Kreiranje zapreminskog 3D modela karlične kosti čoveka u uslovima nepotpunih ulaznih volumetrijskih podataka

Abstract

Human hip bone represents a very complex morphological structure of irregular shape, resulting from the fusion of three primarily stand-alone bones. So, obtaining an accurate 3D model is a complex process, with the condition that a sufficiently dense point cloud is provided. In the first phase of the research, the hip bone model is obtained in reverse engineering process. The procedure itself is time consuming and requires a dedicated CT scan. So, the method of parametric regions is developed. The method allows obtaining a 3D model, even in cases where the volumetric data are not complete or when obtaining data is only possible from a two-dimensional, 2D scans. Anatomical landmarks (a total of 34) were defined at the bones. These anatomical landmarks are interconnected by parameters. Therefore, 58 parameters were defined, classified in two groups: parameters whose values are measured (21), and parameters whose values are obtained on the basis of regression equations (37). The points on the curves obtained by cutting the polygonal model with planes that are passing through given parameters are defined. The points at the parts of the polygonal models which describe the edges of the hip bone and the points that belong to certain parts of the bone are also defined. Parts of the surface that are bound with parameters represent the regions. In order to automate the processes three VBA macros are developed. The results were tested at the arbitrarily selected hip bone, using the methodology for creating the prediction model, which allows the creation of complete polygonal model or each region separately. It is also possible to create parts of the region - sub-regions, on the external or internal side of the hip bone or on both of its sides. Neighboring regions may be brought together. Connecting the region with parts of the obtained polygonal surfaces which describe the edges of the hip bone is also enabled.