Spatial calibration of an optical see-through head-mounted display

We present here a method for calibrating an optical see-through Head Mounted Display (HMD) using techniques usually applied to camera calibration (photogrammetry). Using a camera placed inside the HMD to take pictures simultaneously of a tracked object and features in the HMD display, we could exploit established camera calibration techniques to recover both the intrinsic and extrinsic properties of the~HMD (width, height, focal length, optic centre and principal ray of the display). Our method gives low re-projection errors and, unlike existing methods, involves no time-consuming and error-prone human measurements, nor any prior estimates about the HMD geometry

REDUCING VISUALLY INDUCED MOTION SICKNESS FROM SELF-MOTION IN HEAD MOUNTED DISPLAY SYSTEMS

Methods and systems for utilizing binocular occlusion in head mounted display systems to reduce motion sickness are disclosed. While experiencing motion within the head mounted display system, the binocular region may be occluded and may present the user with the same image, while decreasing the visual signals sent to the brain, optimizing user experience, and reducing motion sickness

Discomfort luminance level of head-mounted displays depending on the adapting luminance

The Images in an immersive head-mounted display (HMD) for virtual reality provide the sole source for visual adaptation. Thus, significant, near-instantaneous increases in luminance while viewing an HMD can result in visual discomfort. Therefore, the current study investigated the luminance change necessary to induce this discomfort. Based on the psychophysical experiment data collected from 10 subjects, a prediction model was derived using four complex images and one neutral image, with four to six levels of average scene luminance. Result showed that maximum area luminance has a significant correlation with the discomfort luminance level than average, median, or maximum pixel luminance. According to the prediction model, the discomfort luminance level of a head-mounted display was represented as a positive linear function in log(10) units using the previous adaptation luminance when luminance is calculated as maximum area luminance

Sorcerer's apprentice: head-mounted display and wand

technical reportSorcerer's Apprentice is an interactive computer graphics system utilizing a head-mounted display and at three-dimensional wand. The system allows three-dimensional interaction with line drawings which are displayed in real time, that is about 20 frames per second. The display, worn like a pair of eye glasses, gives an illusion to the observer that he is surrounded by three-dimensional, computer-generated objects. The observer's view is continuously modified to compensate for his motion, allowing the objects to appear stationary as he walks among them. A hand-held wand lets the observer interact with the objects by "touching" them, moving them, changing their shapes, or joining them together. With the wand the observer can also create new objects and add to existing ones. The major activity described here dealt with communication from the observer to the computer. Problems inherent to this communication such as sending commands to the computer in a simple yet expandable manner, sensing when the wand is "touching" an object, and real time processing of a changing data base have been solved. In the solutions we have used a wall chart, a hash addressed data structure, and a dual-copy data structure, respectively. Many minor problems s till distract one while using the Sorcerer's Apprentice system, yet the ability to observe and modify three-dimensional objects in real time and in natural manner is very striking and very realistic

Injection Molding Eyepieces for Head Mounted Display

A technique is provided for manufacturing eyepieces for a head mounted display by forming the eyepiece in two parts: a coated, smaller insert part with a first coating (e.g. chiolite), and a second, larger supporting part with an opening or gap for the coated smaller part. The inset and supporting parts are formed from an eyepiece material via injection molding, and the inset part is then coated with the first coating. The inset is inserted into the gap of the supporting part, and the two parts are cast with an index matching material. The casting forms a front and back shell around the eyepiece, and also bonds the two parts together. By forming the lens in this way, the amount of material used in eyepiece formation is reduced. Further, the formation of ophthalmic lenses is simplified

Interactive Gaming Reduces Experimental Pain With or Without a Head Mounted Display

While virtual reality environments have been shown to reduce pain, the precise mechanism that produces the pain attenuating effect has not been established. It has been suggested that it may be the ability to command attentional resources with the use of head mounted displays (HMDs) or the interactivity of the environment. Two experiments compared participants’ pain ratings to high and low levels of electrical stimulation while engaging in interactive gaming with an HMD. In the first, gaming with the HMD was compared to a positive emotion induction condition; and in the second experiment the HMD was compared to a condition in which the game was projected onto a wall. Interactive gaming significantly reduced numerical ratings of painful stimuli when compared to the baseline and affect condition. However, when the two gaming conditions were directly compared, they equally reduced participants’ pain ratings. These data are consistent with past research showing that interactive gaming can attenuate experimentally induced pain and its effects are comparable whether presented in a head mounted display or projected on a wall

Endoscopic Camera Control by Head Movements for Thoracic Surgery

In current video-assisted thoracic surgery, the endoscopic camera is operated by an assistant of the surgeon, which has several disadvantages. This paper describes a system which enables the surgeon to control the endoscopic camera without the help of an assistant. The system is controlled using head movements, so the surgeon can use his/her hands to oper- ate the instruments. The system is based on a flexible endoscope, which leaves more space for the surgeon to operate his/her instruments compared to a rigid endoscope. The endoscopic image is shown either on a monitor or by means of a head- mounted display. Several trial sessions were performed with an anatomical model. Results indicate that the developed concept may provide a solution to some of the problems currently encountered in video-assisted thoracic surgery. The use of a head-mounted display turned out to be a valuable addition since it ensures the image is always in front of the surgeon’s eyes

An Immersive Telepresence System using RGB-D Sensors and Head Mounted Display

We present a tele-immersive system that enables people to interact with each other in a virtual world using body gestures in addition to verbal communication. Beyond the obvious applications, including general online conversations and gaming, we hypothesize that our proposed system would be particularly beneficial to education by offering rich visual contents and interactivity. One distinct feature is the integration of egocentric pose recognition that allows participants to use their gestures to demonstrate and manipulate virtual objects simultaneously. This functionality enables the instructor to ef- fectively and efficiently explain and illustrate complex concepts or sophisticated problems in an intuitive manner. The highly interactive and flexible environment can capture and sustain more student attention than the traditional classroom setting and, thus, delivers a compelling experience to the students. Our main focus here is to investigate possible solutions for the system design and implementation and devise strategies for fast, efficient computation suitable for visual data processing and network transmission. We describe the technique and experiments in details and provide quantitative performance results, demonstrating our system can be run comfortably and reliably for different application scenarios. Our preliminary results are promising and demonstrate the potential for more compelling directions in cyberlearning.Comment: IEEE International Symposium on Multimedia 201