Latency compensation by horizontal scanline selection for head- mounted displays

Head mounted displays (HMDs) can present visual information to operators at times when this would otherwise be difficult or impossible using standard visual displays. HMDs have been shown to benefit anesthetists in simulated medical environments. Operators, however, may have trouble extracting information from the HMD in dynamic environments. Operators may also fail to consciously perceive visual events that are important, meaningful, or bizarre if attending to other aspects of the visual scene. We investigated how attention manipulations (Focused, Divided, Just Watch) interact with display type (HMD, Standard Display) and found that participants were less likely to detect unexpected events using the HMD. We also found that unexpected event detection decreased from the Just Watch to Divided to Focused attention conditions. We suggest further testing be taken to ensure that HMDs to not result in failures to detect unexpected events in anesthesia monitoring.

Extended-Reality Technologies: An Overview of Emerging Applications in Medical Education and Clinical Care.

Virtual reality (VR) is usually used to simulate complex visual scenes with a head-mounted display (HMD). However, VR can also be used to obtain better control over the visual environment and to monitor ocular dynamics during listening experiments. In this study, a low-cost HMD was used to track eye gaze and pupil diameter during a dichotic listening task in a simple virtual environment that simulated a computer display. The pupillometry results from the VR environment were compared to those obtained on the same task with a desktop monitor research-grade eye tracker. Participants recalled digits in the right ear and ignored interfering digits in the left ear. It was hypothesized that greater pupil dilation would be observed for dichotic compared to monotic listening with both HMD and research-grade eye trackers. Preliminary data support this hypothesis. The HMD was also evaluated for its potential to collect eye-tracking data in tablet-based clinical speech-in-noise tasks not originally designed for pupillometry. Results suggest that the task-evoked pupil response can be measured with the HMD on clinical tasks and a VR-based system has potential as a low-cost clinical tool to collect objective measures of listening effort.

Recupera algunos de los elementos menos estudiados y reconocidos en el ensayo latinoamericano: su profunda vocación de reflexión, diálogo y mediación intelectual; su plasticidad y apertura a la búsqueda del sentido; su vínculo con la sociabilidad, la conversación y la generación de un espacio simbólico de encuentro; su capa cidad de establecer una nueva retroalimentación entre lectura y escritura.

BackgroundVideo-assisted thoracoscopic surgery (VATS) has become a standard approach for the treatment of lung cancer. However, its minimally invasive nature limits the field of view and reduces tactile feedback. These limitations make it vital that surgeons thoroughly familiarize themselves with the patient’s anatomy preoperatively. We have developed a virtual reality (VR) surgical navigation system using head-mounted displays (HMD). The aim of this study was to investigate the potential utility of this VR simulation system in both preoperative planning and intraoperative assistance, including support during thoracoscopic sublobar resection.MethodsThree-dimensional (3D) polygon data derived from preoperative computed tomography data was loaded into BananaVision software developed at Colorado State University and displayed on an HMD. An interactive 3D reconstruction image was created, in which all the pulmonary structures could be individually imaged. Preoperative resection simulations were performed with patient-individualized reconstructed 3D images.ResultsThe 3D anatomic structure of pulmonary vessels and a clear vision into the space between the lesion and adjacent tissues were successfully appreciated during preoperative simulation. Surgeons could easily evaluate the real patient’s anatomy in preoperative simulations to improve the accuracy and safety of actual surgery. The VR software and HMD allowed surgeons to visualize and interact with real patient data in true 3D providing a unique perspective.ConclusionsThis initial experience suggests that a VR simulation with HMD facilitated preoperative simulation. Routine imaging modalities combined with VR systems could substantially improve preoperative planning and contribute to the safety and accuracy of anatomic resection.

Upper Extremity Rehabilitation Using Fully Immersive Virtual Reality Games With a Head Mount Display: A Feasibility Study.

This paper describes improvements to the virtual reality (VR) brachytherapy system that we have previously designed and implemented. Brachytherapy is a cancer treatment modality whereby, needles are inserted into a patient to act as channels to deliver radioactive sources to the diseased tissue. The focus of this paper is on the advances that have been made on the system. More software tools have been added to the system, as well as the interfacing of a new head mounted display (HMD). The method in which the user inputs information into the system has changed from a graphical user interface to a voice user interface (VUI). Some preliminary work has been carried out on an artificial intelligence (AI) component, which will suggest optimal needle placement to the user. This early work on the Al component involves the use of Simulated Annealing to find optimal needle positions within a single 2D slice of a cancerous tumour. The new software tools have been found to be very useful. The new HMD, has been successfully interfaced to the VR system and far exceeds the usefulness of the previous device. The VUI has a high level of accuracy and greatly increases the usability of the VR system. Preliminary results from the AI component of the system suggest that further research will lead to a very useful optimization method for use in the VR brachytherapy system.

Video games and sport are an essential part in the life of millions of people. With recent advances of immersive virtual reality devices such as the HTC Vive, Oculus Rift, or PlayStation VR, the use of virtual environments (VE) for exergames is becoming more and more popular. An exergame combines a physical activity with video game elements by tracking body movements or reactions of user, attempting to engage users in a more enjoyable system. In this paper, we present the results of a subjective experiment carried out with the aim to compare different kinds of virtual environments with each other. A rowing ergometer, connected either to a virtual reality system using a head-mounted display (HMD) or to a CAVE environment, was used as an exergame device. While for rowing experts, fitness and performance improvements are of major interest, we wanted to focus on the motivation and engagement of non-professionals. By means of a series of questionnaires and a follow-up interview, the Quality of Experience of participants using the system was assessed. Measurements include concepts such as flow, presence, video quality and well-being. Results show significant advantages of the HMD as well as of the CAVE compared to a system without a VE for the overall quality, system feedback, and flow. While the CAVE and HMD system mainly differed in their autotelic experience, the HMD was favored by the majority of participants due to a superior feeling of presence.

