NOTE: to be extended to 12/30/2014 per CoI (Ed., 4/25/14)

To address the limitations of the current NASA standards, this study will address the following two objectives: 1) Develop a Finite Element (FE) model of Test device for Human Occupant Restraint (THOR) Anthropomorphic Test Device (ATD), and 2) Conduct data mining of existing human injury and response data using the THOR FE model.

In order to develop updated standards, adequate injury assessment tools must be chosen and developed. In the case of dynamic loads, the THOR ATD was chosen as the appropriate human surrogate. For the data mining portion of the task, re-creation of the conditions of each impact case is needed to determine injury risk. Since physical re-creation of each case is not feasible, a numerical model of the THOR ATD is desired. An existing THOR FE model will be refined and validated. To supplement available THOR ATD validation data, additional THOR ATD testing will be conducted at two facilities and ATD response data will be collected. The FE model responses will then be assessed against the physical ATD responses. Once the ATD model is validated, it can be used for the data mining portion of the study.

Because analogous spaceflight injury biomechanics data are very limited, data mining of other analogous environments will be used. These datasets are chosen as they have similarities with the landing environment expected in future vehicles. The existing human injury and response data from other sources include historical military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), IndyCar impacts, and NASCAR impacts. These data sources can allow better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested in humans. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would then be incorporated with the results of other Tasks to update the NASA standards.

Task Description:

The ultimate aim of this project is to develop Occupant Protection standards for NASA that would apply to all future crewed spacecraft.

1. Conduct ATD dynamic tests to relate human and ATD responses.

2. Mine existing human injury and tolerance data and simulate dynamic environments using Finite Element (FE) models. Relate human injury and responses to ATD estimated responses from FE models.

3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions.

The objectives of this study are to use current modeling techniques and industry standard approaches to analyze existing human databases to develop new NASA standards and requirements for occupant protection. To accomplish these objectives we began by determining which critical injuries NASA needs to mitigate. We then defined the anthropomorphic test device (ATD) and the associated injury metrics of interest. Finally, we conducted a literature review of available data for the Test Device for Human Occupant Restraint (THOR) ATD to determine injury assessment reference values (IARV) to serve as a baseline for further development.

The first objective of this study was to assess the THOR for use by NASA in developing and validating occupant protection standards. THOR was impact tested in various orientations and multiple peak acceleration levels, and responses to these impacts differed from human responses under identical impact conditions and do not replicate human bracing for impact. As part of this study, a finite element model (FEM) of the THOR was developed, calibrated, and optimized. The FEM proved a good match to the ATD. The FEM simulations (at a wide range of impacts that military subjects participated in) historically revealed that the FEM correlated to lower-peak acceleration impacts better than to higher-peak accelerations.

The second objective of this study was to mine existing human injury and exposure data. The U.S. Air Force maintains thousands of human-impact-test results. Data collected from 1976 to 2004 have been downloaded and converted into a user-friendly MATLAB data structure format. The team created IARVs for several metrics mined from existing injury literature. The IARVs for the spine and chest deflection subsequently were refined based upon statistical models of combined non-injurious and injurious literature data. This work culminated in the development of an acceptable risk of injury from spaceflight, which included a newly developed operationally relevant injury scale.

NOTE: to be extended to 12/30/2014 per CoI (Ed., 4/25/14)

To address the limitations of the current NASA standards, this study will address the following two objectives: 1) Develop a Finite Element (FE) model of Test device for Human Occupant Restraint (THOR) Anthropomorphic Test Device (ATD), and 2) Conduct data mining of existing human injury and response data using the THOR FE model.

In order to develop updated standards, adequate injury assessment tools must be chosen and developed. In the case of dynamic loads, the THOR ATD was chosen as the appropriate human surrogate. For the data mining portion of the task, re-creation of the conditions of each impact case is needed to determine injury risk. Since physical re-creation of each case is not feasible, a numerical model of the THOR ATD is desired. An existing THOR FE model will be refined and validated. To supplement available THOR ATD validation data, additional THOR ATD testing will be conducted at two facilities and ATD response data will be collected. The FE model responses will then be assessed against the physical ATD responses. Once the ATD model is validated, it can be used for the data mining portion of the study.

Because analogous space flight injury biomechanics data are very limited, data mining of other analogous environments will be used. These datasets are chosen as they have similarities with the landing environment expected in future vehicles. The existing human injury and response data from other sources include historical military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), IndyCar impacts, and NASCAR impacts. These data sources can allow better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested in humans. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would then be incorporated with the results of other Tasks to update the NASA standards.

