Use Of Biomechanical Models Research Articles

Equine biomechanical models for three-dimensional kinematics analysis: literature review/ Modelos biomecânicos equinos para análise de cinemática tridimensional: revisão de literatura

Three-dimensional analysis in horses has been widely used in the past years due to technological advancement. With the objective of conducting a literature review of the applicability of existing evidence in horses of a biomechanical model focusing on three-dimensional kinematics and its production in Veterinary Medicine, we searched in the databases: ScienceDirect, SciELO and PubMed. To access them, using as key-words: "Three-dimensional kinematic model in equines", "equine kinematic analysis", "biomechanics of equine locomotion", "equine kinematic model". Selection criteria were papers published between: paper published between 1990 and 2020, in English, with free electronic access and in which characteristics of a three-dimensional kinematic model in horses were mentioned. Most studies were experimental, and population included both healthy horses and pathological ones. Three-dimensional kinematic model was used mainly to understand the analysed movement and using as model the full body. There is scientific evidence on the use of biomechanical models for three-dimensional kinematic analysis in horses published in the period studied, used by professionals in veterinary medicine. The objectives of using the model were specific to the type of movement or pathology of the horse and consistent with the characteristics of the studies.

Abstract PS3-21: Predicting cardiac dysfunction in breast cancer patients undergoing aromatase inhibitor treatment using biomechanical model-based elasticity imaging

Abstract Introduction Premenopausal women with intermediate-high risk HR+ breast cancer often receive near-complete estrogen deprivation with ovarian function suppression concurrent with an AI. Hypoestrogenemia is associated with cardiotoxicity, but the cardiovascular impact of this newer breast cancer treatment is largely unknown. With increases in survival rates and younger women being diagnosed, methods to monitor and predict cardiac damage due to OFS+AI therapy are needed. Left ventricle (LV) ejection fraction is currently used for monitoring cancer treatment-related cardiovascular degradation, and can detect major heart defects, but is insensitive to subclinical left ventricle function. Emerging methods include T1 mapping and estimation of myocardial strain to indicate fibrosis. We propose an extension of these methods by estimating cardiac tissue elasticity using LV wall deformation to drive a biomechanical model. Elasticity is a more functional and direct measurement of tissue response based on structural mechanics driven by patient-specific cardiac magnetic resonance imaging (CMR) data. Elasticity measurements may serve as a predictive biomarker of early AI-induced cardiac changes.MethodsThis study is a retrospective initial proof-of-concept correlative imaging study to an existing clinical study for the use of CMR to detect cardiovascular damage (ESPRIT). Two cohorts of premenopausal breast cancer patients either: (1) undergoing OFS+AI for HR+ breast cancer or (2) triple negative breast cancer (TNBC) patients that have already received chemotherapy, were imaged twice, 3-6 months apart using CINE CMR. TNBC patients serve as the control, with no expectation of further cancer treatment-related cardiac damage. Time steps during passive ventricular diastole were visually selected from CINE CMRs. Each slice was non-rigidly registered to estimate LV deformation during passive filling. Deformation was simulated on a finite element mesh of the LV based on linear elastic transverse isotropic mechanical equilibrium. Using an inverse problem formulation, simulated deformation was compared to model-calculated deformation to estimate the spatial tissue longitudinal and transverse elasticity. Elasticity maps of the LV at initial and final points are compared to determine regional stiffening of the LV wall, to be used as early biomarkers for LV fibrosis. ResultsIn this initial investigation, elasticity maps were analyzed for four patients (n=2 from each cohort). Passive LV tissue stiffening was observed in each AI patient, with 100% and 25% relative increases observed for longitudinal elasticity and 50% increases for transverse elasticity in the basal inferior region, and mid anterior region of the LV in each patient, respectively. No increases in stiffness of the LV were observed for TNBC patients. Ejection fraction remained consistent for all patients. ConclusionIn this proof-of-concept study, we demonstrate that elasticity maps indicate local stiffening of the LV using a biomechanical model-based elasticity imaging method that could be used to indicate cardiac dysfunction in breast cancer patients receiving AIs. Spatial elasticity mapping allows direct observation of structural mechanics to reveal specific areas of LV stiffening. Moving beyond traditional strain imaging, our method yields a functional measure of tissue stiffness to directly indicate cardiac fibrosis. This study demonstrates the use of biomechanical models to interpret CMR and provides potential for use of more advanced constitutive models. Our non-invasive biomechanical model-based elasticity imaging method shows significant promise to indicate early cardiac function deterioration, critical for premenopausal women undergoing extended cancer therapies. Citation Format: Caroline Elizabeth Miller, Jennifer Jordan, Alexandra Thomas, Jared Weis. Predicting cardiac dysfunction in breast cancer patients undergoing aromatase inhibitor treatment using biomechanical model-based elasticity imaging [abstract]. In: Proceedings of the 2020 San Antonio Breast Cancer Virtual Symposium; 2020 Dec 8-11; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2021;81(4 Suppl):Abstract nr PS3-21.

