Three dimensional patient-specific collagen architecture modulates cartilage responses in the knee joint during gait

We present processing methods and visualization techniques for accurately characterizing and interpreting kinematical data of flexion–extension motion of the knee joint based on helical axes. We make use of the Lie group of rigid body motions and particularly its Lie algebra for a natural representation of motion sequences. This allows to analyze and compute the finite helical axis (FHA) and instantaneous helical axis (IHA) in a unified way without redundant degrees of freedom or singularities. A polynomial fitting based on Legendre polynomials within the Lie algebra is applied to provide a smooth description of a given discrete knee motion sequence which is essential for obtaining stable instantaneous helical axes for further analysis. Moreover, this allows for an efficient overall similarity comparison across several motion sequences in order to differentiate among several cases. Our approach combines a specifically designed patient-specific three-dimensional visualization basing on the processed helical axes information and incorporating computed tomography (CT) scans for an intuitive interpretation of the axes and their geometrical relation with respect to the knee joint anatomy. In addition, in the context of the study of diseases affecting the musculoskeletal articulation, we propose to integrate the above tools into a multiscale framework for exploring related data sets distributed across multiple spatial scales. We demonstrate the utility of our methods, exemplarily processing a collection of motion sequences acquired from experimental data involving several surgery techniques. Our approach enables an accurate analysis, visualization and comparison of knee joint articulation, contributing to the evaluation and diagnosis in medical applications.

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Numerical computation of blood flow for a patient-specific hemodialysis shunt model

Japan Journal of Industrial and Applied Mathematics ◽

10.1007/s13160-021-00469-9 ◽

2021 ◽

Author(s):

Surabhi Rathore ◽

Tomoki Uda ◽

Viet Q. H. Huynh ◽

Hiroshi Suito ◽

Toshitaka Watanabe ◽

...

Keyword(s):

Stokes Equations ◽

Three Dimensional ◽

Arteriovenous Shunt ◽

Navier Stokes ◽

Patient Specific ◽

Stabilized Finite Element ◽

Computed Tomography Scanning ◽

Outflow Boundary ◽

Stage Renal Disease ◽

End Stage

AbstractHemodialysis procedure is usually advisable for end-stage renal disease patients. This study is aimed at computational investigation of hemodynamical characteristics in three-dimensional arteriovenous shunt for hemodialysis, for which computed tomography scanning and phase-contrast magnetic resonance imaging are used. Several hemodynamical characteristics are presented and discussed depending on the patient-specific morphology and flow conditions including regurgitating flow from the distal artery caused by the construction of the arteriovenous shunt. A simple backflow prevention technique at an outflow boundary is presented, with stabilized finite element approaches for incompressible Navier–Stokes equations.

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Application of subject-specific adaptive mechanical loading for bone healing in a mouse tail vertebral defect

Scientific Reports ◽

10.1038/s41598-021-81132-8 ◽

2021 ◽

Vol 11 (1) ◽

Cited By ~ 1

Author(s):

Angad Malhotra ◽

Matthias Walle ◽

Graeme R. Paul ◽

Gisela A. Kuhn ◽

Ralph Müller

Keyword(s):

Mechanical Loading ◽

Bone Defect ◽

Bone Healing ◽

Three Dimensional ◽

Patient Specific ◽

Dependent Manner ◽

Micro Computed Tomography ◽

Computed Tomography Images ◽

Bone Defect Healing ◽

Subject Specific

AbstractMethods to repair bone defects arising from trauma, resection, or disease, continue to be sought after. Cyclic mechanical loading is well established to influence bone (re)modelling activity, in which bone formation and resorption are correlated to micro-scale strain. Based on this, the application of mechanical stimulation across a bone defect could improve healing. However, if ignoring the mechanical integrity of defected bone, loading regimes have a high potential to either cause damage or be ineffective. This study explores real-time finite element (rtFE) methods that use three-dimensional structural analyses from micro-computed tomography images to estimate effective peak cyclic loads in a subject-specific and time-dependent manner. It demonstrates the concept in a cyclically loaded mouse caudal vertebral bone defect model. Using rtFE analysis combined with adaptive mechanical loading, mouse bone healing was significantly improved over non-loaded controls, with no incidence of vertebral fractures. Such rtFE-driven adaptive loading regimes demonstrated here could be relevant to clinical bone defect healing scenarios, where mechanical loading can become patient-specific and more efficacious. This is achieved by accounting for initial bone defect conditions and spatio-temporal healing, both being factors that are always unique to the patient.

