Injured skull zone determination by piecewise Bézier curve model.

• Ano de defesa: 2020
• Autor(a) principal: Ueda, Edson Kenji
• Tipo de documento: Tese
• Tipo de acesso: Acesso aberto
• Idioma: eng
• Instituição de defesa: Biblioteca Digitais de Teses e Dissertações da USP
• Palavras-chave em Português: Ajuste de curvas; Bézier curve; Crânio (Lesões); Curva de Bézier; Curve fitting; Injured skull; Prótese craniana; Recozimento; Simulated annealing; Skull prosthesis
• Link de acesso: https://www.teses.usp.br/teses/disponiveis/3/3152/tde-24082022-084849/

It is highly important to determine the fitting between the injured skull and the fabricated prosthesis in the Cranioplasty surgical procedure. This requires a precise definition of the contact surface between the injured skull and the prosthesis. A geometric representation that determines this surface is named as injured zone. It is possible, with the aid of the injured zone, to develop a more accurate prosthesis and evaluate the contact between the prosthesis and injured skull by determining the gaps between them. An iterative semi-automatic method is proposed to determine the injured zone, in which a curve model is used as reference to determine all the points of this area. The adaptive neighborhood simulated annealing algorithm determines the curve model, in which the curve parameters are adjusted to determine a curve that approximates the required zone. A piecewise cubic Bézier curve is used, in which each curve segment approximates only a part of the injured zone. Points are added and removed to the injured zone and a new injured zone curve model is determined in each new iteration. This procedure of adding and removing points is done until there are no more holes in the injured zone. The proposed method was tested in four examples; three artificially created injuries and one natural injury; and the method successfully determined the injured zone in all the four tests.