Head Mounted Display with a Roof Mirror Array Fold

NASA Technical Reports Server (NTRS)

Olczak, Eugene (Inventor)

2014-01-01

The present invention includes a head mounted display (HMD) worn by a user. The HMD includes a display projecting an image through an optical lens. The HMD also includes a one-dimensional retro reflective array receiving the image through the optical lens at a first angle with respect to the display and deflecting the image at a second angle different than the first angle with respect to the display. The one-dimensional retro reflective array reflects the image in order to project the image onto an eye of the user.

Multifocal planes head-mounted displays.

PubMed

Rolland, J P; Krueger, M W; Goon, A

2000-07-01

Stereoscopic head-mounted displays (HMD's) provide an effective capability to create dynamic virtual environments. For a user of such environments, virtual objects would be displayed ideally at the appropriate distances, and natural concordant accommodation and convergence would be provided. Under such image display conditions, the user perceives these objects as if they were objects in a real environment. Current HMD technology requires convergent eye movements. However, it is currently limited by fixed visual accommodation, which is inconsistent with real-world vision. A prototype multiplanar volumetric projection display based on a stack of laminated planes was built for medical visualization as discussed in a paper presented at a 1999 Advanced Research Projects Agency workshop (Sullivan, Advanced Research Projects Agency, Arlington, Va., 1999). We show how such technology can be engineered to create a set of virtual planes appropriately configured in visual space to suppress conflicts of convergence and accommodation in HMD's. Although some scanning mechanism could be employed to create a set of desirable planes from a two-dimensional conventional display, multiplanar technology accomplishes such function with no moving parts. Based on optical principles and human vision, we present a comprehensive investigation of the engineering specification of multiplanar technology for integration in HMD's. Using selected human visual acuity and stereoacuity criteria, we show that the display requires at most 27 equally spaced planes, which is within the capability of current research and development display devices, located within a maximal 26-mm-wide stack. We further show that the necessary in-plane resolution is of the order of 5 microm.

In the blink of an eye: head mounted displays development within BAE Systems

NASA Astrophysics Data System (ADS)

Cameron, Alex

2015-05-01

There has been an explosion of interest in head worn displays in recent years, particularly for consumer applications with an attendant ramping up of investment into key enabling technologies to provide what is essence a mobile computer display. However, head mounted system have been around for over 40 years and today's consumer products are building on a legacy of knowledge and technology created by companies such as BAE Systems who have been designing and fielding helmet mounted displays (HMD) for a wide range of specialist applications. Although the dominant application area has been military aviation, solutions have been fielded for solider, ground vehicle, simulation, medical, racing car and even subsea navigation applications. What sets these HMDs apart is that they provide the user with accurate conformal information embedded in the users real world view where the information presented is intuitive and easy to use because it overlays the real world and enables them to stay head up, eyes out, - improving their effectiveness, reducing workload and improving safety. Such systems are an enabling technology in the provision of enhanced Situation Awareness (SA) and reducing user workload in high intensity situations. These capabilities are finding much wider application in new types of compact man mounted audio/visual products enabled by the emergence of new families of micro displays, novel optical concepts and ultra-compact low power processing solutions. This paper therefore provides a personal summary of BAE Systems 40 year's journey in developing and fielding Head Mounted systems, their applications.

Head-mounted display systems and the special operations soldier

NASA Astrophysics Data System (ADS)

Loyd, Rodney B.

1998-08-01

In 1997, the Boeing Company, working with DARPA under the Smart Modules program and the US Army Soldier Systems Command, embarked on an advanced research and development program to develop a wearable computer system tailored for use with soldiers of the US Special Operations Command. The 'special operations combat management system' is a rugged advanced wearable tactical computer, designed to provide the special operations soldier with enhanced situation awareness and battlefield information capabilities. Many issues must be considered during the design of wearable computers for a combat soldier, including the system weight, placement on the body with respect to other equipment, user interfaces and display system characteristics. During the initial feasibility study for the system, the operational environment was examined and potential users were interviewed to establish the proper display solution for the system. Many display system requirements resulted, such as head or helmet mounting, Night Vision Goggle compatibility, minimal visible light emissions, environmental performance and even the need for handheld or other 'off the head' type display systems. This paper will address these issues and other end user requirements for display systems for applications in the harsh and demanding environment of the Special Operations soldier.

Tracking a head-mounted display in a room-sized environment with head-mounted cameras

NASA Astrophysics Data System (ADS)

Wang, Jih-Fang; Azuma, Ronald T.; Bishop, Gary; Chi, Vernon; Eyles, John; Fuchs, Henry

1990-10-01

This paper presents our efforts to accurately track a Head-Mounted Display (HMD) in a large environment. We review our current benchtop prototype (introduced in {WCF9O]), then describe our plans for building the full-scale system. Both systems use an inside-oui optical tracking scheme, where lateraleffect photodiodes mounted on the user's helmet view flashing infrared beacons placed in the environment. Church's method uses the measured 2D image positions and the known 3D beacon locations to recover the 3D position and orientation of the helmet in real-time. We discuss the implementation and performance of the benchtop prototype. The full-scale system design includes ceiling panels that hold the infrared beacons and a new sensor arrangement of two photodiodes with holographic lenses. In the full-scale system, the user can walk almost anywhere under the grid of ceiling panels, making the working volume nearly as large as the room.

Recent advances in head-mounted light field displays for virtual and augmented reality (Conference Presentation)

NASA Astrophysics Data System (ADS)

Hua, Hong

2017-02-01

Head-mounted light field displays render a true 3D scene by sampling either the projections of the 3D scene at different depths or the directions of the light rays apparently emitted by the 3D scene and viewed from different eye positions. They are capable of rendering correct or nearly correct focus cues and addressing the very well-known vergence-accommodation mismatch problem in conventional virtual and augmented reality displays. In this talk, I will focus on reviewing recent advancements of head-mounted light field displays for VR and AR applications. I will demonstrate examples of HMD systems developed in my group.

Spatial calibration of an optical see-through head mounted display

PubMed Central

Gilson, Stuart J.; Fitzgibbon, Andrew W.; Glennerster, Andrew

2010-01-01

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. PMID:18599125

A review of adjustable lenses for head mounted displays

NASA Astrophysics Data System (ADS)

Stevens, Robert E.; Jacoby, Thomas N. L.; Aricescu, Ilinca Å.ž.; Rhodes, Daniel P.

2017-06-01

Adjustable lens technology has the potential to improve Head Mounted Displays (HMDs) through style and comfort by providing optical prescription correction and focussing mechanisms integrated within the HMD. It can also reduce simulator sickness and user experience of 3D through resolution of Vergence Accommodation Conflict, and age-related user problems (presbyopia). We review the available technology and the design constraints to show how a fluid filled lens may be appropriate for AR and MR, and an Alvarez lens may be appropriate for VR.

Visual cueing considerations in Nap-of-the-Earth helicopter flight head-slaved helmet-mounted displays

NASA Technical Reports Server (NTRS)

Grunwald, Arthur J.; Kohn, Silvia

1993-01-01

The pilot's ability to derive Control-Oriented Visual Field Information from teleoperated Helmet-Mounted displays in Nap-of-the-Earth flight, is investigated. The visual field with these types of displays, commonly used in Apache and Cobra helicopter night operations, originates from a relatively narrow field-of-view Forward Looking Infrared Radiation Camera, gimbal-mounted at the nose of the aircraft and slaved to the pilot's line-of-sight, in order to obtain a wide-angle field-of-regard. Pilots have encountered considerable difficulties in controlling the aircraft by these devices. Experimental simulator results presented here indicate that part of these difficulties can be attributed to head/camera slaving system phase lags and errors. In the presence of voluntary head rotation, these slaving system imperfections are shown to impair the Control-Oriented Visual Field Information vital in vehicular control, such as the perception of the anticipated flight path or the vehicle yaw rate. Since, in the presence of slaving system imperfections, the pilot will tend to minimize head rotation, the full wide-angle field-of-regard of the line-of-sight slaved Helmet-Mounted Display, is not always fully utilized.

A Real-Time Optical 3D Tracker for Head-Mounted Display Systems

DTIC Science & Technology

1990-03-01

paper. OPTOTRAK [Nor88] uses one camera with two dual-axis CCD infrared position sensors. Each position sen- sor has a dedicated processor board to...enhance the use- [Nor88] Northern Digital. Trade literature on Optotrak fulness of head-mounted display systems. - Northern Digital’s Three Dimensional

A compact eyetracked optical see-through head-mounted display

NASA Astrophysics Data System (ADS)

Hua, Hong; Gao, Chunyu

2012-03-01

An eye-tracked head-mounted display (ET-HMD) system is able to display virtual images as a classical HMD does, while additionally tracking the gaze direction of the user. There is ample evidence that a fully-integrated ETHMD system offers multi-fold benefits, not only to fundamental scientific research but also to emerging applications of such technology. For instance eyetracking capability in HMDs adds a very valuable tool and objective metric for scientists to quantitatively assess user interaction with 3D environments and investigate the effectiveness of various 3D visualization technologies for various specific tasks including training, education, and augmented cognition tasks. In this paper, we present an innovative optical approach to the design of an optical see-through ET-HMD system based on freeform optical technology and an innovative optical scheme that uniquely combines the display optics with the eye imaging optics. A preliminary design of the described ET-HMD system will be presented.

Integration Head Mounted Display Device and Hand Motion Gesture Device for Virtual Reality Laboratory

NASA Astrophysics Data System (ADS)

Rengganis, Y. A.; Safrodin, M.; Sukaridhoto, S.

2018-01-01

Virtual Reality Laboratory (VR Lab) is an innovation for conventional learning media which show us whole learning process in laboratory. There are many tools and materials are needed by user for doing practical in it, so user could feel new learning atmosphere by using this innovation. Nowadays, technologies more sophisticated than before. So it would carry in education and it will be more effective, efficient. The Supported technologies are needed us for making VR Lab such as head mounted display device and hand motion gesture device. The integration among them will be used us for making this research. Head mounted display device for viewing 3D environment of virtual reality laboratory. Hand motion gesture device for catching user real hand and it will be visualized in virtual reality laboratory. Virtual Reality will show us, if using the newest technologies in learning process it could make more interesting and easy to understand.

Head-mounted display for use in functional endoscopic sinus surgery

NASA Astrophysics Data System (ADS)

Wong, Brian J.; Lee, Jon P.; Dugan, F. Markoe; MacArthur, Carol J.

1995-05-01

Since the introduction of functional endoscopic sinus surgery (FESS), the procedure has undergone rapid change with evolution keeping pace with technological advances. The advent of low cost charge coupled device 9CCD) cameras revolutionized the practice and instruction of FESS. Video-based FESS has allowed for documentation of the surgical procedure as well as interactive instruction during surgery. Presently, the technical requirements of video-based FESS include the addition of one or more television monitors positioned strategically in the operating room. Thought video monitors have greatly enhanced surgical endoscopy by re- involving nurses and assistants in the actual mechanics of surgery, video monitors require the operating surgeon to be focused on the screen instead of the patient. In this study, we describe the use of a new low-cost liquid crystal display (LCD) based device that functions as a monitor but is mounted on the head on a visor (PT-O1, O1 Products, Westlake Village, CA). This study illustrates the application of these HMD devices to FESS operations. The same surgeon performed the operation in each patient. In one nasal fossa, surgery was performed using conventional video FESS methods. The contralateral side was operated on while wearing the head mounted video display. The device had adequate resolution for the purposes of FESS. No adverse effects were noted intraoperatively. The results on the patients ipsalateral and contralateral sides were similar. The visor did eliminated significant torsion of the surgeon's neck during the operation, while at the same time permitted simultaneous viewing of both the patient and the intranasal surgical field.

Google Glass Glare: disability glare produced by a head-mounted visual display.

