A novel evolutionary method for spine detection in ultrasound samples of spina bifida cases.

Background And Objectives: Spina bifida is a fetal spine defect observed during pregnancy. The defect is caused by unfinished closure of the embryonic neural column. Common diagnosis of the defect is still based on manual examination which aims to detect any deformation on spinal axis.

A Nature-Inspired Search Space Reduction Technique for Spine Identification on Ultrasound Samples of Spina Bifida Cases.

Spina bifida is a birth defect caused by incomplete closing around the spinal cord. Spina bifida is diagnosed in a number of different ways. One approach involves searching for a deformity in the spinal axis via ultrasound.

Estimation of depth-dependent material properties of biphasic soft tissues through finite element optimization and sensitivity analysis.

A knowledge of material properties of soft tissue, such as articular cartilage, is essential to assess its mechanical function. It is also increasingly more evident that the inhomogeneity of the tissues plays a significant role in its in vivo functioning. Hence, efficient and reliable tools are needed to accurately characterize the inhomogeneity of the soft tissue mechanical properties.

An analytical method to create patient-specific deformed bone models using X-ray images and a healthy bone model.

Generation of patient-specific bone models from X-ray images is useful for various medical applications such as total hip replacement, implant manufacturing, knee kinematic studies and deformity correction. These models may provide valuable information required for a more reliable operation. In this work, we propose a new algorithm for generating patient-specific 3D models of femur and tibia with deformity, using only a generic healthy bone model and some simple measurements taken on the X-ray images of the diseased bone.

Determination of Nerve Fiber Diameter Distribution From Compound Action Potential: A Continuous Approach.

When a signal is initiated in the nerve, it is transmitted along each nerve fiber via an action potential (called single fiber action potential (SFAP)) which travels with a velocity that is related with the diameter of the fiber. The additive superposition of SFAPs constitutes the compound action potential (CAP) of the nerve. The fiber diameter distribution (FDD) in the nerve can be computed from the CAP data by solving an inverse problem.

A penetration-based finite element method for hyperelastic 3D biphasic tissues in contact. Part II: finite element simulations.

The penetration method allows for the efficient finite element simulation of contact between soft hydrated biphasic tissues in diarthrodial joints. Efficiency of the method is achieved by separating the intrinsically nonlinear contact problem into a pair of linked biphasic finite element analyses, in which an approximate, spatially and temporally varying contact traction is applied to each of the contacting tissues. In Part I of this study, we extended the penetration method to contact involving nonlinear biphasic tissue layers, and demonstrated how to derive the approximate contact traction boundary conditions.

The effects of side-artifacts on the elastic modulus of trabecular bone.

Determining accurate density-mechanical property relationships for trabecular bone is critical for correct characterization of this important structure-function relation. When testing any excised specimen of trabecular bone, an unavoidable experimental artifact originates from the sides of the specimen where peripheral trabeculae lose their vertical load-bearing capacity due to interruption of connectivity, a phenomenon denoted here as the 'side-artifact'. We sought in this study to quantify the magnitude of such side-artifact errors in modulus measurement and to do so as a function of the trabecular architecture and specimen size.

A penetration-based finite element method for hyperelastic 3D biphasic tissues in contact: Part 1--Derivation of contact boundary conditions.

In this study, we extend the penetration method, previously introduced to simulate contact of linear hydrated tissues in an efficient manner with the finite element method, to problems of nonlinear biphasic tissues in contact. This paper presents the derivation of contact boundary conditions for a biphasic tissue with hyperelastic solid phase using experimental kinematics data. Validation of the method for calculating these boundary conditions is demonstrated using a canonical biphasic contact problem.