Evaluation of a Device to Reduce Motion Sickness and Spatial Disorientation

59th Medical Wing36 enrolled

Overview

The purpose of this research study is to learn how a wearable nerve stimulation device, the Spark Biomedical's Sparrow Ascent System™, impacts the development of spatial disorientation and/or motion sickness in a healthy population. Spatial disorientation is when there is a "mismatch" between where a person is, and where the sense organs in their body tell them where they are. These sense organs include the inner ear (the vestibular system), the eyes (the visual system), the sense of where one's legs, back, and neck are (proprioceptive system), and one's higher thinking (cognitive centers). If spatial disorientation is severe or occurs in motion-naïve individuals, spatial disorientation can lead to motion sickness. The Sparrow Ascent System™ is a wearable, battery-operated transcutaneous auricular (ear) neurostimulation (tAN) device. This means that it uses electrical pulses to stimulate branches of nerves on and/or around the ear, specifically the "vagus" and "trigeminal" nerves. These nerves are also responsible for your sensation of nausea and your heart rate (vagus nerve), as well as headaches (trigeminal nerve). The Sparrow System utilizes a flexible earpiece with embedded hydrogel electrodes that stick to the skin, the earpiece is disposable after use. This device is already Food and Drug Administration (FDA) approved for use in humans and is safely used for control of symptoms in a variety of other medical conditions, such as opioid withdrawal and acute stress reaction. In this study, we will determine if the Sparrow Ascent System™ impacts the development of spatial disorientation or motion sickness.

The purpose of this research study is to learn how a wearable nerve stimulation device, the Spark Biomedical's Sparrow Ascent System™, impacts the development of spatial disorientation and/or motion sickness in a healthy population. Study participants will be given monitoring equipment to wear during the study, which will record the participant's vital signs throughout the experiment. Participants will be randomly assigned to one of two groups. Randomization is a process like flipping a coin and meaning there is a chance of being assigned to either of the groups. The two groups include one group where the Sparrow Ascent System™ is turned on. The second group will be given a "sham" Sparrow Ascent System™. A sham device is an inactive Spark Sparrow Therapy System™ that looks like the normal device, but that does not provide any therapy. Participants will be given different stimuli that may cause spatial disorientation and motion sickness. This will include an electronic flight simulator and a rotating chair. In the flight simulator, participants will be given different tasks to complete that often cause some minor spatial disorientation. In the rotating chair, investigators will spin participants around at a steady rate for 10 minutes and ask the participants to change the participants head position in ways that often cause motion sickness. Before, during, and after these stimuli participants will be asked to complete a series of tests to determine if the participants are becoming susceptible to either spatial disorientation or motion sickness. These tests will include asking how the participants are feeling throughout the stimuli, written questionnaires about how the participants feel. Before and after stimuli, participants will also be asked to perform simple tasks to test the participants orientation and performance including hand-eye-coordination, object tracking, and reaction time.

Interventions

Transcutaneous Auricular Neurostimulation deviceDEVICE

The Sparrow Ascent device will be programmed to the preset stimulation parameters. Two individual stimulation frequencies will be set: 15 Hz at cymba concha (Region 1/Channel 1; vagal innervation) and 100 Hz adjacently anterior to the tragus (Region 2/Channel 2; trigeminal innervation). The pulse duration will be set to 250 #s for all participants. The stimulation intensities (mA) will be set to 1.0 and 1.4 (for Region 1 and 2, respectively) based on the median values observed in the previous data set. If the participant states that the stimulation intensity is discomforting, the research coordinator will gradually decrease/increase until a comfortable stimulation intensity is achieved

Eligibility

Sex: ALLMin age: 18 YearsMax age: 50 YearsHealthy volunteers:

Medical Language ↔ Plain English

* Inclusion Criteria: 1. Healthy males and non-pregnant females between the ages of 18-50 who do not experience symptoms of motion sickness. 2. Participants who are English speaking. 3. Participants who are able to read and understand study procedures in order to provide informed consent. * Exclusion Criteria: 1. Females who are pregnant 2. Cardiac pathology (congestive heart failure, history of myocardial infarction, cardiac stent placement, pacemaker placement, heart surgery) 3. Hypertension requiring daily medication 4. Active vestibular disease to include Meniere's disease, migraine associated vertigo, benign paroxysmal positional vertigo, labyrinthitis 5. Neck pain or spinal pathology 6. Medications impacting cardiac, vestibular, or neurologic function 7. Recently ill or hospitalized within 30 days 8. Pilots and individuals formally desensitized to motion sickness 9. Use of vestibular suppressing medications or drugs within 24 hours of the study (antihistamines, histamine-1 receptor agonists, benzodiazepines, anticholinergics, dopamine receptor agonists, alcohol, marijuana, tobacco, opiates) 10. Participant has a history of epileptic seizures 11. Participant has a history of neurological diseases or traumatic brain injury 12. Abnormal vital signs obtained during pre-experimentation phase: * Heart Rate \>100 or \<50 * Systolic blood pressure \>150 or \<90 * Respiratory rate \>24 or \<8 13. Participant has presence of devices, e.g., pacemakers, cochlear prosthesis, neurostimulators 14. Participant has abnormal ear anatomy or ear infection present 15. Participant has any other significant disease or disorder which, in the opinion of the Investigator, may either put the participants at risk because of participation in the trial, or may influence the result of the trial, or the participant's ability to participate in the trial

Outcomes

Primary Outcomes

Graybiel Scale

The Graybiel scale is a commonly used scale for identifying and rating motion sickness symptoms. It was designed to survey multiple dimensions of motion sickness characterized by the degree of 6 representative cardinal symptoms: Nausea and vomiting, skin color, cold sweating, increased salivation, drowsiness, pain and central nervous system symptoms. Each cardinal symptom category is rated by the participant and a corresponding score is calculated. Lesser symptoms are scored with lower point values, 1, 2 or 4 points depending on the severity of that particular symptom with higher scores indicating increased severity. More severe symptoms are scored 8 or 16 points. Values greater than or equal to 16 total points is categorized as frank sickness, 8 to 15 points is severe malaise, 5 to 7 points is moderate malaise A, 3 to 4 points is moderate malaise B, and 1 to 2 points is categorized as slight malaise.

