Shock Wave as a Mechanism of Injury in Soft Tissues

2011 ◽  
Author(s):  
Kaveh Laksari ◽  
Kurosh Darvish ◽  
Keyanoush Sadeghipour
Keyword(s):  
Soft Tissues ◽  
Linear Models ◽  
Initial Conditions ◽  
Soft Tissue Injuries ◽  
High Rate ◽  
Loading Conditions ◽  
Mechanism Of Injury ◽  
Nonlinear Viscoelastic ◽  
Nonlinear Viscoelastic Materials ◽  
High Rate Loading

The aim of this study is to investigate the propagation of shock waves and self-preserving waves in soft tissues such as aorta and brain as a mechanism of injury in high rate loading conditions as seen in blunt trauma and blast-induced trauma (BIT). It is shown that such phenomena can only be seen in nonlinear viscoelastic materials and the existing linear and quasi-linear models predict only decaying waves. Based on the results of this study, it is shown that when studying such high-rate loading conditions as in a blast, it is critical to consider the discontinuities predicted in strain and stress in certain realistic initial conditions to accurately determine the extent of soft tissue injuries.

Shock Wave Propagation as a Mechanism of Injury in Nonlinear Viscoelastic Soft Tissues

2011 ◽  
Author(s):  
Kaveh Laksari ◽  
Mehdi Shafieian ◽  
Kurosh Darvish ◽  
Keyanoush Sadeghipour
Keyword(s):  
Wave Propagation ◽  
Shock Waves ◽  
Brain Tissue ◽  
Soft Tissues ◽  
Material Model ◽  
High Rate ◽  
Loading Conditions ◽  
Mechanism Of Injury ◽  
Nonlinear Viscoelastic ◽  
Blast Induced Neurotrauma

This study investigates the propagation of shock waves and self-preserving waves in soft tissues such as brain as a mechanism of injury in high rate loading conditions as seen in blast-induced neurotrauma (BINT). The derived mathematical models indicate that whereas linear viscoelastic models predict only decaying waves, instances of such phenomena as shock can be achieved in nonlinear media. In this study, a nonlinear viscoelastic material model for brain tissue was developed in compression. Furthermore, nonlinear viscoelastic wave propagation in brain tissue was studied and a criterion for the development of shock waves was formulated. It was shown that discontinuities in the acceleration that happen in blast loading conditions may evolve to shock waves, resulting in large discontinuities in strain and stress at the wave front leading to tissue injuries.

Mechanical and microstructural aspects of material failure due to localized shear under high-rate loading conditions

2018 ◽  
Author(s):  
Mikhail Sokovikov ◽  
Mikhail Simonov ◽  
Dmitry Bilalov ◽  
Vasiliy Chudinov ◽  
Vladimir Oborin ◽  
...  
Keyword(s):  
High Rate ◽  
Material Failure ◽  
Loading Conditions ◽  
High Rate Loading

scholarly journals Titanium Wear of Dental Implants from Placement, under Loading and Maintenance Protocols

2021 ◽  
Vol 22 (3) ◽  
pp. 1067
Author(s):  
Georgios Romanos ◽  
Gerard Fischer ◽  
Rafael Delgado-Ruiz
Keyword(s):  
Adverse Effects ◽  
Inflammatory Response ◽  
Dental Implants ◽  
Soft Tissues ◽  
Loading Conditions ◽  
Material Change ◽  
Implant Placement ◽  
Implant Abutment ◽  
Hard Tissues ◽  
Titanium Nanoparticles

The objective of this review was to analyze the process of wear of implants leading to the shedding of titanium particles into the peri-implant hard and soft tissues. Titanium is considered highly biocompatible with low corrosion and toxicity, but recent studies indicate that this understanding may be misleading as the properties of the material change drastically when titanium nanoparticles (NPs) are shed from implant surfaces. These NPs are immunogenic and are associated with a macrophage-mediated inflammatory response by the host. The literature discussed in this review indicates that titanium NPs may be shed from implant surfaces at the time of implant placement, under loading conditions, and during implant maintenance procedures. We also discuss the significance of the micro-gap at the implant-abutment interface and the effect of size of the titanium particles on their toxicology. These findings are significant as the titanium particles can have adverse effects on local soft and hard tissues surrounding implants, implant health and prognosis, and even the health of systemic tissues and organs.