Task Description:

The ultimate aim of this project is to develop Occupant Protection standards for NASA that would apply to all future crewed spacecraft.

1. Conduct ATD dynamic tests to relate human and ATD responses.

2. Mine existing human injury and tolerance data and simulate dynamic environments using Finite Element (FE) models. Relate human injury and responses to ATD estimated responses from FE models.

3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions.

Specific Aim 1. Conduct Anthropomorphic Test Device (ATD) dynamic tests to relate human and ATD Responses

a. Conduct impact testing of the Test device for Human Occupant Restraint (THOR). This portion of the specific aim is complete. Testing of the THOR ATD was completed in January of 2013.

b. Mine existing human injury and tolerance data. This portion of the specific aim is ongoing. Several datasets have been mined and several more are in work. In addition, significant work has been accomplished to obtain the racing driver collision data from IndyCar.

c. Correlate THOR ATD responses to historical human responses under the same impact conditions. This specific aim is complete. The results of the study were recently published in the Stapp Car Crash Journal.

d. Develop a Finite Element (FE) model of the updated THOR ATD. This specific aim is complete. The Test Device for Human Occupant Restraint (THOR) Anthropomorphic Test Device (ATD) Finite Element (FE) model was updated in collaboration with the National Highway Traffic Safety Administration (NHTSA). The resulting model was then optimized using physical test data and validated with an alternate set of data.

Specific Aim 2. After mining existing human injury and tolerance data, simulate dynamic environments using Finite Element (FE) models.

a. Evaluate the accuracy of the model against the physical test data collected in Specific Aim 1. This specific aim is complete. Using a similar method used in Specific Aim 1c along with the data collected in Specific Aim 1a, the FE model was optimized and validated.

b. Model human exposure data collected from IndyCar, NASCAR, and military volunteer data. This specific aim is planned to be completed by the end of the project. Now that the FE THOR model is validated, additional seating configurations will be developed.

Specific Aim 3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions.

This specific aim is expected to be completed at the end of the project.

To address the limitations of the current NASA standards, this study will address the following two objectives: 1) Develop a Finite Element (FE) model of Test device for Human Occupant Restraint (THOR) Anthropomorphic Test Device (ATD), and 2) Conduct data mining of existing human injury and response data using the THOR FE model.

In order to develop updated standards, adequate injury assessment tools must be chosen and developed. In the case of dynamic loads, the THOR ATD was chosen as the appropriate human surrogate. For the data mining portion of the task, re-creation of the conditions of each impact case is needed to determine injury risk. Since physical re-creation of each case is not feasible, a numerical model of the THOR ATD is desired. An existing THOR FE model will be refined and validated. To supplement available THOR ATD validation data, additional THOR ATD testing will be conducted at two facilities and ATD response data will be collected. The FE model responses will then be assessed against the physical ATD responses. Once the ATD model is validated, it can be used for the data mining portion of the study.

Because analogous space flight injury biomechanics data are very limited, data mining of other analogous environments will be used. These datasets are chosen as they have similarities with the landing environment expected in future vehicles. The existing human injury and response data from other sources include historical military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), IndyCar impacts, and NASCAR impacts. These data sources can allow better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested in humans. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would then be incorporated with the results of other Tasks to update the NASA standards.

Task Description:

The ultimate aim of this project is to develop Occupant Protection standards for NASA that would apply to all future crewed spacecraft.

1. Conduct ATD dynamic tests to relate human and ATD responses.

2. Mine existing human injury and tolerance data and simulate dynamic environments using Finite Element (FE) models. Relate human injury and responses to ATD estimated responses from FE models.

3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions

1. Conduct ATD dynamic tests to relate human and ATD responses.

2. Mine existing human injury and tolerance data and simulate dynamic environments using Finite Element (FE) models. Relate human injury and responses to ATD estimated responses from FE models.

