title: Vertical accelerator device to apply loads simulating blast environments in the military to human surrogates.
abstract: The objective of the study was to develop a simple device, Vertical accelerator (Vertac), to apply vertical impact loads to Post Mortem Human Subject (PMHS) or dummy surrogates because injuries sustained in military conflicts are associated with this vector; example, under-body blasts from explosive devices/events. The two-part mechanically controlled device consisted of load-application and load-receiving sections connected by a lever arm. The former section incorporated a falling weight to impact one end of the lever arm inducing a reaction at the other/load-receiving end. The "launch-plate" on this end of the arm applied the vertical impact load/acceleration pulse under different initial conditions to biological/physical surrogates, attached to second section. It is possible to induce different acceleration pulses by using varying energy absorbing materials and controlling drop height and weight. The second section of Vertac had the flexibility to accommodate different body regions for vertical loading experiments. The device is simple and inexpensive. It has the ability to control pulses and flexibility to accommodate different sub-systems/components of human surrogates. It has the capability to incorporate preloads and military personal protective equipment (e.g., combat helmet). It can simulate vehicle roofs. The device allows for intermittent specimen evaluations (x-ray and palpation, without changing specimen alignment). The two free but interconnected sections can be used to advance safety to military personnel. Examples demonstrating feasibilities of the Vertac device to apply vertical impact accelerations using PMHS head-neck preparations with helmet and booted Hybrid III dummy lower leg preparations under in-contact and launch-type impact experiments are presented.
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States. Electronic address: yoga@mcw.edu.
authors.forename: Narayan
authors.initials: N
authors.lastname: Yoganandan
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Frank A
authors.initials: FA
authors.lastname: Pintar
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Schlick
authors.affiliation: Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, United States.
authors.forename: John R
authors.initials: JR
authors.lastname: Humm
authors.affiliation: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, United States.
authors.forename: Liming
authors.initials: L
authors.lastname: Voo
authors.affiliation: Applied Physics Laboratory, Johns Hopkins University, Laurel, MD, United States.
authors.forename: Andrew
authors.initials: A
authors.lastname: Merkle
authors.affiliation: US Army Research Laboratory, Soldier Protection Sciences Branch, Aberdeen Proving Ground, MD, United States.
authors.forename: Michael
authors.initials: M
authors.lastname: Kleinberger
mesh_terms: D000054:Acceleration; D005107:Explosions; D006257:Head / Q000502:physiology; D006801:Humans; D008422:Materials Testing / Q000295:instrumentation*; D008889:Military Personnel; D009333:Neck / Q000502:physiology; D016474:Weight-Bearing
keywords: Impact biomechanics; Military events; Under-body blasts; Vertical loading