Fall, Crush, Kick: Mechanisms and Outcomes in a Cohort of Equine-Related Injuries

2021 ◽  
pp. 000313482110488
Author(s):  
Pratik Bhade ◽  
Amelia Parsons ◽  
Abbey Smiley ◽  
Jacob Shreffler ◽  
Nick Nash ◽  
...  
Keyword(s):  
Traumatic Injury ◽  
The United States ◽  
Rib Fractures ◽  
High Rate ◽  
Protective Equipment ◽  
Solid Organ ◽  
Mechanism Of Injury ◽  
Severe Injuries ◽  
Protective Devices ◽  
Animal Size

Introduction The potential for significant traumatic injury to individuals who interact with horses remains high due to animal size, forces applied, and unpredictability. Despite an estimated 30 million riders in the United States annually, few recent publications have addressed this patient population. Objectives This study describes characteristics of patients injured in interactions with horses, focusing on mechanism of injury and use of protective equipment. Methods We queried our institution’s trauma registry for all patients admitted for equine-related injuries (ERI) between January 1, 2013 and December 31, 2017. We categorized by specific mechanism of injury (fall, crush, kick, fall + crush, and fall + kick) and presence or absence of protective devices. Results We discovered 143 patients admitted for injuries in equine-related accidents. Patients averaged 49.2 years old, and 62.2% were female. Crush injuries resulted in a high rate of rib fractures. Riders who were kicked had an increased chance of solid organ and facial injuries and falls most commonly led to rib fractures and extremity trauma. Despite lack of documentation on most subjects, protective devices were associated with less severe injuries in those with data (n = 36). Conclusions In this relatively large series of patients with ERI, we found mechanism differences within injury groups. Providers should more carefully document specific circumstances of ERIs. All individuals working with or around horses should exercise prudence and consider using protective equipment.

Development and Verification of a Dynamic TKR Model

2002 ◽  
Author(s):  
Jason P. Halloran ◽  
Anthony J. Petrella ◽  
Paul J. Rullkoetter
Keyword(s):  
Finite Element ◽  
Contact Mechanics ◽  
Dynamic Loading ◽  
Soft Tissues ◽  
Dynamic Models ◽  
Total Joint Replacement ◽  
Fe Model ◽  
Loading Conditions ◽  
Dynamic Loading Conditions

The success of current total knee replacement (TKR) devices is contingent on the kinematics and contact mechanics during in vivo activity. Indicators of potential clinical performance of total joint replacement devices include contact stress and area due to articulations, and tibio-femoral and patello-femoral kinematics. An effective way of evaluating these parameters during the design phase or before clinical use is via computationally efficient computer models. Previous finite element (FE) knee models have generally been used to determine contact stresses and/or areas during static or quasi-static loading conditions. The majority of knee models intended to predict relative kinematics have not been able to determine contact mechanics simultaneously. Recently, however, explicit dynamic finite element methods have been used to develop dynamic models of TKR able to efficiently determine joint and contact mechanics during dynamic loading conditions [1,2]. The objective of this research was to develop and validate an explicit FE model of a TKR which includes tibio-femoral and patello-femoral articulations and surrounding soft tissues. The six degree-of-freedom kinematics, kinetics and polyethylene contact mechanics during dynamic loading conditions were then predicted during gait simulation.

scholarly journals Magnetic resonance elastography in nonlinear viscoelastic materials under load

2018 ◽  
Vol 18 (1) ◽  
pp. 111-135 ◽  
Author(s):  
Adela Capilnasiu ◽  
Myrianthi Hadjicharalambous ◽  
Daniel Fovargue ◽  
Dharmesh Patel ◽  
Ondrej Holub ◽  
...  
Keyword(s):  
Magnetic Resonance ◽  
Magnetic Resonance Elastography ◽  
Viscoelastic Materials ◽  
Nonlinear Viscoelastic ◽  
Nonlinear Viscoelastic Materials
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