An Eye Tracking Based Virtual Reality System for Use Inside Magnetic Resonance Imaging Systems

Abstract

Patients undergoing Magnetic Resonance Imaging (MRI) often experience anxiety and sometimes distress prior to and during scanning. Here a full MRI compatible virtual reality (VR) system is described and tested with the aim of creating a radically different experience. Potential benefits could accrue from the strong sense of immersion that can be created with VR, which could create sense experiences designed to avoid the perception of being enclosed and could also provide new modes of diversion and interaction that could make even lengthy MRI examinations much less challenging. Most current VR systems rely on head mounted displays combined with head motion tracking to achieve and maintain a visceral sense of a tangible virtual world, but this technology and approach encourages physical motion, which would be unacceptable and could be physically incompatible for MRI. The proposed VR system uses gaze tracking to control and interact with a virtual world. MRI compatible cameras are used to allow real time eye tracking and robust gaze tracking is achieved through an adaptive calibration strategy in which each successive VR interaction initiated by the subject updates the gaze estimation model. A dedicated VR framework has been developed including a rich virtual world and gaze-controlled game content. To aid in achieving immersive experiences physical sensations, including noise, vibration and proprioception associated with patient table movements, have been made congruent with the presented virtual scene. A live video link allows subject-carer interaction, projecting a supportive presence into the virtual world.

Hybrid Swin Transformer-Based Classification of Gaze Target Regions

“…Gaze tracking technology is a technology aimed at understanding user intent and interests [10], focusing on the relationship between image data and gaze direction. Gaze tracking technology has a wide range of applications in various fields, including human-computer interaction [11], [12], medical diagnosis [13], defense and military [14], aviation safety [15], traffic safety [16], [17], [18], virtual reality [19], [20], biosecurity [21], and more. Gaze can be considered one of the behaviors that reflect human attention.…”

An Improved Cross-Ratio Based Gaze Estimation Method Using Weighted Average and Polynomial Compensation

“…Taking the virtual tangent plane determined by the corneal reflection points of light sources as the medium, the screen point corresponding to the 3D pupil center is calculated using the CR invariance, which is regarded as the POR. However, this method has two deficiencies: (1) The CR mapping point on the screen of the pupil center is essentially the intersection of the OA and the screen (POA), rather than the actual POR; (2) The premise of CR calculation is that the corneal reflection points of four light sources are coplanar with the 3D pupil center, but they are only assumed to be coplanar. This deviation is related to parameters such as the distance from 3D corneal center to 3D pupil center and the corneal radius [6].…”