Engineering topics

Rosenberg, M. J. F.

Publications and source records attributed to Rosenberg, M. J. F..

9 records

NASA NTRS2017

MS Non-Pharmacological Countermeasure to Decrease Landing Sickness and Improve Functional Performance While Disorientad

Upon return from spaceflight, a majority of crewmembers experience motion sickness (MS) symptoms. The interactions between crewmembers' adaptation to a gravitational transition, the performance decrements resulting from MS and/or use of promethazine (PMZ), and the constraints imposed by mission task demands could significantly challenge and limit an astronaut's ability to perform functional tasks during gravitational transitions. No operational countermeasure currently exists to mitigate the risks associated with these sensorimotor disturbances. Stochastic resonance (SR) can be thought of simply as "noise benefit" or an increase in information transfer by a system when in the presence of a non-zero level of noise. We have shown that low levels of stochastic vestibular stimulation (SVS) improve balance and locomotor performance due to SR (Goel et al. 2015, Mulavara et al. 2011, 2015). Additionally, a study in a 6-hydroxydopamine (6-OHDA) hemi-lesioned rat model of Parkinson's disease demonstrated improvements in locomotor activity after low-level SVS delivery possibly due to an increase in nigral gamma-aminobutyric acid (GABA) release in a dopamine independent way (Samoudi et al. 2012). SVS specifically increased GABA release on the lesioned, but not the intact side. These results suggest that SVS can cause targeted alterations of GABA release to affect performance of functional tasks. Activation of the GABA pathway is important in modulating MS and promoting adaptability (Cohen 2008). Magnusson et al. (2000) supported this finding by showing that the administration of a GABAB agonist caused a reversal of the symptoms that is normally seen after unilateral labyrinthectomy. Thus, GABA could play a significant role in reducing MS and promoting adaptability. We have taken advantage of the SR mechanism as a modulator of neurotransmitters to develop a unique SVS countermeasure system to mitigate MS symptoms and improve functional performance after landing. Healthy subjects (n=20) participated in two test sessions, one in which they received +/-400 microA of SVS and one where they received no stimulation (0 microA); the study design was counterbalanced. Subjects began by performing a series of four functional tasks 3-5 times as baseline measurements of task performance. Then, to induce MS, subjects walked an obstacle course with up-down reversing prisms. If they completed the course before achieving our pre-determined level of MS, they were asked to read a poster while making large up-down head movements to a metronome while still wearing the reversing prism goggles. Subjects were stopped every two minutes and asked to report their MS symptoms. Using the Pensacola Scale for motion sickness, test operators evaluated the level of MS of each subject. Once a subject reached an 8 on this scale, which is equivalent to mild malaise, or 30 minutes had passed since the start of the MS induction, this protocol was stopped. Finally, immediately after MS induction, subjects were asked to complete the four functional tasks again. Although, 100% of our subjects experienced at least one MS symptom, only 55% of our subjects experienced stomach awareness to any degree. Without SVS, only 40% of subjects lasted the full 30-minute MS induction protocol, while 65% of subjects lasted the full 30 minutes with SVS, which is nearly a significant increase (p=0.056). In addition, subjects showed significant improvement from baseline when performing a tandem walk and a prone-to-stand test immediately after the MS induction protocol was stopped but the stimulation level was continued. The results are promising and future work includes comparing MS progression between PMZ and SVS directly in subjects that are provoked to a minimum of nausea. Low levels of SVS stimulation may serve as a non-pharmacological countermeasure to replace or reduce the PMZ dosage requirements and concurrently improve functional performance during transitions to new gravitational environments after spaceflight.