Time frame: Baseline, and at 5- and 10-minutes post motion sickness and at 5- and 10-minutes post spatial disorientation challenges.

Secondary Outcomes

Vitals: Blood pressure

The force of blood pushing against the walls of arteries. Two pressures are measured in mm Hg and are captured via a blood pressure cuff. The systolic pressure in the arteries when the heart contracts and the diastolic pressure in the arteries when the heart relaxes. This is shown numerically with the systolic pressure over the diastolic pressure.

Time frame: Baseline and immediately post spatial disorientation challenge and immediately post motion sickness challenge. At 90 minutes post motion sickness challenge.

Misery Scale (MISC)

Misery Scale (MISC); an 11-point rating scale used to measure the severity of motion sickness symptoms, ranging from no symptoms at all (0) to severe nausea and vomiting (10), with intermediate levels representing increasing discomfort. It measures how "miserable" one feels due to motion sickness. It provides a detailed progression of symptoms to better understand the severity of motion sickness.

Time frame: Baseline, and at 3 times during the spatial disorientation challenge, at 5- and 10-minutes post spatial disorientation challenge as well as 1-minute intervals during the motion sickness challenge and 5- and 10-minutes post motion sickness challenge.

Motion Sickness Assessment Questionnaire (MSAQ)

Motion Sickness Assessment Questionnaire (MSAQ). An instrument that helps assess the experience of motion sickness on a multi-dimensional level. The MSAQ measures four dimensions of motion sickness, gastrointestinal, central, peripheral, and sopite-related (drowsiness, yawning, disengagement). Motion sickness can be a complex set of interacting psychophysiological symptoms that are hard to define. Moreover, one person may experience one symptom to a greater degree than another person, yet both would be experiencing "motion sickness". Additionally, an individual may experience a different feeling of motion sickness depending on the context of what is causing the motion sickness, (boat vs. vehicle vs. visual stimulus) with each potentially eliciting different symptoms. Participants are asked to assess their motion sickness experience by rating 16 statements (ex. I felt sick to my stomach, I felt faint like) from 1-9 with increasing numbers indicating increased severity.

Time frame: Baseline, and 5- and 10-minutes post spatial disorientation challenge and 5- and 10-minutes post motion sickness challenge.

Simulator sickness questionnaire (SSQ)

The Simulator Sickness Questionnaire (SSQ), a tool that helps assess the effects of the environment on an individual's health. A set of sixteen symptoms qualified under nausea, oculomotor discomfort, and disorientation categories are rated from one to four from (1 none, 2 slight, 3 moderate, 4 severe). These symptoms include general discomfort, fatigue, headache, eye strain, difficulty focusing, increased salivation, sweating, nausea, difficulty concentrating, fullness of head, blurred vision, dizzy (eyes open), dizzy (eyes closed), vertigo, stomach awareness and burping. Via calculations the answer to each symptom specific severity question results in three representative sub scores, Nausea related, Oculomotor related, and Disorientation related. These are then combined to get an overall simulator sickness severity score. The SSQ was developed in response to motion sickness questionnaires being deficient or irrelevant in measuring simulator sickness.

Time frame: Baseline and at 5- and 10-minutes post spatial disorientation challenge and 5- and 10-minutes post motion sickness challenge.

Motion sickness susceptibility questionnaire

The Motion sickness Susceptibility Questionnaire predicts individual differences in motion sickness based on stimuli. This questionnaire considers motion type (cars, fair rides, trains, planes etc.), sickness severity ratings, childhood versus adult experiences to find out how susceptible an individual may be to motion sickness and what sorts of motion are the most effective in causing sickness. The participant is asked to rate each motion type as never felt sick, rarely felt sick, sometimes felt sick, frequently felt sick or not applicable if they never traveled via that particular motion type. They are asked the same questions for "As a child" and "Over the last 10 years".

Time frame: Baseline

Functional Ability Assessment

The Senaptec Sensory Station is a state-of-art sensory evaluation \& training station which assesses 10 visual and sensorimotor skills including visual clarity, contrast sensitivity, depth perception, near-far quickness, perception span, multiple object tracking, reaction time, target capture, eye-hand coordination and go / no go. This assessment will give the study team a baseline reference for the subject's functional ability which will then be compared/contrasted to the same assessment given post each spatial disorientation and motion sickness challenge.

Time frame: Baseline and 15 minutes post spatial disorientation challenge and 15 minutes post motion sickness challenge.

Vitals: Heart rate

The number of times a person's heart beats in one minute. Source: Polar H10 Heart Rate Sensor.

Time frame: Continuously throughout the study day, starting at baseline and stopping 90 minutes post motion sickness challenge.

Vitals: Heart Rate Variability

Heart rate variability is the variation in time between heart beats. It is a measure of how well your body can handle stress and recover from physical activity. Source: Polar H10 Heart Rate Sensor.