SA-6900 automated blood rheology analyzer adopts cone/plate type measurement mode. The product imposes a controlled stress on the fluid to be measured through a low inertial torque motor. The drive shaft is maintained in the central position by a low resistance magnetic levitation bearing, which transfers the imposed stress to the fluid to be measured and whose measuring head is cone-plate type. The whole mensuration is automatically controlled by the computer. The shear rate can be set randomly at the range of (1～200) s-1, and can trace two-dimensional curve for shear rate and viscosity in real time. The measuring principle is drawn on the Newton Viscidity Theorem.
|Principle||Whole blood: Rotation method;|
|Plasma: Rotation method, capillary method|
|Method||Cone plate method,|
|Signal collection||Cone plate method:High-precision raster subdivision technologyCapillary method: Differential capture technology with fluid autotracking function|
|Working Mode||Dual probes, dual plates and dual methodologies work simultaneously|
|Test time||Whole blood≤30 sec/T,|
|Sampling volume||Whole blood: 200-800ul adjustable, plasma≤200ul|
|Mechanism||Titanium alloy, jewel bearing|
|Sample position||90 sample position with single rack|
|Liquid system||Dual squeezing peristaltic pump，Probe with liquid sensor and automatic-plasma-separation function|
|Control||L-J control chart with save, query, print function;|
|Original Non-Newtonian fluid control with SFDA certification.|
|Calibration||Newtonian fluid calibrated by national primary viscosity liquid;|
|Non-Newtonian fluid win national standard marker certification by AQSIQ of China.|
1. Selection and dosage of anticoagulant
1.1 Selection of anticoagulant: It is advisable to choose heparin as an anticoagulant. Oxalate or sodium citrate can cause fine Cell shrinkage affects the aggregation and deformability of red blood cells, resulting in increased blood viscosity, so it is not suitable for use.
1.1.2 Dosage of anticoagulant: heparin anticoagulant concentration is 10-20IU/mL blood, solid phase or high concentration liquid phase is used for anticoagulation Agent. If liquid anticoagulant is used directly, its dilution effect on blood should be considered. The same batch of trials should
Use the same anticoagulant with the same batch number.
1.3 Production of anticoagulant tube: if liquid phase anticoagulant is used, it should be placed in a dry glass tube or glass bottle and dried in an oven After drying, the drying temperature should be controlled at no more than 56°C.
Note: The amount of anticoagulant should not be too large to minimize the dilution effect on the blood; the amount of anticoagulant should not be too small, otherwise it will reach no anticoagulant effect.
2. Sample collection
2.1 Time: Generally, blood should be collected early in the morning on an empty stomach and in a quiet state.
2.2 Location: When taking blood, take a sitting position and take blood from the venous anterior elbow.
2.3 Shorten the venous block time as much as possible during blood collection. After the needle is pierced into the blood vessel, immediately loosen the cuff to be quiet About 5 seconds to start blood collection.
2.4 The blood collection process should not be too fast, and the possible damage to the red blood cells caused by the shearing force should be avoided. For this, the lancet the inner diameter of the tip is better (it is better to use a needle above 7 gauge). It is not advisable to draw too much force during blood collection, to avoid abnormal shearing force when blood flows through the needle.
2.2.5 Specimen mixing: After the blood is collected, unscrew the injection needle, and slowly inject the blood into the test tube along the wall of the test tube, and then hold the middle of the test tube with your hand and rub it or slide it in a circular motion on the table to make the blood fully mixed with the anticoagulant.
To avoid blood clotting, but avoid vigorous shaking to avoid hemolysis.
3.Preparation of plasma
The plasma preparation adopts clinical routine methods, centrifugal force is about 2300×g for 30 minutes, and the upper layer of blood is extracted Pulp, for the measurement of plasma viscosity.
4. Sample placement
4.1 Storage temperature: specimens cannot be stored below 0°C. Under freezing conditions, it will affect the physiological state of blood.
State and rheological properties. Therefore, blood samples are generally stored at room temperature (15°C-25°C).
4.2 Placement time: The specimen is generally tested within 4 hours at room temperature, but if the blood is taken immediately ,that is to say, if the test is performed, the result of the test is low. Therefore, it is appropriate to let the test stand for 20 minutes after taking the blood.
4.3 Specimens cannot be frozen and stored below 0°C. When blood samples must be stored for a longer period of time under special circumstances, they should be marked Put it in the refrigerator at 4℃, and the storage time is generally no more than 12 hours. Store specimens adequately before testing, Shake well, and the storage conditions should be indicated in the result report.