We all know that blood tests are the most common in daily life, so do you know the principle behind it? In fact, blood tests are all excited by laser diodes. Today, Xiaobian will tell you about its role.

Laser diodes are like doctors' "eyes" in medical testing equipment, which help them to see the subtle changes that are invisible to the naked eye. For example, in blood testing equipment, whether it is to detect the number of blood cells, analyze the concentration of hemoglobin, or distinguish various blood cell types, it is inseparable from the role of light.

In the blood analyzer, when blood samples are diluted and dispersed into single cells, they will pass through a very thin laser beam one by one. At this time, the laser diode starts to work, and the light it emits will shine on every cell. Different types of cells have different light scattering and absorption characteristics. These small changes are collected by photoelectric detectors, and then the type and number of cells can be judged by data analysis.

In the past, when there was no laser diode, blood testing mainly relied on microscope observation, which was inefficient and subjective, and an experienced doctor could see hundreds of samples a day.

But with the laser diode, the detection equipment can analyze tens of thousands of cells in a few minutes, with accurate data and high repeatability, and can also detect many early abnormalities.

From a technical point of view, laser diodes for blood testing are generally very demanding. Stability, life and spot quality should be excellent. Because once the equipment is turned on, it often works for hours or even days. If the light intensity fluctuates, the test results will be biased. Our common wavelengths are red light (630~670nm) and blue light (about 450nm). Red light has strong penetrating ability and is suitable for cell scattering detection. Blue light can excite fluorescent dyes more obviously, which can be used to analyze special proteins or markers in blood.

In addition, laser diode has another advantage: small volume and fast response. This is very important for the precision equipment such as blood analyzer. The design of equipment is becoming more and more compact, which is very demanding on the heating, energy consumption and space of internal components, and laser diodes can just meet these requirements.