Background. Robotic-assisted thoracic surgery (RATS) is now standard for lung cancer treatment, offering advantages over traditional methods. However, RATS’s minimally invasive approach poses challenges like limited visibility and tactile feedback, affecting surgeons’ navigation through com-plex anatomy. To enhance preoperative familiarization with patient-specific anatomy, we devel-oped a virtual reality (VR) surgical navigation system. Using head-mounted displays (HMDs), this system provides a comprehensive, interactive view of the patient’s anatomy pre-surgery, aiming to improve preoperative simulation and intraoperative navigation. Methods. We integrated 3D data from preoperative CT scans into Perspectus VR Education software, displayed via HMDs for in-teractive 3D reconstruction of pulmonary structures. This detailed visualization aids in tailored preoperative resection simulations. During RATS, surgeons access these 3D images through Tile-ProTM multi-display for real-time guidance. Results. The VR system enabled precise visualization of pulmonary structures and lesion relations, enhancing surgical safety and accuracy. The HMDs offered true 3D interaction with patient data, facilitating surgical planning. Conclusions. VR sim-ulation with HMDs, akin to a robotic 3D viewer, offers a novel approach to developing robotic surgical skills. Integrated with routine imaging, it improves preoperative planning, safety, and accuracy of anatomical resections. This technology particularly aids in lesion identification in RATS, optimizing surgical outcomes.

We are studying the virtual reality which is used as mean of human interface between the patients and the Hyper Hospital-a network based virtual reality mediated medical care system. For making the Hyper Hospital come true, it is important to investigate the effect of the virtual reality system (V. R. system) on the human body. In the present study, twenty healthy young subjects underwent the physiological measurements while using our own head mounted display (HMD). We measured the auditory response time which is regarded as a measure of a net activity of the central nervous system and is known to be affected by many physiological conditions such as fatigue. We also measured the critical flicker frequency (CFF) values before, during, and after the application of the V. R. system. The psychological fatigue was measured quantitatively by standard questionnaires and the Kraepelin test. The Yatabe-Guilford (YG) test was also carried out to investigate the influence of the individual character on the psychological fatigue. Some discomforts were complained after 30 minutes use of our HMD by almost all of the subjects. Examination of the CFF values did not show any significant changes due to the application of the V. R. system. No statistically significant difference was found by the usage of the V. R. system. The subjective fatigue measured using a standard questionnaires suggested that psychological fatigue was more significant than physical fatigue. No significant correlations were found between the result of the Kraepelin test and the individual character measured by YG test. No statistically significant fatigue was found by the usage of the V. R. system, and it was therefore suggested that the short time application of the V. R. system does not affect the human neurological and psychological response.

Perceptual thresholds for display lag in a real visual environment are not affected by field of view or psychophysical technique

There are few negative effects to make people discomfort using virtual reality systems. In this paper, we investigated the effects of visual fatigue when wearing head-mounted displays (HMD) and compared the results with those from the smartphones. Forty subjects were recruited and divided into two different groups. The visual fatigue scale was measured to assess the subjects' performance. The results indicated that visual fatigue caused by the conflict of focal distance and vergence distance was less severe than visual fatigue caused by long-term focus without accommodation.

We present a low-cost solution for yaw drift in head-mounted display systems that performs better than current commercial solutions and provides a wide capture area for pose tracking. Our method applies an extended Kalman filter to combine marker tracking data from an overhead camera with onboard head-mounted display accelerometer readings. To achieve low latency, we accelerate marker tracking with color blob localisation and perform this computation on the camera server, which only transmits essential pose data over WiFi for an unencumbered virtual reality system.

In this paper, we present a new system for a highly immersive virtual reality experience utilizing head-mounted displays (HMDs) with accurate indoor-position tracking abilities. The system is designed to have six degrees of freedom in the virtual world, which allows users to physically move around in the real world while wearing the wireless system with an HMD. Three-dimensional X, Y, and Z coordinate data are estimated in real time using ultrasonic sensors. In addition, the pitch, roll, and yaw values are also measured. Unlike previously developed systems which require external input devices to move in the virtual environment, our system provides a natural virtual reality experience by precisely matching the physical movements in a real world to those in a virtual environment. Results show that the system is able to estimate accurate positions of a user, and delivers a highly immersive virtual/mixed reality experience.

Virtual reality (VR) games are currently becoming part of the public-space entertainment (e.g., VR amusement parks). Therefore, VR games should be attractive for players, as well as for bystanders. Current VR systems are still mostly focused on enhancing the experience of the head-mounted display (HMD) users; thus, bystanders without an HMD cannot enjoy the experience together with the HMD users. We propose the "ReverseCAVE": a proof-of-concept prototype for public VR visualization using CAVE-based projection with translucent screens for bystanders toward a shareable VR experience. The screens surround the HMD user and the VR environment is projected onto the screens. This enables the bystanders to see the HMD user and the VR environment simultaneously. We designed and implemented the ReverseCAVE, and evaluated it in terms of the degree of attention, attractiveness, enjoyment, and shareability, assuming that it is used in a public space. Thus, we can make the VR world more accessible and enhance the public VR experience of the bystanders via the ReverseCAVE.