An Image Registration-Based Morphing Technique for Generating Subject-Specific Brain Finite Element Models.

Finite element (FE) models of the brain are crucial for investigating the mechanisms of traumatic brain injury (TBI). However, FE brain models are often limited to a single neuroanatomy because the manual development of subject-specific models is time consuming. The objective of this study was to develop a pipeline to automatically generate subject-specific FE brain models using previously developed nonlinear image registration techniques, preserving both external and internal neuroanatomical characteristics. To verify the morphing-induced mesh distortions did not influence the brain deformation response, strain distributions predicted using the morphed model were compared to those from manually created voxel models of the same subject. Morphed and voxel models were generated for 44 subjects ranging in age, and simulated using head kinematics from a football concussion case. For each subject, brain strain distributions predicted by each model type were consistent, and differences in strain prediction was less than 4% between model type. This automated technique, taking approximately 2 h to generate a subject-specific model, will facilitate interdisciplinaryresearch between thebiomechanics and neuroimagingfields and could enable future use of biomechanical models in the clinical setting as a tool for improving diagnosis.

Testing of tractor mounted and self propelled coconut climber for coconut harvesting

The coconut is known as Kalpa Vriksa to the world for being its multi faceted uses, which provide livelihood security to millions of people. Every part of it useful to humans in one of the other ways. The coconut palm is grown in more than 93 countries of the tropics. Its botanical name is Cocos-Nucifera L. and belongs to the aracaceae (Palm) family. The climbing methods of coconuts like manual, mechanical and climbing by Tractor Operated Hydraulic Elevator (TOME) were studied. The stability, safety, harvesting efficiency, drudgery of coconut harvesting is reduced by Tractor Mounted and Self Propelled Coconut Climber (TMSPCC) developed by considering the drawbacks of the above methods. The testing of developed TMSPCC was carried out at a Coconut Research Station, Bhyte Ratnagiri, India. To assess the physiological cost and the drudgery involved in the traditional method of tree climbing operation. The digital polar hart rate meter RS400TM having infrared connectivity sensor was used for recording the heart rates. The technical assessments included the use of biomechanical models, ODR, BPDS. The ergonomical evaluation of TMSPCC was carried out for testing feasibility, ease of operation; workers jeopardize safety health and efficiency for coconut harvesting. Ergonomically operational safe and controlled heart rates are recorded. The fourteen to seventeen number of coconut orchards were harvested in one hour by using TMSPCC. The tractor mounted and self propelled coconut climber founds suitable for harvesting 100 to 120 coconut trees in a day. The net coconut harvesting by using TMSPCC are 4000 coconuts/day. Also TMSPCC is safe, less hazardous and economical as compared to manual climbing coconut harvesting and climbing by the existing tractor mounted hydraulic elevator.

