Active Research Projects:
(Updated January 2023)
Skill Retention using AI-Assisted Point-of-Care Ultrasound in Novice, Technically Competent Users
Point-of-care ultrasonography (POCUS) is a clinical tool that has been widely used for the diagnosis and monitoring of many acute medical conditions in hospital settings. While maintaining the ability to capture high quality images, POCUS remains a lightweight, portable, and low cost imaging modality. These characteristics are distinctly necessary to be effective in austere environments where resources are limited. A significant challenge associated with POCUS is the operator’s skill level and its degradation over time. Previous studies have focused on initial ultrasonography training and ability, but have not assessed skill decay and the temporal effects of training with artificial intelligence assistance. Providing data on this subject will be critical to understanding the utility of POCUS in remote settings, such as human spaceflight. The results of the research will inform POCUS training regimens for future operational medical assessments relevant to the military, human spaceflight, and austere medicine.
Collaborators: Dr. Matthew Riscinti (Denver Health, University of Colorado - Anschutz), Dr. Michael Del Valle (Denver Health), Dr. Arian Anderson (University of Colorado - Anschutz, NASA Exploration Medical Capabilities), Dr. Mike Heffler (Denver Health), Dr. William Mundo (Denver Health)
Multi-Environment Virtual Training for Long Duration Exploration Missions
Pre-flight training is an essential part of preparing crews to perform mission critical tasks in a spaceflight environment. In long duration exploration missions, such as a journey to Mars, maintaining high-fidelity performance of these tasks may require continued training throughout transit and skill refreshers before execution on the surface. Virtual reality (VR) technology is an effective tool for training and skill development that may assist astronauts in maintaining performance of mission critical tasks. Through this project, we are developing effective VR training environments for mission critical tasks in entry descent and landing (EDL), habitat maintenance and repair, and planetary surface extravehicular activity (EVA). We are investigating how skills transfer from virtual training environments to physical settings, the degree to which VR training enables performance maintenance over long durations, and how well skills learned in the training environment generalize to un-trained tasks. Training in a complex, adaptive VR environment may also serve as a countermeasure to spaceflight associated neural decrements.
Collaborators: Dr Torin Clark
Subject participting in a vehicle mock up simulation with vitrual reality.
We are investigating non-pharmaceutical countermeasures to mental performance decrements experienced in spaceflight. We are currently evaluating stochastic resonance, which is a phenomenon in nonlinear systems where noise can increase the throughput of a signal. Previous studies have suggested that stochastic resonance improves perception within one sensory modality (e.g. auditory white noise improves auditory perception) or across separate sensory modalities (e.g. auditory white noise improves visual perception). This creates the potential to improve neural function and reduce mental workload in a non-invasive way. We aim to investigate the utility of this phenomenon and its applications to perception and higher-order mental processing.
Collaborators: Dr Torin Clark
PhD: Jamie Voros*
Undergraduates: Maria Callas, Ponder Stine, James Rizkallah, Sasha Kryuchkov, Maya Greenstein
Funding: Translational Research Institute for Space Health through NASA NNX16AO69A under award number T0402.
Participant participating in a BrainStim experiment where white noise is added to stimulous into order to increase a visual theshold.
Real-time Unobtrusive Monitoring of Trust, Workload, and Situation Awareness through Psychophysiological and Embedded Measures
As humans venture farther from Earth, the spaces they inhabit will increasingly rely on autonomous systems to keep them alive, happy, healthy, and productive. Current mission architectures, such as that of the ISS, are able to rely heavily on frequent resupply missions and near-constant ground support; however, next-generation architectures will require efficient teaming between human crews and largely autonomous habitats. An intimate understanding of factors like crew trust in autonomy, workload, and situation awareness (TWSA) will lay the groundwork for robust deep-space human-habitat teaming. Current gold-standard measures of TWSA are often very subjective in nature and require the administering of obtrusive questionnaires. Additionally, humans’ psychophysiological responses have long been studied as a proxy for TWSA, yet much of this work has been constrained to the laboratory environment and has tended to monitor only one facet of TWSA at a time. Our research aims to develop a novel methodology for monitoring and discriminating TWSA cognitive states, given a lean and unobtrusive psychophysiological data stream. We have begun this process by developing an immersive and contextualized piloting task inside our HL-20 DreamChaser mockup, where we can manipulate and measure TWSA. Psychophysiological measures collected include electrocardiogram (ECG), respiration rate, electrodermal analysis (EDA), and eye tracking. Moreover, we have developed embedded measures that leverage specific aspects of task performance to infer TWSA cognitive states. These techniques have larger implications for the field of human-computer interaction as a whole and will be increasingly relevant for aerospace and more as autonomous systems become more ubiquitous.
