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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

Neck axial compression force injury risk function. (A) Original Pintar risk function (Pintar et al., 1998a) with confidence limits (dashed lines) and (B) expanded risk functions for male and female astronauts. Solid line represents mean astronaut age (47.1 and 43.3 for males and females, respectively), dashed lines represent the youngest and oldest astronauts (male: 35 and 56; female: 32 and 54). Note that force tolerance declines with age.
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Figure 5: Neck axial compression force injury risk function. (A) Original Pintar risk function (Pintar et al., 1998a) with confidence limits (dashed lines) and (B) expanded risk functions for male and female astronauts. Solid line represents mean astronaut age (47.1 and 43.3 for males and females, respectively), dashed lines represent the youngest and oldest astronauts (male: 35 and 56; female: 32 and 54). Note that force tolerance declines with age.

Mentions: Pintar et al. (1998b) report an injury risk function based on cervical compression force (Figure 5A). Using this risk function as a starting point, the results of another Pintar et al. (1990a,b, 1998a) study were investigated, which was based on data collected previously. Equation 12 gives the 50% injury risk function based on multiple factors including loading rate, age, and gender. Combining the logistic regression equation with Eq. 12 gives Eq. 13. This equation can then be rewritten to determine injury risk based on a neck axial compression force (Eq. 14).


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)

Neck axial compression force injury risk function. (A) Original Pintar risk function (Pintar et al., 1998a) with confidence limits (dashed lines) and (B) expanded risk functions for male and female astronauts. Solid line represents mean astronaut age (47.1 and 43.3 for males and females, respectively), dashed lines represent the youngest and oldest astronauts (male: 35 and 56; female: 32 and 54). Note that force tolerance declines with age.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

Figure 5: Neck axial compression force injury risk function. (A) Original Pintar risk function (Pintar et al., 1998a) with confidence limits (dashed lines) and (B) expanded risk functions for male and female astronauts. Solid line represents mean astronaut age (47.1 and 43.3 for males and females, respectively), dashed lines represent the youngest and oldest astronauts (male: 35 and 56; female: 32 and 54). Note that force tolerance declines with age.
Mentions: Pintar et al. (1998b) report an injury risk function based on cervical compression force (Figure 5A). Using this risk function as a starting point, the results of another Pintar et al. (1990a,b, 1998a) study were investigated, which was based on data collected previously. Equation 12 gives the 50% injury risk function based on multiple factors including loading rate, age, and gender. Combining the logistic regression equation with Eq. 12 gives Eq. 13. This equation can then be rewritten to determine injury risk based on a neck axial compression force (Eq. 14).

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