The development of a computational workflow for the semi-automated construction of patient-specific finite element models of tibial fracture fixation

Introduction: Tibial fracture healing complications occur frequently with reported non-union rates up to 23%. Preoperative patient-specific finite element (FE) modelling of fracture fixation may help to minimize these complications. However, developing such models requires labour-intensive work including (manual) segmentation of bones from...

Data-driven generation of 4D velocity profiles in the aneurysmal ascending aorta

Background and Objective: Numerical simulations of blood flow are a valuable tool to investigate the pathophysiology of ascending thoratic aortic aneurysms (ATAA). To accurately reproduce in vivo hemodynamics, computational fluid dynamics (CFD) models must employ realistic inflow boundary conditions (BCs). However, the limited availability of...

Statistical shape model of the talus bone morphology: A comparison between impinged and nonimpinged ankles

Diagnosis of ankle impingement is performed primarily by clinical examination, whereas medical imaging is used for severity staging and treatment guidance. The association of impingement symptoms with regional three-dimensional (3D) bone shape variaties visible in medical images has not been systematically explored, nor do we know the type...

EquiSim: An Open-Source Articulatable Statistical Model of the Equine Distal Limb

Most digital models of the equine distal limb that are available in the community are static and/or subject specific; hence, they have limited applications in veterinary research. In this paper, we present an articulatable model of the entire equine distal limb based on statistical shape modeling. The model describes the inter-subject...

Subject-specific identification of three dimensional foot shape deviations using statistical shape analysis

The high prevalence of foot pain, and its relation to foot shape, indicates the need for an expert system to identify foot shape abnormalities. Yet, to date, no such expert system exists that examines the full 3D foot shape and produces an intuitive explanation of why a foot is abnormal. In this work, we present the first such expert system that...

The effect of nasal shape on the thermal conditioning of inhaled air: Using clinical tomographic data to build a large-scale statistical shape model

In this paper, we investigate the heating function of the nasal cavity qualitatively, using a high-quality, large-scale statistical shape model. This model consists of a symmetrical and an asymmetrical part and provides a new and unique way of examining changes in nasal heating function resulting from natural variations in nasal shape (as...

Design and optimisation of an additively manufactured patient-specific partial mandible reconstruction implant

Additive manufacturing (AM) provides the opportunity for complex porous designs, without the costs depending on batch size. Therefore patient-specific implants can be rapidly manufactured. In clinical practice, reconstruction of the mandible is needed in case of bone tumors or trauma. Part of the mandible is removed and the shape of the missing...

The development of a Statistical Shape- and Finite Element-Model of the human pelvis to analyse the performance of current acetabular implants and validate the concept of a new deformable design

Background: Patients who suffer from acetabular bone defects are often subjected to a decreased mobility and a loss of independence. To treat these bone defects, standard hemispherical acetabular implants offer in most cases the solution. However, when these defects are large, a custom triflange acetabular implant is needed. Although this type...

Segmentation of Carpal Bones: Based on Statistical Shape Models using Spherical Harmonics

A study has been conducted on the application of Spherical Harmonics based Statistical Shape Modelling for Image Segmentation. This study is focused on the segmentation of Wrist bones using the above mentioned technique.

Aortic root sizing for transcatheter aortic valve implantation using a shape model parameterisation

During a transcatheter aortic valve implantation, an axisymmetric implant is placed in an irregularly shaped aortic root. Implanting an incorrect size can cause complications such as leakage of blood alongside or through the implant. The aim of this study was to construct a method that determines the optimal size of the implant based on the...

Typical shape differences in the subtalar joint bones between subjects with chronic ankle instability and controls

Bone shapes, particularly those defining the subtalar joint (STJ), have not received much attention yet as a risk factor for developing chronic ankle instability (CAI) after sustaining a lateral ankle sprain (LAS). This study aimed to compare three-dimensional (3D) shape variations in the STJ bones within individuals with CAI and healthy...

Posture normalisation of 3D body scans

For product developers that design near-body products, virtual mannequins that represent realistic body shapes, are valuable tools. With statistical shape modelling, the variability of such body shapes can be described. Shape variation captured by statistical shape models (SSMs) is often polluted by posture variations, leading to less compact...

Integrating statistical shape modelling into a silhouette-based 3D reconstruction process to model a transradial defect

Background: In low- and middle-income countries there is a high demand for prosthetic devices. An automatic system, in which hand prostheses are manufactured with 3D printers can potentially offer a solution for patients having a transradial defect in these areas. As part of such a system, a detailed 3D model of the residual limbs is needed. In...

Automatic Measurement of The Human Upper Limb Dimensions for Prosthetic Socket: The Multiple Statistical Shape Model Approach

An upper limb prosthesis, i.e. a hand prosthesis, is a device to replace the function of an upper limb on upper limb amputees. In developing countries, amputees’ access to the device is scarce to unavailable. In addition to the absence of experts in those areas, currently there are no automatic measurement methods for upper limb amputees...

Shape model-based point set registration with local density weighting applied to the incomplete femur

Pre-operative planning aids clinicians by providing insight into patient-specific problems before surgery is performed. For treatment of femoroacetabular impingement (FAI), a range of motion (ROM) simulation is used, based on collision detection on segmented CT or MRI-data. Imaging data of the femur is often incomplete, due to the fact that...

Automated Expansion of Statistical Shape Model Training Set for Femur

Active Shape Model (ASM) uses Statistical Shape Model (SSM) to fit the manually labeled landmark point in Magnetic Resonance Image (MRI) scan and segment the femur from the MRI scan. The SSM is trained from a training set containing 275 complete femur meshes. In general, with more femur meshes in the training set, there would be more shape...

Landmark Influence Visualization in Active Shape Models

Segmentation of shapes in Magnetic Resonance Image (MRI) data is a non-trivial problem. Active Shape Models (ASM) is an approach that attempts to fit a Statistical Shape Model to landmarks. One possible approach is to let a user fit the model onto the MRI data by placing landmarks for ASM. Usually, the user can only see the global fit of the...