Using virtual environment technology for preadapting astronauts to the novel sensory conditions of microgravity

A unique training device is being developed at the Johnson Space Center Neurosciences Laboratory to help reduce or eliminate Space Motion Sickness (SMS) and spatial orientation disturbances that occur during spaceflight. The Device for Orientation and Motion Environments Preflight Adaptation Trainer (DOME PAT) uses virtual reality technology to simulate some sensory rearrangements experienced by astronauts in microgravity. By exposing a crew member to this novel environment preflight, it is expected that he/she will become partially adapted, and thereby suffer fewer symptoms inflight. The DOME PAT is a 3.7 m spherical dome, within which a 170 by 100 deg field of view computer-generated visual database is projected. The visual database currently in use depicts the interior of a Shuttle spacelab. The trainee uses a six degree-of-freedom, isometric force hand controller to navigate through the virtual environment. Alternatively, the trainee can be 'moved' about within the virtual environment by the instructor, or can look about within the environment by wearing a restraint that controls scene motion in response to head movements. The computer system is comprised of four personal computers that provide the real time control and user interface, and two Silicon Graphics computers that generate the graphical images. The image generator computers use custom algorithms to compensate for spherical image distortion, while maintaining a video update rate of 30 Hz. The DOME PAT is the first such system known to employ virtual reality technology to reduce the untoward effects of the sensory rearrangement associated with exposure to microgravity, and it does so in a very cost-effective manner

I Am The Passenger: How Visual Motion Cues Can Influence Sickness For In-Car VR

This paper explores the use of VR Head Mounted Displays (HMDs) in-car and in-motion for the first time. Immersive HMDs are becoming everyday consumer items and, as they offer new possibilities for entertainment and productivity, people will want to use them during travel in, for example, autonomous cars. However, their use is confounded by motion sickness caused in-part by the restricted visual perception of motion conflicting with physically perceived vehicle motion (accelerations/rotations detected by the vestibular system). Whilst VR HMDs restrict visual perception of motion, they could also render it virtually, potentially alleviating sensory conflict. To study this problem, we conducted the first on-road and in motion study to systematically investigate the effects of various visual presentations of the real-world motion of a car on the sickness and immersion of VR HMD wearing passengers. We established new baselines for VR in-car motion sickness, and found that there is no one best presentation with respect to balancing sickness and immersion. Instead, user preferences suggest different solutions are required for differently susceptible users to provide usable VR in-car. This work provides formative insights for VR designers and an entry point for further research into enabling use of VR HMDs, and the rich experiences they offer, when travelling

Motion sickness evaluation and comparison for a static driving simulator and a dynamic driving simulator

This paper deals with driving simulation and in particular with the important issue of motion sickness. The paper proposes a methodology to evaluate the objective illness rating metrics deduced from the motion sickness dose value and questionnaires for both a static simulator and a dynamic simulator. Accelerations of the vestibular cues (head movements) of the subjects were recorded with and without motion platform activation. In order to compare user experiences in both cases, the head-dynamics-related illness ratings were computed from the obtained accelerations and the motion sickness dose values. For the subjective analysis, the principal component analysis method was used to determine the conflict between the subjective assessment in the static condition and that in the dynamic condition. The principal component analysis method used for the subjective evaluation showed a consistent difference between the answers given in the sickness questionnaire for the static platform case from those for the dynamic platform case. The two-tailed Mann–Whitney U test shows the significance in the differences between the self-reports to the individual questions. According to the two-tailed Mann–Whitney U test, experiencing nausea (p = 0.019 < 0.05) and dizziness (p = 0.018 < 0.05) decreased significantly from the static case to the dynamic case. Also, eye strain (p = 0.047 < 0.05) and tiredness (p = 0.047 < 0.05) were reduced significantly from the static case to the dynamic case. For the perception fidelity analysis, the Pearson correlation with a confidence interval of 95% was used to study the correlations of each question with the x illness rating component IRx, the y illness rating component IRy, the z illness rating component IRz and the compound illness rating IRtot. The results showed that the longitudinal head dynamics were the main element that induced discomfort for the static platform, whereas vertical head movements were the main factor to provoke discomfort for the dynamic platform case. Also, for the dynamic platform, lateral vestibular-level dynamics were the major element which caused a feeling of fear