TESTING AND ERGONOMICALLY EVALUATION OF TRACTOR MOUNTED AND SELF MOUNTED COCONUT CLIMBER

The coconut is known as Kalpa Vriksa to the world for being its multi faceted uses, which provide livelihood security to millions of people, every part of it useful to humans in one of the other ways. The coconut palm is grown in more than 93 countries of the tropics. Its botanical name is cocos-nucifera L. and belongs to the aracaceae (Palm) family. The climbing methods of coconuts like manual, mechanical and climbing by Tractor Mounted Hydraulic Elevator (THME) were studied. The stability, safety, harvesting efficiency, drudgery of coconut harvesting is reduced by Tractor Mounted and Self Propelled Coconut Climber (TMSPCC) developed by considering the drawbacks of the above methods. The testing of developed TMSPCC was carried out at a Coconut Research Station, Bhyte Ratnagiri, India. To assess the physiological cost and the drudgery involved in the traditional method of tree climbing operation. The digital polar hart rate meter RS400TM having infrared connectivity sensor was used for recording the heart rates. The technical assessments included the use of biomechanical models, ODR, BPDS. The ergonomical evaluation of TMSPCC was carried out for testing feasibility, ease of operation; workers jeopardize safety health and efficiency for coconut harvesting. Ergonomically operational safe and controlled heart rates are recorded. The fourteen to seventeen number of coconut orchards were harvested in one hour by using TMSPCC. The tractor mounted and self propelled coconut climber founds suitable for harvesting 100 to 120 coconut trees in a day. The net coconut harvesting by using TMSPCC are 4000 coconuts/day. Also TMSPCC is safe, less hazardous and economical as compared to manual climbing coconut harvesting and climbing by the existing tractor mounted hydraulic elevator

Stability and Ergonomic Design Features of Tractor Mounted Hydraulic Elevator for Coconut Harvesting

Problem statement: The most important design criterion of mechanized device was safety; safety comprises both the safety of operator and safety of maintenance personnel. Failures and safety of harvesting platform of Tractor Mounted Hydraulic Elevator (TMHE) powered by tractor PTO was tested by finite element method for the mechanical harvesting of coconut orchards using digital ergonomic hart rate meter. The objective of this study was to study the stability of the THME by finite element method, operational safety and power requirement for the use of this elevator for coconut harvesting. Provide sufficient adjustment and space to account for variation in body sizes, ensure controls were situated within suitable reach and were properly marked. Approach: The modal analysis was carried out for the whole assembly of tractor mounted hydraulic elevator by using Ansis software. The digital polar hart rate meter RS400TM having infrared connectivity sensor was used for recording the hart rates. The research stusy was conducted at, Dr. Balasaheb Sawant Kokan Krishi Vidyapeeth Dapoli. The harvesting of coconuts was performed by manual climbing labor and by tractor mounted hydraulic elevator. The technical assessments included the use of biomechanical models, vibration testing equipment, ODR, BPDS. The ergonomical evaluation results of the above study were correlates to decide the feasibility, safety and efficiency of Tractor mounted hydraulic elevator for coconut harvesting. The PTO rpm influence for the lifting and lowering of the harvesting platform was studied experimentally by using digital tachometer. Results: The better stability results with the controlled vibrations and frequency of the lifting platform and welded joints were recorded by keeping constrained boundary conditions. Ergonomically operational safe and controlled heart rates were recorded. Hence the labors can continuously do the coconut harvesting work by using the tractor mounted hydraulic elevator. The minimum PTO power was required for the coconut harvesting by using tractor mounted hydraulic elevator. Conclusion/Recommendation: The tractor mounted hydraulic elevator is suitable, safe, less hazardous and economical as compared to manual climbing for coconut harvesting. Hence it is recommended to use tractor mounted hydraulic elevator for harvesting, cleaning and breeding of coconut orchards upto 14 m height.