Rosenberg, M. J. F.↗

NASA NTRS2017

Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness in Crewmembers Returning from Long-Duration Spaceflight

Long-term exposure to microgravity causes sensorimotor adaptations that result in functional deficits upon returning to a gravitational environment. At landing, the vestibular system and the central nervous system, responsible for coordinating head and eye movements via the vestibulo-occular reflex (VOR), are adapted to microgravity and must re-adapt to the Earth's gravitational environment. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with astronauts reporting oscillopsia and blurred vision. These effects are caused by retinal slip, or the inability to keep an image focused on their retina, which is thought to drive motion sickness symptoms experienced upon landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Peters et al. (2011) find that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. Previously, the use of stroboscopic goggles has shown to be effective in minimizing motion sickness symptoms due to retinal slip (Reschke et al. 2007). In this study, we simulated the decrement in DVA caused by sensorimotor re-adaptation by using minifying lenses and then testing the efficacy of stroboscopic goggles in preventing retinal slip and improving DVA. Dynamic visual acuity is assessed using an oscillating chair developed in the Neuroscience Laboratory at JSC. This chair is motor-driven and oscillates vertically at 2 Hz with a vertical displacement of +/- 2 cm to simulate the vertical translations that occur while walking. As the subject is being oscillated, they are asked to discern the direction of Landolt-C optotypes of varying sizes and record their direction using a gamepad. The visual acuity thresholds are determined using an algorithm that alters the size of the optotype based on the previous responses of the subject using a forced-choice best parameter estimation that is able to rapidly converge on the threshold value. Visual acuity thresholds were determined both for static (seated) and dynamic (oscillating) conditions. Dynamic visual acuity is defined as the difference between the dynamic and static conditions. We found that healthy subjects (n=20) have a significantly impaired DVA while wearing the minifying lenses, demonstrating that the VOR is in an adaptive state and retinal slip is occurring. When subjects' acuity was tested wearing the stroboscopic goggles with the minifying lenses, there was no significant difference in their DVA compared to their baseline DVA. This suggests that stroboscopic goggles are preventing retinal slip and would function as an efficient countermeasure for VOR adaptations and thus help mitigate landing sickness symptoms experienced by long-duration crewmembers. These goggles might also be used to counter blurred vision (caused by retinal slip) experienced by crewmembers during launch where the vehicle vibrations are greatest. The stroboscopic effect could be built into a section of their head mounted displays on the visor of their helmets to be used in these high vibration situation if a mission critical task is necessary.

Rosenberg, M. J. F.↗

NASA NTRS2017

Validation of a Manually Oscillating Chair for In-The-Field Assessment of Dynamic Visual Acuity on Crewmembers Within Hours of Returning From Long-Duration Spaceflight

Long-duration spaceflight results in sensorimotor adaptations, which cause functional deficits during gravitational transitions, such as landing on a planetary surface after long-duration microgravity exposure. Both the vestibular system and the central nervous system are affected by gravitational transitions. These systems are responsible for coordinating head and eye movements via the vestibulo-ocular reflex (VOR) and go through an adaptation period upon exposure to microgravity. Consequently, they must also re-adapt to Earth's gravitational environment upon landing. This re-adaptation causes decrements in gaze control and dynamic visual acuity, with crewmembers reporting oscillopsia and blurred vision caused by retinal slip, or the inability to keep an image focused on their retina. This is thought to drive motion sickness symptoms experienced by most crewmembers following landing. Retinal slip can be estimated by dynamic visual acuity (DVA); visual acuity while in motion. Previously, DVA has been assessed in the laboratory where subjects walked at 6.4 km/hr on a motorized treadmill. Using this method, Peters et al. (2011) found that DVA is worsened in astronauts by an average of 0.75 eye-chart lines one day after landing. However, it is believed that re-adaptation occurs quickly and that DVA might be worse immediately upon re-exposure to a gravitational environment. Since many crewmembers are unable to walk safely upon landing, it was necessary to develop a method for replicating the vertical head movements associated with walking. In addition, the use of a chair to imitate the head displacement caused by walking isolates eye-head interactions without allowing for trunk and lower-body compensation, as seen with treadmill walking (Mulavara & Bloomberg 2003). Therefore, a modality for assessing DVA in the field within a few hours of landing was developed. In this study, we validated the ability of a manually operated oscillating chair to reproduce the oscillatory frequency of walking on a treadmill. Healthy non-astronaut subjects (n=14) participated in one test session and completed three static (seated) and three dynamic (walking/oscillated) visual acuity tests. DVA was assessed using a motorized treadmill, an automated oscillating chair, and a manually operated chair, both developed in the Neuroscience Laboratory at JSC. The automated chair was motor-driven and set to oscillate vertically at 2 Hz with a vertical displacement of +/- 5 cm to simulate vertical translation while walking. The manually operated chair was oscillated vertically by a test operator to the beat of a metronome at 120 beats/min (2 Hz) and a vertical displacement of approximately +/- 5 cm. As the subject was oscillated, they were asked to discern the direction gap of Landolt-C optotypes of varying sizes and verbally reported the direction while an operator recorded their response using a gamepad. Subjects were outfitted with accelerometers (sampling rate = 128 Hz) on their head, trunk and lumbar spine. A fast Fourier transform was performed on the vertical trunk acceleration to compare the peak and spread of the distribution of oscillation frequencies for each oscillating condition. The spread of the frequency distribution for the manual chair was not significantly different from either the treadmill or the automated chair. However, all three conditions had similar non-zero standard error values, suggesting a variance in head movement frequency which may affect DVA. The average oscillation frequency of the manual chair (1.85 Hz) was significantly different (α=0.05) from that of treadmill walking (2.24 Hz), but not significantly different from that of the automated chair (1.85 Hz) and all three conditions had small standard errors (SEM = 0.04, 0.06, and 0.08 Hz for manual, treadmill, and automated respectively). This implies that both chairs oscillate at a frequency below that of treadmill walking, but are comparable to each other and reproducible across sessions. Additionally, DVA scores did not vary significantly across conditions. The smaller spread values of the oscillating chairs' frequencies indicated mitigation of variation induced by locomotor strategies, which enables better examination of the issue of VOR adaptation. Furthermore, due to the deconditioned state of crewmembers in the initial hours after landing, it is easier to transport a manual bouncing chair into the field and safer to perform a vision test while seated in a chair versus walking on a treadmill. Therefore, the manually oscillating chair has been deemed to meet and exceed the DVA testing capabilities previously obtained by treadmill walking.

