1. Application background
Biochemical analyzer is one of the necessary instruments for clinical diagnosis, life science, biochemical research and other research institutions in medical institutions. It is mainly used to determine various routine biochemical indicators in human body fluids. With the continuous progress of modern science and technology, the development of medical devices is becoming more and more high-tech. Biochemical analyzers have also moved from manual operation to full automation.
The automatic biochemical analyzer has the functions of accurate sampling and automatic loading, with high precision, good repeatability, complete functions, multiple test items and other characteristics, and its fast, simple, micro and other characteristics are particularly outstanding. In the pharmaceutical filling, different from the traditional stepper motor driving mode, linear stepper motor is more and more widely used in the automatic biochemical instrument.
In the automatic biochemical instrument, the sampling function is realized through the sampling system, the accuracy of the sampling system determines the accuracy of the whole instrument to a large extent. The sampling system is generally composed of "cantilever mechanism + drive mechanism", and the transmission mechanism is connected with the cantilever mechanism, so as to realize the automatic sampling function. The traditional driving mechanism is generally composed of "rotary stepper motor + transmission mechanism".
The traditional transmission mechanism generally includes synchronous belt, rack and pinion, ball screw. Synchronization belt, rack and pinion accuracy is not high, noise is relatively large, the most critical is that the life can not be guaranteed; Ball screw has high precision and long life, but its volume is large, the cost is high, and the adjustment level of the mechanism is high.
The linear lead screw step realizes the conversion from rotary motion to linear motion inside the motor, so that the cantilever mechanism is directly connected with the motor, making the mechanism as delicate as possible. At the same time, no intermediate transmission link enables it to achieve higher accuracy, higher efficiency and higher life.
2. Main structure and process of sampling system of biochemical analyzer
The sample adding system of the automatic biochemical analyzer is mainly composed of the following three parts, as follows:
Part I, sample turntable
The biochemical analyzer can be placed in a small sample cup or test tube.
Part II. Reagent Room (Warehouse)
Different automatic biochemical analyzer reagent rooms can accommodate different numbers of kits, generally can accommodate more than 20 kinds of reagents. Some reagent rooms are equipped with cold storage devices, and reagent rooms with barcode recognition devices can be arbitrarily placed in the position of the kit.
The third part, sampling device
Some automatic biochemical analyzer sample and reagent use the same sampling needle, controlled by the internal diverter valve sample and reagent; Some automatic biochemical analyzer has two sets of sampling devices, respectively sampling and reagent. There is a liquid level sensor at the front end of the sampling needle to prevent suction or liquid hanging on the outer wall of the sampling needle, and a pre-temperature device in the sampling arm.
3.vertical three linear lead screw step system
The application of vertical linear screw stepper motor in the sampling system of biochemical analyzer makes its structure simple and effective, improves the overall quality and grade of domestic biochemical analyzer, and is in a favorable position in the competition with similar products at home and abroad.