Spatial orientation and navigation in microgravity

Manuscript for Spatial Processing in Navigation, Imagery and Perception, F. Mast and L. Janeke, eds.This chapter summarizes the spatial disorientation problems and navigation difficulties described by astronauts and cosmonauts, and relates them to research findings on orientation and navigation in humans and animals. Spacecraft crew are uniquely free to float in any relative orientation with respect to the cabin, and experience no vestibular and haptic cues that directly indicate the direction of “down”. They frequently traverse areas with inconsistently aligned visual vertical cues. As a result, most experience “Visual Reorientation Illusions” (VRIs) where the spacecraft floors, walls and ceiling surfaces exchange subjective identities. The illusion apparently results from a sudden reorientation of the observer’s allocentric reference frame. Normally this frame realigns to local interior surfaces, but in some cases it can jump to the Earth beyond, as with “Inversion Illusions” and EVA height vertigo. These perceptual illusions make it difficult for crew to maintain a veridical perception of orientation and place within the spacecraft, make them more reliant upon landmark and route strategies for 3D navigation, and can trigger space motion sickness. This chapter distinguishes VRIs and Inversion Illusions, based on firsthand descriptions from Vostok, Apollo, Skylab, Mir, Shuttle and International Space Station crew. Theories on human “gravireceptor” and “idiotropic” biases, visual “frame” and “polarity” cues, top-down processing effects on object orientation perception, mental rotation and “direction vertigo” are discussed and related to animal experiments on limbic head direction and place cell responses. It is argued that the exchange in perceived surface identity characteristic of human VRIs is caused by a reorientation of the unseen allocentric navigation plane used by CNS mechanisms coding place and direction, as evidenced in the animal models. Human VRI susceptibility continues even on long flights, perhaps because our orientation and navigation mechanisms evolved to principally support 2D navigation.NASA Cooperative Research Agreement NCC9-58 with the National Space Biomedical Research Institut

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 324)

This bibliography lists 200 reports, articles and other documents introduced into the NASA Scientific and Technical Information System during May, 1989. Subject coverage includes: aerospace medicine and psychology, life support systems and controlled environments, safety equipment, exobiology and extraterrestrial life, and flight crew behavior and performance

The Effects of Different Optokinetic Drum Rotation Speeds on Motion Sickness Symptoms, Cognitive Performance and Sleep Amount

Symptoms of motion sickness can be disruptive to human performance. If vection-induced motion sickness symptoms, sleep amount disruptions, and worsening of cognitive performance can be measured and characterized, there are practical implications for equipment design, especially for virtual reality devices and simulators. The researcher conducted three studies. The first study examined the effects of different rotation speeds (0 RPM, 5 RPM, and 10 RPM) of the optokinetic drum on motion sickness symptoms. Motion sickness symptoms were measured using the Simulator Sickness Questionnaire (SSQ). Before exposure to the optokinetic drum, participants were not significantly different from one another in terms of motion sickness symptoms. During exposure to the optokinetic drum, the 5 and 10 RPM conditions experienced significantly more motion sickness symptoms than the 0 RPM condition. Comparing the 5 and 10 RPM conditions during the time of exposure to the optokinetic drum, the 5 and 10 RPM conditions were not significantly different from each other most of the time, with minor exceptions, where the 10 RPM condition induced significantly more motion sickness symptoms than the 5 RPM condition. The second study examined the effects of different rotation speeds of the optokinetic drum and time on cognitive performance. Cognitive performance was measured using the Switching test of the Automated Neuropsychological Assessment Metrics. Cognitive performance, accuracy and mean reaction time were not affected by exposure to the optokinetic drum. The third study examined the effects of different rotation speeds of the optokinetic drum and time on sleep amount. Sleep amount was measured using actigraphs and sleep logs. Sleep amount was not affected by exposure to the optokinetic drum. This project shows that the optokinetic drum is an effective tool to induce and study motion sickness symptoms. Future studies may use the optokinetic drum as a tool to study preventive measures against motion sickness in various environments

Virtual reality in vestibular assessment and rehabilitation

Previous experiences on vestibular compensation showed that multisensorial stimulations affect postural unbalance recovery. Virtual Environment (VE) exposure seems very useful in vestibular rehabilitation, since the experience gained during VE exposure is transferable to the reai world. The rearrangement of the hierarchy of the postural cues was evaluated in 105 patients affected by visual, labyrinthic and somatosensory pathology in normal conditions and during sensoriai deprivation. They were divided into five groups according to pathology and compared to 50 normal controls. Our data show that VE exposure is a reliable method to identify the deficient subsystem and the level of substitution. Moreover, Virtual Reality (VR) would accelerate the compensation of an acute loss of labyrinthine function, related to adaptive modifications of thevestibulo-ocularandvestibulo-spinal reflexes, overstimulating the residual labyrinthine function. The residual labyrinthine function is poor in chronic bilateral vestibular deficit and VE exposure should provide sensory substitution or sensory motor reorganisation, thereby modulating the external spatial reference and promoting the reorganisation of the multiple sensory input. The potential for VE exposure perspectives seerns very promising when dealing with the vestibular system where there is a continuous rearrangement of different sensorial informations as a result of environmental and age-related changes

Aerospace medicine and biology: A continuing bibliography with indexes (supplement 382)

This bibliography lists 119 reports, articles, and other documents recently introduced into the NASA Scientific and Technical Information System. Subject coverage includes the following: aerospace medicine and physiology, life support systems and man/system technology, protective clothing, exobiology and extraterrestrial life, planetary biology, and flight crew behavior and performance