A TILTING INTERFACE FOR MOTION SICKNESS
Motion sickness in vehicles is elevated when passengers perform visual tasks like reading, messaging, and navigating. An interesting find with users, while testing smart glass based solutions to perform digital tasks while commuting, were that passengers claimed to feel less sick when using smart glasses as compared to while using mobile devices.
Project Details:
Hardware and Software Lab Project
University of Washington (MS in Technology Innovation)
National University of Singapore (Research Intern)
Role:
Conducting Literature Research, Developing Research Questions, Ideating, Designing Experiments, Conducting Experiments, Synthesizing and Visualizing Findings.
Team:
Vinitha Erusu (UX Research & Design)
Soojin Hwang (UX Design)
Sebastian Kuhn (Software Development) Manasa Sama (Hardware Development)
Duration:
6.5 Months
January 2022- March 2022 October 2019- Jan 2020
THIS LED TO EXPLORING SMART GLASSES AS A SOLUTION TO ALLEVIATE MOTION SICKNESS
1 in every 3 people face motion sickness in vehicles. Motion sickness is elevated when passengers perform non-driving tasks, which visually disconnect you from the motion of the vehicle. With today’s fast-paced life, people are bound to perform various non-driving tasks in vehicles. With increasing self-driving cars, the hands-free nature of passengers leads to them performing various non-driving tasks.
Smart-glasses allow for different tasks (here, digital) to be performed, with the ability to be visually connected with your surroundings through your peripheral vision. This enables the smart glass user to be able to perceive the motion of the vehicles, in a heads-up posture, while performing the task. This characteristic of smart glasses to digitally overlay on the human vision has the potential to help reduce the visual and cochlear disparity in motion perception and reduce motion sickness.
WE THEN EXPLORED EXISTING SOLUTIONS TO THE PROBLEM
KineStop (App),
Motion Sickness Glasses (Product),
Bubble Margin (Research Paper),
Light cues (Research Paper)
Visual Cues
Efficacy either not significant or not backed by research
Motion Sickness Bands / Bracelets
Dramamine
Motion Sickness Pills
Can induce side effects
LIMITATIONS
TYPE
EXAMPLES
High in price or very
low effectivity
Acustimulation Bracelets,
Sea - Band
AS PASSENGERS ALSO PERFORM NON-DIGITAL/NON-SMART GLASS TASKS THAT INCLUDE HAVING THE PASSENGERS GAZE AWAY FROM THE ROAD, WE CONSIDERED PROVIDING VISUAL CUES TO ADDRESS THESE USE CASES
PROVIDING VISUAL CUES WHEN LOOKING AWAY FROM THE ROAD
For such tasks, the digital overlay of smart glasses on the human vision can be used to provide a digital visual cue of the state of motion of the body as part of the user's secondary task, while the passenger performs the non-digital task as part of the user's primary task.
A LOT OF NON-DIGITAL/NON-SMART GLASS TASKS PERFORMED IN VEHICLES INCLUDE HAVING PASSENGERS GAZE AWAY FROM THE ROAD
Passengers perform various tasks in a vehicle where they look away from the road, like communicating with fellow passengers, operating the infotainment system, reading from a book, and watching videos.
THESE FINDINGS LED US TO TWO PURUSE TWO RESEARCH QUESTIONS
How does the design of digital visual cues on smart glasses help reduce motion sickness in vehicular passengers performing non-driving tasks?
Does performing digital tasks on smart glasses reduce motion sickness in vehicular passengers?
APPROACHES TO ANSWERING THE RESEARCH QUESTIONS
Does performing digital tasks on smart glasses reduce motion sickness in vehicular passengers?
COMPARING MOTION SICKNESS ON THE PHONE AND THE SMART GLASS PLATFORMS USING AN ESTABLISHED MOTION SICKNESS TEST BED
For the experiment, we replicated an established test bed by Mcity (University of Michigan) to measure motion sickness. It included a fixed closed driving track to enable a continuous drive that provided a range of time-weighted, lateral, and longitudinal accelerations within the most frequent bands of travel speed that corresponded to a representative set of naturalistic driving parameters. The scripted route consisted of 90 degree turns, accelerations, breaks, and lane changes. The participants (passengers) were to be made to perform 3 different task conditions during the driving experiment 1) No task condition 2) Reading text on phone 3) Reading text on smart glass. While performing the different task conditions, measurements of the motion of the vehicle, subjective and objective measurements of motion sickness of the participant were to be recorded. The results of the experiment were to be collected and analyzed.