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Effects of intracorneal ring segments implementation technique and design on corneal biomechanics and keratometry in a personalized computational analysis

Scientific Reports ◽

10.1038/s41598-021-93821-5 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Niksa Mohammadi Bagheri ◽

Mahmoud Kadkhodaei ◽

Shiva Pirhadi ◽

Peiman Mosaddegh

Keyword(s):

Clinical Data ◽

Three Dimensional ◽

Element Model ◽

Von Mises Stress ◽

Patient Specific ◽

Average Error ◽

Constant Thickness ◽

Arc Length ◽

Implementation Techniques ◽

Von Mises

AbstractThe implementation of intracorneal ring segments (ICRS) is one of the successfully applied refractive operations for the treatment of keratoconus (kc) progression. The different selection of ICRS types along with the surgical implementation techniques can significantly affect surgical outcomes. Thus, this study aimed to investigate the influence of ICRS implementation techniques and design on the postoperative biomechanical state and keratometry results. The clinical data of three patients with different stages and patterns of keratoconus were assessed to develop a three-dimensional (3D) patient-specific finite-element model (FEM) of the keratoconic cornea. For each patient, the exact surgery procedure definitions were interpreted in the step-by-step FEM. Then, seven surgical scenarios, including different ICRS designs (complete and incomplete segment), with two surgical implementation methods (tunnel incision and lamellar pocket cut), were simulated. The pre- and postoperative predicted results of FEM were validated with the corresponding clinical data. For the pre- and postoperative results, the average error of 0.4% and 3.7% for the mean keratometry value ($$\text {K}_{\text{mean}}$$ K mean ) were predicted. Furthermore, the difference in induced flattening effects was negligible for three ICRS types (KeraRing segment with arc-length of 355, 320, and two separate 160) of equal thickness. In contrast, the single and double progressive thickness of KeraRing 160 caused a significantly lower flattening effect compared to the same type with constant thickness. The observations indicated that the greater the segment thickness and arc-length, the lower the induced mean keratometry values. While the application of the tunnel incision method resulted in a lower $$\text {K}_{\text{mean}}$$ K mean value for moderate and advanced KC, the induced maximum Von Mises stress on the postoperative cornea exceeded the induced maximum stress on the cornea more than two to five times compared to the pocket incision and the preoperative state of the cornea. In particular, an asymmetric regional Von Mises stress on the corneal surface was generated with a progressive ICRS thickness. These findings could be an early biomechanical sign for a later corneal instability and ICRS migration. The developed methodology provided a platform to personalize ICRS refractive surgery with regard to the patient’s keratoconus stage in order to facilitate the efficiency and biomechanical stability of the surgery.

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Mass transfer and blood flow in a patient-specific three-dimensional Willis circle

International Communications in Heat and Mass Transfer ◽

10.1016/j.icheatmasstransfer.2021.105369 ◽

2021 ◽

Vol 126 ◽

pp. 105369

Author(s):

Alessio Pignani ◽

Ivan Di Venuta ◽

Andrea Boghi ◽

Fabio Gori

Keyword(s):

Mass Transfer ◽

Blood Flow ◽

Three Dimensional ◽

Patient Specific

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A flexible framework for sequential estimation of model parameters in computational hemodynamics

Advanced Modeling and Simulation in Engineering Sciences ◽

10.1186/s40323-020-00186-x ◽

2020 ◽

Vol 7 (1) ◽

Author(s):

Christopher J. Arthurs ◽

Nan Xiao ◽

Philippe Moireau ◽

Tobias Schaeffter ◽

C. Alberto Figueroa

Keyword(s):

