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3 results on '"David O. Keyser"'

1. An Objective Assessment of Neuromotor Control Using a Smartphone App After Repeated Subconcussive Blast Exposure

Author

Charlend K. Howard, Masahiro Yamada, Marcia Dovel, Rie Leverett, Alexander Hill, Kenneth A. Manlapaz, David O. Keyser, Rene S. Hernandez, Sheilah S. Rowe, Walter S. Carr, Michael J. Roy, and Christopher K. Rhea

Subjects
neuromotor, balance, military, blast exposure, subconcussive, smartphone app, Chemical technology, TP1-1185
Abstract

Subconcussive blast exposure has been shown to alter neurological functioning. However, the extent to which neurological dysfunction persists after blast exposure is unknown. This longitudinal study examined the potential short- and long-term effects of repeated subconcussive blast exposure on neuromotor performance from heavy weapons training in military personnel. A total of 214 participants were assessed; 137 were exposed to repeated subconcussive blasts and 77 were not exposed to blasts (controls). Participants completed a short stepping-in-place task while an Android smartphone app placed on their thigh recorded movement kinematics. We showed acute suppression of neuromotor variability 6 h after subconcussive blast exposure, followed by a rebound to levels not different from baseline at the 72 h, 2-week, and 3-month post-tests. It is postulated that this suppression of neuromotor variability results from a reduction in the functional degrees of freedom from the subconcussive neurological insult. It is important to note that this change in behavior is short-lived, with a return to pre-blast exposure movement kinematics within 72 h.

Published
2024
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2. Methodology of the INVestigating traIning assoCiated blasT pAthology (INVICTA) study

Author

Michael J. Roy, David O. Keyser, Sheilah S. Rowe, Rene S. Hernandez, Marcia Dovel, Holland Romero, Diana Lee, Matthew Menezes, Elizabeth Magee, Danielle J. Brooks, Chen Lai, Jessica Gill, Suthee Wiri, Elizabeth Metzger, J. Kent Werner, Douglas Brungart, Devon M. Kulinski, Dominic Nathan, and Walter S. Carr

Subjects
Traumatic brain injury, subconcussive injury, concussion, military blast exposure, Medicine (General), R5-920
Abstract

Abstract Background Subconcussive blast exposure during military training has been the subject of both anecdotal concerns and reports in the medical literature, but prior studies have often been small and have used inconsistent methods. Methods This paper presents the methodology employed in INVestigating traIning assoCiated blasT pAthology (INVICTA) to assess a wide range of aspects of brain function, including immediate and delayed recall, gait and balance, audiologic and oculomotor function, cerebral blood flow, brain electrical activity and neuroimaging and blood biomarkers. Results A number of the methods employed in INVICTA are relatively easy to reproducibly utilize, and can be completed efficiently, while other measures require greater technical expertise, take longer to complete, or may have logistical challenges. Conclusions This presentation of methods used to assess the impact of blast exposure on the brain is intended to facilitate greater uniformity of data collection in this setting, which would enable comparison between different types of blast exposure and environmental circumstances, as well as to facilitate meta-analyses and syntheses across studies.

Published
2022
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3. Body-mounted blast overpressure sensor data analysis for the INVICTA program

Author

MED, Suthee Wiri, Andrea Gonzales, Matthew Menezes, David O. Keyser, Walter S. Carr, Sheilah Rowe, Rene S. Hernandez, Marcia Dovel, Holland Romero, Diana Lee, Michael Roy, MED, Suthee Wiri, and Andrea Gonzales, Matthew Menezes, David O. Keyser, Walter S. Carr, Sheilah Rowe, Rene S. Hernandez, Marcia Dovel, Holland Romero, Diana Lee, Michael Roy

Abstract

Acknowledgements Quality Control Body-mounted blast overpressure sensor data analysis for the INVICTA program Funding: Defense Health Agency Using high-fidelity CFD simulations, for reconstructing blast environments provide valuable information. It can determine how positioning, orientation, and environment affect the blast exposure on personnel in combat training. The calculation values can be used to understand overpressure exposure, mitigate exposure where possible, and can be correlated with ongoing research to address concerns associated with medical outcomes. Collected exposure data included Range Safety Officers (RSO) and trainees (subjects) in combat training scenarios. A total of 64 participants were analyzed , including 11 RSO and 53 trainees. The total number of gauge triggers for all subjects is 1,529. The number of “good” waveforms is 1,114. Taking exposure locations one step further, ARA has looked at specifically the head location and compared to the peak overpressure values. R003 has the highest values at 14 psi with 11 exposures. R008 has the lowest exposure count as well as the lowest peak overpressure value. Understanding blast exposure is important for protecting our service members. Body-mounted blast overpressure sensors are used to quantify blast exposure magnitude and frequency on personnel in combat training. Through the Investigating Training Associated Blast Pathology (INVICTA) program, the collection and analysis of body-mounted blast sensor information was used to better understand blast exposure on personnel and correlate with medical outcomes specifically Traumatic Brain Injury (TBI). Background RSO/Trainee Results RSO/Trainee Results Blast overpressure data was collected with Blast Gauges (BG) by BlackBox Biometrics worn in sets of three on the body: head (nape of neck), chest, and non-firing shoulder. The BG records overpressure exposure data on the subjects and a date and time stamp. When worn during combat training, the gauges reco, RITM0028170, Understanding blast exposure is important for protecting our service members. Body-mounted blast overpressure sensors are used to quantify blast exposure magnitude and frequency on personnel in combat training. Through the Investigating Training Associated Blast Pathology (INVICTA) program, the collection and analysis of body-mounted blast sensor information was used to better understand blast exposure on personnel and correlate with medical outcomes specifically Traumatic Brain Injury (TBI).

Published
2022

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