MEASURING MOTION SICKNESS IN PARTICIPANTS WITH OBJECTIVE AND SUBJECTIVE MEASURES
Motion sickness in vehicles is caused due to continuous exposure to longitudinal and lateral acceleration of the vehicle. The higher the magnitude of acceleration, the more sick one feels. Motion sickness experienced by an individual can be objectively measured using physiological data such as heart rate, skin temperature, and electrodermal activity. These can be measured using physiological sensors. Subjective measurement of motion sickness also can be obtained by using the motion sickness assessment questionnaire (MSAQ) and also by a verbal rating of motion sickness.
How does the design of digital visual cues on smart glasses help reduce motion sickness in vehicular passengers performing non-driving tasks?
RESEARCH FINDINGS:
Research suggests that different non-driving tasks require different levels of visual/cognitive focus to perform the tasks and hence induce different levels of motion sickness in the passengers.
At the same time, to experience the effect of visual cues in reducing motion sickness it is important to shift the partial cognitive load of the user from the primary task to the secondary task, which is perceiving the visual cues.
Research also suggests that the levels and symptoms of motion sickness experienced vary from person to person making it difficult to find a one size fits all solution to motion sickness.
APPROACH AND HYPOTHESIS:
Hence to come up with the most appropriate design solutions for visual cues we considered two factors-
level of reduction in motion sickness
level of visual/cognitive focus on performing the primary task
We hypothesize that different types of tasks would demand different combinations of cognitive focus demands and reduction in motion sickness that would lead to different solutions for visual cues for different types of tasks.
THE ADVANTAGE OF SMART GLASSES TO SATISFY THESE NEEDS:
At the same time, with levels of motion sickness experienced varying from person to person, smart glass can provide customizable levels of these factors that can adjust to individual user needs.
With different tasks requiring different solutions, smart glasses can provide visual cues that adapt to the type of the task being performed.
RESEARCH INTO MOTION SICKNESS LED US TO A FINDING THAT PROVED TO BE MORE EFFECTIVE IN REDUCING MOTION SICKNESS
Active head-tilt against the lateral acceleration of the vehicle, just like the driver does while driving, significantly reduces motion sickness in passengers too.
It is known that drivers don’t feel motion sickness but passengers do.
AS THIS SOLUTION PROVED TO BE MORE EFFECTIVE IN REDUCING MOTION SICKNESS, WE PROPOSED A SOLUTION THAT WAS BASED ON THIS FINDING
We vision this solution would provide as an effective solution for performing visual tasks on any kind of platform, whether it be a smart glass that directly overlays on your vision, or a screen based device like a smartphone or a tablet.
A Tilting the interface to assist passengers to tilt their head.
The interface would tilt in response to the lateral acceleration of the vehicle.
The passenger would intutitively tilt his head in the direction of the tilting interface to better perform the task.
DESIGN CONSIDERATIONS
Design for head tilt angles of -40 degrees to 40 degrees.
Higher acceleration should correspond to a higher tilt angle.
Provide gradual tilt of interface, to assist users to tilt their head.
Filter out jerky motions of the vehicle to avoid rapid tilts in the interface.
TESTING THE CONCEPT WITH USERS
We tested with 5 participants (4 Males and 1 Female), who claimed to normally experience motion sickness and use digital devices like tablets or mobile phones while commuting.
The study design was based on the MCity test bed but was directed toward only studying the usability of the tilting interface. This was done because validating the concept of the tilting interface would require a minimum of 60 participants, which was out of the scope of the project.
The experiment was conducted in an outdoor parking lot under controlled conditions. A single driver performed all drives, having practiced a set driving path, acceleration, and vehicle speed beforehand to guarantee repeatability.
During the experiment, participants read a passage from the tilting QP interface for 10 minutes and were then interviewed to share their experience with the prototype for 5 minutes.
Image processing-based head-roll angle tracking during the test.
RESULTS
Using image processing to track head-roll angles in a car is difficult due to changing lighting conditions, as seen in the figure.
DESIGN CHANGES
Based on the insights we made the following design changes:
Adding a tutorial showing the users how to tilt their heads, as the users said that they did not think about tilting their heads until they were told about the purpose of the interface.
The tilt angle of the interface was limited to +/- 40°.
Future design explorations:
Fine-tuning of the acceleration-to-tilt conversion factor could probe towards finding the least amount of interface tilt that still effectively induces passenger head-tilt.