PubMed

Longley, Chris; Whitaker, David

2016-03-01

Head mounted displays are a type of wearable technology - a market that is projected to expand rapidly over the coming years. Probably the most well known example is the device Google Glass (or 'Glass'). Here we investigate the extent to which the device display can interfere with normal visual function by producing monocular disability glare. Contrast sensitivity was measured in two normally sighted participants, 32 and 52 years of age. Data were recorded for the right eye, the left eye and then again in a binocular condition. Measurements were taken both with and without the Glass in place, across a range of stimulus luminance levels using a two-alternative forced-choice methodology. The device produced a significant reduction in contrast sensitivity in the right eye (>0.5 log units). The level of disability glare increased as stimulus luminance was reduced in a manner consistent with intraocular light scatter, resulting in a veiling retinal illuminance. Sensitivity in the left eye was unaffected. A significant reduction in binocular contrast sensitivity occurred at lower luminance levels due to a loss of binocular summation, although binocular sensitivity was not found to fall below the sensitivity of the better monocular level (binocular inhibition). Head mounted displays such as Google Glass have the potential to cause significant disability glare in the eye exposed to the visual display, particularly under conditions of low luminance. They can also cause a more modest binocular reduction in sensitivity by eliminating the benefits of binocular summation. © 2015 The Authors Ophthalmic & Physiological Optics © 2015 The College of Optometrists.

Head-mounted display (HMD) assessment for tracked vehicles

NASA Astrophysics Data System (ADS)

Nicholson, Gail

2011-06-01

Providing the warfighter with Head or Helmet Mounted Displays (HMDs) while in tracked vehicles provides a means to visually maintain access to systems information while in a high vibration environment. The high vibration and unique environment of military tracked and turreted vehicles impact the ability to distinctly see certain information on an HMD, especially small font size or graphics and information that requires long fixation (staring), rather than a brief or peripheral glance. The military and commercial use of HMDs was compiled from market research, market trends, and user feedback. Lessons learned from previous military and commercial use of HMD products were derived to determine the feasibility of HMDs use in the high vibration and the unique environments of tracked vehicles. The results are summarized into factors that determine HMD features which must be specified for successful implementation.

Optical Head-Mounted Computer Display for Education, Research, and Documentation in Hand Surgery.

PubMed

Funk, Shawn; Lee, Donald H

2016-01-01

Intraoperative photography and capturing videos is important for the hand surgeon. Recently, optical head-mounted computer display has been introduced as a means of capturing photographs and videos. In this article, we discuss this new technology and review its potential use in hand surgery. Copyright © 2016 American Society for Surgery of the Hand. Published by Elsevier Inc. All rights reserved.

Hybrid diffractive-refractive optical system design of head-mounted display for augmented reality

NASA Astrophysics Data System (ADS)

Zhang, Huijuan

2005-02-01

An optical see-through head-mounted display for augmented reality is designed in this paper. Considering the factors, such as the optical performance, the utilization ratios of energy of real world and virtual world, the feelings of users when he wears it and etc., a structure of the optical see-through is adopted. With the characteristics of the particular negative dispersive and the power of realizing random-phase modulation, the diffractive surface is helpful for optical system of reducing weight, simplifying structure and etc., and a diffractive surface is introduced in our optical system. The optical system with 25 mm eye relief, 12 mm exit pupil and 20° (H)x15.4° (V) field-of-view is designed. The utilization ratios of energy of real world and virtual world are 1/4 and 1/2, respectively. The angular resolution of display is 0.27 mrad and it less than that of the minimum of human eyes. The diameter of this system is less than 46mm, and it applies the binocular. This diffractive-refractive optical system of see-through head-mounted display not only satisfies the demands of user"s factors in structure, but also with high resolution, very small chromatic aberration and distortion, and satisfies the need of augmented reality. In the end, the parameters of the diffractive surface are discussed.

A see-through holographic head-mounted display with the large viewing angle

NASA Astrophysics Data System (ADS)

Chen, Zhidong; sang, Xinzhu; Lin, Qiaojun; Li, Jin; Yu, Xunbo; Gao, Xin; Yan, Binbin; Wang, Kuiru; Yu, Chongxiu; Xie, Songlin

2017-02-01

A novel solution for the large view angle holographic head-mounted display (HHMD) is presented. Divergent light is used for the hologram illumination to construct a large size three-dimensional object outside the display in a short distance. A designed project-type lens with large numerical aperture projects the object constructed by the hologram to its real location. The presented solution can realize a compact HHMD system with a large field of view. The basic principle and the structure of the system are described. An augmented reality (AR) prototype with the size of 50 mm×40 mm and the view angle above 60° is demonstrated.

A Depth-Based Head-Mounted Visual Display to Aid Navigation in Partially Sighted Individuals

PubMed Central

Hicks, Stephen L.; Wilson, Iain; Muhammed, Louwai; Worsfold, John; Downes, Susan M.; Kennard, Christopher

2013-01-01

Independent navigation for blind individuals can be extremely difficult due to the inability to recognise and avoid obstacles. Assistive techniques such as white canes, guide dogs, and sensory substitution provide a degree of situational awareness by relying on touch or hearing but as yet there are no techniques that attempt to make use of any residual vision that the individual is likely to retain. Residual vision can restricted to the awareness of the orientation of a light source, and hence any information presented on a wearable display would have to limited and unambiguous. For improved situational awareness, i.e. for the detection of obstacles, displaying the size and position of nearby objects, rather than including finer surface details may be sufficient. To test whether a depth-based display could be used to navigate a small obstacle course, we built a real-time head-mounted display with a depth camera and software to detect the distance to nearby objects. Distance was represented as brightness on a low-resolution display positioned close to the eyes without the benefit focussing optics. A set of sighted participants were monitored as they learned to use this display to navigate the course. All were able to do so, and time and velocity rapidly improved with practise with no increase in the number of collisions. In a second experiment a cohort of severely sight-impaired individuals of varying aetiologies performed a search task using a similar low-resolution head-mounted display. The majority of participants were able to use the display to respond to objects in their central and peripheral fields at a similar rate to sighted controls. We conclude that the skill to use a depth-based display for obstacle avoidance can be rapidly acquired and the simplified nature of the display may appropriate for the development of an aid for sight-impaired individuals. PMID:23844067

System requirements for head down and helmet mounted displays in the military avionics environment

DOE Office of Scientific and Technical Information (OSTI.GOV)

Flynn, M.F.; Kalmanash, M.; Sethna, V.

1996-12-31

The introduction of flat panel display technologies into the military avionics cockpit is a challenging proposition, due to the very difficult system level requirements which must be met. These relate to environmental extremes (temperature and vibrational), sever ambient lighting conditions (10,000 fL to nighttime viewing), night vision system compatibility, and wide viewing angle. At the same time, the display system must be packaged in minimal space and use minimal power. The authors will present details on the display system requirements for both head down and helmet mounted systems, as well as information on how these challenges may be overcome.

Comparison of optical see-through head-mounted displays for surgical interventions with object-anchored 2D-display

PubMed Central

Barthel, Alexander; Johnson, Alex; Osgood, Greg; Kazanzides, Peter; Navab, Nassir; Fuerst, Bernhard

2018-01-01

Purpose Optical see-through head-mounted displays (OST-HMD) feature an unhindered and instantaneous view of the surgery site and can enable a mixed reality experience for surgeons during procedures. In this paper, we present a systematic approach to identify the criteria for evaluation of OST-HMD technologies for specific clinical scenarios, which benefit from using an object-anchored 2D-display visualizing medical information. Methods Criteria for evaluating the performance of OST-HMDs for visualization of medical information and its usage are identified and proposed. These include text readability, contrast perception, task load, frame rate, and system lag. We choose to compare three commercially available OST-HMDs, which are representatives of currently available head-mounted display technologies. A multi-user study and an offline experiment are conducted to evaluate their performance. Results Statistical analysis demonstrates that Microsoft HoloLens performs best among the three tested OST-HMDs, in terms of contrast perception, task load, and frame rate, while ODG R-7 offers similar text readability. The integration of indoor localization and fiducial tracking on the HoloLens provides significantly less system lag in a relatively motionless scenario. Conclusions With ever more OST-HMDs appearing on the market, the proposed criteria could be used in the evaluation of their suitability for mixed reality surgical intervention. Currently, Microsoft HoloLens may be more suitable than ODG R-7 and Epson Moverio BT-200 for clinical usability in terms of the evaluated criteria. To the best of our knowledge, this is the first paper that presents a methodology and conducts experiments to evaluate and compare OST-HMDs for their use as object-anchored 2D-display during interventions. PMID:28343301

Comparison of optical see-through head-mounted displays for surgical interventions with object-anchored 2D-display.

PubMed

Qian, Long; Barthel, Alexander; Johnson, Alex; Osgood, Greg; Kazanzides, Peter; Navab, Nassir; Fuerst, Bernhard

2017-06-01

Optical see-through head-mounted displays (OST-HMD) feature an unhindered and instantaneous view of the surgery site and can enable a mixed reality experience for surgeons during procedures. In this paper, we present a systematic approach to identify the criteria for evaluation of OST-HMD technologies for specific clinical scenarios, which benefit from using an object-anchored 2D-display visualizing medical information. Criteria for evaluating the performance of OST-HMDs for visualization of medical information and its usage are identified and proposed. These include text readability, contrast perception, task load, frame rate, and system lag. We choose to compare three commercially available OST-HMDs, which are representatives of currently available head-mounted display technologies. A multi-user study and an offline experiment are conducted to evaluate their performance. Statistical analysis demonstrates that Microsoft HoloLens performs best among the three tested OST-HMDs, in terms of contrast perception, task load, and frame rate, while ODG R-7 offers similar text readability. The integration of indoor localization and fiducial tracking on the HoloLens provides significantly less system lag in a relatively motionless scenario. With ever more OST-HMDs appearing on the market, the proposed criteria could be used in the evaluation of their suitability for mixed reality surgical intervention. Currently, Microsoft HoloLens may be more suitable than ODG R-7 and Epson Moverio BT-200 for clinical usability in terms of the evaluated criteria. To the best of our knowledge, this is the first paper that presents a methodology and conducts experiments to evaluate and compare OST-HMDs for their use as object-anchored 2D-display during interventions.

Retinal projection type super multi-view head-mounted display

NASA Astrophysics Data System (ADS)

Takahashi, Hideya; Ito, Yutaka; Nakata, Seigo; Yamada, Kenji

2014-02-01

We propose a retinal projection type super multi-view head-mounted display (HMD). The smooth motion parallax provided by the super multi-view technique enables a precise superposition of virtual 3D images on the real scene. Moreover, if a viewer focuses one's eyes on the displayed 3D image, the stimulus for the accommodation of the human eye is produced naturally. Therefore, although proposed HMD is a monocular HMD, it provides observers with natural 3D images. The proposed HMD consists of an image projection optical system and a holographic optical element (HOE). The HOE is used as a combiner, and also works as a condenser lens to implement the Maxwellian view. Some parallax images are projected onto the HOE, and converged on the pupil, and then projected onto the retina. In order to verify the effectiveness of the proposed HMD, we constructed the prototype HMD. In the prototype HMD, the number of parallax images and the number of convergent points on the pupil is three. The distance between adjacent convergent points is 2 mm. We displayed virtual images at the distance from 20 cm to 200 cm in front of the pupil, and confirmed the accommodation. This paper describes the principle of proposed HMD, and also describes the experimental result.

Psycho-physiological effects of head-mounted displays in ubiquitous use

NASA Astrophysics Data System (ADS)

Kawai, Takashi; Häkkinen, Jukka; Oshima, Keisuke; Saito, Hiroko; Yamazoe, Takashi; Morikawa, Hiroyuki; Nyman, Göte

2011-02-01

In this study, two experiments were conducted to evaluate the psycho-physiological effects by practical use of monocular head-mounted display (HMD) in a real-world environment, based on the assumption of consumer-level applications as viewing video content and receiving navigation information while walking. In the experiment 1, the workload was examined for different types of presenting stimuli using an HMD (monocular or binocular, see-through or non-see-through). The experiment 2 focused on the relationship between the real-world environment and the visual information presented using a monocular HMD. The workload was compared between a case where participants walked while viewing video content without relation to the real-world environment, and a case where participants walked while viewing visual information to augment the real-world environment as navigations.

Arthroscopic knee surgery using the advanced flat panel high-resolution color head-mounted display

NASA Astrophysics Data System (ADS)

Nelson, Scott A.; Jones, D. E. Casey; St. Pierre, Patrick; Sampson, James B.

1997-06-01

The first ever deployed arthroscopic knee surgeries have been performed using a high resolution color head-mounted display (HMD) developed under the DARPA Advanced Flat Panel HMD program. THese procedures and several fixed hospital procedures have allowed both the system designers and surgeons to gain new insight into the use of a HMD for medical procedures in both community and combat support hospitals scenarios. The surgeons demonstrated and reported improved head-body orientation and awareness while using the HMD and reported several advantages and disadvantages of the HMD as compared to traditional CRT monitor viewing of the arthroscopic video images. The surgeries, the surgeon's comments, and a human factors overview of HMDs for Army surgical applications are discussed here.

