Specific Aim 1: This aim will compare motion sickness symptom onset, severity, and recovery across four conditions: intranasal scopolamine (0.4 mg) and placebo control with and without sensory augmentation. The six degree-of-freedom (CKAS) platform was assembled in our laboratory space and the capsule wave pseudorandom motion stimuli consisting of combined pitch, roll, and heave motion centered around 0.2 Hz has been implemented. Defender Pharmaceuticals, Inc. (Tampa, FL) has provided the study medication (intranasal formulation of scopolamine hydrobromide, 0.4 mg dosage) including placebo control using a nasal pump delivery device. Engineering Acoustics, Inc (Orlando, FL) provided a wearable vibrotactile array to provide feedback about pitch and roll tilts. The functional and cognition tasks have also been implemented in the capsule cabin. We are conducting a preliminary pilot study with 10 subjects to verify the wave motion stimuli is sufficiently provocative to elicit symptoms and assess efficacy of the interventions. This pilot study data will also be used to complete and verify the data analysis scripts for the test battery.
Specific Aim 2: This aim will compare motion sickness symptom severity and recovery for intranasal scopolamine (0.4 mg) and placebo control subjects will self-administer during the simulated capsule wave motion following symptom onset. We are currently evaluating moving this study arm to utilize the Disorientation Research Device (Kraken) located at the Naval Medical Research Unit – Dayton (NAMRU-D) at the Wright-Patterson Air Force Base in Ohio. This device has the capability to provide a greater range in levels of sea states for the capsule wave motion.
Specific Aim 3: This aim is a clinical field study to examine the efficacy of intranasal scopolamine in various operational settings including SpaceX missions, Orion splashdown recovery simulations, and centrifuge training. The field test aim was initiated during the 3-day orbital free-flyer mission (Inspiration4) onboard the SpaceX Crew Dragon capsule this past year. Commercial crewmembers were trained in standardized self-administration of intranasal scopolamine for mild-to-moderate motion sickness (0.2 mg per nostril, 0.4 mg total dose). Each crewmember was supplied with one scopolamine nasal applicator, stowed in an accessible pocket of the IVA (intravehicular activity) suit. No restriction was placed upon the use of prophylactic anti-emetics, with decision for prophylactic use for each crewmember based on observed motion sickness susceptibility during training. Nausea levels (1 = no nausea, 20 = severe nausea) were recorded as a standard part of regularly scheduled Private Medical Conferences (PMCs). PMCs occurred shortly after initial orbital insertion, nightly prior to crew sleep, and post-splashdown. Two of four crewmembers utilized intranasal scopolamine during the hours of the spaceflight. Both Crewmembers reported a peak nausea level of 8 on the 0-20 scale prior to INSCOP (Intranasal Scopolamine) self-administration, reducing to 5 after 15 minutes. Side effects reported included drowsiness, dry mouth, and nasal irritation (n=1 for each). Duration of reported relief was 2.5 hrs. and 3.5 hrs. for each crewmember, respectively, later requiring more aggressive treatment for higher symptom scores. Nausea resolved by mission day 1, resulting in no further use of anti-emetics in flight. Despite the later need for anti-emetics, this novel tool effectively mitigated immediate symptoms of nausea and was easily self-administered by crewmembers with minimal training and did not impede flight operations by requiring unscheduled suit doffing or medical equipment access.