The Digital Astronaut Project (DAP)    Applying computational models and simulations to inform life science research      ...
AcknowledgmentsDr. Jean Sibonga, PhD        Christian Otto, MD HACD Bone Discipline Lead    VIIP Project Scientist        ...
Overview• Goals of the Digital Astronaut Project• Processes DAP follows to accomplish its goals• The modeling and simulati...
Introduction• Mars and NEO missions will expose astronaut to extended  durations of reduced-gravity, isolation and higher ...
DAP’s Model Development and  Implementation Process                              5
How Models Can be Applied to Enhance       Life Science Research                                       6
Current Focus Areas1. Exercise countermeasures modeling and simulation   –   Advanced Resistive Exercise Device (ARED)   –...
ARED Exercise Modeling                         8
ARED Exercise Modeling Kick-off Plan                                       9
Exercise Countermeasures Modeling• Human exercise simulation in micro-gravity   –   Squat   –   Single-leg squat   –   Dea...
Exercise Countermeasures ModelingTargeted HRP risk knowledge gaps:B15: (a) What exercise protocols are necessary to mainta...
ARED Hardware Model• High fidelity dynamics  model of ARED/VIS  developed in MSC Adams™   – Mass and inertial properties  ...
ARED Hardware ModelNOT VALIDATED       Modeler: Brad Humphreys   13
Force generated at the bar in 1-g                                                14NOT VALIDATED         Modeler: Brad Hum...
Force generated at the bar in 0-g                                                15NOT VALIDATED         Modeler: Brad Hum...
ARED Exercise Modeling Kick-off PlanDeveloped in parallelwith ARED/VIS model                                              ...
ARED Exercise Models• Developed with LifeMOD™ using motion capture data  acquired on the ARED ground unit at JSC          ...
Integrated ARED-Dead Lift Exercise Model               NOT VALIDATED                                             18    Mod...
Integrated ARED-Dead Lift Exercise Model               NOT VALIDATED                                            19   Model...
Integrated ARED-Squat Exercise Model            NOT VALIDATED        Modeler: Bill Thompson         20
Integrated ARED-Exercise Squat Model            NOT VALIDATED        Modeler: Bill Thompson         21
Integrated ARED-Exercise Squat Model            NOT VALIDATED        Modeler: Bill Thompson         22
ARED Exercise Modeling and Implementation Process                                                    23
Muscle Adaptation Model• Conceptual phase• Enhance the fidelity of muscle representation  in the LifeMOD biomechanics mode...
Bone Adaptation Model• Predicted muscle force from biomechanics  models is an input to the bone adaptation  model• Bone ad...
Risk of Bone FractureTargeted HRP risk knowledge gaps:B15: (a) What exercise protocols are necessary to maintain skeletal ...
Risk of Bone Fracture• Implement biomechanical modules to  predict the forces experienced at  specific bone sites during v...
Advanced Exercise Devices Modeling• Develop device models for advanced exercise (AEC)  devices:   – Multi-mode Exercise De...
Advanced Exercise Devices Modeling• Objectives:   1. Gain insight into the efficacy of AEC devices for exercise      count...
Visual Impairment and Intracranial Pressure (VIIP)                 Intracranial                Papilledema                ...
Current Status for VIIP Modeling                                   31
VIIP Targeted Gaps• VIIP6: How do changes in vascular compliance/ pressures  influence intraocular pressure or intracrania...
Recent Successes
ARED Model used for Flywheel              Preventative Maintenance• The ARED flywheels were disengaged due to ground  evid...
ARED Model used for Flywheel         Preventative MaintenanceAnalysts: Nate Newby, Erin Caldwell and Brad Humphreys   35
ARED Model used for Exercise Envelope Analysis      Analysts: Nate Newby and Erin Caldwell     36
ARED Model used for Exercise Envelope Analysis• The ISS Program Office requested an analysis to assess if the  ISS operati...
Contributions to the Field for V&V of       Biomedical Models and Simulations• The FDA is leveraging a lot of the methodol...
Synapses• DAP has established a systematic process to closely  work with researchers to leverage computational  models inf...
“All models are wrong, but some are useful.”                            - George E. P. Box
The DAP TeamBeth Lewandowski, PhD – Muscle ModelBill Thompson, MS – Squat IntegrationBrad Humphreys – Exercise Device Mode...
Questions?
DAP Mission StatementThe DAP implements well-vetted computational modelsto predict and assess spaceflight health and perfo...
NASA Standard 7009A comprehensive set of requirements andprocesses for developing and applyingmodels and simulations, whil...
NASA-STD-7009 Background• NASA M&S that impact on the crew or mission will be  required to follow NASA-STD-7009, including...
Upcoming SlideShare
Loading in...5
×

The Digital Astronaut Project: Applying computational modeling and simulation to inform space life science research

506
-1

Published on

I gave this presentation to the NASA space life science research community regarding the modeling and simulation tools the Digital Astronaut Project is developing to inform research regarding the preservation of musculoskeletal and visual system health of astronauts.

