Virtual Human Simulation Framework
Project Description
Focused Investigation Project
Long-duration human space flight requires new approaches to translating terrestrial medical technologies for use in space. Level Ex develops medical simulation apps used for physician training and proposes to adapt its simulation framework to the environment and conditions found in spacecraft. Multiple factors impact medical care in space environments including anatomical changes to the human body when exposed to microgravity over long durations, activity differences in microgravity, and spatial limitations. Multiple programs are devoted to studying space medicine, such as a four-week aerospace medicine clerkship at NASA Johnson Space Center and two military residency programs. However, the ultimate method of studying medical procedures in space and training astronauts on these procedures is within an actual environment, such as the International Space Station (ISS), although this is infeasible for all except for those few astronauts assigned to the ISS. Another option is training during a low-gravity parabolic flight but this scenario is expensive and would still lack the ability to induce changes in human physiology that would occur during a long-duration space flight. Thus, there exists a critical need to expand the accessibility of medical research and training through simulated environments that account for space conditions and their impact on the human body. Both NASA and the private sector have worked toward developing capabilities to simulate many health aspects of space flight. These studies and virtual simulations by NASA and third-party vendors, such as within the Digital Astronaut Project and now the Integrated Medical Model Project, have focused on how a specific component of human anatomy and physiology is impacted by long periods in microgravity. Simulations and mathematical models of the heart, eyes, and skeletal structure have been developed to a high degree of fidelity to enable a clearer scientific understanding of human health needed for space flight planning and research. However, simulations to date have a key limitation, in that they are discrete programs that capture only a single individual component of the human system. None of the work to date has been capable of incorporating all of the known research around space health into a cohesive, simulated, and interactive hyper-realistic environment.
To address this need, Level Ex proposes to adapt its real-time medical simulation platform to include the effects of long-duration space flight. Through a significant investment in R&D, the existing Level Ex platform has been developed by a team of top video game/ simulation developers/artists, biomedical engineers, and physicians from around the United States who are expert in the simulation of medical reality in mobile, virtual reality (VR), and augmented reality (AR) environments. Major components include tissue recreation and rendering technology used for high-resolution visualization. Level Ex also applies its extensive experience in building physics-based computational models (such as fluid dynamics) that run in real time and enable medical professionals to practice complex medical procedures based on medical data.
To adapt its current simulation framework to a space medical environment, Level Ex proposed the following project objectives:
(1) Simulate and render the environmental physics of the spacecraft (physical modeling of volume, interiors, mass, temperature, light, radiation, barometric pressure, sound, and gas).
(2) Develop or adapt the virtual human simulation to include anatomical and physiological changes caused by long-duration exposure to space.
(3) Demonstrate the use of medical tool technologies relevant to space flight.
(4) Research and report on existing data simulation gaps and future simulation needs.
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Anticipated Benefits
During the first year of the Virtual Human Simulation (VHS) project the Level Ex team demonstrated the ability to adapt existing medical research and simulation development practices from the commercial terrestrial medical industry to meet the space flight medicine needs identified by NASA stakeholders as well as risks and gaps contained within Human Research Roadmap. The Anatomy Viewer component of VHS platform prototype provides users with a robust and scalable framework for the aggregation and visualization of data from space flight medical research studies, terrestrial medical research, and best practice guidelines. The Anatomy Viewer content is informed by medical conditions identified in the NASA Summary of Human Risk of Spaceflight and Exploration Medical Conditions list. Medical content from cardiovascular, ocular, and pulmonary research topic areas was incorporated into the Anatomy Viewer in the first year. Specific conditions were selected, based upon input from subject matter experts (SME) interviews, for additional detailed visual content development and inclusion into the initial iteration:
• Vasodilation associated with microgravity fluid shifts and potential internal jugular vein (IJV) thrombosis.
• Spaceflight Associated Neuro-ocular Syndrome (SANS).
• Cardiac rhythm problems and changes in the shape of the heart due to prolonged microgravity exposure, specifically atrial fibrillation.
• Adverse health effects due to host-microorganism interaction, specifically respiratory infections: Bronchitis.
One of the most substantial technological innovations developed during the first project year is a real-time virtual ultrasound simulation and volumetric anatomical reference modeling process. For this project, Level Ex's R&D team developed some of the most advanced real-time ultrasound simulation technology available to date and demonstrated its application within the VHS platform. Features include:
• Physics-based ultrasound simulation including simulated wave propagation and backscatter, which produces realistic interactions with a range of participating media.
• Real-time rendering through highly optimized Graphics Processing Unit (GPU) acceleration.
• Realistic ultrasound artifacts including ringdown and acoustic shadowing. These artifacts emerge from the mathematical properties of the simulation, as opposed to artifacts added on as a special-case visual effect.
• Validation against phantom tissue analogs used to test and calibrate real transducer arrays.
• Ability to dynamically generate realistic ultrasound images from voxelized patient data.
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Primary U.S. Work Locations and Key Partners
| Organizations Performing Work | Role | Type | Location |
|---|---|---|---|
| Translational Research Institute for Space Health (TRISH) | Lead Organization | Academia | Houston, Texas |
| Level Ex | Supporting Organization | Industry | Chicago, Illinois |
Primary U.S. Work Locations
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Illinois
