Kalman filtering based method for detecting mechanical property of cell through AFM (Atomic Force Microscope)

Abstract

The invention discloses a Kalman filtering based method for detecting the mechanical property of a cell through an AFM (Atomic Force Microscope). The method conducts Kalman filtering on the micro-cantilever offset obtained in a cell indentation experiment to obtain an optimal estimated value for the micro-cantilever offset; an MIIC (modeling-free inversion-based iterative learning control) algorithm is used to iteratively track the optimal estimated value on a hard material, meanwhile, the micro-cantilever offset of the hard material obtained in each iterative process is subjected to Kalman filtering, a z-axis displacement is obtained after the iteration is terminated; and the elasticity modulus of the cell is calculated according to a Hertz model. The micro-cantilever offsets obtained in the cell indentation experiment and the hard material tracking experiment are filtered through a Kalman filtering model to obtain the optimal estimated value of the micro-cantilever offset, the noise and the clutter introduced in the experiment process are reduced, so that the MIIC algorithm effectively tracks the hard material in the tracking experiment, the operation efficiency is improved, meanwhile, the more accurate cell indentation depth value is acquired, and the measurement accuracy of the mechanical property of the cell is improved.

Description

technical field [0001] The invention relates to the technical field of nano-manipulation, and more specifically relates to a method for detecting cell mechanical properties based on a Kalman filter-based AFM (AtomicForce Microscope, atomic force microscope). Background technique [0002] The measurement of the mechanical properties of living cells is a hot direction of AFM in biological applications. AFM obtains the mechanical properties of the cell, such as hardness and viscoelasticity, by applying a weak force to the cell, and then obtains information on the internal structure changes of the cell (such as the cytoskeleton). In recent years, the research on the mechanical properties of cells has shown that the mechanical properties of cells are closely related to pathogenesis and pathophysiology. Therefore, the study of mechanical properties of cells will help to better understand the physiological mechanism of diseases, and lay a foundation for the early stages of diseases...

AI Technical Summary

Problems solved by technology

[0004] However, due to the influence of noise and clutter during the experiment, the offset of the microcantilever obtained by the AFM indentation experiment on the cell usually has many burrs, which makes the algorithm not converge when the MIIC algorithm is used to track on the hard material, and the experimental operation is difficult. Large, and the accuracy of the obtained cell indentation depth is low

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