0 Comments
0 Likes
Statistics
Notes
  • Be the first to comment

  • Be the first to like this

No Downloads
Views
Total Views
506
On Slideshare
0
From Embeds
0
Number of Embeds
1
Actions
Shares
0
Downloads
19
Comments
0
Likes
0
Embeds 0
No embeds

No notes for slide

The Digital Astronaut Project: Applying computational modeling and simulation to inform space life science research

  1. 1. The Digital Astronaut Project (DAP) Applying computational models and simulations to inform life science research Lealem Mulugeta DAP Project Scientist mulugeta@dsls.usra.edu lealem.mulugeta@nasa.gov USRA DSLS Brown Bag Lunch Seminar - April 19th, 2012
  2. 2. AcknowledgmentsDr. Jean Sibonga, PhD Christian Otto, MD HACD Bone Discipline Lead VIIP Project Scientist Marlei Walton, PhD IMM Project Scientist 2
  3. 3. Overview• Goals of the Digital Astronaut Project• Processes DAP follows to accomplish its goals• The modeling and simulation tools currently under development• Video demonstration of the ARED and exercise modules• Our recent achievements 3
  4. 4. Introduction• Mars and NEO missions will expose astronaut to extended durations of reduced-gravity, isolation and higher radiation• These new operation conditions pose health risks that are not well understood and perhaps unanticipated• Advanced computational simulation environments can beneficially augment research to predict, assess and mitigate potential hazards to astronaut health• The Digital Astronaut Project (DAP) strives to achieve this goal 4
  5. 5. DAP’s Model Development and Implementation Process 5
  6. 6. How Models Can be Applied to Enhance Life Science Research 6
  7. 7. Current Focus Areas1. Exercise countermeasures modeling and simulation – Advanced Resistive Exercise Device (ARED) – Biomechanics of exercise – Bone adaptation – Muscle adaptation – Advanced Exercise Concept Devices2. Risk of bone fracture – Bone adaptation – Biomechanics of post-flight activities for bone load predictions3. Visual Impairment and Intracranial Pressure (VIIP) – Preliminary stages 7
  8. 8. ARED Exercise Modeling 8
  9. 9. ARED Exercise Modeling Kick-off Plan 9
  10. 10. Exercise Countermeasures Modeling• Human exercise simulation in micro-gravity – Squat – Single-leg squat – Dead-lift – Heel-raise• Prediction of: – Muscle forces – Muscle adaptation – Ground reaction forces – Joint torque – Mechanical load bones/joints – Bone adaptation• Influence of: – Anthropometric variation – Stance variation – Range of motion 10
  11. 11. Exercise Countermeasures ModelingTargeted HRP risk knowledge gaps:B15: (a) What exercise protocols are necessary to maintain skeletal health? And (b) Can exercise hardware be designed to provide these?M7: Can the current in-flight performance be maintained with reduced exercise volume?M8: What is the minimum exercise regimen needed to maintain fitness levels for tasks?M9: What is the minimum set of exercise hardware needed to maintain those (M8) fitness levels?M24: What is the time course of changes in muscle protein turnover, muscle mass, and function during long-term spaceflight? 11
  12. 12. ARED Hardware Model• High fidelity dynamics model of ARED/VIS developed in MSC Adams™ – Mass and inertial properties – Friction forces – Gas laws• Currently allows for simulation of bar exercises only Modeler: Brad Humphreys 12
  13. 13. ARED Hardware ModelNOT VALIDATED Modeler: Brad Humphreys 13
  14. 14. Force generated at the bar in 1-g 14NOT VALIDATED Modeler: Brad Humphreys
  15. 15. Force generated at the bar in 0-g 15NOT VALIDATED Modeler: Brad Humphreys
  16. 16. ARED Exercise Modeling Kick-off PlanDeveloped in parallelwith ARED/VIS model 16
  17. 17. ARED Exercise Models• Developed with LifeMOD™ using motion capture data acquired on the ARED ground unit at JSC Dead lift Normal Squat Single-leg squat Muscle Module Joint Module Modelers: Nate Newby and Erin Caldwell 17
  18. 18. Integrated ARED-Dead Lift Exercise Model NOT VALIDATED 18 Modelers: Nate Newby and Erin Caldwell
  19. 19. Integrated ARED-Dead Lift Exercise Model NOT VALIDATED 19 Modelers: Nate Newby and Erin Caldwell
  20. 20. Integrated ARED-Squat Exercise Model NOT VALIDATED Modeler: Bill Thompson 20