Optical see-through head-mounted display with occlusion capability

NASA Astrophysics Data System (ADS)

Gao, Chunyu; Lin, Yuxiang; Hua, Hong

2013-05-01

Lack of mutual occlusion capability between computer-rendered and real objects is one of fundamental problems for most existing optical see-through head-mounted displays (OST-HMD). Without the proper occlusion management, the virtual view through an OST-HMD appears "ghost-like", floating in the real world. To address this challenge, we have developed an innovative optical scheme that uniquely combines the eyepiece and see-through relay optics to achieve an occlusion-capable OST-HMD system with a very compelling form factor and high optical performances. The proposed display system was based on emerging freeform optical design technologies and was designed for highly efficient liquid crystal on silicon (LCoS) type spatial light modulator (SLM) and bright Organic LED (OLED) microdisplay. The proposed display technology was capable of working in both indoor and outdoor environments. Our current design offered a 1280x1024 color resolution based on 0.8" microdisplay and SLM. The MTF values for the majority of the fields at the cutoff frequency of 40lps/mm, which is determined by the pixel size of the microdisplay, are better than 15%. The design achieved a diagonal FOV of 40 degrees, 31.7 degrees horizontally and 25.6 degrees vertically, an exit pupil diameter of 8mm (non-vignetted), and an eye clearance of 18mm. The optics weights about 20 grams per eye. Our proposed occlusion capable OST-HMD system can easily find myriads of applications in various military and commercial sectors such as military training, gaming and entertainment.

Passive method of eliminating accommodation/convergence disparity in stereoscopic head-mounted displays

NASA Astrophysics Data System (ADS)

Eichenlaub, Jesse B.

2005-03-01

The difference in accommodation and convergence distance experienced when viewing stereoscopic displays has long been recognized as a source of visual discomfort. It is especially problematic in head mounted virtual reality and enhanced reality displays, where images must often be displayed across a large depth range or superimposed on real objects. DTI has demonstrated a novel method of creating stereoscopic images in which the focus and fixation distances are closely matched for all parts of the scene from close distances to infinity. The method is passive in the sense that it does not rely on eye tracking, moving parts, variable focus optics, vibrating optics, or feedback loops. The method uses a rapidly changing illumination pattern in combination with a high speed microdisplay to create cones of light that converge at different distances to form the voxels of a high resolution space filling image. A bench model display was built and a series of visual tests were performed in order to demonstrate the concept and investigate both its capabilities and limitations. Results proved conclusively that real optical images were being formed and that observers had to change their focus to read text or see objects at different distances

Registration of an on-axis see-through head-mounted display and camera system

NASA Astrophysics Data System (ADS)

Luo, Gang; Rensing, Noa M.; Weststrate, Evan; Peli, Eli

2005-02-01

An optical see-through head-mounted display (HMD) system integrating a miniature camera that is aligned with the user's pupil is developed and tested. Such an HMD system has a potential value in many augmented reality applications, in which registration of the virtual display to the real scene is one of the critical aspects. The camera alignment to the user's pupil results in a simple yet accurate calibration and a low registration error across a wide range of depth. In reality, a small camera-eye misalignment may still occur in such a system due to the inevitable variations of HMD wearing position with respect to the eye. The effects of such errors are measured. Calculation further shows that the registration error as a function of viewing distance behaves nearly the same for different virtual image distances, except for a shift. The impact of prismatic effect of the display lens on registration is also discussed.

Latency Requirements for Head-Worn Display S/EVS Applications

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Trey Arthur, J. J., III; Williams, Steven P.

2004-01-01

NASA s Aviation Safety Program, Synthetic Vision Systems Project is conducting research in advanced flight deck concepts, such as Synthetic/Enhanced Vision Systems (S/EVS), for commercial and business aircraft. An emerging thrust in this activity is the development of spatially-integrated, large field-of-regard information display systems. Head-worn or helmet-mounted display systems are being proposed as one method in which to meet this objective. System delays or latencies inherent to spatially-integrated, head-worn displays critically influence the display utility, usability, and acceptability. Research results from three different, yet similar technical areas flight control, flight simulation, and virtual reality are collectively assembled in this paper to create a global perspective of delay or latency effects in head-worn or helmet-mounted display systems. Consistent definitions and measurement techniques are proposed herein for universal application and latency requirements for Head-Worn Display S/EVS applications are drafted. Future research areas are defined.

Latency requirements for head-worn display S/EVS applications

NASA Astrophysics Data System (ADS)

Bailey, Randall E.; Arthur, Jarvis J., III; Williams, Steven P.

2004-08-01

NASA's Aviation Safety Program, Synthetic Vision Systems Project is conducting research in advanced flight deck concepts, such as Synthetic/Enhanced Vision Systems (S/EVS), for commercial and business aircraft. An emerging thrust in this activity is the development of spatially-integrated, large field-of-regard information display systems. Head-worn or helmet-mounted display systems are being proposed as one method in which to meet this objective. System delays or latencies inherent to spatially-integrated, head-worn displays critically influence the display utility, usability, and acceptability. Research results from three different, yet similar technical areas - flight control, flight simulation, and virtual reality - are collectively assembled in this paper to create a global perspective of delay or latency effects in head-worn or helmet-mounted display systems. Consistent definitions and measurement techniques are proposed herein for universal application and latency requirements for Head-Worn Display S/EVS applications are drafted. Future research areas are defined.

Continued Testing of Head-Mounted Displays for Deaf Education in a Planetarium

NASA Astrophysics Data System (ADS)

Hintz, Eric G.; Jones, M.; Lawler, J.; Bench, N.; Mangrubang, F. R.

2013-06-01

For more than a year now we have been developing techniques for using Head-Mounted Displays (HMD) to help accommodate a deaf audience in a planetarium environment. Our target audience is primarily children from 8 to 13 years of age, but the methodologies can be used for a wide variety of audiences. Applications also extend beyond the planetarium environment. Three tests have been done to determine if American Sign Language (ASL) can be delivered to the HMD and the student view both the planetarium show and the ASL ‘sound track’. From those early results we are now at the point of testing for comprehension improvement on a number of astronomical subjects. We will present a number of these early results.

Helmet-Mounted Display Design Guide

NASA Technical Reports Server (NTRS)

Newman, Richard L.; Greeley, Kevin W.

1997-01-01

Helmet Mounted Displays (HMDs) present flight, navigation, and weapon information in the pilot's line of sight. The HMD was developed to allow the pilot to retain aircraft and weapon information while looking off boresight. This document reviews current state of the art in HMDs and presents a design guide for the HMD engineer in identifying several critical HMD issues: symbol stabilization, inadequate definitions, undefined symbol drive laws, helmet considerations, and Field Of View (FOV) vs. resolution tradeoff requirements. In particular, display latency is a key issue for HMDs. In addition to requiring further experimental studies, it impacts the definition and control law issues. Symbol stabilization is also critical. In the case of the Apache helicopter, the lack of compensation for pilot head motion creates excessive workload during hovering and Nap Of the Earth (NOE) flight. This translates into excessive training requirements. There is no agreed upon set of definitions or descriptions for how HMD symbols are driven to compensate for pilot head motion. A set of definitions is proposed to address this. There are several specific areas where simulation and flight experiments are needed: development of hover and NOE symbologies which compensate for pilot head movement; display latency and sampling, and the tradeoff between FOV, sensor resolution and symbology.

An automated calibration method for non-see-through head mounted displays.

PubMed

Gilson, Stuart J; Fitzgibbon, Andrew W; Glennerster, Andrew

2011-08-15

Accurate calibration of a head mounted display (HMD) is essential both for research on the visual system and for realistic interaction with virtual objects. Yet, existing calibration methods are time consuming and depend on human judgements, making them error prone, and are often limited to optical see-through HMDs. Building on our existing approach to HMD calibration Gilson et al. (2008), we show here how it is possible to calibrate a non-see-through HMD. A camera is placed inside a HMD displaying an image of a regular grid, which is captured by the camera. The HMD is then removed and the camera, which remains fixed in position, is used to capture images of a tracked calibration object in multiple positions. The centroids of the markers on the calibration object are recovered and their locations re-expressed in relation to the HMD grid. This allows established camera calibration techniques to be used to recover estimates of the HMD display's intrinsic parameters (width, height, focal length) and extrinsic parameters (optic centre and orientation of the principal ray). We calibrated a HMD in this manner and report the magnitude of the errors between real image features and reprojected features. Our calibration method produces low reprojection errors without the need for error-prone human judgements. Copyright © 2011 Elsevier B.V. All rights reserved.

Demonstration of a broad band spectral head-mounted display with freeform mirrors.

PubMed

Pan, Jui-Wen; Che-Wen, Chiang; Huang, Kuan-Da; Wu, Chung-Yu

2014-06-02

It has been demonstrated that electrical stimulation of the retina can produce visual perception for blind patients suffering from macular degeneration and retinitis pigmentosa. In order to let the retinal chip generate enough electrical stimulation, the near infrared ray source is added to enhance the stimulation current. However, it is a challenge to design a head-mounted display (HMD) that covers both visible and infrared rays. Since the HMD system covers such a broad spectral band, large color aberrations will be induced. In order to eliminate these large aberrations, a mirror system is adopted that will create a no color aberration system. We also use two freeform mirrors (FFMs) to reduce residual aberrations such as spherical aberrations and coma. The FFMs serve as the near-eye viewing optics that magnifies the image which is displayed through a microdisplay. Based on a 0.61 in. microdisplay, the HMD system demonstrates a diagonal field of view (FOV) of 30 degree and an f/# of 3.75, with an exit pupil diameter of 8 mm and eye clearance of 15mm.

Usability Comparisons of Head-Mounted vs. Stereoscopic Desktop Displays in a Virtual Reality Environment with Pain Patients.

PubMed

Tong, Xin; Gromala, Diane; Gupta, Dimple; Squire, Pam

2016-01-01

Researchers have shown that immersive Virtual Reality (VR) can serve as an unusually powerful pain control technique. However, research assessing the reported symptoms and negative effects of VR systems indicate that it is important to ascertain if these symptoms arise from the use of particular VR display devices, particularly for users who are deemed "at risk," such as chronic pain patients Moreover, these patients have specific and often complex needs and requirements, and because basic issues such as 'comfort' may trigger anxiety or panic attacks, it is important to examine basic questions of the feasibility of using VR displays. Therefore, this repeated-measured experiment was conducted with two VR displays: the Oculus Rift's head-mounted display (HMD) and Firsthand Technologies' immersive desktop display, DeepStream3D. The characteristics of these immersive desktop displays differ: one is worn, enabling patients to move their heads, while the other is peered into, allowing less head movement. To assess the severity of physical discomforts, 20 chronic pain patients tried both displays while watching a VR pain management demo in clinical settings. Results indicated that participants experienced higher levels of Simulator Sickness using the Oculus Rift HMD. However, results also indicated other preferences of the two VR displays among patients, including physical comfort levels and a sense of immersion. Few studies have been conducted that compare usability of specific VR devices specifically with chronic pain patients using a therapeutic virtual environment in pain clinics. Thus, the results may help clinicians and researchers to choose the most appropriate VR displays for chronic pain patients and guide VR designers to enhance the usability of VR displays for long-term pain management interventions.

Performance considerations for high-definition head-mounted displays

NASA Technical Reports Server (NTRS)

Edwards, Oliver J.; Larimer, James; Gille, Jennifer

1992-01-01

Design image-optimization for helmet-mounted displays (HMDs) for military systems is presently discussed within the framework of a systems-engineering approach that encompasses (1) a description of natural targets in the field; (2) the characteristics of human visual perception; and (3) device specifications that directly relate to these ecological and human-factors parameters. Attention is given to target size and contrast and the relationship of the modulation transfer function to image resolution.

The head-mounted microscope.

