The classic symptoms of motion sickness include the loss of alertness, the occurrence, yawning, pallor, sweating, nausea, vomiting and other symptoms. Such symptoms are experienced when traveling or during motion thus leading to very uncomfortable and debilitating situations commonly seen in people experiencing ‘seasickness.’ Motion sickness glasses are a possible solution for motion sickness. This article discusses the anatomy and physiology of the inner ear and explains how these glasses alleviate these symptoms.

Anatomy and structure of the vestibular sensor: a three-dimensional motion sensor
The vestibular sense provides information on the physical movement of the head. Although active permanently, it has the characteristic, that it arrives to the conscious only when a problem appear. We are generally aware of its existence in case of motion sickness or vertigo dizziness Meniere when sensorial conflict exists. For the movement, vestibular cues and somatosensory cues dependent of the inertia have two peculiarities compared to other sensory cues:

1. The vestibular signals cannot be interrupted as is for example the visual signal when closing the eyes.
2. Then they measure the acceleration in the physical space, a non-zero messages automatically mean a movement in space.

This could be the signification of that there is no feeling improvement if the eyes are closed after the beginning of the motion sickness.

In contrast, other sensory signals such as vision:

1. May be interrupted as needed.
2. The information they provide is relative and ambiguous.

Thus, based solely on the vision, the subject cannot know if it’s moving or it’s the environment that moves.

The vestibular sensor is located in the inner ear and composed by two types of sensors:

1. The semicircular canals that are rotation sensors of the head.
2. The otolith or macular sensors which detect linear accelerations.

The acceleration is transmitted either as a translation of the head or orientation thereof with respect to gravity.

There are three semicircular canals:

1. an anterior channel.
2. an posterior channel.
3. an horizontal channel.

These channels are composed of a part of the properly-said channel (hemi-torus) and a bulge also called bulb, which contains the sensory cells. These are:

1. The utricle which is right at the base of the semicircular canals.
2. The saccules are located below the latter.

The semicircular canals are fixed relative to the head, and are oriented in three planes of physical space.

The horizontal channel is inclined (about 25-30 degrees in humans) [1] with respect to anatomic horizontal plane of the head, that it’s means that horizontal channels are aligned with the horizontal line defined with respect to the earth (Figure 1 below).

Anterior and posterior vertical channels are oriented diagonally with respect to the head, along two lines passing through two anatomical landmarks (Figure 2). More generally, the spatial organization of the semicircular canals following two principles:

1. Bilateral symmetry.
2. A two orthogonally two ductal planes.

Motion sickness – a visual block device
Boarding ring motion sickness glasses (see Figure 3) relates to a “visual block device” composed by glass and four colorized levels of liquid incorporated on the rings (from ¼ to ½ of the volume). Two of them are placed in front of the glasses and the two other one are on each side of the spectacles.

The visual wedge device consists of a closed ring that is waterproof and transparent, wherein there are two states of different substances such that the interfaces between substances materialize visible pins which transmit the information of the movement by inertial as on the vestibular system.

During use, the liquid in the rings moves according to motion. By the peripheral view the eyes will catch the information of the movement and give it to the brain. This information of the movement represents the same information (inertial movement) of the movement that is perceived by the inner ear (vestibular sensor).

This is to provide users, at least one marker linked to gravity in their peripheral visual field and thereby prevent any disturbance (motion sickness in general) related to differing perceptions of balance and sight.

Boarding ring stall the vision of the user in harmony with the inner ear. The device permits that at least one of the pins is positioned in the peripheral visual field of one or both eyes of the user, directly or indirectly.

Thanks to the peripheral location of pins or wedges of the device, relative to the central visual field, the individual is not hampered in its perception of the central image when using the device.

Moreover, it is recalled for information that peripheral vision is the location of the image environment “voluntary” and the use of the peripheral visual field as much as the present levels by tracking all the ergonomic advantages an easy adaptation.

Indeed, the level variation of the substances contained in the device (and thus their interfaces) follows the movement of the head or of the mobile and then corresponds to the variation in perception of the inner ear. The perception of the eye is wedged at any time by these benchmarks or interfaces such as the inner ear. With the positioning of the hold device around or on the side of at least one eye, the difference in perception is mitigated by the provision at the best location of the visual field of information of the same kind as that of the inner ear.

Authors

1. Lea Jeannin, PhD of Pharmacy
2. Eole Picot, MSc – picot.eole@hotmail.fr
3. Christopher Ian Wright, BSc, PhD, MBA
4. Hubert Jeannin

About the Author

Eole Picot has a master’s degree from the CESI engineering school in Paris, France. Eole currently works for Alte Technologies, part of the Schaltbau Group, developing modular interiors, WC systems and HVAC systems using composite technologies. Customers include Bombardier transport, Altstom and CAF.

REFERENCE LIST

[1] Landouzy JM. La posture clinique et physiologie. Source: http://www.seret-medecine.org/postures.htm Accessed: 24th April 2016.

[2] Pfeiffer C, Serino A, Blanke O. The vestibular system: a spatial reference for bodily self-consciousness. Front. Integr. Neurosci., 17 April 2014 | http://dx.doi.org/10.3389/fnint.2014.00031 Source: http://journal.frontiersin.org/article/10.3389/fnint.2014.00031/full Accessed: 24th April 2016.

[3] Picot E, Wright CI. Motion sickness – newly engineering glasses may offer a solution. Journal of Applied Mechanical Engineering 2016: 5:2. http://dx.doi.org/10.4172/2168-9873.1000197 Source: http://www.omicsgroup.org/journals/motion-sickness–newly-engineering-glasses-may-offer-a-solution-2168-9873-1000197.pdf Accessed: 24th April 2016.

Please contact the author for reference materials cited in this article.