  21. 21. Integrated ARED-Exercise Squat Model NOT VALIDATED Modeler: Bill Thompson 21
  22. 22. Integrated ARED-Exercise Squat Model NOT VALIDATED Modeler: Bill Thompson 22
  23. 23. ARED Exercise Modeling and Implementation Process 23
  24. 24. Muscle Adaptation Model• Conceptual phase• Enhance the fidelity of muscle representation in the LifeMOD biomechanics models in terms of space flight changes• Gain insight on muscle adaptation factors: – Neuromuscular drive and activation – Muscle atrophy and fiber morphology – Blood flow and intramuscular pressure – Metabolic processes – Fatigue Modeler: Beth Lewandowski, PhD 24
  25. 25. Bone Adaptation Model• Predicted muscle force from biomechanics models is an input to the bone adaptation model• Bone adaptation model factors : – Cortical bone tissue rate of change – Bone fluid calcium rate of change – Biochemical equations – Mechanical stimulus – Cellular dynamics Modeler: Jim Pennline, PhD 25
  26. 26. Risk of Bone FractureTargeted HRP risk knowledge gaps:B15: (a) What exercise protocols are necessary to maintain skeletal health?B1: (a) Is there an increased lifetime risk of fragility fractures/osteoporosis in astronauts? (b) Is bone strength completely recovered post-flight, and does BMD reflect it? (c) What are the risk factors for poor recovery of BMD/bone strengthB30: What are the loads applied to bone in-flight and during EVA activities and do they increase fracture risk in light of expected bone loss? Modeler: Jim Pennline, PhD 26
  27. 27. Risk of Bone Fracture• Implement biomechanical modules to predict the forces experienced at specific bone sites during various activities (not exercise)• Enhance bone adaptation module to (Hewett et al., 2008) determine changes in the macro- and microstructure of bone during long- duration spaceflight and implications on long-term bone health risks Modeler: Jim Pennline, PhD 27
  28. 28. Advanced Exercise Devices Modeling• Develop device models for advanced exercise (AEC) devices: – Multi-mode Exercise Device (M-MED) – NSBRI / UC Irvine – Gas spring device (ZIN) – Streamline ergometer (SBIR) 28 Modeler: Brad Humphreys
  29. 29. Advanced Exercise Devices Modeling• Objectives: 1. Gain insight into the efficacy of AEC devices for exercise countermeasures 2. Provide timely input for design, development, and refinement of AEC devices 3. Help reduce the time and cost to develop the exercise devices 4. Help reduce the time and cost to clinically test new exercise devices 29
  30. 30. Visual Impairment and Intracranial Pressure (VIIP) Intracranial Papilledema Pressure Intracranial Changes in visual acuity Compliance Primary focus: • biomechanical responses to the ofIntracranial the intracranial and ocular structureHemodynamics while microgravity environment that may affect visual acuityIntra-ocular Model types under consideration:Pressure • Lumped parameter models of the Cerebrospinal intracranial and spinal compartments Fluid Flow • Finite element model of the eye • Computational fluid dynamics of the intracranial and spinal space (Adapted from Google Body – http://bodybrowser.googlelabs.com) • High fidelity tissue models to capture nonlinear/viscoelastic properties 30
  31. 31. Current Status for VIIP Modeling 31
  32. 32. VIIP Targeted Gaps• VIIP6: How do changes in vascular compliance/ pressures influence intraocular pressure or intracranial pressure?• Gap VIIP2: Does exposure to microgravity cause changes in visual acuity, intraocular pressure and/or intracranial pressure? Are the effects related to mission duration?• Gap VIIP4: Are changes in visual acuity related to changes in: 1) deformation of the optic nerve head; 2) chronic choroidal engorgement; 3) elevated intraocular pressure; and/or 4) intracranial pressure? 32
  33. 33. Recent Successes
  34. 34. ARED Model used for Flywheel Preventative Maintenance• The ARED flywheels were disengaged due to ground evidence that suggested the flywheel set screws may back out of their engagement to cause damage to the ARED• Substantiation was requested from the ISS Program Office on whether or not crew time should be allocated to re-torque the set-screws as a short term fix to buy enough time to investigate a long-term fix• The exercise lab at JSC leveraged the Beta ARED hardware model to partially substantiate the benefit of having the inertial wheels engaged during exercise Analysts: Nate Newby, Erin Caldwell and Brad Humphreys 34
