NASA Exercise Wearables Nate Newby & Meghan Downs NASA Johnson Space Center – TCC MEMBER TCC Wearable Technologies Event - April 26, 2016 – Held at the NASA Johnson Space Center – tcc-houston.org

NASA EXERCISE WEARABLES Nate Newby1, Meghan Downs2, & Andrea Hanson3 1Wyle Science, Technology, and Engineering Group 2University of Houston 3NASA Johnson Space Center Wearable Technologies Event Technology Collaboration Center of Houston April 26, 2016

Introduction Humans adapt to weightlessness by shedding unnecessary bone and muscle strength. This becomes problematic upon return to gravitational environments. Several countermeasures have been developed to try to maintain 1g fitness levels while aboard the ISS. A principal countermeasure is daily bouts of exercise lasting ~2 hours. NASA is interested in biosensor technology that can monitor daily exercise performance, and assess cumulative training adaptations. Future exploration missions will be particularly challenging because of ground support communication delays. Crew will need to make decisions more autonomously. It is important to use ISS as a test bed for evaluating wearable sensors. Known issues with current data collections methods on ISS: Requires large equipment Need for time-consuming setup and calibrations Interference with the suit or environment

Force Shoes Portable load monitoring devices are being considered by NASA’s Human Research Program (HRP) to measure exercise loads on the Advanced Resistance Exercise Device (ARED) One category of devices are wearables or force shoes ISS and HRP have developed the X2 force shoe (X2FS) in house Adidas weightlifting shoe with an embedded custom sensor suite Measures forces, moments, translational accelerations and rotation rates in the heel and toe of each shoe Precision is comparable to large and expensive laboratory force plates Can store data locally on the shoe, or Bluetooth to a laptop Each shoe powered by a Lithium ion battery Load Cells & IMUs Battery & Processor Heel & Toe Force Plates

Force Shoes Why measure under foot forces? When combined with kinematic measurements we can compute ankle, knee, and hip joint torques. Can also get an estimate of muscle activations and forces This is important because exercise in weightlessness is different than on the ground No body weight unique exercise loads Vibration isolation unique exercise motion Considerable variability in post-flight strength losses/preservation Exercise quality may explain some of this variability Why use shoes? A set of traditional force plates weigh 30-40 kg. This is way too much mass and volume for future expeditions. The mass of the entire exercise device for Orion is required to be < 10 kg Current X2FS mass is 0.9 kg per shoe Unmet challenges: Shoes still too heavy, especially for running

Motion Capture Suit NASA Exercise Physiology and Countermeasures owns a MVN Biomech Suit Full-body human motion measurement system based on inertial sensors Could be used to assess exercise kinematics on the ISS Potentially could also be used to understand how astronauts move within the space suit during extravehicular activity (EVA)

Motion Capture Suit Traditional video-based motion capture is difficult on ISS because: Limited space available in the ISS nodes Full 3D video capture can require up to 12 cameras Difficult to place cameras far enough back, or to remove distortion due to wide angle lenses Wearable motion suits offer several advantages Lightweight Can operate in confined spaces Ease of setup and use Unmet challenges Most suits use gravity vector for initial position of the IMU on each limb Magnetometers are used to correct for drift, and may not work correctly on ISS

Ear Bud Biosensor Development Efforts to Date: WHAT: Partnered with Cooper Consulting to develop an earbud based biometric monitoring system that measures heart rate, core temperature, blood oxygen saturation. WHY: This device could be used to improve and expand biometric monitoring capabilities during daily ISS exercise and EVA activities. Development Efforts to Date: Evaluated data quality and accuracy during exercise and pressurized suit conditions. Results led to improved filters, algorithms, conformal coatings, electronic shielding, and updated firmware for real-time assessment. Developed industrial design for self-contained earbud. Pursuing collaborations with military, commercial industry, and use during studies in analog space environments. Unmet Challenges: Development of real-time display and health risk assessment algorithm. Improved data quality in spacesuit testing environments 2-way communication capabilities

Summary Sensors presented demonstrate improvements over current systems on ISS but need improvement prior to using as a standalone system. Force shoes are lighter than force plates while maintaining precision. Still too heavy for running. Motion capture suits are lightweight and can be used in confined space. Accuracy in microgravity is a concern. Earbud sensors provide additional monitoring tools compared to what is available in ISS today but data quality in suited environments needs improvement. Modifying these tools for use in microgravity will help us prepare for exploration missions by: Assessing real-time exercise data Cumulative training effectiveness Autonomous feedback and algorithm development to assist decision-making for crew with long communication delays to ground THANKS! Contact Info: Nate Newby: nathaniel.newby@nasa.gov Meghan Downs: meghan.e.downs@nasa.gov Andrea Hanson: andrea.m.hanson@nasa.gov