Validation of a Biomechanical Injury and Disease Assessment Platform Applying an Inertial-Based Biosensor and Axis Vector Computation.

Inertial kinetics and kinematics have substantial influences on human biomechanical function. A new algorithm for Inertial Measurement Unit (IMU)-based motion tracking is presented in this work. The primary aims of this paper are to combine recent developments in improved biosensor technology with mainstream motion-tracking hardware to measure the overall performance of human movement based on joint axis-angle representations of limb rotation.

A stochastic model validated with human test data causally associating target vehicle Delta V, occupant cervicocranial biomechanics, and injury during rear-impact crashes.

Even at low to moderate-speeds, rear-end motor vehicle crashes have been strongly associated with occupant cervicocranial biomechanics that lead to head and neck injury. In this paper, we present the development of an analytic mechanics model of occupant head and neck motion as associated with modeled target vehicle Delta V during rear-end vehicular crashes. The inclusion of stochastic mechanical input variables further developed the model beyond the deterministic framework by reflecting aspects of the random nature of real-world crashes and the resulting injuries.

A temporospatial histomorphometric analysis of bone density adjacent to acid-etched self-tapping dental implants with an external hexagon connection in the female baboon.

Objective: To characterize osseointegration as the percent of bone-implant contact (%BIC) along the surface (0.0 mm) as well as at surface profiles 0.5 mm and 1.

Application of flexural and membrane stress analysis to distinguish tensile and compressive moduli of biologic materials.

Three-point bending is often used during the mechanical determination of tissue material properties. When taken to failure, the test samples often experience high deformations. The objective of this study was to present beam and plate theories as analytical tools for determining tensile and compressive elastic moduli during the transition from flexure to membrane stress states.

Affordance-Based Surgical Design Methods Considering Biomechanical Artifacts.

Surgical design in personalized medicine is often based on native anatomy, which may not accurately reflect the interaction between native musculoskeletal tissues and biomechanical artifacts. To overcome this problem, researchers have developed alternative methods based on affordance-based design. The design process can be viewed in terms of action possibilities provided by the (biological) environment.

Crestal bone loss due to abutment manipulation and an internal silver deposition implant design in a canine model.

Objective: The study aimed to evaluate the effect of internal silver coating as a countermeasure to crestal bone loss around implants with or without multiple abutment disconnections/reconnections.

Materials And Methods: Following tooth extraction, 48 implants with connected healing abutments (24 implants internally coated with elemental silver) were placed in the mandible of eight beagle dogs. Two months after implant surgery one side of the mandible was randomly assigned to four abutment manipulations (disconnection/reconnection) on a weekly basis.

A Deterministic Model of Human Motion Based on Algebraic Techniques and a Sensor Network to Simulate Shoulder Kinematics.

Limiting the quantitative characterization of ambulatory mobility to only the two-dimensional sagittal plane through the investigation of key kinematic parameters, may still inform scientists and bioengineers of critical elements of joint locomotion. This paper presents the initial validation of a deterministic biomechanical gait model that was derived from an inverse kinematic analysis of three-dimensional upper extremity movement. Algebraic methods were applied to generate shoulder flexion and extension angles during a single gait cycle during normal walking.

The Influence of Vitamin D Metabolism on Gene Expression, Matrix Production and Mineralization During Osteoprecursor Cell-Based Bone Development.

Background: Multipotential precursor cell lines derived from human bone marrow, capable of differentiating into cartilage or bone, may provide a useful tissue development model for studying the regulation and metabolism of putative growth and differentiation factors necessary for tissue regeneration. In mammals, the process of bone development depends on the proliferation and differentiation of osteoblast lineage cells, and the subsequent synthesis and mineralization of bone extracellular matrix (ECM). Vitamin D metabolites play a pivotal role in bone and mineral homeostasis, and are positive factors on bone development.

Novel computational approaches characterizing knee physiotherapy.

