NOTE: End date changed to 9/30/2019 per E. Connell/HFBP/JSC (Ed., 11/17/17)

NOTE: Element change to Human Factors & Behavioral Performance; previously Space Human Factors & Habitability (Ed., 1/19/17)

NOTE: Change to start date per E. Connell/SHFH/HRP (Ed., 2/3/16)

NOTE: Added "Development" to title, per E. Connell/SHFH/HRP (Ed., 10/7/15)

NOTE: Change in title to "ATD Injury Metric" from "THOR Injury Metric Development" per E. Connell/SHFH HRP (Ed., 8/19/15)

NOTE: Period of performance changed to 5/1/2015-9/30/2017 (previously 7/3/2014-10/31/2016) due to delayted start, per E. Connell/JSC SHFH element (Ed., 4/15/2015)

Specific Aims

1. Identify appropriate datasets for ATD comparison

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing

3. Use historical human data to establish tolerance and injury risk focusing on lower neck injury, lateral responses, and sex differences

4. Perform survival analysis with human tolerance to estimate injury risk and use results of prior data mining and existing literature as prior distribution

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis.

For each phase of this study, historical PMHS test cases were first selected from the Medical College of Wisconsin (MCW) database for matched-pair testing. Selection of these cases was made based on their similarity to spaceflight loading dynamics and astronaut demographics. Once these data were selected, the Hybrid III 50th percentile male and THOR ATD are tested in identical conditions. The following injury criteria were evaluated:

1. Lower neck injury in rearward loading

2. Vertical neck loading

3. Upper and lower neck under lateral loading

4. Thorax in lateral loading

5. Pelvis in lateral loading

A survival analysis was used to relate the resulting dynamic responses to identified PMHS injuries and develop injury risk correlation. This correlation was used to improve upon the injury metrics previously developed under the Occupant Protection (OP) Data Mining and Modeling Task. The resulting metrics will be used to update NASA standards and provided to the Orion and Commercial Crew programs to allow additional insight into verification, validation, and risk analysis.

2 Vertical Neck Loading. A total of 36 PMHS were selected for this phase of the study. There were 2 groups used for testing, a group that was tested in an upright orientation, and the other tested in an inverted orientation. Each PMHS head-neck was loaded axially inducing a compression force. Because of the nature of the loading, and because ATD responses are not biofidelic, matched pair testing of the Hybrid III and THOR ATDs could not be conducted. As with the previous phase, the injury metric (axial force) was calculated using parametric survival analysis for the PMHS. The resulting IRCs were calculated along with confidence intervals with the same quality assessment used. The axial force was evaluated at the 5% risk level and found have a good fit quality in both the upright and inverted tests, as well as with the combined female data set of all ages.

3. Upper and Lower Neck under Lateral Loading. A total of 11 PMHS were selected for this phase of the study. There were 3 groups used for testing, with varying torso restraint used. Each PMHS was accelerated laterally, inducing a combined lateral moment, lateral shear force, and axial tension force in the neck of the PMHS. Matched pair testing of the Hybrid III and THOR ATD were also conducted in the same loading conditions, allowing direct comparison of the ATD responses and injury outcomes reported in the PMHS tests. As with the previous phase, the injury metric (lower lateral neck injury criteria, lower LatNij) was calculated using parametric survival analysis for the PMHS. The resulting IRCs were calculated along with confidence intervals with the same quality assessment used. The lower LatNij was evaluated at the 5% risk level. For the PMHS and THOR ATD, the lower LatNij was found to be an excellent fit. For the Hybrid III ATD, the lower LatNij fit was found to be a good.

4. Thorax in Lateral Loading. A total of 17 PMHS were selected for this phase of the study. Each PMHS was accelerated laterally, inducing chest deflection in the torso of the PMHS. Matched pair testing of the THOR ATD was also conducted in the same loading conditions; however, the instrumentation in the THOR chest did not respond significantly to the lateral deflections. The Hybrid III lacks lateral instrumentation required to respond to lateral loading and was not tested. As with the previous phase, the injury metric (lateral chest deflection) was calculated using parametric survival analysis for the PMHS. The resulting IRCs were calculated along with confidence intervals with the same quality assessment used. The lateral chest deflection was evaluated at the 5% risk level on the PHMS and was found to be an excellent fit.

5. Pelvis in Lateral Loading. A total of 22 PMHS were selected for this phase of the study. Each PMHS was loaded directly with a pendulum mass centered on the greater trochanter. Matched pair testing of the THOR ATD was also conducted in the same loading conditions; however, the instrumentation in the THOR acetabulum load cells reached their maximum range before reaching the injury conditions in the PMHS and thus the results were not able to be used to create IARVs. The Hybrid III lacks lateral instrumentation required to respond to lateral loading and was not tested. As with the previous phase, the injury metric (lateral greater trochanter force) was calculated using parametric survival analysis for the PMHS. The resulting IRCs were calculated along with confidence intervals with the same quality assessment used. The lateral greater trochanter force was evaluated at the 5% risk level on the PHMS and was found to be a good fit.