PubMed

Chen, Ting; Dailey, Seth H; Naze, Sawyer A; Jiang, Jack J

2012-04-01

Microsurgical equipment has greatly advanced since the inception of the microscope into the operating room. These advancements have allowed for superior surgical precision and better post-operative results. This study focuses on the use of the Leica HM500 head-mounted microscope for the operating phonosurgeon. The head-mounted microscope has an optical zoom from 2× to 9× and provides a working distance from 300 mm to 700 mm. The headpiece, with its articulated eyepieces, adjusts easily to head shape and circumference, and offers a focus function, which is either automatic or manually controlled. We performed five microlaryngoscopic operations utilizing the head-mounted microscope with successful results. By creating a more ergonomically favorable operating posture, a surgeon may be able to obtain greater precision and success in phonomicrosurgery. Phonomicrosurgery requires the precise manipulation of long-handled cantilevered instruments through the narrow bore of a laryngoscope. The head-mounted microscope shortens the working distance compared with a stand microscope, thereby increasing arm stability, which may improve surgical precision. Also, the head-mounted design permits flexibility in head position, enabling operator comfort, and delaying musculoskeletal fatigue. A head-mounted microscope decreases the working distance and provides better ergonomics in laryngoscopic microsurgery. These advances provide the potential to promote precision in phonomicrosurgery. Copyright © 2011 The American Laryngological, Rhinological, and Otological Society, Inc.

Amblyopia treatment of adults with dichoptic training using the virtual reality oculus rift head mounted display: preliminary results.

PubMed

Žiak, Peter; Holm, Anders; Halička, Juraj; Mojžiš, Peter; Piñero, David P

2017-06-28

The gold standard treatments in amblyopia are penalizing therapies, such as patching or blurring vision with atropine that are aimed at forcing the use of the amblyopic eye. However, in the last years, new therapies are being developed and validated, such as dichoptic visual training, aimed at stimulating the amblyopic eye and eliminating the interocular supression. To evaluate the effect of dichoptic visual training using a virtual reality head mounted display in a sample of anisometropic amblyopic adults and to evaluate the potential usefulness of this option of treatment. A total of 17 subjects (10 men, 7 women) with a mean age of 31.2 years (range, 17-69 year) and anisometropic amblyopia were enrolled. Best corrected visual acuity (BCVA) and stereoacuity (Stereo Randot graded circle test) changes were evaluated after 8 sessions (40 min per session) of dichoptic training with the computer game Diplopia Game (Vivid Vision) run in the Oculus Rift OC DK2 virtual reality head mounted display (Oculus VR). Mean BCVA in amblyopic eye improved significantly from a logMAR value of 0.58 ± 0.35 before training to a post-training value of 0.43 ± 0.38 (p < 0.01). Forty-seven percent of the participants achieved BCVA of 20/40 or better after the training as compared to 30% before the training. Mean stereoacuity changed from a value of 263.3 ± 135.1 before dichoptic training to a value of 176.7 ± 152.4 s of arc after training (p < 0.01). A total of 8 patients (47.1%) before dichoptic treatment had unmeasurable stereoacuity while this only occurred in 2 patients (11.8%) after training. Dichoptic training using a virtual reality head mounted display seems to be an effective option of treatment in adults with anisometropic amblyopia. Future clinical trials are needed to confirm this preliminary evidence. Trial ID: ISRCTN62086471 . Date registered: 13/06/2017. Retrospectively registered.

Optical gesture sensing and depth mapping technologies for head-mounted displays: an overview

NASA Astrophysics Data System (ADS)

Kress, Bernard; Lee, Johnny

2013-05-01

Head Mounted Displays (HMDs), and especially see-through HMDs have gained renewed interest in recent time, and for the first time outside the traditional military and defense realm, due to several high profile consumer electronics companies presenting their products to hit market. Consumer electronics HMDs have quite different requirements and constrains as their military counterparts. Voice comments are the de-facto interface for such devices, but when the voice recognition does not work (not connection to the cloud for example), trackpad and gesture sensing technologies have to be used to communicate information to the device. We review in this paper the various technologies developed today integrating optical gesture sensing in a small footprint, as well as the various related 3d depth mapping sensors.

A head-mounted compressive three-dimensional display system with polarization-dependent focus switching

NASA Astrophysics Data System (ADS)

Lee, Chang-Kun; Moon, Seokil; Lee, Byounghyo; Jeong, Youngmo; Lee, Byoungho

2016-10-01

A head-mounted compressive three-dimensional (3D) display system is proposed by combining polarization beam splitter (PBS), fast switching polarization rotator and micro display with high pixel density. According to the polarization state of the image controlled by polarization rotator, optical path of image in the PBS can be divided into transmitted and reflected components. Since optical paths of each image are spatially separated, it is possible to independently focus both images at different depth positions. Transmitted p-polarized and reflected s-polarized images can be focused by convex lens and mirror, respectively. When the focal lengths of the convex lens and mirror are properly determined, two image planes can be located in intended positions. The geometrical relationship is easily modulated by replacement of the components. The fast switching of polarization realizes the real-time operation of multi-focal image planes with a single display panel. Since it is possible to conserve the device characteristic of single panel, the high image quality, reliability and uniformity can be retained. For generating 3D images, layer images for compressive light field display between two image planes are calculated. Since the display panel with high pixel density is adopted, high quality 3D images are reconstructed. In addition, image degradation by diffraction between physically stacked display panels can be mitigated. Simple optical configuration of the proposed system is implemented and the feasibility of the proposed method is verified through experiments.

A Review of Head-Worn Display Research at NASA Langley Research Center

NASA Technical Reports Server (NTRS)

Arthur, Jarvis (Trey) J., III; Bailey, Randall E.; Williams, Steven P.; Prinzel, Lawrence J., III; Shelton, Kevin J.; Jones, Denise R.; Houston, Vincent

2015-01-01

NASA Langley has conducted research in the area of helmet-mounted/head-worn displays over the past 30 years. Initially, NASA Langley's research focused on military applications, but recently it has conducted a line of research in the area of head-worn displays for commercial and business aircraft. This work has revolved around numerous simulation experiments as well as flight tests to develop technology and data for industry and regulatory guidance. The paper summarizes the results of NASA's helmet-mounted/head-worn display research. Of note, the work tracks progress in wearable collimated optics, head tracking, latency reduction, and weight. The research lends credence that a small, sunglasses-type form factor of the head-worn display would be acceptable to commercial pilots, and this goal is now becoming technologically feasible. The research further suggests that a head-worn display may serve as an "equivalent" Head-Up Display (HUD) with safety, operational, and cost benefits. "HUD equivalence" appears to be the economic avenue by which head-worn displays can become main-stream on the commercial and business aircraft flight deck. If this happens, NASA's research suggests that additional operational benefits using the unique capabilities of the head-worn display can open up new operational paradigms.

A review of head-worn display research at NASA Langley Research Center

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J.; Bailey, Randall E.; Williams, Steven P.; Prinzel, Lawrence J.; Shelton, Kevin J.; Jones, Denise R.; Houston, Vincent

2015-05-01

NASA Langley has conducted research in the area of helmet-mounted/head-worn displays over the past 30 years. Initially, NASA Langley's research focused on military applications, but recently has conducted a line of research in the area of head-worn displays for commercial and business aircraft. This work has revolved around numerous simulation experiments as well as flight tests to develop technology and data for industry and regulatory guidance. The paper summarizes the results of NASA's helmet-mounted/head-worn display research. Of note, the work tracks progress in wearable collimated optics, head tracking, latency reduction, and weight. The research lends credence that a small, sunglasses-type form factor of the head-worn display would be acceptable to commercial pilots, and this goal is now becoming technologically feasible. The research further suggests that a head-worn display may serve as an "equivalent" Head-Up Display (HUD) with safety, operational, and cost benefits. "HUD equivalence" appears to be the economic avenue by which head-worn displays can become main-stream on the commercial and business aircraft flight deck. If this happens, NASA's research suggests that additional operational benefits using the unique capabilities of the head-worn display can open up new operational paradigms.

Optimization of illumination schemes in a head-mounted display integrated with eye tracking capabilities

NASA Astrophysics Data System (ADS)

Pansing, Craig W.; Hua, Hong; Rolland, Jannick P.

2005-08-01

Head-mounted display (HMD) technologies find a variety of applications in the field of 3D virtual and augmented environments, 3D scientific visualization, as well as wearable displays. While most of the current HMDs use head pose to approximate line of sight, we propose to investigate approaches and designs for integrating eye tracking capability into HMDs from a low-level system design perspective and to explore schemes for optimizing system performance. In this paper, we particularly propose to optimize the illumination scheme, which is a critical component in designing an eye tracking-HMD (ET-HMD) integrated system. An optimal design can improve not only eye tracking accuracy, but also robustness. Using LightTools, we present the simulation of a complete eye illumination and imaging system using an eye model along with multiple near infrared LED (IRLED) illuminators and imaging optics, showing the irradiance variation of the different eye structures. The simulation of dark pupil effects along with multiple 1st-order Purkinje images will be presented. A parametric analysis is performed to investigate the relationships between the IRLED configurations and the irradiance distribution at the eye, and a set of optimal configuration parameters is recommended. The analysis will be further refined by actual eye image acquisition and processing.

A low-cost multimodal head-mounted display system for neuroendoscopic surgery.

PubMed

Xu, Xinghua; Zheng, Yi; Yao, Shujing; Sun, Guochen; Xu, Bainan; Chen, Xiaolei

2018-01-01

With rapid advances in technology, wearable devices as head-mounted display (HMD) have been adopted for various uses in medical science, ranging from simply aiding in fitness to assisting surgery. We aimed to investigate the feasibility and practicability of a low-cost multimodal HMD system in neuroendoscopic surgery. A multimodal HMD system, mainly consisted of a HMD with two built-in displays, an action camera, and a laptop computer displaying reconstructed medical images, was developed to assist neuroendoscopic surgery. With this intensively integrated system, the neurosurgeon could freely switch between endoscopic image, three-dimensional (3D) reconstructed virtual endoscopy images, and surrounding environment images. Using a leap motion controller, the neurosurgeon could adjust or rotate the 3D virtual endoscopic images at a distance to better understand the positional relation between lesions and normal tissues at will. A total of 21 consecutive patients with ventricular system diseases underwent neuroendoscopic surgery with the aid of this system. All operations were accomplished successfully, and no system-related complications occurred. The HMD was comfortable to wear and easy to operate. Screen resolution of the HMD was high enough for the neurosurgeon to operate carefully. With the system, the neurosurgeon might get a better comprehension on lesions by freely switching among images of different modalities. The system had a steep learning curve, which meant a quick increment of skill with it. Compared with commercially available surgical assistant instruments, this system was relatively low-cost. The multimodal HMD system is feasible, practical, helpful, and relatively cost efficient in neuroendoscopic surgery.

Development of a surgical navigation system based on augmented reality using an optical see-through head-mounted display.

PubMed

Chen, Xiaojun; Xu, Lu; Wang, Yiping; Wang, Huixiang; Wang, Fang; Zeng, Xiangsen; Wang, Qiugen; Egger, Jan

2015-06-01

The surgical navigation system has experienced tremendous development over the past decades for minimizing the risks and improving the precision of the surgery. Nowadays, Augmented Reality (AR)-based surgical navigation is a promising technology for clinical applications. In the AR system, virtual and actual reality are mixed, offering real-time, high-quality visualization of an extensive variety of information to the users (Moussa et al., 2012) [1]. For example, virtual anatomical structures such as soft tissues, blood vessels and nerves can be integrated with the real-world scenario in real time. In this study, an AR-based surgical navigation system (AR-SNS) is developed using an optical see-through HMD (head-mounted display), aiming at improving the safety and reliability of the surgery. With the use of this system, including the calibration of instruments, registration, and the calibration of HMD, the 3D virtual critical anatomical structures in the head-mounted display are aligned with the actual structures of patient in real-world scenario during the intra-operative motion tracking process. The accuracy verification experiment demonstrated that the mean distance and angular errors were respectively 0.809±0.05mm and 1.038°±0.05°, which was sufficient to meet the clinical requirements. Copyright © 2015 Elsevier Inc. All rights reserved.