Kreutzberg, G. A.↗

NASA NTRS2017

Field Test: Results from the One Year Mission

The One Year Mission was designed to aid in determining the effect that extending the duration on orbit aboard the International Space Station (ISS) would have on a number of biological and physiological systems. Two crewmembers were selected to participate in this endeavor, one U.S. On-Orbit Segment (USOS) astronaut and one Russian cosmonaut. The Neuroscience and Cardiovascular and Vision Laboratories at the Johnson Space Center and the Sensory-Motor and Countermeasures Division within the Institute for Biomedical Problems were selected to investigate vestibular, sensorimotor and cardiovascular function with the two long-duration crewmembers using the established methodology developed for the Field Test (FT).

Reschke, M. F.↗

NASA NTRS2017

Stroboscopic Goggles as a Countermeasure for Dynamic Visual Acuity and Landing Sickness After Long-Duration Spaceflight

Gravity transitions cause changes in the vestibulo-occular reflex (VOR), which manifests as poor gaze control, a decrement in dynamic visual acuity (the ability to maintain gaze while in motion), both of which are caused by retinal slip. Retinal slip, the inability to keep an image focused on the retina, can drive or worsen sensory conflict, resulting in motion sickness (MS). Currently 100% of returning crewmembers report MS symptoms, which might affect their ability to perform mission critical tasks immediately after landing. Reschke et al. (2007) demonstrate that stroboscopic vision goggles improve motion sickness onset and symptom severity in motion sickness driven by retinal slip.

Rosenberg, M. J. F.↗

NASA NTRS2017

Non-Pharmacological Countermeasure to Decrease Landing Sickness and Improve Functional Performance

Upon return from long-duration spaceflight, 100% of crewmembers experience motion sickness (MS) symptoms. The interactions between crewmembers' adaptation to a gravitational transition, the performance decrements resulting from MS and/or use of promethazine (PMZ), and the constraints imposed by mission task demands could significantly challenge and limit an astronaut's ability to perform functional tasks during gravitational transitions. Stochastic resonance (SR) is "noise benefit": adding noise to a system might increase the information (examples to the left and above). Stochastic vestibular stimulation (SVS), or low levels of noise applied to the vestibular system, improves balance and locomotor performance (Goel et al. 2015, Mulavara et al. 2011, 2015). In hemi-lesioned rat models, Samoudi et al. 2012 found that SVS increased GABA release on the lesioned, but not the intact side. Activation of the GABA pathway is important in modulating MS and promoting adaptability (Cohen 2008) and was seen to reverse MS symptoms in rats after unilateral labyrinthectomy (Magnusson et al. 2000). Thus, SVS could be used to promote GABA pathways to reduce MS and promote adaptability, eliminate the need for PMZ or other performance-inhibiting drugs.

