The Application Of Digital Signal Process In Hematology Analyzer

With the rapid development of fundamental medicine and extensive applicationof advance science and technology and laboratorial instrument, laboratory medicinebecome more and more importance in the clinical making diagnosis and givingtreatment. In this paper a design of auto hematology analyzer of 5-part based on PC ispresented, which realized testing of white blood cell, red blood cell, platelet andhemoglobin. The analyzer can carry out essential parameters of testing such as WBC,RBC, PLT, HCT, MCV, MCH, MCHC, RDW, MPV, PCT and PDW etc. and drawhistogram of testing of white blood cell, red blood cell and platelet simultaneously. Itssoftware possesses querying results of testing that can be reported to print.It is very important of accurate, reliable result. It is because of some interferencesignal in the counted signal which will be influenced the result, therefore it'snecessary to filter the influence of the interference.In this paper, firstly, introduce the counted method—(Coulter Principle), thenintroduce structure of the auto hematology analyzer, and how to enlarge the signal,then collect the signal. The improved direct method—Welch method used in thispaper to estimate the power spectral of the counted signal, and the frequencycharacteristics of the actual counted signal and the interference signal in countedsignal are taken, forth more institutes the design performance characteristic of filter.Because the filter effects with filter methods for the counted signal are unsatisfied,this paper adopts the by-pass finite impulse response (FIR) digital filter with linearphase to deal with counted signal. At last the filter designed with Chebyshevequripple approximation is the optional under the given performance characteristic.MATLAB is used to simulate, the result shows that the filter designed withChebyshev equripple has the fast computation speed and narrow transition band.Satisfied effect of interference rejection has proved.