Rapid P300 brain-computer interface communication with a head-mounted display

PubMed Central

Käthner, Ivo; Kübler, Andrea; Halder, Sebastian

2015-01-01

Visual ERP (P300) based brain-computer interfaces (BCIs) allow for fast and reliable spelling and are intended as a muscle-independent communication channel for people with severe paralysis. However, they require the presentation of visual stimuli in the field of view of the user. A head-mounted display could allow convenient presentation of visual stimuli in situations, where mounting a conventional monitor might be difficult or not feasible (e.g., at a patient's bedside). To explore if similar accuracies can be achieved with a virtual reality (VR) headset compared to a conventional flat screen monitor, we conducted an experiment with 18 healthy participants. We also evaluated it with a person in the locked-in state (LIS) to verify that usage of the headset is possible for a severely paralyzed person. Healthy participants performed online spelling with three different display methods. In one condition a 5 × 5 letter matrix was presented on a conventional 22 inch TFT monitor. Two configurations of the VR headset were tested. In the first (glasses A), the same 5 × 5 matrix filled the field of view of the user. In the second (glasses B), single letters of the matrix filled the field of view of the user. The participant in the LIS tested the VR headset on three different occasions (glasses A condition only). For healthy participants, average online spelling accuracies were 94% (15.5 bits/min) using three flash sequences for spelling with the monitor and glasses A and 96% (16.2 bits/min) with glasses B. In one session, the participant in the LIS reached an online spelling accuracy of 100% (10 bits/min) using the glasses A condition. We also demonstrated that spelling with one flash sequence is possible with the VR headset for healthy users (mean: 32.1 bits/min, maximum reached by one user: 71.89 bits/min at 100% accuracy). We conclude that the VR headset allows for rapid P300 BCI communication in healthy users and may be a suitable display option for severely

Visual field information in Nap-of-the-Earth flight by teleoperated Helmet-Mounted displays

NASA Technical Reports Server (NTRS)

Grunwald, Arthur J.; Kohn, S.; Merhav, S. J.

1991-01-01

The human ability to derive Control-Oriented Visual Field Information from teleoperated Helmet-Mounted displays in Nap-of-the-Earth flight, is investigated. The visual field with these types of displays originates from a Forward Looking Infrared Radiation Camera, gimbal-mounted at the front of the aircraft and slaved to the pilot's line-of-sight, to obtain wide-angle visual coverage. Although these displays are proved to be effective in Apache and Cobra helicopter night operations, they demand very high pilot proficiency and work load. Experimental work presented in the paper has shown that part of the difficulties encountered in vehicular control by means of these displays can be attributed to the narrow viewing aperture and head/camera slaving system phase lags. Both these shortcomings will impair visuo-vestibular coordination, when voluntary head rotation is present. This might result in errors in estimating the Control-Oriented Visual Field Information vital in vehicular control, such as the vehicle yaw rate or the anticipated flight path, or might even lead to visuo-vestibular conflicts (motion sickness). Since, under these conditions, the pilot will tend to minimize head rotation, the full wide-angle coverage of the Helmet-Mounted Display, provided by the line-of-sight slaving system, is not always fully utilized.

Optical methods for enabling focus cues in head-mounted displays for virtual and augmented reality

NASA Astrophysics Data System (ADS)

Hua, Hong

2017-05-01

Developing head-mounted displays (HMD) that offer uncompromised optical pathways to both digital and physical worlds without encumbrance and discomfort confronts many grand challenges, both from technological perspectives and human factors. Among the many challenges, minimizing visual discomfort is one of the key obstacles. One of the key contributing factors to visual discomfort is the lack of the ability to render proper focus cues in HMDs to stimulate natural eye accommodation responses, which leads to the well-known accommodation-convergence cue discrepancy problem. In this paper, I will provide a summary on the various optical methods approaches toward enabling focus cues in HMDs for both virtual reality (VR) and augmented reality (AR).

Light-Field Correction for Spatial Calibration of Optical See-Through Head-Mounted Displays.

PubMed

Itoh, Yuta; Klinker, Gudrun

2015-04-01

A critical requirement for AR applications with Optical See-Through Head-Mounted Displays (OST-HMD) is to project 3D information correctly into the current viewpoint of the user - more particularly, according to the user's eye position. Recently-proposed interaction-free calibration methods [16], [17] automatically estimate this projection by tracking the user's eye position, thereby freeing users from tedious manual calibrations. However, the method is still prone to contain systematic calibration errors. Such errors stem from eye-/HMD-related factors and are not represented in the conventional eye-HMD model used for HMD calibration. This paper investigates one of these factors - the fact that optical elements of OST-HMDs distort incoming world-light rays before they reach the eye, just as corrective glasses do. Any OST-HMD requires an optical element to display a virtual screen. Each such optical element has different distortions. Since users see a distorted world through the element, ignoring this distortion degenerates the projection quality. We propose a light-field correction method, based on a machine learning technique, which compensates the world-scene distortion caused by OST-HMD optics. We demonstrate that our method reduces the systematic error and significantly increases the calibration accuracy of the interaction-free calibration.

Talk to the Virtual Hands: Self-Animated Avatars Improve Communication in Head-Mounted Display Virtual Environments

PubMed Central

Dodds, Trevor J.; Mohler, Betty J.; Bülthoff, Heinrich H.

2011-01-01

Background When we talk to one another face-to-face, body gestures accompany our speech. Motion tracking technology enables us to include body gestures in avatar-mediated communication, by mapping one's movements onto one's own 3D avatar in real time, so the avatar is self-animated. We conducted two experiments to investigate (a) whether head-mounted display virtual reality is useful for researching the influence of body gestures in communication; and (b) whether body gestures are used to help in communicating the meaning of a word. Participants worked in pairs and played a communication game, where one person had to describe the meanings of words to the other. Principal Findings In experiment 1, participants used significantly more hand gestures and successfully described significantly more words when nonverbal communication was available to both participants (i.e. both describing and guessing avatars were self-animated, compared with both avatars in a static neutral pose). Participants ‘passed’ (gave up describing) significantly more words when they were talking to a static avatar (no nonverbal feedback available). In experiment 2, participants' performance was significantly worse when they were talking to an avatar with a prerecorded listening animation, compared with an avatar animated by their partners' real movements. In both experiments participants used significantly more hand gestures when they played the game in the real world. Conclusions Taken together, the studies show how (a) virtual reality can be used to systematically study the influence of body gestures; (b) it is important that nonverbal communication is bidirectional (real nonverbal feedback in addition to nonverbal communication from the describing participant); and (c) there are differences in the amount of body gestures that participants use with and without the head-mounted display, and we discuss possible explanations for this and ideas for future investigation. PMID:22022442

Talk to the virtual hands: self-animated avatars improve communication in head-mounted display virtual environments.

PubMed

Dodds, Trevor J; Mohler, Betty J; Bülthoff, Heinrich H

2011-01-01

When we talk to one another face-to-face, body gestures accompany our speech. Motion tracking technology enables us to include body gestures in avatar-mediated communication, by mapping one's movements onto one's own 3D avatar in real time, so the avatar is self-animated. We conducted two experiments to investigate (a) whether head-mounted display virtual reality is useful for researching the influence of body gestures in communication; and (b) whether body gestures are used to help in communicating the meaning of a word. Participants worked in pairs and played a communication game, where one person had to describe the meanings of words to the other. In experiment 1, participants used significantly more hand gestures and successfully described significantly more words when nonverbal communication was available to both participants (i.e. both describing and guessing avatars were self-animated, compared with both avatars in a static neutral pose). Participants 'passed' (gave up describing) significantly more words when they were talking to a static avatar (no nonverbal feedback available). In experiment 2, participants' performance was significantly worse when they were talking to an avatar with a prerecorded listening animation, compared with an avatar animated by their partners' real movements. In both experiments participants used significantly more hand gestures when they played the game in the real world. Taken together, the studies show how (a) virtual reality can be used to systematically study the influence of body gestures; (b) it is important that nonverbal communication is bidirectional (real nonverbal feedback in addition to nonverbal communication from the describing participant); and (c) there are differences in the amount of body gestures that participants use with and without the head-mounted display, and we discuss possible explanations for this and ideas for future investigation.

A helmet mounted display to adapt the telerobotic environment to human vision

NASA Technical Reports Server (NTRS)

Tharp, Gregory; Liu, Andrew; Yamashita, Hitomi; Stark, Lawrence

1990-01-01

A Helmet Mounted Display system has been developed. It provides the capability to display stereo images with the viewpoint tied to subjects' head orientation. The type of display might be useful in a telerobotic environment provided the correct operating parameters are known. The effects of update frequency were tested using a 3D tracking task. The effects of blur were tested using both tracking and pick-and-place tasks. For both, researchers found that operator performance can be degraded if the correct parameters are not used. Researchers are also using the display to explore the use of head movements as part of gaze as subjects search their visual field for target objects.

Tackling the challenges of fully immersive head-mounted AR devices

NASA Astrophysics Data System (ADS)

Singer, Wolfgang; Hillenbrand, Matthias; Münz, Holger

2017-11-01

The optical requirements of fully immersive head mounted AR devices are inherently determined by the human visual system. The etendue of the visual system is large. As a consequence, the requirements for fully immersive head-mounted AR devices exceeds almost any high end optical system. Two promising solutions to achieve the large etendue and their challenges are discussed. Head-mounted augmented reality devices have been developed for decades - mostly for application within aircrafts and in combination with a heavy and bulky helmet. The established head-up displays for applications within automotive vehicles typically utilize similar techniques. Recently, there is the vision of eyeglasses with included augmentation, offering a large field of view, and being unobtrusively all-day wearable. There seems to be no simple solution to reach the functional performance requirements. Known technical solutions paths seem to be a dead-end, and some seem to offer promising perspectives, however with severe limitations. As an alternative, unobtrusively all-day wearable devices with a significantly smaller field of view are already possible.

Optical See-Through Head Mounted Display Direct Linear Transformation Calibration Robustness in the Presence of User Alignment Noise

NASA Technical Reports Server (NTRS)

Axholt, Magnus; Skoglund, Martin; Peterson, Stephen D.; Cooper, Matthew D.; Schoen, Thomas B.; Gustafsson, Fredrik; Ynnerman, Anders; Ellis, Stephen R.

2010-01-01

Augmented Reality (AR) is a technique by which computer generated signals synthesize impressions that are made to coexist with the surrounding real world as perceived by the user. Human smell, taste, touch and hearing can all be augmented, but most commonly AR refers to the human vision being overlaid with information otherwise not readily available to the user. A correct calibration is important on an application level, ensuring that e.g. data labels are presented at correct locations, but also on a system level to enable display techniques such as stereoscopy to function properly [SOURCE]. Thus, vital to AR, calibration methodology is an important research area. While great achievements already have been made, there are some properties in current calibration methods for augmenting vision which do not translate from its traditional use in automated cameras calibration to its use with a human operator. This paper uses a Monte Carlo simulation of a standard direct linear transformation camera calibration to investigate how user introduced head orientation noise affects the parameter estimation during a calibration procedure of an optical see-through head mounted display.

Binocular vision in a virtual world: visual deficits following the wearing of a head-mounted display.

PubMed

Mon-Williams, M; Wann, J P; Rushton, S

1993-10-01

The short-term effects on binocular stability of wearing a conventional head-mounted display (HMD) to explore a virtual reality environment were examined. Twenty adult subjects (aged 19-29 years) wore a commercially available HMD for 10 min while cycling around a computer generated 3-D world. The twin screen presentations were set to suit the average interpupillary distance of our subject population, to mimic the conditions of public access virtual reality systems. Subjects were examined before and after exposure to the HMD and there were clear signs of induced binocular stress for a number of the subjects. The implications of introducing such HMDs into the workplace and entertainment environments are discussed.

Head-mounted spatial instruments: Synthetic reality or impossible dream

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Grunwald, Arthur; Velger, Mordekhai

1988-01-01

A spatial instrument is defined as a display device which has been either geometrically or symbolically enhanced to better enable a user to accomplish a particular task. Research conducted over the past several years on 3-D spatial instruments has shown that perspective displays, even when viewed from the correct viewpoint, are subject to systematic viewer biases. These biases interfere with correct spatial judgements of the presented pictorial information. It is also found that deliberate, appropriate geometric distortion of the perspective projection of an image can improve user performance. These two findings raise intriguing questions concerning the design of head-mounted spatial instruments. The design of such instruments may not only require the introduction of compensatory distortions to remove the neutrally occurring biases but also may significantly benefit from the introduction of artificial distortions which enhance performance. These image manipulations, however, can cause a loss of visual-vestibular coordination and induce motion sickness. Additionally, adaptation to these manipulations is apt to be impaired by computational delays in the image display. Consequently, the design of head-mounted spatial instruments will require an understanding of the tolerable limits of visual-vestibular discord.

Development of an immersive virtual reality head-mounted display with high performance.