Collaborators: Dr. Torin Clark, University of California-Davis, University of Southern California
Undergraduates: Evie Clare
Masters: Neil Banerjee, Johnny Zhang
Funding: NASA Habitats Optimized for Missions of Exploration Space Technology Research Institute
Subject partcipating in HOME experiment
Hybrid Spacesuit Design for Martian Surface Exploration
This research aims to explore and develop a novel spacesuit architecture in order to advance the effort of exploring the Martian surface. The suit concept would incorporate novel uses of developed materials for an advance material layup specifically designed for Martian surface exploration as well an exploration of a suit concept that comprise of both mechanical counter pressure (MCP) and gas pressure (GP) systems to achieve a more dynamic pressure system that utilizes advantageous aspects of each design, as well as offers redundancies for additional safety. As we set our sights towards Mars, extravehicular activity (EVA) will continue to be fundamental to human space exploration and will be one of the driving objectives of such a mission. Improvements and adaptations to current EVA spacesuits are imperative in order to enable our astronauts to successfully perform tasks on the Martian surface without risk of injury from the spacesuit or the environment. During the Apollo era, injuries from gas pressurized suits were common and well documented with many astronauts experiencing shoulder, hand, and neck injuries from the extra space, lack of fit, and stiffness of the GP spacesuits. Those missions were only a fraction of the duration of a future Mars mission. We continue to see these injuries and limitations today with our astronauts performing tasks on satellites and ISS. In addition, the metabolic work needed to move and perform tasks in the current spacesuit put astronauts at risk of over exertion and fatigue, because of the bulk and mobility restriction. This could lead to an increase in potentially catastrophic errors and place astronauts at risk. Because of the unique challenges of the Martian surface and the increased duration that explorers will be spending in the suits, current designs will be a limiting factor in the success of surface exploration and the main cause of injuries for the crew. Through a capstone demonstration of a hybrid EVA glove, we will show improvements in dexterity, pressure, and comfort in comparison to the current glove design.
Collaborators: Ministry of Supplies (Boston, MA), MIT Human Systems Lab
PhD: Ella Schauss
Funding: RIO Seed Grant Program
Schematic of the hybrid spacesuit concept.
Wearable Textile ECG Sport Bra for Real Time Health Monitoring
Wearable biosignal monitoring systems are becoming increasingly ubiquitous as tools for autonomous health monitoring and biofeedback during human-computer interaction. Despite the continual advancements in this field, anthropomorphic considerations for the female form are often overlooked in the design process, making systems ill-fit or less effective. In this paper, we present a full garment assembly, ARGONAUT, with integrated textile electrocardiogram (ECG) electrodes in a 3-lead configuration that is designed specifically for the female form. Through the exploration of materials, anthropometry, and garment assembly, we designed and tested ARGONAUT against the industry standard to determine performance through signal peak detection and noise interference. We investigated common issues faced with designing a wearable ECG garment such as fit, motion artifact mitigation, and social wearability to develop a dynamic design process that can be utilized to expand the advancing technology to all individuals in order to allow for equal access to potential health benefits.