Rosenberg, M. J. F.↗

NASA NTRS2017

Validation of a Manually Oscillating Chair for In-The-Field Assessment of Dynamic Visual Acuity on Crewmembers Within Hours of Returning from Long-Duration Spaceflight

Due to the deconditioned state of crewmembers in the initial hours after landing, it is safer and more practical to perform a vision test while seated in a chair versus walking on a treadmill. The purpose of this study was to validate the ability of a manually operated oscillating chair to produce the oscillatory frequency and displacement equivalent of walking on a treadmill at a 4 mph pace. A fast Fourier transform (FFT)was performed on the vertical trunk acceleration to compare the peak and spread of the distribution of oscillation frequencies for each oscillating condition. Peak oscillation frequencies achieved with the manual chair were lower and more variable than those of treadmill walking and the automatic chair. This can mostly be attributed to operator fatigue. However, DVA scores across conditions were not significantly different, indicating that the manual chair can provide adequate vertical oscillation frequency and displacement with the added advantage of being portable enough for testing outside a laboratory. Furthermore the automatic chair very closely matches the oscillation frequency of treadmill walking, making it an ideal method for testing DVA in a laboratory setting.

Kreutzberg, G. A.↗

NASA NTRS2016

Sensorimotor Results from the Joint NASA and Russian Pilot Field Test

Testing of crew responses following long-duration flights has not previously been possible until a minimum of 24 hours after landing. As a result, it has not been possible to estimate the nonlinear trend of the early (<24 hours) recovery process, nor has it been possible to accurately assess the full impact of the decrements associated with long-duration flight. To overcome these limitations, both the Russian and U.S. programs have implemented testing at the Soyuz landing site. This research effort has been identified as the Field Test (FT). For operational reasons the FT has been divided into two phases: the full FT and a preliminary pilot version (PFT) of the FT that is reduced in both length and scope. The PFT has now been completed with the landing of the crew of International Space Station Increment 42/43 (Soyuz expedition 41S). RESEARCH: The primary goal of this research was to determine functional abilities associated with long-duration space flight crews beginning as soon after landing as possible (< 2 hours) with an additional two follow-up measurement sessions within 24 hours after landing. This study goal has both sensorimotor and cardiovascular elements. The PFT represented a initial evaluation of the feasibility of testing in the field and was comprised of a jointly agreed upon subset of tests drawn from the full FT and relied heavily on Russia's Institute of Biomedical Problems Sensory-Motor and Countermeasures Department for content and implementation. Data from the PFT was collected following several ISS missions. Testing on the U.S. side has included: (1) a sit-to-stand test, (2) recovery from a fall stand test where the crewmember begins in the prone position on the ground and then stands for 3.5 minutes while cardiovascular performance and postural ataxia data are acquired, and (3) a tandem heel-to-toe walk test to determine changes in the central locomotor program. Video, cardiovascular parameters (heart rate and blood pressure), data from body-worn inertial sensors, and severity of postflight motion sickness were collected during each test session. In addition our Russian investigators have made measurements associated with: (a) obstacle avoidance, (b) muscle compliance, (c) postural adjustments to perturbations (pushes) applied to the subject's chest area and (d) center of mass measurements made across most test objectives with insoles inserted into the subjects' shoes. Data from 18 subjects have been obtained for a majority of the PFT objectives. SUMMARY: The increased level of functional deficit observed in the crewmembers tested with the PFT objectives has been typically greater than previously observed when measurements were collected after the 2 hr window. Significant improvement in crew performance was observed within 24 hours, but full recovery appears to require 6 to 16 days. Clearly measureable performance parameters such as ability to perform a seat egress, recovery from a fall or the ability to see clearly when walking, and related physiologic data (orthostatic responses) are required to provide an evidence base for characterizing programmatic risks and the variability among crewmembers for exploration missions where the crew will be unassisted after landing. Overall, these early functional and related physiologic measurements will allow the estimation of nonlinear sensorimotor and cardiovascular recovery trends that have not been previously captured.

