Limits...
Investigation of the THOR Anthropomorphic Test Device for Predicting Occupant Injuries during Spacecraft Launch Aborts and Landing.

Somers JT, Newby N, Lawrence C, DeWeese R, Moorcroft D, Phelps S - Front Bioeng Biotechnol (2014)

Bottom Line: Although all spacecraft designs were considered, the primary focus was the National Aeronautics and Space Administration Orion capsule, as the authors have the most knowledge and experience related to this design.In addition, the team down-selected the list of available injury metrics to the following: head injury criteria 15, kinematic brain rotational injury criteria, neck axial tension and compression force, maximum chest deflection, lateral shoulder force and displacement, acetabular lateral force, thoracic spine axial compression force, ankle moments, and average distal forearm speed limits.Musculoskeletal deconditioning due to exposure to reduced gravity over time can affect injury risk during landing; therefore a deconditioning factor was applied to all IARVs.

View Article: PubMed Central - PubMed

Affiliation: Science Technology and Engineering Group, Wyle , Houston, TX , USA.

ABSTRACT
The objective of this study was to investigate new methods for predicting injury from expected spaceflight dynamic loads by leveraging a broader range of available information in injury biomechanics. Although all spacecraft designs were considered, the primary focus was the National Aeronautics and Space Administration Orion capsule, as the authors have the most knowledge and experience related to this design. The team defined a list of critical injuries and selected the THOR anthropomorphic test device as the basis for new standards and requirements. In addition, the team down-selected the list of available injury metrics to the following: head injury criteria 15, kinematic brain rotational injury criteria, neck axial tension and compression force, maximum chest deflection, lateral shoulder force and displacement, acetabular lateral force, thoracic spine axial compression force, ankle moments, and average distal forearm speed limits. The team felt that these metrics capture all of the injuries that might be expected by a seated crewmember during vehicle aborts and landings. Using previously determined injury risk levels for nominal and off-nominal landings, appropriate injury assessment reference values (IARVs) were defined for each metric. Musculoskeletal deconditioning due to exposure to reduced gravity over time can affect injury risk during landing; therefore a deconditioning factor was applied to all IARVs. Although there are appropriate injury data for each anatomical region of interest, additional research is needed for several metrics to improve the confidence score.

No MeSH data available.


Related in: MedlinePlus

Head injury criteria 15 injury risk function (Funk et al., 2007).
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Figure 2: Head injury criteria 15 injury risk function (Funk et al., 2007).

Mentions: Recent studies of mild traumatic brain injury (mTBI) in football players can be very useful for determining the appropriate threshold for head injury. Since AIS 1 and 2 injuries to the brain are of primary concern, the HIC injury risk functions from Funk et al. (2007) will be used (Eq. 2). These data were chosen over the Virginia Tech data reported by Funk in 2012 because the HIC values from the 2007 study are more conservative (Funk et al., 2012). Because concussion injury risk determined from NASCAR head injury modeling resulted in much higher allowable HIC values (Somers et al., 2011), the Funk HIC 15 curve will be used to be conservative until the NASCAR results can be verified with additional datasets. In addition, the THOR ATD is assumed to have similar head kinematics as the Hybrid-III ATD. That allows for the use of identical HIC limits for both ATDs. Figure 2 shows the resultant HIC 15 injury risk function.


Investigation of the THOR Anthropomorphic Test Device for Predicting Occupant Injuries during Spacecraft Launch Aborts and Landing.

Somers JT, Newby N, Lawrence C, DeWeese R, Moorcroft D, Phelps S - Front Bioeng Biotechnol (2014)

Head injury criteria 15 injury risk function (Funk et al., 2007).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4126482&req=5

Figure 2: Head injury criteria 15 injury risk function (Funk et al., 2007).
Mentions: Recent studies of mild traumatic brain injury (mTBI) in football players can be very useful for determining the appropriate threshold for head injury. Since AIS 1 and 2 injuries to the brain are of primary concern, the HIC injury risk functions from Funk et al. (2007) will be used (Eq. 2). These data were chosen over the Virginia Tech data reported by Funk in 2012 because the HIC values from the 2007 study are more conservative (Funk et al., 2012). Because concussion injury risk determined from NASCAR head injury modeling resulted in much higher allowable HIC values (Somers et al., 2011), the Funk HIC 15 curve will be used to be conservative until the NASCAR results can be verified with additional datasets. In addition, the THOR ATD is assumed to have similar head kinematics as the Hybrid-III ATD. That allows for the use of identical HIC limits for both ATDs. Figure 2 shows the resultant HIC 15 injury risk function.

Bottom Line: Although all spacecraft designs were considered, the primary focus was the National Aeronautics and Space Administration Orion capsule, as the authors have the most knowledge and experience related to this design.In addition, the team down-selected the list of available injury metrics to the following: head injury criteria 15, kinematic brain rotational injury criteria, neck axial tension and compression force, maximum chest deflection, lateral shoulder force and displacement, acetabular lateral force, thoracic spine axial compression force, ankle moments, and average distal forearm speed limits.Musculoskeletal deconditioning due to exposure to reduced gravity over time can affect injury risk during landing; therefore a deconditioning factor was applied to all IARVs.

View Article: PubMed Central - PubMed

Affiliation: Science Technology and Engineering Group, Wyle , Houston, TX , USA.

ABSTRACT
The objective of this study was to investigate new methods for predicting injury from expected spaceflight dynamic loads by leveraging a broader range of available information in injury biomechanics. Although all spacecraft designs were considered, the primary focus was the National Aeronautics and Space Administration Orion capsule, as the authors have the most knowledge and experience related to this design. The team defined a list of critical injuries and selected the THOR anthropomorphic test device as the basis for new standards and requirements. In addition, the team down-selected the list of available injury metrics to the following: head injury criteria 15, kinematic brain rotational injury criteria, neck axial tension and compression force, maximum chest deflection, lateral shoulder force and displacement, acetabular lateral force, thoracic spine axial compression force, ankle moments, and average distal forearm speed limits. The team felt that these metrics capture all of the injuries that might be expected by a seated crewmember during vehicle aborts and landings. Using previously determined injury risk levels for nominal and off-nominal landings, appropriate injury assessment reference values (IARVs) were defined for each metric. Musculoskeletal deconditioning due to exposure to reduced gravity over time can affect injury risk during landing; therefore a deconditioning factor was applied to all IARVs. Although there are appropriate injury data for each anatomical region of interest, additional research is needed for several metrics to improve the confidence score.

No MeSH data available.


Related in: MedlinePlus