PubMed

Wang, Yunqi; Liu, Weiqi; Meng, Xiangxiang; Fu, Hanyi; Zhang, Daliang; Kang, Yusi; Feng, Rui; Wei, Zhonglun; Zhu, Xiuqing; Jiang, Guohua

2016-09-01

To resolve the contradiction between large field of view and high resolution in immersive virtual reality (VR) head-mounted displays (HMDs), an HMD monocular optical system with a large field of view and high resolution was designed. The system was fabricated by adopting aspheric technology with CNC grinding and a high-resolution LCD as the image source. With this monocular optical system, an HMD binocular optical system with a wide-range continuously adjustable interpupillary distance was achieved in the form of partially overlapping fields of view (FOV) combined with a screw adjustment mechanism. A fast image processor-centered LCD driver circuit and an image preprocessing system were also built to address binocular vision inconsistency in the partially overlapping FOV binocular optical system. The distortions of the HMD optical system with a large field of view were measured. Meanwhile, the optical distortions in the display and the trapezoidal distortions introduced during image processing were corrected by a calibration model for reverse rotations and translations. A high-performance not-fully-transparent VR HMD device with high resolution (1920×1080) and large FOV [141.6°(H)×73.08°(V)] was developed. The full field-of-view average value of angular resolution is 18.6  pixels/degree. With the device, high-quality VR simulations can be completed under various scenarios, and the device can be utilized for simulated trainings in aeronautics, astronautics, and other fields with corresponding platforms. The developed device has positive practical significance.

A head-mounted display-based personal integrated-image monitoring system for transurethral resection of the prostate.

PubMed

Yoshida, Soichiro; Kihara, Kazunori; Takeshita, Hideki; Fujii, Yasuhisa

2014-12-01

The head-mounted display (HMD) is a new image monitoring system. We developed the Personal Integrated-image Monitoring System (PIM System) using the HMD (HMZ-T2, Sony Corporation, Tokyo, Japan) in combination with video splitters and multiplexers as a surgical guide system for transurethral resection of the prostate (TURP). The imaging information obtained from the cystoscope, the transurethral ultrasonography (TRUS), the video camera attached to the HMD, and the patient's vital signs monitor were split and integrated by the PIM System and a composite image was displayed by the HMD using a four-split screen technique. Wearing the HMD, the lead surgeon and the assistant could simultaneously and continuously monitor the same information displayed by the HMD in an ergonomically efficient posture. Each participant could independently rearrange the images comprising the composite image depending on the engaging step. Two benign prostatic hyperplasia (BPH) patients underwent TURP performed by surgeons guided with this system. In both cases, the TURP procedure was successfully performed, and their postoperative clinical courses had no remarkable unfavorable events. During the procedure, none of the participants experienced any HMD-wear related adverse effects or reported any discomfort.

EMU helmet mounted display

NASA Technical Reports Server (NTRS)

Marmolejo, Jose (Inventor); Smith, Stephen (Inventor); Plough, Alan (Inventor); Clarke, Robert (Inventor); Mclean, William (Inventor); Fournier, Joseph (Inventor)

1990-01-01

A helmet mounted display device is disclosed for projecting a display on a flat combiner surface located above the line of sight where the display is produced by two independent optical channels with independent LCD image generators. The display has a fully overlapped field of view on the combiner surface and the focus can be adjusted from a near field of four feet to infinity.

Raster graphic helmet-mounted display study

NASA Technical Reports Server (NTRS)

Beamon, William S.; Moran, Susanna I.

1990-01-01

A design of a helmet mounted display system is presented, including a design specification and development plan for the selected design approach. The requirements for the helmet mounted display system and a survey of applicable technologies are presented. Three helmet display concepts are then described which utilize lasers, liquid crystal display's (LCD's), and subminiature cathode ray tubes (CRT's), respectively. The laser approach is further developed in a design specification and a development plan.

Comanche Helmet-Mounted Display Heading-Tape Simulation

NASA Technical Reports Server (NTRS)

Turpin, Terry; Dowell, Susan; Atencio, Adolph

2006-01-01

The Aeroflightdynamics Directorate (AMRDEC) conducted a simulation to assess the performance associated with a Contact Analog, world-referenced heading tape as implemented on the Comanche Helmet Integrated Display Sight System (HIDSS) when compared with a Compressed heading tape similar to that specified by the former Military Standard (MIL-STD) 1295. Six experienced pilots flew three modified Aeronautical Design Standards (ADS)-33 maneuvers (Hover Turn, Bob-up, Transient Turn) and a precision traffic pattern in the NASA Vertical Motion Simulator (VMS). Analysis of the pilot objective performance data and subjective handling qualities ratings (HQRs) showed the following: Compressed symbology in the Velocity Stabilization (VelStab) flight mode generally produced the most precise performances over Contact Analog symbology with respect to the heading, altitude, position, and time criteria specified for the maneuvers tested. VelStab outperformed the Automatic Flight Control System (AFCS) on all maneuvers achieving desired performance on most maneuvers for both symbol sets. Performance in the AFCS mode was generally desirable to adequate for heading and altitude and did not meet adequate standards for hover position and time for the Hover Turn and Bob-up maneuvers. VelStab and AFCS performance were nearly the same for the Transient Turn. Pilot comments concerning the Contact Analog heading-tape implementation were generally unfavorable in spite of the achieved levels of performance. HQRs showed Compressed symbology in the VelStab flight mode produced the lowest mean HQR, encompassing mixed ratings of satisfactory handling and needing improvement. All other symbology/flight-mode combinations yielded higher HQRs, which characterized opinions that deficiencies in aircraft handling due to HMD symbology would need improvement. Contact Analog heading tape and other symbology require improvement, especially when operating in the AFCS mode. NASA-TLX rated Compressed symbology

Visual task performance using a monocular see-through head-mounted display (HMD) while walking.

PubMed

Mustonen, Terhi; Berg, Mikko; Kaistinen, Jyrki; Kawai, Takashi; Häkkinen, Jukka

2013-12-01

A monocular see-through head-mounted display (HMD) allows the user to view displayed information while simultaneously interacting with the surrounding environment. This configuration lets people use HMDs while they are moving, such as while walking. However, sharing attention between the display and environment can compromise a person's performance in any ongoing task, and controlling one's gait may add further challenges. In this study, the authors investigated how the requirements of HMD-administered visual tasks altered users' performance while they were walking. Twenty-four university students completed 3 cognitive tasks (high- and low-working memory load, visual vigilance) on an HMD while seated and while simultaneously performing a paced walking task in a controlled environment. The results show that paced walking worsened performance (d', reaction time) in all HMD-administered tasks, but visual vigilance deteriorated more than memory performance. The HMD-administered tasks also worsened walking performance (speed, path overruns) in a manner that varied according to the overall demands of the task. These results suggest that people's ability to process information displayed on an HMD may worsen while they are in motion. Furthermore, the use of an HMD can critically alter a person's natural performance, such as their ability to guide and control their gait. In particular, visual tasks that involve constant monitoring of the HMD should be avoided. These findings highlight the need for careful consideration of the type and difficulty of information that can be presented through HMDs while still letting the user achieve an acceptable overall level of performance in various contexts of use. PsycINFO Database Record (c) 2013 APA, all rights reserved.

Assessment of a head-mounted miniature monitor

NASA Technical Reports Server (NTRS)

Hale, J. P., II

1992-01-01

Two experiments were conducted to assess the capabilities and limitations of the Private Eye, a miniature, head-mounted monitor. The first experiment compared the Private Eye with a cathode ray tube (CRT) and hard copy in both a constrained and unconstrained work envelope. The task was a simulated maintenance and assembly task that required frequent reference to the displayed information. A main effect of presentation media indicated faster placement times using the CRT as compared with hard copy. There were no significant differences between the Private Eye and either the CRT or hard copy for identification, placement, or total task times. The goal of the second experiment was to determine the effects of various local visual parameters on the ability of the user to accurately perceive the information of the Private Eye. The task was an interactive video game. No significant performance differences were found under either bright or dark ambient illumination environments nor with either visually simple or complex task backgrounds. Glare reflected off of the bezel surrounding the monitor did degrade performance. It was concluded that this head-mounted, miniature monitor could serve a useful role for in situ operations, especially in microgravity environments.

Integrated helmet mounted display concepts for air combat

NASA Technical Reports Server (NTRS)

Clark, Joseph W.

1995-01-01

A piloted simulation study was conducted in a dome simulator to evaluate several Helmet Mounted Display (HMD) formats developed as part of the NASA High Alpha Technology Program (HATP). The display formats conveyed energy management, spatial orientation, and weapons management information. The HMD format was compared to a generic Heads Up Display (HUD) typical of current operational fighter aircraft. Pilots were tasked to spend as much time in a weapon solution as possible, to have the correct weapon selected for the envelope they were in, and to avoid the adversary's weapon envelope as much as possible. Several different displays were tested individually and simultaneously to see how separate display concepts coexisted. Objective results showed that the ability for the pilot to select the correct weapon for the envelope he was in increased by 50% in a moderate workload condition and 90% in a high workload condition with the HMD format. In the post-test comments pilots generally favored the helmet display formats over the HUD formats with a few instances where pilots preferred a simple numeric readout of the parameter. Short term exposure effects of the HMD on visual acuity were also measured and showed no advers results.

The use of optical waveguides in head up display (HUD) applications

NASA Astrophysics Data System (ADS)

Homan, Malcolm

2013-06-01

The application of optical waveguides to Head Up Displays (HUD) is an enabling technology which solves the critical issues of volume reduction (including cockpit intrusion) and mass reduction in an affordable product which retains the high performance optical capabilities associated with today's generation of digital display based HUDs. Improved operability and pilot comfort is achieved regardless of the installation by virtue of the intrinsic properties of optical waveguides and this has enabled BAE Systems Electronic Systems to develop two distinct product streams for glareshield and overhead HUD installations respectively. This paper addresses the design drivers behind the development of the next generation of Head Up Displays and their compatibility with evolving cockpit architectures and structures. The implementation of large scale optical waveguide combiners capable of matching and exceeding the display performances normally only associated with current digital display sourced HUDs has enabled BAE Systems Electronic Systems to solve the volume and installation challenges of the latest military and civil cockpits with it's LiteHUD® technology. Glareshield mounted waveguide based HUDs are compatible with the trend towards the addition of Large Area Displays (LAD) in place of the traditional multiple Head Down Displays (HDD) within military fast jet cockpits. They use an "indirect view" variant of the display which allows the amalgamation of high resolution digital display devices with the inherently small volume and low mass of the waveguide optics. This is then viewed using the more traditional technology of a conventional HUD combiner. This successful combination of technologies has resulted in the LPHUD product which is specifically designed by BAE Systems Electronic Systems to provide an ultra-low profile HUD which can be installed behind a LAD; still providing the level of performance that is at least equivalent to that of a conventional large volume

A new head-mounted display-based augmented reality system in neurosurgical oncology: a study on phantom.

PubMed

Cutolo, Fabrizio; Meola, Antonio; Carbone, Marina; Sinceri, Sara; Cagnazzo, Federico; Denaro, Ennio; Esposito, Nicola; Ferrari, Mauro; Ferrari, Vincenzo

2017-12-01

Benefits of minimally invasive neurosurgery mandate the development of ergonomic paradigms for neuronavigation. Augmented Reality (AR) systems can overcome the shortcomings of commercial neuronavigators. The aim of this work is to apply a novel AR system, based on a head-mounted stereoscopic video see-through display, as an aid in complex neurological lesion targeting. Effectiveness was investigated on a newly designed patient-specific head mannequin featuring an anatomically realistic brain phantom with embedded synthetically created tumors and eloquent areas. A two-phase evaluation process was adopted in a simulated small tumor resection adjacent to Broca's area. Phase I involved nine subjects without neurosurgical training in performing spatial judgment tasks. In Phase II, three surgeons were involved in assessing the effectiveness of the AR-neuronavigator in performing brain tumor targeting on a patient-specific head phantom. Phase I revealed the ability of the AR scene to evoke depth perception under different visualization modalities. Phase II confirmed the potentialities of the AR-neuronavigator in aiding the determination of the optimal surgical access to the surgical target. The AR-neuronavigator is intuitive, easy-to-use, and provides three-dimensional augmented information in a perceptually-correct way. The system proved to be effective in guiding skin incision, craniotomy, and lesion targeting. The preliminary results encourage a structured study to prove clinical effectiveness. Moreover, our testing platform might be used to facilitate training in brain tumour resection procedures.

Active and passive distraction using a head-mounted display helmet: effects on cold pressor pain in children.

