The Nonlinearity Error Analysis of 2D-PSD and Its Application in Medical Engineering

The structure, the characteristic and the principle of position sensitive detector (PSD) are expounded. By thoroughly analyzing the non-linearity provided by 2D-PSD, a new method using bridge theory to analyze the non-linearity is introduced. This method is very simpler in comparison with interpolation algorithms, optimization method of neural network and analytic method. The improved 2D-PSD signal debugging circuit board is designed and debugged by using front-end amplifier with low temperature drift and high precision and high-input impedance, summator, subtracter, divisor and other components. By using the improved 2D-PSD and continuous-emitting laser as optical source, a 3D non-contact optical measuring system with high precision is designed. This system can be used to measure the parameters of 3D object with anomalous form such as the abnormality of man's skin. Furthermore, combined with computer technology, tomography and chromatography, this high precision photoelectric device can be developed into various medical equipment, which have extremely wide application in the diagnosis of difficult pathological changes, especially in the early diagnosis of parameters for the abnormality of man's skin.