Development of patient specific implants for Minimum Invasive Spine Surgeries (MISS) from non-invasive imaging techniques by reverse engineering and additive manufacturing techniques

Abstract

Reverse Engineering and Rapid Prototyping are extensively used technologies by both research and industrial community for rapid developments in various industrial as well as Bio-medical applications. Recent advances in computer technology and Bio-medicines enabled Computer Aided Design (CAD) to find many novel applications in Bio-medical engineering and integration of CAD and Bio-medical technology is usually referred as Bio-CAD. The major objective of the current research work is to generate an efficient algorithm for generation of free form surface from non-invasive CT scan images. Minimally Invasive Spine Surgery (MISS) have enabled spinal surgeons to select patients and treat several spinal disorders like degenerative disc disease, herniated disc, fractures, tumors, infections, instability, deformity, etc. with less disruption of muscles, which enables patient towards faster recovery to normal functions, reduces operative blood loss. In this paper, it is proposed to extract point cloud data from stalk of non-invasive CT scan images by using Image Processing techniques and Reverse Engineering approach. This point cloud data is to be processed for noise reduction, point cloud data segmentation and CAD model generation. This image-based CAD modeling approach begins with the acquisition of CT scan in DICOM 3.0 format. The point cloud estimation is based on threshold techniques and edge detection method. This point cloud data is used for construction of 3D CAD model by fitting free form NURB surface between theses points and then fitting surface between these curve networks by swept blend technique. An efficient and robust algorithm has been developed for generation of curves from unorganized point cloud data.