https://doi.org/10.46335/IJIES.2022.7.1.5 e-ISSN: 2456-3463 Vol. 7, No. 1, 2022, PP. 23-27 International Journal of Innovations in Engineering and Science, www.ijies.net 23 The Solid Model Development by Point Cloud and Planar Counter Fitted Curves for Medical Images of Knee Joint Jitesh Madhavi 1 , Jayesh Dange 2 , Vivek Sunnapwar 3 1 Research Scholar, Mechanical Department, Lokmanya Tilak College of Engineering, Mumbai, 400708. 2 Professor, Mechanical Department, Lokmanya Tilak College of Engineering, Mumbai,400708. 3 Principal, Lokmanya Tilak College of Engineering, 400708 Received on: 05 January,2022 Revised on: 02 February,2022 Published on: 04 February,2022 Abstract – Presently three-dimensional digital model developments of anatomical structures are in much interest of bio-medical praxis. Application of computers helps for pre-planning surgery, optimized implant in terms of geometry and fixture or surgical templates development for accurate positioning and orientation of implant. Lack of image processing technology in extracting the boundaries and inherent complexities of tissue anatomical structure, the software’s developed for 3D construction is not much effective to convert CT/MRI images to solid models. This paper presents the problems of image processing technology and inefficiency of CAD to develop models with a proposed solution to remove unwanted curves by reducing the noise level of the curve to make it suitable to reconstruct solid model. Keywords- Bio-CAD, reverse engineering, CAD, noise, Bio-modeling. I- INTRODUCTION CT/MRI data are used to construct 3D CAD model. There are pros and cons for CT/MRI depending upon the tissue which is used for the study. Software’s like 3D Doctor by Abel software, USA, and Mimics by Materialize, Belgium, etc., are developed to build the CAD model directly from Dicom images. The output of this software is either in point cloud data, surfaces or in stl. This output data, when imported into any CAD packages, have problems of data loss in terms of holes, spikes, and noise which make the quality of CAD model poor. This makes the most difficult task to mature the CAD to Solid model. High expertise and time are required to remove holes and, spikes and noise. The Software can build the stl (Stereo lithography) model quickly which can be imported in any CAD software. Since stl data is in the faceted model, the surface needs to be fitted to these data. The operation to fit the surface is very tedious and losses its accuracy. The data can be cleaned and NURBS can be fitted applying tangency and Curvature continuity but the geometry deviates with actual bone geometry. The below Figure shows the various ways to construct solid based model from CT/MRI scan data. The output data from each method have different application.