Collaborators: Dr. Katya Arquilla, Massachusetts Institute of Technology
PhD: Ella Schauss
Funding: GAANN Fellowship, CU ROI Seed Grant
Implementation of Dynamic Body Shape Models to Improve Spacesuit Boot Fit
Current spacesuit boots have fit issues leading to contact injuries and mismatched kinematics during gait. Many of these fit issues are dynamic: occurring while the foot is moving. As future missions target planetary destinations, such as the Moon or Mars, it will be important to have a spacesuit boot that is properly fitted, comfortable, and moves in coordination with the spacesuit operator. Spacesuit components are currently designed using linear anthropometric measurements and static body shape models. We hypothesize that by designing a boot around the changes in foot shape during gait, the boot will be better fit to the operator’s foot. Dynamic foot shape data was collected from a custom 4D foot scanner developed for this project. A dynamic parametric statistical foot shape model was constructed to predict foot shape from anthropometry and kinematic inputs. This dynamic foot shape model will be integrated into a new planetary spacesuit boot design, constructed, and tested for fit and mobility.
Creating a Predictive Equivalent Model of Woven Textile Electrodes designed for Long Term Capture of ElectroCardioGraph.
When approaching healthcare from the perspective of wellness monitoring, there is a clear demand for continuously monitoring the full ECG waveform. The introduction of wearable technology solutions is a giant leap in the development of long term ambulatory monitoring. Commercially available wearable devices are functional but they fall short by failing to capture the full ECG waveform, relying on blood flow observation instead. The traditional methods of capturing the full ECG waveform dont work well in long term applications outside the clinical setting. Textile electrodes have the potential to capture the full ECG waveform for long periods of time while being low-profile, comfortable, and reusable. In order to realize this potential solution the textile electrodes must be able to be designed and manufactured consistently for meaningful measurements. Currently there is an element of unpredictability between their manufacture and behavior, and so a predictive equivalent model is needed to bridge the gap and allow for consistent performance electrodes. The goal of this research is to develop an equivalent circuit model for textile electrodes.
Wearable Inertial Sensors for Human Motion Capture Inside Spacesuits
A high incidence of injury is currently observed among crewmembers during extravehicular activity (EVA) and while training for EVA. Although it is known that this is a result of adverse mechanical interactions between the human and the spacesuit, designing spacesuits that more safely accommodate the wearer proves challenging due to the inability to observe the motion of the wearer relative to the suit. The current project investigates the use of inertial measurement units (IMUs) to observe human motion inside the suit and seeks to develop a wearable sensor system complete with self-contained power and data-handling. Contrary to past work in this area, this project seeks to achieve accurate joint kinematics estimation without the use of magnetometers, which have been shown to be unreliable due to the presence of time-varying magnetic disturbances inside spacesuits and in indoor environments in general. Instead, the project investigates techniques for improving attitude estimation with only inertial sensors using a variety of techniques including IMU arrays, bandpass filter linear acceleration modeling, and two-speed integration of attitude kinematics. The current project also investigates methods for quantifying and improving the performance of wearable sensor systems in the areas of comfort, mobility, and durability, each of which has hindered the application of such sensors inside the spacesuit in the past. The techniques developed in this work will provide spacesuit designers with unprecedented insight into human-spacesuit interactions, which could facilitate the design of spacesuits that safely enable longer and more frequent EVAs, as required by future human exploration mission architectures.
Monitoring Behavioal Health in Operational Environments
Behavioral health problems are among the highest risks for astronauts on long-duration space exploration missions. These high-performing individuals are expected to maintain psychological health and cognitive performance while being exposed to an isolated, confined, and extreme (ICE) environment that delivers constant psychological stressors for extended durations. In this work, we are investigating different methods of monitoring these individuals within three main areas: 1) survey instruments, 2) wearable textile-integrated physiological sensors, and 3) automated stress-detection algorithms based on physiological signals. We have developed and tested different types of textile electrodes for heart monitoring, including the woven electrodes pictured below (developed in collaboration with Prof. Laura Devendorf). We are working on methods of detecting acute stress using novel parts of the electrocardiogram (ECG) and electrodermal activity (EDA, i.e., sweat response) signals for operational use. With this research we aim to improve our understanding of the stressors of long-duration spaceflight and their impact on behavioral health.
