Various
biochemical automatic analyzers can be divided into four categories: continuous flow type (pipeline type), discrete type, centrifugal type and dry chip type according to different structural principles of the instrument.
1. Definition of fully automatic biochemical analyzer
The so-called fully automatic biochemical analyzer is a biochemical analysis instrument that automates the steps of sampling, adding reagents, mixing, insulating reaction, detection, result calculation and display, and cleaning during the analysis process.
Due to its high degree of automation and calibration and automatic correction functions, the subjective errors and systematic errors are relatively small and it is easy to use.
2 Working principle
The working principle of the fully automatic biochemical analyzer is based on spectrophotometry. Its basic measurement principle is based on Beer's law.
Structurally, a fully automatic biochemical analyzer contains the main components of a spectrophotometer: light source, monochromator (dispersion device), colorimetric cell, detector, etc.; in addition, it also includes unique parts required for biochemical analysis ． Such as sampling system, cleaning system, temperature control system, software system, etc.
It is mostly used for routine biochemistry, special protein and drug monitoring and other testing, with diversified program selection and microcomputer control. It can be freely programmed and can perform statistical processing. Some analyzers use chemically inert "capsule chemistry technology" to strictly isolate analysis specimens or test items to prevent cross-contamination.
3. Quick troubleshooting method
For large-scale equipment such as biochemical analyzers, if we can understand the principle of the machine and conduct block searches, we can quickly detect faults.
3.1 Realization conditions
If you want to quickly eliminate equipment faults, you must first master the principles; secondly, you must have a complete set of maintenance procedures; thirdly, clinical engineers must have a strong sense of responsibility, and it is best to ensure that maintenance data is technically available.
3.2 Functional segmentation of biochemical analyzers
Generally speaking, the hardware of various biochemical analyzers can be divided into three major parts: one is the optical system; the other is the liquid distribution and transmission system; the third is the temperature part.
These three major systems are connected by computers, and parameter selection operations are performed through software editing. Therefore, when a user encounters a problem, he first determines which system the problem may occur in. Achieve rapid positioning.
Under normal circumstances, there are few problems with circuits, and most of them are problems with the optical system and distribution system. Light energy detectors in optical systems are generally closed, almost impossible to disassemble, and have a long life. Generally, the most problematic part is the light path from the bulb through the condenser through the reactants in the cuvette to the adapter lens. Among them, the most common problem is the aging of light bulbs. In some devices, there will be an alarm prompt for insufficient light intensity. According to the prompt content, it is helpful to quickly locate.
The distribution system is more complex. There are many pipes in this part. Its module can be subdivided into three parts: one is reagent distribution; the other is sample distribution; and the third is cleaning. Specifically including pipes, deionized water, mixer, turntable, distribution needle, cleaning arm, mechanism arm, syringe pump, etc. Problems such as air leakage, inaccurate sample aspiration, and blockage of pipes and needle holes may occur in this part. The length of pinhole cleaning time can be edited by the program. Generally speaking, when doing strong acid and strong alkali projects, they must be edited separately. It is best to have other weak acid and weak alkali projects in the middle to form a buffer, and the quality of pure water during cleaning is also very important. The requirements for water quality are generally reverse osmosis water of grade two or above, and the water resistivity is required to be above 1 MQ.
The software function of the biochemical analyzer mainly includes three aspects: First, it provides users with an operation interface to enable editing. Sample/reagent settings, project application and execution, result output and historical record query, etc.; second, controlling the work of each part of the instrument to implement various biochemical analysis methods and some auxiliary functions. For a biochemical analysis instrument, the degree of automation The higher the instrument, the stronger the function; the third is data analysis, processing and calculation, such as patient information and raw data storage, laboratory results summary report, out-of-control report, quality control data calculation and drawing, quality control retrospective inspection and analysis, quality control retrospective inspection and analysis, etc. Control materials and quality control data management, etc.
3.3 After positioning. Adopt corresponding processing strategies. Based on the above analysis, you can be aware of common equipment faults, so that maintenance can be easier. Can speed up problem resolution.
Troubleshooting any kind of fault actually has levels. One is to start from high to low, that is, start from the big principles and divide functions into functional blocks as mentioned earlier.
The other is from low to high, that is, starting from the most direct fault symptoms. Some problems are relatively simple, and many machines have error reporting functions. You can directly find the fault point according to the prompts. If there is a problem with the light source, if the bulb is damaged, just replace it. There is no need to classify functions from beginning to end. This requires engineers to be flexible when dealing with specific problems.
During the positioning process, make full use of the machine's self-alarm information. However, sometimes the error message is not the direct cause of the fault and must be analyzed based on specific principles. Another way to quickly determine the hardware and software faults of the equipment is to determine that the equipment has a software problem based on the repeatability of the instrument test results. Or is there something wrong with the hardware itself. If the repeatability is poor, it indicates that there may be a problem with the machine hardware; if it is the opposite, it indicates that there is no problem with the machine itself, and the technical files may need to be re-edited.
4 Conclusion
When repairing various medical equipment, especially large-scale equipment, it is necessary to understand the principles before repairing. Because it involves a lot of knowledge, functional segmentation and positioning are the keys to rapid repair.