Unscented Kalman Filter ◽

Three Dimensional ◽

Synthetic Data ◽

Sequential Estimation ◽

Wall Material ◽

Patient Specific ◽

Model Parameters ◽

Computational Framework ◽

Lumped Parameter ◽

Estimation Of Model Parameters

AbstractA major challenge in constructing three dimensional patient specific hemodynamic models is the calibration of model parameters to match patient data on flow, pressure, wall motion, etc. acquired in the clinic. Current workflows are manual and time-consuming. This work presents a flexible computational framework for model parameter estimation in cardiovascular flows that relies on the following fundamental contributions. (i) A Reduced-Order Unscented Kalman Filter (ROUKF) model for data assimilation for wall material and simple lumped parameter network (LPN) boundary condition model parameters. (ii) A constrained least squares augmentation (ROUKF-CLS) for more complex LPNs. (iii) A “Netlist” implementation, supporting easy filtering of parameters in such complex LPNs. The ROUKF algorithm is demonstrated using non-invasive patient-specific data on anatomy, flow and pressure from a healthy volunteer. The ROUKF-CLS algorithm is demonstrated using synthetic data on a coronary LPN. The methods described in this paper have been implemented as part of the CRIMSON hemodynamics software package.

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The Accuracy of Three-Dimensional Planned Bone Tumor Resection Using Patient-Specific Instrument

Cancer Management and Research ◽

10.2147/cmar.s228038 ◽

2020 ◽

Vol Volume 12 ◽

pp. 6533-6540

Author(s):

Daniel A Müller ◽

Yannik Stutz ◽

Lazaros Vlachopoulos ◽

Mazda Farshad ◽

Philipp Fürnstahl

Keyword(s):

Bone Tumor ◽

Tumor Resection ◽

Three Dimensional ◽

Patient Specific ◽

Specific Instrument ◽

Bone Tumor Resection

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Three-Dimensional Correction of Distal Radius Intra-Articular Malunions Using Patient-Specific Drill Guides

The Journal Of Hand Surgery ◽

10.1016/j.jhsa.2013.09.023 ◽

2013 ◽

Vol 38 (12) ◽

pp. 2339-2347 ◽

Cited By ~ 74

Author(s):

Andreas Schweizer ◽

Philipp Fürnstahl ◽

Ladislav Nagy

Keyword(s):

Distal Radius ◽

Three Dimensional ◽

Patient Specific

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BIOMECHANICAL ANALYSIS OF THE STANDING LONG JUMP

Biomedical Engineering Applications Basis and Communications ◽

10.4015/s1016237203000286 ◽

2003 ◽

Vol 15 (05) ◽

pp. 186-192 ◽

Cited By ~ 12

Author(s):

WEN-LAN WU ◽

JIA-HROUNG WU ◽

HWAI-TING LIN ◽

GWO-JAW WANG

Keyword(s):

Knee Joint ◽

Motion Analysis ◽

Joint Angle ◽

Three Dimensional ◽

The Body ◽

Initial Angle ◽

Knee Joint Angle ◽

Standing Long Jump ◽

Long Jump ◽

Arm Motion

The purposes of the present study were to (1) investigate the effects of the arm movement and initial knee joint angle employed in standing long jump by the ground reaction force analysis and three-dimensional motion analysis; and (2) investigate how the jump performance of the female gender related to the body configuration. Thirty-four healthy adult females performed standing long jump on a force platform with full effort. Body segment and joint angles were analyzed by three-dimensional motion analysis system. Using kinetic and kinematic data, the trajectories on mass center of body, knee joint angle, magnitude of peak takeoff force, and impulse generation in preparing phase were calculated. Average standing long jump performances with free arm motion were +1.5 times above performance with restricted arm motion in both knee initial angles. The performances with knee 90° initial flexion were +1.2 times above performance with knee 45° initial flexion in free and restricted arm motions. Judging by trajectories of the center mass of body (COM), free arm motion improves jump distance by anterior displacement of the COM in starting position. The takeoff velocity with 90° knee initial angle was as much as 11% higher than in with 45° knee initial angle. However, the takeoff angles on the COM trajectory showed no significant differences between each other. It was found that starting jump from 90° bend knee relatively extended the time that the force is applied by the leg muscles. To compare the body configurations and the jumping scores, there were no significant correlations between jump scores and anthropometry data. The greater muscle mass or longer leg did not correlated well with the superior jumping performance.

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