  35. 35. ARED Model used for Flywheel Preventative MaintenanceAnalysts: Nate Newby, Erin Caldwell and Brad Humphreys 35
  36. 36. ARED Model used for Exercise Envelope Analysis Analysts: Nate Newby and Erin Caldwell 36
  37. 37. ARED Model used for Exercise Envelope Analysis• The ISS Program Office requested an analysis to assess if the ISS operational envelope for ARED exercise to assess if the envelope is being exceeded during exercise due to excess stowage in the exercise area• DAP modelers used the dead lift/ARED model within the currently assigned ISS operational envelope for ARED exercise to assess if the envelope is being exceeded during exercise• DAP modelers developed a model of a 95th % male performing a bench press on the ARED to perform the same analysis• The results were shared with the ISS Program Office to determine the necessary operational envelope Analysts: Nate Newby and Erin Caldwell 37
  38. 38. Contributions to the Field for V&V of Biomedical Models and Simulations• The FDA is leveraging a lot of the methodologies DAP and IMM have laid out for verification, validation and credibility assessment of M&S• Collaboration talks are currently underway with FDA• The NIH Multiscale Modeling Working group meeting in October 2012 is going to have a large emphasis on V&V and credibility assent 38
  39. 39. Synapses• DAP has established a systematic process to closely work with researchers to leverage computational models inform HRP risk knowledge gaps• Current areas of focus are exercise countermeasures, risk of bone fracture and VIIP• Substantial strides have been made in the past year in biomechanical and exercise device modeling• Making notable contributions to the field in verification and validation, and credibility assessment of computational models 39
  40. 40. “All models are wrong, but some are useful.” - George E. P. Box
  41. 41. The DAP TeamBeth Lewandowski, PhD – Muscle ModelBill Thompson, MS – Squat IntegrationBrad Humphreys – Exercise Device ModelingChris Sheehan – Exercise Device Modeling Task LeadChris Werner – ARED V&VDeVon Griffin, PhD - Project ManagerEmily Nelson, PhD – VIIP M&SErin Caldwell , MS - Biomechanics Modeling and Dead Lift IntegrationJennifer Stein – Exercise Device V&V ProcessesJim Pennline, PhD – Bone Modeling LeadJerry Myers, PhD – M&S AdvisorLealem Mulugeta, MS - Project ScientistNate Newby, MS – Biomechanics Modeling and Dead Lift integration 41
  42. 42. Questions?
  43. 43. DAP Mission StatementThe DAP implements well-vetted computational modelsto predict and assess spaceflight health and performancerisks, and enhance countermeasure development. TheDAP aims to accomplish these goals by:1. Partnering with subject matter experts to address Human Research Program (HRP) knowledge gaps and countermeasure development decisions2. Modeling, simulating, and analyzing the physiologic responses to exposure to reduced gravity and analog environments3. Providing timely input to mission architecture and operations decisions in areas where clinical data are lacking 43
  44. 44. NASA Standard 7009A comprehensive set of requirements andprocesses for developing and applyingmodels and simulations, while ensuringappropriate verification, validation andcredibility of the M&S results 44
  45. 45. NASA-STD-7009 Background• NASA M&S that impact on the crew or mission will be required to follow NASA-STD-7009, including biological models• It was initially developed for engineering systems• DAP and Integrated Medical Model (IMM) have adapted NASA-STD-7009 for biomedical models for clinical and research applications• Given the highly comprehensive nature of the standard, DAP and IMM are working to establish a systematic process to apply it to vet M&S 45
  1. A particular slide catching your eye?

    Clipping is a handy way to collect important slides you want to go back to later.

×