Abstract: Compare various linear superposition methods to reduce the random errors in the sequences of aperiodic physiological signals and analyze the distribution function adaptable to the myocytes Ca⁺ fluointersity and draw the characteristic parameters-slopes and time constants. Methods: make the group of CRPR and the group of blank control for three different kinds of potency with six cells of cavy and note dawn the data of 24 groups of myocytes Ca⁺ fluointersity with focusing microscope. Calibrate, superpose and make nonlinear fitting to these data and dawn the characteristic parameters from them.The methods of superposition include average superposition with equal weight, superposition of principal component, decomposition of the singular values and maximum likelihood superposition. Take the Gamma distribution function as the fitting function, fit with the way of least square and calculate the characteristic parameters from the Gamma function. Results: ① Give out the weighting coefficients from four superposition methods. The coefficients are approximate, especially the one from the method of principal component, decomposition singular values and maximum likelihood are nearly equal. In the method of principal component, the weighting coefficients of six cells are 0.162, 0.171, 0.167, 0.162, 0.170 and 0.168. ② The characteristics of the fluointersity after superposition is more clear. ③ Give out the characteristic parameters of slopes and time constants. The slopes of CGRP group and blank control group,which have three different kinds of potency and come from the superposition of principal component are 1277, 1326, 2039 and 818, while the time constants are 0.33, 0.29, 0.19 and 0.27. In the case of sample data with only one principal component, the superposition of principal component is recommended. This is a simple way. By this way, we can get a good result of superposition, fit the distribution very well and draw the characteristic parameters.

Key words: linear superposition, myocytes Ca⁺ fluointersity, Gamma distribution function, slope, time constant