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Published in A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha, Clark’s Procedures in Diagnostic Imaging: A System-Based Approach, 2020
A Stewart Whitley, Jan Dodgeon, Angela Meadows, Jane Cullingworth, Ken Holmes, Marcus Jackson, Graham Hoadley, Randeep Kumar Kulshrestha
Three shock wave sources are commercially available. These are the electromagnetic, electrohydraulic and piezoelectric sources (Figs 7.38a–c). The electromagnetic source consists of a magnetic coil surrounded by a shock tube containing a metallic membrane. When an electrical charge is applied to the coil, the metallic membrane is repelled due to its opposite charge. This creates a shock wave that is focussed by means of an acoustic lens. This style of generator has a large skin entry zone and small focal point, which is associated with less pain than electrohydraulic lithotripters [60].
Environmental enrichment: A preclinical model of neurorehabilitation for traumatic brain injury
Published in Mark J. Ashley, David A. Hovda, Traumatic Brain Injury, 2017
Corina O. Bondi, Anthony E. Kline
EE has also been reported to exert benefits after blast TBI (bTBI) produced via a compression-driven shock tube as reported by Kovesdi et al.63 Following the bTBI, the rats were evaluated for behavioral performance on the elevated plus maze (EPM) and Barnes maze commencing on day 15 and extending to day 66 postinjury. EE did not normalize anxiety postinjury on the EPM. However, EE did significantly improve spatial memory performance in the Barnes maze compared to the non-EE rats.63 Furthermore, the signaling protein vascular endothelial growth factor, a positive regulator of adult hippocampal neurogenesis,64 and tau protein, a marker of axonal degeneration, were normalized in the dorsal hippocampus in the rats exposed to EE. EE also reduced IL-6 expression in the ventral hippocampus.63 That EE is able to provide benefit in a model of bTBI, which is taking on more significance given the nature of injuries in the military, strengthens the paradigm.
Biomechanical Perspective on Blast Injury Comorbid Brain and Somatic Trauma
Published in Rolland S. Parker, Concussive Brain Trauma, 2016
Mariusz. Ziejewski, Ghodrat. Karami
Cernak et al. (2001b) simulated a blast exposure on rats using an air-driven shock tube. The duration of the shock wave was varied by changing the length of the high-pressure chamber. With the tube end open, a single blast wave could be simulated.
The Roles of Vitreous Biomechanics in Ocular Disease, Biomolecule Transport, and Pharmacokinetics
Published in Current Eye Research, 2023
Richard H. Luo, Nguyen K. Tram, Ankur M. Parekh, Raima Puri, Matthew A. Reilly, Katelyn E. Swindle-Reilly
In addition to these models and studies designed to explore the pharmacokinetics of intravitreal injection, several efforts have been made to develop models that allow for characterization of the vitreous’ mechanical properties and response to injuries. Pokki et al. (2015) used ex vivo pig and human eyes to validate a viscoelasticity measurement system using round magnetic microparticles and externally applied magnetic fields to exert force on the vitreous humor, with camera observation used to evaluate the vitreous humor’s deformation response.13 Evans et al. (2018) recently made use of mice as a model to evaluate how the vitreoretinal interface responds to blast-induced traumatic brain injury (TBI), finding evidence of vitreous hemorrhage and detachment from the retina as well as retinal tissue damage.85 While the mouse eye is smaller, has a proportionally larger lens, and lacks a fovea compared to human eyes, its anatomical similarities with the human eye make mice a useful model for human retinal disease and injury.85 Liu et al. (2021) used rabbit eyes in similar evaluations of vitreous response to blast forces, finding slight vitreous hemorrhage at 5000 kPa, but no evidence of other vitreoretinal injury or detachment.86 Watson et al. (2015) used both computational models and shock tube systems to determine that in blast injuries, the viscoelastic properties of the vitreous played a key role during traumatic loading, as did the strength of adhesion to the retina.87
The pros and cons of motor, memory, and emotion-related behavioral tests in the mouse traumatic brain injury model
Published in Neurological Research, 2022
Ruoyu Zhang, Junming Wang, Leo Huang, Tom J. Wang, Yinrou Huang, Zefu Li, Jinxin He, Chen Sun, Jing Wang, Xuemei Chen, Jian Wang
The human TBI pathophysiology can be simulated by three main types of mouse models: the closed head injury (CHI) model [21], the open head injury model [22], and the repetitive mild brain injury model [23]. The CHI model, which is characterized by the skull remaining intact until an injury, consists of two subtypes: the weight-drop (WD) model and the blast model [24]. The WD model causes local blunt injury on the exposed cranial dura by a standardized weight-drop device. This results in a highly consistent and repetitive neuroinflammatory response in the intrathecal space and may lead to blood-brain barrier breakdown, edema formation, and neurologic deficits [21,25]. The blast model, on the other hand, is designed to mimic the typical injuries sustained by soldiers in modern warfare as a result of various explosives [26]. The model’s mechanism consists of an explosive pressure wave driven by a compressed gas-driven shock tube projected onto the head of an anesthetized mouse [27].
Original experimental rat model of blast-induced mild traumatic brain injury: a pilot study
Published in Brain Injury, 2021
Hiroshi Matsuura, Mitsuo Ohnishi, Yoshichika Yoshioka, Yuki Togami, Sanae Hosomi, Yutaka Umemura, Takeshi Ebihara, Kentaro Shimizu, Hiroshi Ogura, Takeshi Shimazu
Several devices are used in blast injury research, such as real explosives, shock tubes, laser-induced shock waves (6), and bench-top blast apparatuses (7,8). Among them, shock tubes and real explosives are the main methods used to produce a primary blast injury model. Especially, shock tubes are most commonly and frequently used in primary blast injury research. However, one of the main issues with the current research using animal models is the inconsistent placement of the animal when performing experiments with shock tubes (9). This makes comparison of the results between different laboratories virtually impossible, and the size of the shock tube is sometimes too large to investigate blast-induced mTBI in small animals except when investigating shock waves that affect the whole body. An animal model receiving a blast wave to its entire body generally does not survive if the pressure is more than 290 kPa due to blast lung injury (9). Chest protection or use of an Advanced Blast Simulator chamber was applied to handle these problems (10). The peak overpressure of the shock wave in much research into mTBI using shock tubes was reported to be less than 150 kPa (10–12).