Development of a Lower Body Positive and Negative Pressure Device
A lower body positive and negative pressure device (LBPP/LBNP) seals the lower half of the body in quasi-airtight space, allowing a differential pressure between the upper and lower bodies to be introduced. This allows researchers to investigate the effects of fluid shifts on the body and to investigate the use of LBNP as a countermeasure to the physiological deconditioning that occurs in microgravity. We are adapting the CU Human Research Lab’s glovebox to be configurable to an LBPP/LBNP state. This includes the development of the lower body interface with the chamber, pressure vessel wall modifications, and the first positive pressure testing for the chamber.
Acute Effects of Pressure and Posture on the Eye
Dr. Anderson led a study during her postdoc at the Geisel School of Medicine at Dartmouth College to investigate how posture as well as lower body positive and negative pressure affect the eye. These acute effects are relevant to the development of SANS because the same mechanisms that may lead to ocular findings in space, fluid shifts, hydrostatic gradients, and tissue weight, can be decoupled and studied on the ground through posture and pressure. We are finalizing analyses of the optical biometer and optical coherence tomography measurements made during this study to elucidate the effect of these three mechanisms on the eye. We hope to contribute to a knowledge of the effects of microgravity on the eye to inform SANS etiology theories as well as SANS countermeasures.
In-Suit Wearable Sensing System
Gas pressurized space suits cause injuries and significantly increase metabolic expenditure. It is challenging to quantify how the person moves relative to the suit, which is the genesis of EVA-related injuries. Many techniques of assessing suit performance cannot evaluate suited human biomechanics because they measure performance from the outside of the suit, characterizing the human and space suit as a whole. We are developing wearable sensing systems for use inside the space suit that integrate pressure sensing, joint angle measurement, and physiologic monitoring. Our emphasis is on modular sensor systems that can be used in different regions of the body over a wide range of anthropometries
Virtual Reality for Space Vehicle Mock-up Design
Space vehicle design is critical to maximize crew efficiency, comfort, and equipment storage. Designers utilize mock-ups early in the design phase to experiment with ideas, but high-fidelity mock ups can be costly and time consuming to produce. Therefore, many design decisions have been set in place by the time a high-fidelity mock-up is created. Engineering drawings allow early assessment of vehicle design, but do not allow experimental evaluation of physical presence of people interacting with the system. Further, when testing mock-ups in 1G, our perspective is limited by our orientation and by interacting with the vehicle in 1G. This limitation is removed in microgravity, where astronauts interact with the vehicle or habitat in ways not possible on Earth. To enable efficient and rapid mock-up of vehicle concepts, we are investigating the use virtual reality earlier in the design process to achieve improved system design.
Distortion Product Otoacoustic Emission Mapping
This project assessed distortion product otoacoustic emissions (DPOAE) as a non-invasive measure of intracranial pressure changes. DPOAEs are created in the inner ear when outer hair cells are stimulated by sound. Changes in intracranial pressure have been shown to cause changes in DPOAEs. The long-term interaction between intracranial pressure and the eye may cause visual acuity changes in spaceflight. Unfortunately, there is no noninvasive, easy-to-perform, on-orbit measure of ICP to test this hypothesis. The technique used here, DPOAE level/phase mapping, collects DPOAE data at multiple sites throughout the cochlea and so provides a comprehensive picture of cochlear responses to ICP changes.
Intraocular Pressure in Artificial Gravity
The purpose of this study is to investigate the effects of artificial gravity (AG) as applied via a human centrifuge on the pressure within the eye. This pressure is known as intraocular pressure (IOP). Astronauts are returning from long duration spaceflight with visual acuity and structural changes to the eye, but the cause has yet to be determined. AG offers a comprehensive countermeasure that may be preventative of these problems, even if the mechanism is not determined. We are investigating AG as a potential countermeasure in conjunction with Prof. Torin Clark’s research team.
*student of Dr. Torin Clark
** student of Dr. Dave Klaus
*** student of Dr. Jim Nabity