NOTE: End date changed to 9/30/2019 per E. Connell/HFBP/JSC (Ed., 11/17/17)

NOTE: Element change to Human Factors & Behavioral Performance; previously Space Human Factors & Habitability (Ed., 1/19/17)

NOTE: Change to start date per E. Connell/SHFH/HRP (Ed., 2/3/16)

NOTE: Added "Development" to title, per E. Connell/SHFH/HRP (Ed., 10/7/15)

NOTE: Change in title to "ATD Injury Metric" from "THOR Injury Metric Development" per E. Connell/SHFH HRP (Ed., 8/19/15)

NOTE: Period of performance changed to 5/1/2015-9/30/2017 (previously 7/3/2014-10/31/2016) due to delayted start, per E. Connell/JSC SHFH element (Ed., 4/15/2015)

Specific Aims

1. Identify appropriate datasets for ATD comparison

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis.

Historical human data will be selected from the Medical College of Wisconsin (MCW) database. The data will be selected based on loading dynamics and subject demographics. Once these data are selected, the Hybrid III 50th percentile male and THOR ATDs will be tested in identical conditions. A Bayesian analysis along with survival analysis will be used to relate the resulting ATD responses to improve injury risk predictions. The results of the Occupant Protection (OP) Data Mining and Modeling Task will be used as prior distributions.

ATD testing in the lateral acetabular loading cases showed that the ATDs are too stiff to match the input conditions of the cadaveric data. Therefore, an injury assessment reference value (IARV) is being created based on the cadaveric data, instead of the ATDs.

The IARV for lateral chest compression is rib fracture. Correlation between cadaveric and ATD chest compression is difficult due to the mechanism to calculate fracture. The method for calculating fracture for the cadaveric and different ATDs are all different and do not necessarily correlated to the same points on the thorax and can not necessarily be used together. Current research includes finding the best way to create the IARV for rib fracture.

Other current research includes finding the injury metrics for pelvis and examining the effect of sex differences in lower neck, lateral thorax, lateral pelvis injuries, as well as sex differences in lordosis.

NOTE: Element change to Human Factors & Behavioral Performance; previously Space Human Factors & Habitability (Ed., 1/19/17)

NOTE: Change to start date per E. Connell/SHFH/HRP (Ed., 2/3/16)

NOTE: Added "Development" to title, per E. Connell/SHFH/HRP (Ed., 10/7/15)

NOTE: Change in title to "ATD Injury Metric" from "THOR Injury Metric Development" per E. Connell/SHFH HRP (Ed., 8/19/15)

NOTE: Period of performance changed to 5/1/2015-9/30/2017 (previously 7/3/2014-10/31/2016) due to delayted start, per E. Connell/JSC SHFH element (Ed., 4/15/2015)

Specific Aims

1. Identify appropriate datasets for ATD comparison

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis.

Historical human data will be selected from the Medical College of Wisconsin (MCW) database. The data will be selected based on loading dynamics and subject demographics. Once these data are selected, the Hybrid III 50th percentile male and THOR ATDs will be tested in identical conditions. A Bayesian analysis along with survival analysis will be used to relate the resulting ATD responses to improve injury risk predictions. The results of the Occupant Protection (OP) Data Mining and Modeling Task will be used as prior distributions.

Currently phase 1 – lower neck injury under rearward impact has been completed. A supplemental phase of this project, cervical spine injury under vertical contact loading, has also been completed. For this supplemental phase injury risk functions were developed from PMHS test only. It was determined that compressive contact loading, used in PMHS testing, had minimal value in matched paired ATD testing due to the inflexibility of the ATD head/neck structure in this loading configuration. The remaining lateral injury metrics for the neck, thorax and pelvis are planned to be completed by September 2019.

NOTE: End date changed to 9/30/2019 per E. Connell/HFBP/JSC (Ed., 11/17/17)

NOTE: Change to start date per E. Connell/SHFH/HRP (Ed., 2/3/16)

NOTE: Added "Development" to title, per E. Connell/SHFH/HRP (Ed., 10/7/15)

NOTE: Change in title to "ATD Injury Metric" from "THOR Injury Metric Development" per E. Connell/SHFH HRP (Ed., 8/19/15)

NOTE: Period of performance changed to 5/1/2015-9/30/2017 (previously 7/3/2014-10/31/2016) due to delayted start, per E. Connell/JSC SHFH element (Ed., 4/15/2015)

Specific Aims

1. Identify appropriate datasets for ATD comparison

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis.

Historical human data will be selected from the Medical College of Wisconsin (MCW) database. The data will be selected based on loading dynamics and subject demographics. Once these data are selected, the Hybrid III 50th percentile male and THOR ATDs will be tested in identical conditions. A Bayesian analysis along with survival analysis will be used to relate the resulting ATD responses to improve injury risk predictions. The results of the Occupant Protection (OP) Data Mining and Modeling Task will be used as prior distributions.