A knee joint's longevity depends on the proper integration of structural components in an axial alignment. If just one of the components is abnormally off-axis, the biomechanical system fails, resulting in arthritis. The complexity of various failures in the knee joint has led orthopedic surgeons to select total knee replacement as a primary treatment.

Biomechanical Analysis of Concealed Pack Load Influences on Terrorist Gait Signatures Derived from Gröbner Basis Theory.

This project examines kinematic gait parameters as forensic predictors of the influence associated with individuals carrying concealed weighted packs up to 20% of their body weight. An initial inverse dynamics approach combined with computational algebra provided lower limb joint angles during the stance phase of gait as measured from 12 human subjects during normal walking. The following paper describes the additional biomechanical analysis of the joint angle data to produce kinetic and kinematic parameters further characterizing human motion.

Tracking Knee Joint Functional Axes through Tikhonov Filtering and Plűcker Coordinates.

Researchers have reported several compensation methods to estimate bone and joint position from a cluster of skin-mounted markers as influenced by Soft Tissue Artifacts (STA). Tikhonov Regularization Filtering (TRF) as a means to estimate Instantaneous Screw Axes (ISA) was introduced here as a means to reduce the displacement of a rigid body to its simplest geometric form. Recent studies have suggested that the ISA of the knee, i.

The relationship between vehicle roof crush and head, neck and spine injury in rollover crashes.

Background: It is well established that rollover crashes are associated with a higher risk of serious injury and death than other types of crashes. Some of the most serious injuries that can result from a rollover crash are those to the head, neck and spine. The mechanism of injury to these body parts in a rollover is a matter of dispute in the literature.

The stationary configuration of the knee.

Background: Ligaments and cartilage contact contribute to the mechanical constraints in the knee joints. However, the precise influence of these structural components on joint movement, especially when the joint constraints are computed using inverse dynamics solutions, is not clear.

Methods: We present a mechanical characterization of the connections between the infinitesimal twist of the tibia and the femur due to restraining forces in the specific tissue components that are engaged and responsible for such motion.

An Informational Algorithm as the Basis for Perception-Action Control of the Instantaneous Axes of the Knee.

Traditional locomotion studies emphasize an optimization of the desired movement trajectories while ignoring sensory feedback. We propose an information based theory that locomotion is neither triggered nor commanded but controlled. The basis for this control is the information derived from perceiving oneself in the world.

Assessing specific causation of mesothelioma following exposure to chrysotile asbestos-containing brake dust.

Background: The question of whether chrysotile asbestos-containing brake dust can plausibly serve as a cause of mesothelioma in an exposed individual has become a matter of heated debate in the medical literature despite multiple international, federal, and state governmental agencies acknowledging a causal association.

Objectives: We describe and provide an analysis of various industry and academic perspectives contributing to the debate.

Methods: A framework is presented for evaluating the general and specific causal relationship between brake dust exposure and mesothelioma utilizing the principles of forensic epidemiology, and by applying the Bradford-Hill criteria.

Cytoskeletal strains in modeled optohydrodynamically stressed healthy and diseased biological cells.

Controlled external chemomechanical stimuli have been shown to influence cellular and tissue regeneration/degeneration, especially with regards to distinct disease sequelae or health maintenance. Recently, a unique three-dimensional stress state was mathematically derived to describe the experimental stresses applied to isolated living cells suspended in an optohydrodynamic trap (optical tweezers combined with microfluidics). These formulae were previously developed in two and three dimensions from the fundamental equations describing creeping flows past a suspended sphere.

Efferent Copy and Corollary Discharge Motor Control Behavior Associated with a Hopping Activity.

Hoppers respond not only to stimuli from the ground surfaces but also to cues generated by their own behaviors. This leads to desensitization because although the afferent and reafferent signals have distinct causes, they are carried by the same sensory channels. From a behavioral viewpoint, it may be necessary to distinguish between signals from the two causes especially when monitoring changes in the external environment separate from those due to self-movement.

Extrahepatic 25-Hydroxylation of Vitamin D in an Engineered Osteoblast Precursor Cell Line Exploring the Influence on Cellular Proliferation and Matrix Maturation during Bone Development.