3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions:

1. Conduct ATD dynamic tests to relate human and ATD responses.

a. Conduct impact testing of the Test device for Human Occupant Restraint (THOR). There were some schedule delays related to borrowing the THOR ATD from NHTSA and also in coordinating with the test facility at Wright Patterson Air Force Base (WPAFB). Testing was ultimately completed in January 2013. A total of 46 tests were conducted in collaboration with WPAFB, 28 tests more than the original 18 tests planned. These additional tests, in the –X orientation, allow for enhanced assessment of the THOR in dynamics similar to expected spaceflight conditions.

b. Mine existing human injury and tolerance data. The OP team received IRB approval of a de-identification protocol for IndyCar driver data in early October and subsequently received the de-identified dataset a few weeks later. Other datasets that have been received and analyzed this past year include additional data from the Air Force Research Laboratory (AFRL) and NASCAR data previously obtained through a Space Act Agreement. The OP team is also in discussions with U.S. Army Aeromedical Research Laboratory personnel to obtain Naval Biodynamics Laboratory data collected over a 25 year period.

c. Correlate THOR ATD responses to historical human responses under the same impact conditions. This work started in January 2013 and is expected to complete in May 2013. An abstract describing the results was accepted by the Stapp Car Crash Conference and the results will be submitted to the Stapp Car Crash Journal in May 2013.

d. Develop a Finite Element (FE) model of the updated THOR ATD. Although an earlier version of the ATD (THOR-NT) was validated previously, the team is working to update the current ATD (THOR-K) in collaboration with the National Highway Traffic Safety Administration, Toyota, University of Virginia and the Partnership for Dummy Biomechanics (PDB). The OP team was specifically tasked with updates to the head and neck and the other collaborators have agreed to update other parts of the model. This work is expected to be completed in early May 2013.

2. After mining existing human injury and tolerance data, simulate dynamic environments using Finite Element (FE) models.

a. Evaluate the accuracy of the model against the physical test data collected in Specific Aim 1. Once an updated THOR FE model is completely assembled in May 2013, a model of the WPAFB configuration will be created to allow assessment of the FE model against the physical test data collected in Specific Aim 1. This work is expected to be completed by the end of October 2013.

b. Model human exposure data collected from IndyCar, NASCAR, and military volunteer data. Simulations of injury and non-injury cases will be conducted. These simulations will be driven by the dynamics recorded onboard the vehicle or sled. This allows estimates of the responses of the humans exposed to the same conditions. This work is expected to be completed by June 2013.

3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions. Using the estimated responses from Specific Aim 2, statistical models will be developed to relate the responses to injury outcomes. The resulting statistical models will allow estimates of injury risk related to the THOR response parameters. Using these injury risk functions, Injury Assessment Reference Values (IARVs) can be determined for off-nominal conditions for future spacecraft. This work is planned for completion by study end (late June 2014), but it is possible that a small extension of the study may be required due to limitations in personnel availability to complete the work.

To address the limitations of the current NASA standards, this study will address the following two objectives: 1) Develop a Finite Element (FE) model of Test device for Human Occupant Restraint (THOR) Anthropomorphic Test Device (ATD), and 2) Conduct data mining of existing human injury and response data using the THOR FE model.

In order to develop updated standards, adequate injury assessment tools must be chosen and developed. In the case of dynamic loads, the THOR ATD was chosen as the appropriate human surrogate. For the data mining portion of the task, re-creation of the conditions of each impact case is needed to determine injury risk. Since physical re-creation of each case is not feasible, a numerical model of the THOR ATD is desired. An existing THOR FE model will be refined and validated. To supplement available THOR ATD validation data, additional THOR ATD testing will be conducted at two facilities and ATD response data will be collected. The FE model responses will then be assessed against the physical ATD responses. Once the ATD model is validated, it can be used for the data mining portion of the study.

Because analogous space flight injury biomechanics data are very limited, data mining of other analogous environments will be used. These datasets are chosen as they have similarities with the landing environment expected in future vehicles. The existing human injury and response data from other sources include historical military volunteer testing, automotive Crash Injury Research Engineering Network (CIREN), IndyCar impacts, and NASCAR impacts. These data sources can allow better extrapolation of the ATD responses to off-nominal conditions above the nominal range that can safely be tested in humans. These elements will be used to develop injury risk functions for each of the injury metrics measured from the ATD. These risk functions would then be incorporated with the results of other Tasks to update the NASA standards.

Task Description:

The ultimate aim of this project is to develop Occupant Protection standards for NASA that would apply to all future crewed spacecraft.

1. Conduct ATD dynamic tests to relate human and ATD responses.

2. Mine existing human injury and tolerance data and simulate dynamic environments using Finite Element (FE) models. Relate human injury and responses to ATD estimated responses from FE models.

3. Develop injury risk functions based on ATD responses and develop NASA standards from these functions