PubMed

Dahlquist, Lynnda M; McKenna, Kristine D; Jones, Katia K; Dillinger, Lindsay; Weiss, Karen E; Ackerman, Claire Sonntag

2007-11-01

The current study tested the effectiveness of interactive versus passive distraction that was delivered via a virtual reality type head-mounted display helmet for children experiencing cold pressor pain. Forty children, aged 5 to 13 years, underwent 1 or 2 baseline cold pressor trials followed by interactive distraction and passive distraction trials in counterbalanced order. Pain threshold and pain tolerance. Children who experienced either passive or interactive distraction demonstrated significant improvements in both pain tolerance and pain threshold relative to their baseline scores. In contrast, children who underwent a second cold pressor trial without distraction showed no significant improvements in pain tolerance or threshold. Although both distraction conditions were effective, the interactive distraction condition was significantly more effective. Implications for the treatment of children's distress during painful medical procedures are discussed. (PsycINFO Database Record (c) 2007 APA, all rights reserved).

The effect of viewing a virtual environment through a head-mounted display on balance.

PubMed

Robert, Maxime T; Ballaz, Laurent; Lemay, Martin

2016-07-01

In the next few years, several head-mounted displays (HMD) will be publicly released making virtual reality more accessible. HMD are expected to be widely popular at home for gaming but also in clinical settings, notably for training and rehabilitation. HMD can be used in both seated and standing positions; however, presently, the impact of HMD on balance remains largely unknown. It is therefore crucial to examine the impact of viewing a virtual environment through a HMD on standing balance. To compare static and dynamic balance in a virtual environment perceived through a HMD and the physical environment. The visual representation of the virtual environment was based on filmed image of the physical environment and was therefore highly similar. This is an observational study in healthy adults. No significant difference was observed between the two environments for static balance. However, dynamic balance was more perturbed in the virtual environment when compared to that of the physical environment. HMD should be used with caution because of its detrimental impact on dynamic balance. Sensorimotor conflict possibly explains the impact of HMD on balance. Copyright © 2016 Elsevier B.V. All rights reserved.

Flat panel displays in the helmet-mounted display

NASA Astrophysics Data System (ADS)

Bartlett, Christopher T.; Freeman, Jonathan P.

2002-08-01

The Helmet Mounted Display has been in development for over 25 years and with few exceptions those systems in service have incorporated a miniature Cathode Ray Tube as the display source. The exceptions have been the use of Light Emitting Diodes in Helmet Sighting displays. The argument for Flat Panel Displays has been well rehearsed and this paper provides a summary of the available technologies but with a rationale for a decision to use Reflective Liquid Crystal devices. The Paper then describes sources of illumination and derives the luminance required from that source.

Design of monocular head-mounted displays for increased indoor firefighting safety and efficiency

NASA Astrophysics Data System (ADS)

Wilson, Joel; Steingart, Dan; Romero, Russell; Reynolds, Jessica; Mellers, Eric; Redfern, Andrew; Lim, Lloyd; Watts, William; Patton, Colin; Baker, Jessica; Wright, Paul

2005-05-01

Four monocular Head-Mounted Display (HMD) prototypes from the Fire Information and Rescue Equipment (FIRE) project at UC Berkeley are presented. The FIRE project aims to give firefighters a system of information technology tools for safer and more efficient firefighting in large buildings. The paper begins by describing the FIRE project and its use of a custom wireless sensor network (WSN) called SmokeNet for personnel tracking. The project aims to address urban/industrial firefighting procedures in need of improvement. Two "user-needs" studies with the Chicago and Berkeley Fire Departments are briefly presented. The FIRE project"s initial HMD prototype designs are then discussed with regard to feedback from the user-needs studies. These prototypes are evaluated in their potential costs and benefits to firefighters and found to need improvement. Next, some currently available commercial HMDs are reviewed and compared in their cost, performance, and potential for use by firefighters. Feedback from the Berkeley Fire Department user-needs study, in which the initial prototypes were demonstrated, is compiled into a concept selection matrix for the next prototypes. This matrix is used to evaluate a variety of HMDs, including some of the commercial units presented, and to select the best design options. Finally, the current prototypes of the two best design options are presented and discussed.

Color Helmet-Mounted Display System for In-Flight Simulation on the RASCAL Research Helicopter

NASA Technical Reports Server (NTRS)

Edwards, Tim; Barnhart, Warren; Sawyer, Kevin; Aiken, Edwin W. (Technical Monitor)

1995-01-01

A high performance color helmet mounted display (HMD) system for in-flight simulation and research has been developed for the Rotorcraft Aircrew Systems Concepts Laboratory (RASCAL). The display system consists of a programmable display generator, a display electronics unit, a head tracker, and the helmet with display optics. The system provides a maximum of 1024 x 1280 resolution, a 4:1 contrast ratio, and a brightness of 1100fL utilizing currently available technologies. This paper describes the major features and components of the system. Also discussed are the measured performance of the system and the design techniques that allowed the development of a full color HMD.

Human factors issues in the development of helmet-mounted displays for tactical fixed-wing aircraft

NASA Astrophysics Data System (ADS)

Barnaba, James M.

1997-06-01

There are many human factors issues that should be considered when designing a helmet mounted display for use in high speed aircraft with ejection seats. The Joint Helmet Mounted Cueing System Program Office, with support from the Armstrong Laboratory and the Naval Air Warfare Center, has been studying many of these issues and is able to report several findings in the areas of anthropometry, limitations in head movement, helmet stability under high gravity forces and mass properties. This paper serves to summarize the findings of the program office in these areas. The paper will include highlights of several studies that have involved anthropometric data manipulation, 3D head scans, and testing of manikin and human subjects in static and dynamic cockpit environment simulations.

Assessing balance through the use of a low-cost head-mounted display in older adults: a pilot study.

PubMed

Saldana, Santiago J; Marsh, Anthony P; Rejeski, W Jack; Haberl, Jack K; Wu, Peggy; Rosenthal, Scott; Ip, Edward H

2017-01-01

As the population ages, the prevention of falls is an increasingly important public health problem. Balance assessment forms an important component of fall-prevention programs for older adults. The recent development of cost-effective and highly responsive virtual reality (VR) systems means new methods of balance assessment are feasible in a clinical setting. This proof-of-concept study made use of the submillimeter tracking built into modern VR head-mounted displays (VRHMDs) to assess balance through the use of visual-vestibular conflict. The objective of this study was to evaluate the validity, acceptability, and reliability of using a VRHMD to assess balance in older adults. Validity was assessed by comparing measurements from the VRHMD to measurements of postural sway from a force plate. Acceptability was assessed through the use of the Simulator Sickness Questionnaire pre- and postexposure to assess possible side effects of the visual-vestibular conflict. Reliability was assessed by measuring correlations between repeated measurements 1 week apart. Variables of possible importance that were found to be reliable ( r ≥0.9) between tests separated by a week were then tested for differences compared to a control group. Assessment was performed as a cross-sectional single-site community center-based study in 13 older adults (≥65 years old, 80.2±7.3 years old, 77% female, five at risk of falls, eight controls). The VR balance assessment consisted of four modules: a baseline module, a reaction module, a balance module, and a seated assessment. There was a significant difference in the rate at which participants with a risk of falls changed their tilt in the anteroposterior direction compared to the control group. Participants with a risk of falls changed their tilt in the anteroposterior direction at 0.7°/second vs 0.4°/second for those without a history of falls. No significant differences were found between pre/postassessment for oculomotor score or total

[Effects on visual functions following several hours' usage of a head mounted display].

PubMed

Hara, N; Ukai, K; Ishikawa, S; Takagi, M; Bando, T; Oyamada, H

1996-07-01

We investigated the effects of viewing video movies with a head-mounted display (HMD) for 4 to 6 hours on visual functions such as refraction, visual acuity, and accommodation-vergence system. Two or three video movies were watched without any breaks by 13 normal volunteers (age: 22 approximately 40). Measurements were made of (1) objective and subjective refraction, (2) corrected visual acuity, (3) tonic level and step response of accommodation with a computer-assisted infrared optometer, and (4) near and far phorias and AC/A ratio. Significant transient myopia was found following 4 hours' viewing, but not following 6 hours' viewing. Scrutinizing individual data, myopia was consistently found in some subjects, and hyperopia in others. We presumed that many subjects might have been influenced by initial instrumental myopia when they adjusted the focus by using the mechanism built in the HMD. No significant change was observed in any other examination. However, there was a tendency for the AC/A ratio to change after a short time, and then to recover to its original value. Based on the results in this study, it appears that some changes in accommodation and vergence systems are caused by viewing video movies with the HMD. Although the amount of changes was within normal physiological variation in this study, the possibility still remains that usage for a longer time may lead to other changes in visual function. Care is also necessary when using the HMD in subjects with subclinical problems.

Time Counts! Some Comments on System Latency in Head-Referenced Displays

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Adelstein, Bernard D.

2013-01-01

System response latency is a prominent characteristic of human-computer interaction. Laggy systems are; however, not simply annoying but substantially reduce user productivity. The impact of latency on head referenced display systems, particularly head-mounted systems, is especially disturbing since not only can it interfere with dynamic registration in augmented reality displays but it also can in some cases indirectly contribute to motion sickness. We will summarize several experiments using standard psychophysical discrimination techniques that suggest what system latencies will be required to achieve perceptual stability for spatially referenced computer-generated imagery. In conclusion I will speculate about other system performance characteristics that I would hope to have for a dream augmented reality system.

Comparison of attitude information for helmet-mounted displays

NASA Astrophysics Data System (ADS)

Davy, Eleanor C.; Selcon, Stephen J.

1997-02-01

There are many potential uses of helmet-mounted displays (HMDs). One is to allow aircrew to spend increased time off- boresight scanning the outside world for threats or targets. Another is for acquiring a target and subsequently employing a weapon whilst looking off-boresight. An experiment was conducted to examine the use of HMDs for both these tasks using four different attitude displays: pitch ladder, cylinder, arc segmented attitude reference and roll-pitch. The task involved subjects flying a simulated low-level, high-speed mission which was divided into two phases. Phase one required subjects to scan off-boresight for air threats and acquire them by using the off-boresight capability of the HMD. Phase two required subjects to use the head-down display (HDD) to locate ground targets and use the HMD off- boresight capability to acquire them. Novel objective performance measures, designed specifically to evaluate HMD symbology, were collected. Overall, it was found that performance was superior when using the pitch ladder than other displays. This was supported by the subjective findings that it provided higher situational awareness than other displays. It was concluded that the advantage for the pitch ladder may have been due to having the same symbology on the HUD and HMD, enhancing smooth transitioning between the two displays. The importance of developing operationally relevant tasks and measures for the evaluation of HMDs are discussed and the implications of this research for future work are considered.

Perceptual issues for color helmet-mounted displays: luminance and color contrast requirements

NASA Astrophysics Data System (ADS)

Harding, Thomas H.; Rash, Clarence E.; Lattimore, Morris R.; Statz, Jonathan; Martin, John S.

2016-05-01

Color is one of the latest design characteristics of helmet-mounted displays (HMDs). It's inclusion in design specifications is based on two suppositions: 1) color provides an additional method of encoding information, and 2) color provides a more realistic, and hence more intuitive, presentation of information, especially pilotage imagery. To some degree, these two perceived advantages have been validated with head-down panel-mounted displays, although not without a few problems associated with visual physiology and perception. These problems become more prevalent when the user population expands beyond military aviators to a general user population, of which a significant portion may have color vision deficiencies. When color is implemented in HMDs, which are eyes-out, see-through displays, visual perception issues become an increased concern. A major confound with HMDs is their inherent see-through (transparent) property. The result is color in the displayed image combines with color from the outside (or in-cockpit) world, possibly producing a false perception of either or both images. While human-factors derived guidelines based on trial and error have been developed, color HMD systems still place more emphasis on colorimetric than perceptual standards. This paper identifies the luminance and color contrast requirements for see-through HMDs. Also included is a discussion of ambient scene metrics and the choice of symbology color.

Effects of videogame distraction using a virtual reality type head-mounted display helmet on cold pressor pain in children.

PubMed

Dahlquist, Lynnda M; Weiss, Karen E; Clendaniel, Lindsay Dillinger; Law, Emily F; Ackerman, Claire Sonntag; McKenna, Kristine D

2009-06-01

To test whether a head-mounted display helmet enhances the effectiveness of videogame distraction for children experiencing cold pressor pain. Forty-one children, aged 6-14 years, underwent one or two baseline cold pressor trials followed by two distraction trials in which they played the same videogame with and without the helmet in counterbalanced order. Pain threshold (elapsed time until the child reported pain) and pain tolerance (total time the child kept the hand submerged in the cold water) were measured for each cold pressor trial. Both distraction conditions resulted in improved pain tolerance relative to baseline. Older children appeared to experience additional benefits from using the helmet, whereas younger children benefited equally from both conditions. The findings suggest that virtual reality technology can enhance the effects of distraction for some children. Research is needed to identify the characteristics of children for whom this technology is best suited.

