In Vitro Chemistry Analyzer: System Principles, Design Difficulties

Life science and medical instrumentation includes a variety of different systems. Examples include in vitro chemistry analyzers, flow cytometry analyzers, infusion pumps, dialysis equipment, ventilators, catheters, and other devices. In vitro chemistry analyzers utilize many electrochemical and optical techniques to analyze blood, urine, cerebrospinal fluid, and other biological samples. 

Among the most widely used techniques are optical measurements, examples of which include colorimetric, absorption, spectroscopic assays, and fluorescence detection methods. Chemical substances such as antigens, molecules and proteins can be measured in body fluids by these means. Because these techniques allow for rapid measurement functions with high sensitivity and high accuracy even when detecting small doses of chemicals, they are widely used at all levels of hospitals, clinics, and services such as immunization stations.

Design considerations and key challenges for in vitro chemistry analyzers

1. 1) Measurement speed is very important
2. 2) Reagent volume control is important to reduce costs and ensure consistency
3. 3) Optical system control and accuracy are key elements of the system

1. 1) I/V converter in photodiode input requires low bias current, high input impedance, low noise, and low-distortion operational amplifier
2. 2) Fast, high precision, synchronous sampling ADC
3. 3) Low noise and stable power supply

1. 1) Enzymes are sensitive to temperature fluctuations
2. 2) Reaction rate is very sensitive to temperature
3. 3) The general temperature range is body temperature with an accuracy of up to ±0.1°C
4. 4) Sometimes integrated heating/cooling equipment for smooth temperature control

1. 1) Precise stepping and position control
2. 2) Multi-axis motor motion control for moving and transferring samples within the instrument
3. 3) Accurate liquid level measurement
4. 4) Pressure detection for blockage detection
5. 5) Precise and fast sample loading and cleaning

1. 1) High-speed processor for multi-channel data processing
2. 2) DSP for accelerating complex analysis
3. 3) Provide inspection reports as fast as possible