None listed
Conditions
Brief summary
Flight simulators have been used to train pilots to experience and recognize spatial disorientation, a condition in which pilots incorrectly perceive the position, location, and movement of their aircrafts. However, during or after simulator training, simulator sickness (SS) may develop. Spatial disorientation and SS share common symptoms and signs and may involve a similar mechanism of dys-synchronization of neural inputs from the vestibular, visual, and proprioceptive systems. Transcutaneous electrical nerve stimulation (TENS), a maneuver used for pain control, was found to influence autonomic cardiovascular responses and enhance visuospatial abilities, postural control, and cognitive function. The purpose of present study was to investigate the protective effects of TENS on SS. Subjects meeting inclusion criteria will be recruited. After informed consent, each participants have to finish four sessions (baseline, SS, TENS, TENS + SS). SS was induced by a flight simulator. TENS treatment involved simultaneous electrical stimulation of the posterior neck and the Zusanli acupoint. SS severity and cognitive function were quantified by the Simulator Sickness Questionnaire (SSQ) and d2 test of attention. Sleepiness symptoms were rated using the Visual Analogue Scales for Sleepiness Symptoms (VAS-SS). Autonomic and stress responses were evaluated by heart rate variability (HRV) and salivary stress biomarkers (salivary alpha-amylase activity and salivary cortisol concentration).
Interventions
Transcutaneous electrical nerve stimulation (TENS) used in a within-subject crossover design wherein each subject will complete 4 test sessions (control, SS, TENS, and TENS + SS) in a randomized order.
[control session: no simulator exposure and no TENS stimulation]
[SS session: simulator Sickness; exposure to flight simulator for 30 minutes to induce simulator sickness]
[TENS session: transcutaneous electrical stimulation: electrical stimulation at midline posterior nuchal region and right Zu
Transcutaneous electrical nerve stimulation (TENS) used in a within-subject crossover design wherein each subject will complete 4 test sessions (control, SS, TENS, and TENS + SS) in a randomized order. [control session: no simulator exposure and no TENS stimulation] [SS session: simulator Sickness; exposure to flight simulator for 30 minutes to induce simulator sickness] [TENS session: transcutaneous electrical stimulation: electrical stimulation at midline posterior nuchal region and right Zusanli acupoint for 30 minutes using a self-contained, battery-operated, dual channel transcutaneous electrical nerve stimulator at a pulse rate of 100 Hz and the level of intensity (1 through 10) at the highest comfortable setting, per the manufacturer’s instructions] [TENS + SS session: treat with TENS for 30 minutes then exposure the subject in flight simulator to induce simulator sickness. Purpose: to observe the effect of the TENS (the intervention)] To prevent the carryover of intervention, sessions were spaced at least 2 days apart. (The wash out period between sessions is at least 2 days apart). Each session consisted of 4 phases: phase 1 (10 minutes), consisting of preparation and recording of baseline physiologic parameters; phase 2 (10 minutes), electrical stimulation (for TENS and TENS + SS sessions); phase 3 (20 minutes), SS stimulation (for SS and TENS + SS sessions) and electrical stimulation (only in TENS + SS sessions); and phase 4 (30 minutes), the post-test period. TENS treatment will last 30 minutes (complete duration of phases 2 and 3) at two sites: (1) the midline posterior nuchal region and (2) the Zusanli acupoint, located 1 finger breadth lateral to the tibial anterior crest, about 4 finger widths below the knee.
Sponsors
Institute of Aerospace and Undersea medicine
Study design
Allocation
Randomised controlled trial
Intervention model
Crossover
Primary purpose
Treatment
Masking
Blinded (masking used)
Eligibility
Sex/Gender
Male
Age
20 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
healthy, non-smoking, young male participants (age 20-40)
Exclusion criteria
vestibular, visual, cardiovascular, respiratory, and gastrointestinal tract disorders.
Outcome results
None listed