NOTE (Ed., 5/5/2014): Continuation (with Michael Schubert as new PI) of "Sensorimotor Assessment and Rehabilitation Apparatus: Procedures and Equipment" due to previous PI Shelhamer's move ; same grant number and period of performance (8/1/2010-7/31/2014) in NASA Shared Services Center information.
UPDATED NOTE (Ed., 6/13/2018): For Task Book purposes, period of performance with Schubert will be 8/1/2013-7/31/2014.
Long-duration flight leads to sensorimotor problems which can be critical during landing, rendezvous, and operations on other planetary surfaces. While specific sensorimotor effects have been identified, it is not known which ones have the most adverse impact, or how best to assess them and apply appropriate rehabilitation procedures. NASA’s current goal in addressing this situation is to develop a means to assess sensorimotor function rapidly with a portable device, so that an astronaut can make a determination as to whether or not he or she is impaired enough to affect mission safety or success before undertaking a demanding task (piloting, landing, reentry, egress, extravehicular activity (EVA), tele-operation, etc.).
Accordingly, the goal of this project is to develop a portable hand-held device that will allow a single crewmember to assess his/her sensorimotor function in no more than 20 minutes. This is to be accomplished with a judicious choice of which sensorimotor functions to assess, and careful design to obtain the maximum data in the minimum time. The device and procedures being developed to meet these requirements are based on a tablet computer and body-mounted motion-sensor units. Through a set of simple software routines, a rapid assessment of sensorimotor capabilities will be made. The final device will be small, require little power and space, and provide what is essentially a self-contained sensorimotor lab/clinic. We term this device and its embedded software the Sensorimotor Assessment and Rehabilitation Apparatus (SARA).
SARA has been designed to measure the following functional behaviors, chosen based on laboratory and parabolic flight studies, as being relevant for safe and effective functioning in the space flight environment and likely also to be affected by long-duration space flight:
1. Vestibulo-ocular function during pitching head movements. Subjects actively make pitch head rotation while viewing a target that moves, which they are then tasked to stabilize during the head motion. Without need to record the eyes, this task provides a non-invasive assay of the vestibulo-ocular reflex and canal-otolith integration; highly relevant for gaze stabilization. We term this task the vestibulo-ocular nulling (VON) test.
2. Vestibulo-ocular function as mediated by the otolith organs. We use a binocular display with lines set by the subject to appear collinear or parallel, to measure vertical skew and disconjugate torsion, which are measures of otolith asymmetry. This is highly relevant for gaze stabilization and may be predictive of motion sickness susceptibility.
3. Postural control, by measuring body sway with eyes closed. This test is enhanced by having the subject make pitching head movements.
4. Locomotion, by measuring alterations in the coupling between pitching head movements and vertical body motions during walking. We also have subjects perform the 'Timed Up and Go' test and walk heel to toe with eyes open and closed.
5. Dynamic visual acuity. Subjects make active head rotations in pitch (or yaw) at a two different velocity thresholds (60 d/s or 120 d/s) while attempting to identify the orientation of the open segment of the letter 'C' (up, down, left, right). This is highly relevant for gaze stabilization.