ABSTRACT
Commercial straight metal plates have been generally used to fix fractured bones, but recently, the need for customized and helical metal plates has emerged. Customized metal plates are designed to fit the shape of the fracture area that is a 3D curved surface, making it more difficult than designing on a 2D plane. Helical plates are researched due to their advantage in avoiding blood vessel damage compared to commercially available straight metal plates. In this paper, we propose a novel algorithm to design a customized helical metal plate for the femur using cylindrical depth images and Boolean operations. We also present the results of 3D printing a metal plate designed using the proposed algorithm, and the shape matching is verified by calculating the minimum distance between the surface of the printed plate and the surface of the femur.
Subject(s)
Bone Plates , Printing, Three-Dimensional , Femur/diagnostic imaging , Algorithms , Prosthesis Design , Equipment Design , HumansABSTRACT
In this paper, a novel method to compute side chain conformational variations for a protein molecule tunnel (or channel) is proposed. From the conformational variations, we compute the flexibly deformed shapes of the initial tunnel, and present a way to compute the maximum size of the ligand that can pass through the deformed tunnel. By using the two types of graphs corresponding to amino acids and their side chain rotamers, the suggested algorithm classifies amino acids and rotamers which possibly have collisions. Based on the divide and conquer technique, local side chain conformations are computed first, and then a global conformation is generated by combining them. With the exception of certain cases, experimental results show that the algorithm finds up to 327,680 valid side chain conformations from 128~1233 conformation candidates within three seconds.
Subject(s)
Algorithms , Amino Acids/chemistry , Protein Conformation , Proteins/chemistry , Models, MolecularABSTRACT
Interactions between protein molecules are essential for the assembly, function, and regulation of proteins. The contact region between two protein molecules in a protein complex is usually complementary in shape for both molecules and the area of the contact region can be used to estimate the binding strength between two molecules. Although the area is a value calculated from the three-dimensional surface, it cannot represent the three-dimensional shape of the surface. Therefore, we propose an original concept of two-dimensional contact area which provides further information such as the ruggedness of the contact region. We present a novel algorithm for calculating the binding direction between two molecules in a protein complex, and then suggest a method to compute the two-dimensional flattened area of the contact region between two molecules based on the binding direction.