Reschke, Millard↗

NASA NTRS2016

Field Test: Results of Tandem Walk Performance Following Long-Duration Spaceflight

BACKGROUND: Coordinated locomotion has proven to be challenging for many astronauts following long duration spaceflight. As NASA's vision for spaceflight points toward interplanetary travel, we must prepare for unassisted landings, where crewmembers may need to perform mission critical tasks within minutes of landing. Thus, it is vital to develop a knowledge base from which operational guidelines can be written that define when astronauts can be expected to safely perform certain tasks. Data obtained during the Field Test experiment (FT) will add important insight to this knowledge base. Specifically, we aim to develop a recovery timeline of functional sensorimotor performance during the first 24 hours and several days after landing. METHODS: FT is an ongoing study of 30 long-duration ISS crewmembers. Thus far, 9 have completed the full FT (5 U.S. Orbital Segment [USOS] astronauts and 4 Russian cosmonauts) and 4 more consented and launching within the next year. This is in addition to the eighteen crewmembers that participated in the pilot FT (11 USOS and 7 Russian crewmembers). The FT is conducted three times preflight and three times during the first 24 hours after landing. All crewmembers were tested in Kazakhstan in either the medical tent at the Soyuz landing site (~one hour post-landing), or at the airport (~four hours post-landing). The USOS crewmembers were also tested at the refueling stop (~12 hours post-landing) and at the NASA Johnson Space Center (~24 hours post-landing) and a final session 7 days post-landing. Crewmembers are instrumented with 9 inertial measurement unit sensors that measure acceleration and angular displacement (APDM's Emerald Sensors) and foot pressure-sensing insoles that measure force, acceleration, and center of pressure (Moticon GmbH, Munich, Germany) along with heart rate and blood pressure recording instrumentation. The FT consists of 12 tasks, but here we will focus on the most challenging task, the Tandem Walk, which was also performed as part of pilot FT. To perform the Tandem Walk, subjects begin with their feet together, their arms crossed at their chest and eyes closed. When ready, they brought one foot forward and touched the heel of their foot to their toe, repeating with the other foot, and continuing for about 10 steps. Three trials were collected with the eyes closed and a fourth trial was collected with eyes open. There are four metrics which are used to determine the performance level of the Tandem Walk. The first is percent correct steps. For a step to be counted as correct, the foot could not touch the ground while bringing it forward (no side stepping), eyes must stay closed during the eyes closed trials, the heel and toe should be touching, or almost touching (no large gaps) and there shouldn't be more than a three second pause between steps. Three judges score each step and the median of the three scores is kept. The second metric is the average step speed, or the number of steps/time to complete them. Thirdly, the root mean squared (RMS) error in the resultant trunk acceleration is used to determine the amount of upper body instability observed during the task. Finally, the RMS error of the mediolateral center of pressure as measured by the Moticon insoles is used to determine the mediolateral instability at the foot level. These four parameters are combined into a new overall Tandem Walk Parameter. RESULTS: Preliminary results show that crewmembers perform the Tandem Walk significantly worse the first 24 hours after landing as compared to their baseline performance. We find that each of the four performance metrics is significantly worse immediately after landing. We will present the results of tandem walk performance during the FT thus far. We will also combine these with the 18 crewmembers that participated in the pilot FT, concentrating on the level of performance and recovery rate. CONCLUSION: The Tandem Walk data collected as part of the FT experiment will provide invaluable information on the performance capabilities of astronauts during the first 24 hours after returning from long-duration spaceflight that can be used in planning future Mars, or other deep-space missions with unassisted landings. FT will determine the average sensorimotor recovery timeline and inform return-to-duty guidelines for unassisted landings.

Rosenberg, M. J. F.↗