Development of Optical Multiparameter Blood Coagulation Analysing System

摘要

Blood coagulation analysis helps the doctors diagnose the disease about the patients' blood. Nowadays, many ways can be used to accomplish the job, such as: optical method, current method, dry reagent method and ultrasonic method. In this paper, a new system for analysing the blood coagulation based on Labview and optical method is introduced. In order to realize the multiparameter measurement, four LEDs whose light beams are collimated by the lens are used as the light sources to illuminate the blood sample in the tube, two of those are blue LEDs with the wavelength of 405nm, the other two are red LEDs with the wavelength of 660nm; the light of LEDs is modulated to avoid the influence of stray light. The light emitted from the fifth LED produces the reference light for compensating the voltage fluctuation. The transmitted light are accepted by silicon photocells on the other side of the tube. During the measurement process, the blood sample is kept 37 degrees constantly using temperature control system. With the coagulant being added into the sample, the plasma begins to congeal, the output signal of the silicon photocells changes. The interface and data process software is programmed based on Labview. The digital data after AD conversion is processed using a 2nd ordered low pass Butterworth to get rid of the additional noise. The new developed system based on four LEDs and Labview can have many items about blood coagulation measured than the conventional system.