“What if”: The use of biomechanical models for understanding and treating upper extremity musculoskeletal disorders

To aid understanding of the working of the upper extremity, several musculoskeletal models of the shoulder and arm have been developed. These models comprise the full shoulder girdle, which implies that the thoracohumeral link is formed by a scapular and clavicular segment. These models are based upon limited anatomical parameter sets and work on the assumption of a general control principle. Upper Extremity models have proven to be useful for different categories of applications, such as quantification of the load on musculoskeletal structures, or the evaluation of changes in the musculoskeletal structure on function and mechanical integrity (“what if” questions). Although these models are increasingly used, validation has long been a difficult issue. With the development of instrumented endoprostheses, a new method for model validation has come within reach. Up till now results have indicated that to obtain ‘true’ force values, models should be scaled, and should allow for cocontraction. Musculoskeletal models will be finding their way in education and in clinical decision making. On the longer run individualized models might become important for application to individual patients, although scaling will for some time remain a difficult issue.

Computation of intra-operative brain shift using dynamic relaxation

Many researchers have proposed the use of biomechanical models for high accuracy soft organ non-rigid image registration, but one main problem in using comprehensive models is the long computation time required to obtain the solution. In this paper, we propose to use the Total Lagrangian formulation of the Finite Element method together with Dynamic Relaxation for computing intra-operative organ deformations. We study the best ways of estimating the parameters involved and we propose a termination criteria that can be used in order to obtain fast results with prescribed accuracy. The simulation results prove the accuracy and computational efficiency of the method, even in cases involving large deformations, nonlinear materials and contacts.

Bending of apricot tree branches under the weight of axillary growth: test of a mechanical model with experimental data

Stem orientation is an important factor for fruit tree growth and branching habit since it influences fruit production as well as training practices. A mechanical model of the bending of a stem under axillary load was written and evaluated using experimental data on apricot trees (Prunus armeniaca L.). A set of 15 1-year-old stems of various shapes was observed during the early stage of the growing season when radial growth is still negligible and the loading of the stem increases considerably. The structural modulus of elasticity (MOE) of the stems was estimated through in situ bending tests assuming homogeneous material behaviour. The effect of viscoelasticity was observed through creep tests performed on similar stems during winter. Inputs of the model are initial shape, initial diameter, and final load, defined at various positions along the stem. The final shape was simulated based on different mechanical assumptions, and compared to observations. Assuming small deflections resulted in an underestimate of the mean slope variation of 48%, accounting for large displacements reduced this underestimate to 29% and accounting for viscoelasticity reduced it further to 14%. An adjustment of the structural MOE to fit the final shape led to an excellent fit of the data in most cases, the residual errors for some axes being attributed to material heterogeneity. The use of biomechanical models to predict the shape of fruit trees based on growth parameters, provided adequate assumptions are made, is discussed.

Spinal Biomechanics

The lumbar spine is a source of disability due to low back pain (LBP), yet the precise diagnosis is unknown in 80-90 percent of patients. The lifetime prevalence is 75 percent with a cost to the U.S. economy as high as 80 billion dollars. The problem is partly caused by mechanical overloading of the tissues and thus, there is some potential for both primary and secondary prevention. Biomechanical techniques have been effective in improving our understanding of the loading conditions leading to LBP, and in developing techniques for improved diagnosis and more effectual methods of treatment. Much progress has been made through the use of biomechanical models. Most models assume that the external moments are balanced by trunk musculature. Multiple muscle system models, employing agonist and antagonists, now are available to define 3D spine reaction forces. The static indeterminacy is taken care of either by simplification of the model or by linear or nonlinear optimization. Dynamic analysis has shown that vibrational and impact conditions (such as vehicle driving) can excite the natural frequency of the spine and lead to high spinal loadings. In vivo measurements have shown the resonant frequency of the lumbar spine to be 4-5 Hz and many vehicles excite those frequencies. New biomechanical techniques employing electromyography can estimate muscle load and muscle fatigue. Stereo photogrammetric techniques for establishing segmental kinematics have great potential for improving the diagnosis of spinal problems. These techniques are solidly based on prior in-vitro measurements of spinal kinematics. Mechanical fixation techniques, such as pedicle fixation, show great promise in improving the treatment of spinal problems. These have been extensively analyzed by both finite element techniques and in-vitro simulation so as to improve design as well as surgical technique.