Application of Hematology Analyzer and Common Fault Diagnosis
With the advancement of laboratory equipment, automated instruments (e.g., hematology analyzers) have improved inspection quality, efficiency, and provided reliable indicators for clinicians, becoming essential in clinics. However, maintaining, servicing, and troubleshooting these high-automation devices to ensure their performance is a key issue for inspection departments. This text focuses on diagnosing and analyzing common faults of hematology analyzers, as their long-term operation with reagents and samples easily causes component wear, corrosion, clogging, etc. Operators must master basic operations, routine maintenance, and fault analysis-all based on understanding the instrument's principles and performance.
1 Analyzer Development and General Principles
Early blood analyzers relied on capacitance and electro-optical colorimetry, only measuring RBC and WBC and prone to interference. In 1948, Coulter's impedance principle greatly improved measurement accuracy but only detected cell size. In the 1980s, laser technology was applied; combining impedance and laser enabled measuring both cell size and nuclear morphology. Mid-1980s: Eltek (US) used impedance, laser, and high-energy electromagnetic waves for single-cell detection and classification (detecting intracellular particle size/density). Bayer (Germany) combined cell chemistry (peroxidase in neutrophils/monocytes, absent in lymphocytes/basophils) and laser for WBC classification, plus flow cytometry for reticulocytes. East Asian companies used membrane lipid levels and sulfurized amino acid binding differences, with hemolytic agents aiding immature cell classification. Tech advancement will further improve detection methods.
2 General Structure of the Analyzer
Hematology analyzers integrate computer, mechanical, optical, electrical, and chemical technologies, divided into four parts:
Control part: Computer for instrument control, data calculation/analysis.
Pressure part: Pressure pump, peristaltic pump, vacuum pump, and pressure control system.
Pipeline part: Air/reagent/sample/waste pipes, filters, pump tubes, electronic valves.
Detection part: Light source lamp, laser, sensor, counting hole.
Laboratory staff must master regular maintenance, cleaning, testing, and part replacement for normal operation.
3 Common Malfunctions of Hematology Analyzers
Major faults (e.g., negative pressure pump water ingress, peristaltic pump fatigue, severe count errors) require manufacturer repair. Common minor, self-solvable faults include: small hole obstruction, sample needle clogging, pump tube aging, filter failure, directional/solenoid valve malfunction, waste cup effusion, insufficient reagent/sample volume.
4 Finding Faults and Handling
Fault prompts: High-grade instruments have prompts (e.g., reagent out of range, insufficient sample) solvable via instrument-suggested methods. For vague prompts (e.g., count errors), check factors like insufficient reagent/sample, pipe/filter/counting hole clogging, vacuum pump water ingress, or program errors one by one. Test fixed parameters (e.g., pressure to check vacuum pump, filter, directional valve status) based on instrument performance/parameters.
No prompts/tests: Observe phenomena to identify causes. For example:
Reagent undetection: Caused by peristaltic pump fatigue, aged pump tubes, old filters, pressure drop, pipe blockage, sensor failure.
No counting: Caused by counting hole clogging, valve malfunction, waste cup effusion (backflow), external magnetic interference.
Electrical issues: Voltage instability/poor grounding causes extended counting time, program errors, or instrument crashes-solve via regulated power supply, ground check, or restart.