1. Identify appropriate datasets for ATD comparison. Work started in February 2016 with the Medical College of Wisconsin (MCW) selecting appropriate matched pair datasets from their test laboratory. Datasets selected include those eliciting low-level AIS injuries in the neck and include a high number of female test data to allow study of sex differences in injury outcome. Datasets were chosen to examine lateral impact neck tolerance, vertical impact neck tolerance, and pelvic/acetabulum injury criteria. PMHS injury data will be used to develop risk curves in a similar process as seen in the 2017 paper “Load-Based Lower Neck Injury Criteria for Females from Rear Impact from Cadaver Experiments.” Additionally, historical human volunteer test data collected at the Air Force Research Laboratory (AFRL) at Wright-Patterson Air Force Base (WPAFB) can be added to the PMHS injury data to further refine the injury risk curves. Matched pair testing will then be performed with the Hybrid III 50th and THOR ATDs to develop injury risk curves for each.

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing. The MCW is documenting match pair tests already completed with the Hybrid III ATD and determining what tests will be required to supplement the existing Hybrid III dataset. The OP team is drafting a Space Act Agreement (SAA) with the National Highway Traffic Safety Administration (NHTSA) to use the THOR ATD for testing at MCW. The MCW has begun ATD match pairing testing for lower-neck shear criteria. Currently, the THOR ATD is unavailable for use until the Summer 2017.

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences. Established injury risk function for the PMHS for the lower-neck shear force bending moment. Work to establish injury risk function for Hybrid III 50th and THOR will begin after match pair testing is complete.

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution. This work will begin after match pair testing is complete.

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis. This work will begin after match pair testing is complete.

NOTE: Change to start date per E. Connell/SHFH/HRP (Ed., 2/3/16)

NOTE: Added "Development" to title, per E. Connell/SHFH/HRP (Ed., 10/7/15)

NOTE: Change in title to "ATD Injury Metric" from "THOR Injury Metric Development" per E. Connell/SHFH HRP (Ed., 8/19/15)

NOTE: Period of performance changed to 5/1/2015-9/30/2017 (previously 7/3/2014-10/31/2016) due to delayted start, per E. Connell/JSC SHFH element (Ed., 4/15/2015)

Specific Aims

1. Identify appropriate datasets for ATD comparison

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis

Historical human data will be selected from the Medical College of Wisconsin (MCW) database. The data will be selected based on loading dynamics and subject demographics. Once these data are selected, the Hybrid III 50th percentile male and THOR ATDs will be tested in identical conditions. A Bayesian analysis along with survival analysis will be used to relate the resulting ATD responses to improve injury risk predictions. The results of the Occupant Protection (OP) Data Mining and Modeling Task will be used as prior distributions.

1. Identify appropriate datasets for ATD comparison. Work started in February 2016. Medical College of Wisconsin (MCW) is currently selecting appropriate match-pair datasets from their test laboratory. Datasets selected include those eliciting low level Abbreviated Injury Scale (AIS) injuries in the neck and include a high number of female test data to allow study of sex differences in injury outcome.

2. Test Hybrid III 50th percentile male and THOR in same conditions as historical testing. MCW is documenting match-pair tests already completed with the Hybrid III ATD and determining what tests will be required to supplement the existing Hybrid III dataset. The OP team is drafting a Space Act Agreement (SAA) with the National Highway Traffic Safety Administration (NHTSA) to use the THOR ATD for testing at MCW.

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences. This work will begin after match-pair testing is complete.

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution. This work will begin after match-pair testing is complete.

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis. This work will begin after match-pair testing is complete.

NOTE: Added "Development" to title, per E. Connell/SHFH/HRP (Ed., 10/7/15)

NOTE: Change in title to "ATD Injury Metric" from "THOR Injury Metric Development" per E. Connell/SHFH HRP (Ed., 8/19/15)

NOTE: Period of performance changed to 5/1/2015-9/30/2017 (previously 7/3/2014-10/31/2016) due to delayted start, per E. Connell/JSC SHFH element (Ed., 4/15/2015)

Specific aims are as follows:

1. Identify appropriate datasets for THOR comparison

2. Test THOR in same conditions as historical testing

3. Use historical human data to establish tolerance and injury risk focusing on lateral responses and sex differences

4. Use Bayesian analysis combined with survival analysis along with human tolerance to estimate injury risk. Use results of prior data mining and existing literature as prior distribution

5. Develop new Injury Assessment Reference Values (IARVs) based on the new statistical analysis

Historical human data will be selected from the Wright-Patterson Collaborative Biodynamics Network (CBDN) and National Highway Traffic Safety Administration (NHTSA) databases. The data will be selected based on loading dynamics and subject demographics. Once these data are selected, the THOR Anthropomorphic Test Device (ATD) will be tested in identical conditions. A Bayesian analysis along with survival analysis will be used to relate the resulting THOR responses to improve injury risk predictions. The results of the Occupant Protection (OP) Data Mining and Modeling Task will be used as prior distributions.

(Ed. Note 4/15/2015: change in period of performance per SHFH element)