation process of plasma.

Add 0.2 ml of reagent to 0.1 ml of plasma sample. Test tube 2 is made of transparent glass or resin with an inner diameter of 8 mmφ and a height of 20 mm, and the horizontal hole for the optical path is 1.
It is mmφ. The tilting motion promotes agitation of the plasma itself and the plasma and reagents and facilitates detection of the reaction. Using a cylinder makes the movement smoother,
Do not apply unnecessary vibration to the detection block.

FIG. 3 shows the inclination of the test tube 2 in states A, B, C, and D as the position of the crank pin 10 changes with the rotation of the disc 11.

15° to the left and right around the fulcrum of the cylinder, total 30°
The fulcrum, the position of the crank pin 10, etc. are determined so that the inclination is repeated at an angle of .degree.

Servo motors can change speed, reverse rotation, etc., but for practical purposes, a small induction motor capable of continuous rotation at a constant speed of 60 RPM is sufficient.

Therefore, in that case, the rotation control circuit 20 is only a switch. The heater control circuit 14 uses a thermistor as a temperature sensor to maintain the detection block 1 at 37°C.

The light source lamp control circuit 13 is a 5V constant voltage circuit.

The detection circuit 15 is a DC amplifier and multipurpose operational amplifier.
IC (709N) is used.

The differential amplification circuit 19 consists of an emitter follower circuit of C, R and a transistor (A495), and the time constant can be adjusted by changing R. The recorder 18 may be a commercially available T,Y recorder.

The timer control circuit 17 includes a circuit equivalent to the differential amplification circuit 19, and processes the signal in combination with the signal from the detection circuit 15. That is, after the signal from the detection circuit 15 reaches a predetermined level or higher, the presence or absence of a change in the differential waveform within a certain period of time is detected, and if there is no signal, the timer 16 is partially stopped.

The timer 16 displays the controlled clotting time and stops the recorder after a certain period of time from the display.

FIG. 5 is a graph of the measurement results according to the example, in which the horizontal axis represents the passage of time and the vertical axis represents the amount of transmitted light (scale numbers are 1/10%). A sample undergoing tilting motion at a constant temperature begins to form fibrin approximately 2 seconds after mixing the reagents, the amount of transmitted light decreases rapidly, and after 15 seconds the fibrin becomes fixed and cannot vibrate, reducing the effects of tilting motion. This indicates that the amount of transmitted light also stops changing when the light is no longer received.

〔Effect of the invention〕

If detection is made only by changes in light transmittance without tilting movement, the graph will be a continuous midpoint of the vertical oscillating parts of A and B in Figure 5, and the graph will be a graph in which the midpoints of the vertical vibration parts of A and B in Figure 5 are continuous, and the point C on the curve in Figure 5 B will be a continuous graph. It is difficult to clearly determine the end of coagulation, and this output is due to the effect of the tilting motion and the differential circuit 19. By using the device of the present invention, a reciprocating tilting motion is performed, and shaking is performed which is very similar to the shaking performed by the conventional manual method for measuring the coagulation function of plasma, and it is possible to obtain results that are highly correlated with the measurement results using the manual method. can.

This device is automatically operated until the reaction is completed by an external switch, and can process multiple samples at the same time. In addition, double recording of the timer and waveform makes it easy to check for operational errors, and by setting the normal clotting time in advance, only abnormal specimens can be screened and compared with the recorder pattern. It is also possible to make pathological findings.

By using this device for inspection, the effects of automation are very large, as it frees people from the troublesomeness and difficulty of conventional inspections.

[Brief explanation of the drawing]

Fig. 1 is a structural diagram of this device, Fig. 2 is a sectional view of the detection block, Fig. 3 is an explanatory diagram showing the operation,
FIG. 4 is an electric circuit diagram, and FIG. 5 is a graph showing an example of measurement results. 1...Detection block, 2...Test tube, 4...Lamp,
5... Photodetection element, 17... Timer control circuit.

Claims (1)

[Claims] 1. A test tube containing a plasma sample to be measured, an optical means for accommodating the test tube and measuring the translucency of the plasma sample in the test tube, and maintaining the optical means, test tube, etc. at a constant temperature. a temperature control device; a device forming a block including the optical means and the temperature control device; and a device having a function of causing the block to reciprocate and tilt within a predetermined angle; a device for simultaneously recording a measured signal and a differential signal of the measured signal, a device that receives the measured signal and detects whether or not there is a change in the differential waveform within a fixed time after the measured signal reaches a predetermined level or higher; A plasma coagulation function measuring device comprising a device that measures coagulation time by partially stopping a timer when there is no signal.