Osteoblastic precursors experience distinct stages during differentiation and bone development, which include proliferation, extracellular matrix (ECM) maturation, and ECM mineralization. It is well known that vitamin D plays a large role in the regulation of bone mineralization and homeostasis via the endocrine system. The activation of vitamin D requires two sequential hydroxylation steps, first in the kidney and then in the liver, in order to carry out its role in calcium homeostasis.

Forensic epidemiologic and biomechanical analysis of a pelvic cavity blowout injury associated with ejection from a personal watercraft (jet-ski).

Jet-propelled personal watercraft (PWC) or jet-skis have become increasingly popular. The means of propulsion of PWC, which is a jet of water forced out of small nozzle at the rear of the craft, combined with a high risk of falling off of the seat and into close proximity with the water jet stream, raise the potential for a unique type of injury mechanism. The most serious injuries associated with PWC falls are those that occur when the perineum passes in close proximity to the jet nozzle and the high-pressure water stream enters the vaginal or rectal orifice.

Plasma levels of polychlorinated biphenyls, non-Hodgkin lymphoma, and causation.

Polychlorinated biphenyls (PCBs) are synthetic chlorinated hydrocarbons that have extensively polluted the environment and bioaccumulated in the food chain. PCBs have been deemed to be probable carcinogens by the Environmental Protection Agency, and exposure to high levels of PCBs has been consistently linked to increased risk of non-Hodgkin lymphoma (NHL). In the present article we present a forensic epidemiologic evaluation of the causal relationship between NHL and elevated PCB levels via application of the Bradford-Hill criteria.

A cell-matrix model of anabolic and catabolic dynamics during cartilage biomolecule regulation.

Physiologic regulation of extracellular matrix (ECM) in articular cartilage tissue is controlled by cellular and molecular mechanisms which are not fully understood. It has been observed that the synthesis of the ECM structural molecules, glycosaminoglycan and collagen are promoted by growth factors such as IGF-1 and TGF-β. Concomitant ECM degradation is promoted by a variety of cytokines such as IL-1.

Ultrasonic wave propagation assessment of native cartilage explants and hydrogel scaffolds for tissue engineering.

Non-destructive techniques characterising the mechanical properties of cells, tissues, and biomaterials provide baseline metrics for tissue engineering design. Ultrasonic wave propagation and attenuation has previously demonstrated the dynamics of extracellular matrix synthesis in chondrocyte-seeded hydrogel constructs. In this paper, we describe an ultrasonic method to analyse two of the construct elements used to engineer articular cartilage in real-time, native cartilage explants and an agarose biomaterial.

An evaluation of applied biomechanics as an adjunct to systematic specific causation in forensic medicine.

Biomechanical tests of post hoc probability have been proposed by prior authors as reliable tests of causation in forensic settings. Biomechanical assessment of injury kinetics and kinematics is a potentially important tool in forensic medicine, but there is also the potential for misapplication. The most reliable application is when biomechanical analysis is used to explain injury mechanisms, such as how an injury may have occurred.

Biokinetic Mechanisms Linked With Musculoskeletal Health Disparities: Stochastic Models Applying Tikhonov's Theorem to Biomolecule Homeostasis.

Multiscale technology and advanced mathematical models have been developed to control and characterize physicochemical interactions, respectively, enhancing cellular and molecular engineering progress. Ongoing tissue engineering development studies have provided experimental input for biokinetic models examining the influence of static or dynamic mechanical stimuli (Saha, A. K.

Three-Dimensional Culture of Cells and Matrix Biomolecules for Engineered Tissue Development and Biokinetics Model Validation.

There has been considerable progress in cellular and molecular engineering due to recent advances in multiscale technology. Such technologies allow controlled manipulation of physiochemical interactions among cells in tissue culture. In particular, a novel chemomechanical bioreactor has recently been designed for the study of bone and cartilage tissue development, with particular focus on extracellular matrix formation.