Applications of centroid coordinates for cell image analysis system in ASIPP microbeam

Abstract

A single-particle microbeam facility has been constructed at the Key Laboratory of Ion Beam Bioengineering of Institute of Plasma Physics, Chinese Academy of Sciences (ASIPP). In the image analysis system, the centroid coordinates of each cell are important features of cell images. For irradiation of nuclei, the centroid coordinates of each nucleus are reference coordinates for the points (the centroid itself or some neighbouring points of the centroid at a specific distance from it) to be irradiated. After the coordinates have been calculated, the irradiation points are found relative to the position of the beam exit aperture, and each cell is then positioned over the exit aperture by stepping motors driving a sample plate. Furthermore, in image acquisition, because the size of an image is limited, cells on the cell plate cannot all be scanned in one image. Therefore, the cell dish is divided into several overlapping districts to be acquired. Centroid coordinates are also a useful application for acquisition and recognition of overlapped images. The scheme and operational procedures for acquiring images accurately and recognizing cells are described; the feasibility and validity of the scheme are also discussed using an example.