Edyta Kawlewska

Modeling and biomechanical analysis of craniosynostosis correction with the use of finite element method

Craniosynostosis is a skull malformation because of premature fusing of one or more cranial sutures. The most common types of craniosynostosis are scaphocephaly (with the sagittal suture fused) and trigonocephaly (with the metopic suture fused). In this paper we describe and discuss how finite element analysis and three-dimensional modeling can be used for preoperative planning of the correction of craniosynostosis and for the postoperative evaluation of the treatment results. We used the engineering software MIMICS MATERIALISE to obtain three-dimensional geometry from computed tomography scans, and applied finite element method for the sake of biomechanical analysis. These simulations help to improve the surgical treatment, making it more accurate, safer, and faster.

Statistical Analysis of Cranial Measurements - Determination of Indices for Assessing Skull Shape in Patients with Isolated Craniosynostosis

This paper presents a morphological analysis of the skull shape in infants under one year of age. Three-dimensional measurements were performed on models generated from images in Mimics software. Subsequently, a multivariate statistical analysis of the measured dimensions was performed to determine key indicators of the skull shape. Eventually it was developed the norms of skull indices for children up to one year of age. Regular values of these indices were compared with abnormal values measured in patients with isolated craniosynostosis. With the use of these indices it is possible to perform a quantitative evaluation of head deformity.

Preoperative Planning of Surgical Treatment with the Use of 3D Visualization and Finite Element Method

This chapter describes a method of engineering support of preoperative planning of surgical procedures with the use of engineering tools, such as state-of-the-art software for medical image processing, or a finite element method. The procedure of pre-operative planning consists in matching individual cases of incision sites and directions, visualization and selection of areas for resection as well as planning the technique of implant positioning and fixation. Also, the final visualization of the result of the planned medical procedure can be performed. This paper presents procedural propositions in surgery planning in the cases of corrections of the head shape in patients with craniosynostosis, corrections of the chest deformity such as pigeon chest and stabilization of the lumbar spine. 3D models created on the basis of computer tomography (CT) or magnetic resonance imaging (MRI) enabled it to conduct a biomechanical analysis as well as an objective quantitative and qualitative virtual evaluation of the surgical procedure. Preoperative planning support gives the physician an opportunity to prepare for the operation in a better way, which results in the selection of the best possible variant of an operative technique, reduction of time of the surgical procedure and minimization of the risk of intraoperative complications.

Impact of Vessel Mechanical Properties on Hemodynamic Parameters of Blood Flow

The main purpose of this work was the analysis of the impact of mechanical properties of blood vessels on the alteration of hemodynamic parameters of blood. Within the framework of this research strength tests of blood vessels were conducted, which aimed to determine mechanical properties by means of a static tensile test and a system of Digital Image Correlation (mDIC). The tests were performed using static strength testing machine MTS Insight 2. Subsequently, on the basis of computer tomography (CT) images, two numerical models of blood vessels were formulated in the Ansys CFX software programme. The first model does not take into consideration the changes of the artery geometry, while in the second model the vessel walls were modelled as deformable elements having preset mechanical properties. The developed numerical models enabled the assessment of the hemodynamic parameters as well as the state of stress and deformation of the walls during the blood flow through the vessel.