Head-motion-controlled video goggles: preliminary concept for an interactive laparoscopic image display (i-LID).

PubMed

Aidlen, Jeremy T; Glick, Sara; Silverman, Kenneth; Silverman, Harvey F; Luks, Francois I

2009-08-01

Light-weight, low-profile, and high-resolution head-mounted displays (HMDs) now allow personalized viewing, of a laparoscopic image. The advantages include unobstructed viewing, regardless of position at the operating table, and the possibility to customize the image (i.e., enhanced reality, picture-in-picture, etc.). The bright image display allows use in daylight surroundings and the low profile of the HMD provides adequate peripheral vision. Theoretic disadvantages include reliance for all on the same image capture and anticues (i.e., reality disconnect) when the projected image remains static, despite changes in head position. This can lead to discomfort and even nausea. We have developed a prototype of interactive laparoscopic image display that allows hands-free control of the displayed image by changes in spatial orientation of the operator's head. The prototype consists of an HMD, a spatial orientation device, and computer software to enable hands-free panning and zooming of a video-endoscopic image display. The spatial orientation device uses magnetic fields created by a transmitter and receiver, each containing three orthogonal coils. The transmitter coils are efficiently driven, using USB power only, by a newly developed circuit, each at a unique frequency. The HMD-mounted receiver system links to a commercially available PC-interface PCI-bus sound card (M-Audiocard Delta 44; Avid Technology, Tewksbury, MA). Analog signals at the receiver are filtered, amplified, and converted to digital signals, which are processed to control the image display. The prototype uses a proprietary static fish-eye lens and software for the distortion-free reconstitution of any portion of the captured image. Left-right and up-down motions of the head (and HMD) produce real-time panning of the displayed image. Motion of the head toward, or away from, the transmitter causes real-time zooming in or out, respectively, of the displayed image. This prototype of the interactive HMD

Assessing balance through the use of a low-cost head-mounted display in older adults: a pilot study

PubMed Central

Saldana, Santiago J; Marsh, Anthony P; Rejeski, W Jack; Haberl, Jack K; Wu, Peggy; Rosenthal, Scott; Ip, Edward H

2017-01-01

Introduction As the population ages, the prevention of falls is an increasingly important public health problem. Balance assessment forms an important component of fall-prevention programs for older adults. The recent development of cost-effective and highly responsive virtual reality (VR) systems means new methods of balance assessment are feasible in a clinical setting. This proof-of-concept study made use of the submillimeter tracking built into modern VR head-mounted displays (VRHMDs) to assess balance through the use of visual–vestibular conflict. The objective of this study was to evaluate the validity, acceptability, and reliability of using a VRHMD to assess balance in older adults. Materials and methods Validity was assessed by comparing measurements from the VRHMD to measurements of postural sway from a force plate. Acceptability was assessed through the use of the Simulator Sickness Questionnaire pre- and postexposure to assess possible side effects of the visual–vestibular conflict. Reliability was assessed by measuring correlations between repeated measurements 1 week apart. Variables of possible importance that were found to be reliable (r≥0.9) between tests separated by a week were then tested for differences compared to a control group. Assessment was performed as a cross-sectional single-site community center-based study in 13 older adults (≥65 years old, 80.2±7.3 years old, 77% female, five at risk of falls, eight controls). The VR balance assessment consisted of four modules: a baseline module, a reaction module, a balance module, and a seated assessment. Results There was a significant difference in the rate at which participants with a risk of falls changed their tilt in the anteroposterior direction compared to the control group. Participants with a risk of falls changed their tilt in the anteroposterior direction at 0.7°/second vs 0.4°/second for those without a history of falls. No significant differences were found between pre

Information requirements and methodology for development of an EVA crewmember's heads up display

NASA Astrophysics Data System (ADS)

Petrek, J. S.

This paper presents a systematic approach for developing a Heads Up Display (HUD) to be used within the helmet of the Extra Vehicular Activity (EVA) crewmember. The information displayed on the EVA HUD will be analogous to EVA Flight Data File (FDF) information, which is an integral part of NASA's current Space Transportation System. Another objective is to determine information requirements and media techniques ultimately leading to the helmet-mounted HUD presentation technique.

Head-mounted display augmented reality to guide pedicle screw placement utilizing computed tomography.

PubMed

Gibby, Jacob T; Swenson, Samuel A; Cvetko, Steve; Rao, Raj; Javan, Ramin

2018-06-22

Augmented reality has potential to enhance surgical navigation and visualization. We determined whether head-mounted display augmented reality (HMD-AR) with superimposed computed tomography (CT) data could allow the wearer to percutaneously guide pedicle screw placement in an opaque lumbar model with no real-time fluoroscopic guidance. CT imaging was obtained of a phantom composed of L1-L3 Sawbones vertebrae in opaque silicone. Preprocedural planning was performed by creating virtual trajectories of appropriate angle and depth for ideal approach into the pedicle, and these data were integrated into the Microsoft HoloLens using the Novarad OpenSight application allowing the user to view the virtual trajectory guides and CT images superimposed on the phantom in two and three dimensions. Spinal needles were inserted following the virtual trajectories to the point of contact with bone. Repeat CT revealed actual needle trajectory, allowing comparison with the ideal preprocedural paths. Registration of AR to phantom showed a roughly circular deviation with maximum average radius of 2.5 mm. Users took an average of 200 s to place a needle. Extrapolation of needle trajectory into the pedicle showed that of 36 needles placed, 35 (97%) would have remained within the pedicles. Needles placed approximated a mean distance of 4.69 mm in the mediolateral direction and 4.48 mm in the craniocaudal direction from pedicle bone edge. To our knowledge, this is the first peer-reviewed report and evaluation of HMD-AR with superimposed 3D guidance utilizing CT for spinal pedicle guide placement for the purpose of cannulation without the use of fluoroscopy.

Effects of Videogame Distraction using a Virtual Reality Type Head-Mounted Display Helmet on Cold Pressor Pain in Children

PubMed Central

Weiss, Karen E.; Dillinger Clendaniel, Lindsay; Law, Emily F.; Ackerman, Claire Sonntag; McKenna, Kristine D.

2009-01-01

Objective To test whether a head-mounted display helmet enhances the effectiveness of videogame distraction for children experiencing cold pressor pain. Method Forty-one children, aged 6–14 years, underwent one or two baseline cold pressor trials followed by two distraction trials in which they played the same videogame with and without the helmet in counterbalanced order. Pain threshold (elapsed time until the child reported pain) and pain tolerance (total time the child kept the hand submerged in the cold water) were measured for each cold pressor trial. Results Both distraction conditions resulted in improved pain tolerance relative to baseline. Older children appeared to experience additional benefits from using the helmet, whereas younger children benefited equally from both conditions. The findings suggest that virtual reality technology can enhance the effects of distraction for some children. Research is needed to identify the characteristics of children for whom this technology is best suited. PMID:18367495

PC-based control unit for a head-mounted operating microscope for augmented-reality visualization in surgical navigation

NASA Astrophysics Data System (ADS)

Figl, Michael; Birkfellner, Wolfgang; Watzinger, Franz; Wanschitz, Felix; Hummel, Johann; Hanel, Rudolf A.; Ewers, Rolf; Bergmann, Helmar

2002-05-01

Two main concepts of Head Mounted Displays (HMD) for augmented reality (AR) visualization exist, the optical and video-see through type. Several research groups have pursued both approaches for utilizing HMDs for computer aided surgery. While the hardware requirements for a video see through HMD to achieve acceptable time delay and frame rate seem to be enormous the clinical acceptance of such a device is doubtful from a practical point of view. Starting from previous work in displaying additional computer-generated graphics in operating microscopes, we have adapted a miniature head mounted operating microscope for AR by integrating two very small computer displays. To calibrate the projection parameters of this so called Varioscope AR we have used Tsai's Algorithm for camera calibration. Connection to a surgical navigation system was performed by defining an open interface to the control unit of the Varioscope AR. The control unit consists of a standard PC with a dual head graphics adapter to render and display the desired augmentation of the scene. We connected this control unit to a computer aided surgery (CAS) system by the TCP/IP interface. In this paper we present the control unit for the HMD and its software design. We tested two different optical tracking systems, the Flashpoint (Image Guided Technologies, Boulder, CO), which provided about 10 frames per second, and the Polaris (Northern Digital, Ontario, Canada) which provided at least 30 frames per second, both with a time delay of one frame.

Head-mounted spatial instruments II: Synthetic reality or impossible dream

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Grunwald, Arthur

1989-01-01

A spatial instrument is defined as a spatial display which has been either geometrically or symbolically enhanced to enable a user to accomplish a particular task. Research conducted over the past several years on 3-D spatial instruments has shown that perspective displays, even when viewed from the correct viewpoint, are subject to systematic viewer biases. These biases interfere with correct spatial judgements of the presented pictorial information. The design of spatial instruments may not only require the introduction of compensatory distortions to remove the naturally occurring biases but also may significantly benefit from the introduction of artificial distortions which enhance performance. However, these image manipulations can cause a loss of visual-vestibular coordination and induce motion sickness. Consequently, the design of head-mounted spatial instruments will require an understanding of the tolerable limits of visual-vestibular discord.

Life test results of OLED-XL long-life devices for use in active matrix organic light emitting diode (AMOLED) displays for head mounted applications

NASA Astrophysics Data System (ADS)

Fellowes, David A.; Wood, Michael V.; Hastings, Arthur R., Jr.; Ghosh, Amalkumar P.; Prache, Olivier

2007-04-01

eMagin Corporation has recently developed long-life OLED-XL devices for use in their AMOLED microdisplays for head-worn applications. AMOLED displays have been known to exhibit high levels of performance with regards to contrast, response time, uniformity, and viewing angle, but a lifetime improvement has been perceived to be essential for broadening the applications of OLED's in the military and in the commercial market. The new OLED-XL devices gave the promise of improvements in usable lifetime over 6X what the standard full color, white, and green devices could provide. The US Army's RDECOM CERDEC NVESD performed life tests on several standard and OLED-XL panels from eMagin under a Cooperative Research and Development Agreement (CRADA). Displays were tested at room temperature, utilizing eMagin's Design Reference Kit driver, allowing computer controlled optimization, brightness adjustment, and manual temperature compensation. The OLED Usable Lifetime Model, developed under a previous NVESD/eMagin SPIE paper presented at DSS 2005, has been adjusted based on the findings of these tests. The result is a better understanding of the applicability of AMOLEDs in military and commercial head mounted systems: where good fits are made, and where further development might be needed.

Recognition of American Sign Language (ASL) Classifiers in a Planetarium Using a Head-Mounted Display

NASA Astrophysics Data System (ADS)

Hintz, Eric G.; Jones, Michael; Lawler, Jeannette; Bench, Nathan

2015-01-01

A traditional accommodation for the deaf or hard-of-hearing in a planetarium show is some type of captioning system or a signer on the floor. Both of these have significant drawbacks given the nature of a planetarium show. Young audience members who are deaf likely don't have the reading skills needed to make a captioning system effective. A signer on the floor requires light which can then splash onto the dome. We have examined the potential of using a Head-Mounted Display (HMD) to provide an American Sign Language (ASL) translation. Our preliminary test used a canned planetarium show with a pre-recorded sound track. Since many astronomical objects don't have official ASL signs, the signer had to use classifiers to describe the different objects. Since these are not official signs, these classifiers provided a way to test to see if students were picking up the information using the HMD.We will present results that demonstrate that the use of HMDs is at least as effective as projecting a signer on the dome. This also showed that the HMD could provide the necessary accommodation for students for whom captioning was ineffective. We will also discuss the current effort to provide a live signer without the light splash effect and our early results on teaching effectiveness with HMDs.This work is partially supported by funding from the National Science Foundation grant IIS-1124548 and the Sorenson Foundation.

Alternative display and interaction devices

NASA Technical Reports Server (NTRS)

Bolas, M. T.; McDowall, I. E.; Mead, R. X.; Lorimer, E. R.; Hackbush, J. E.; Greuel, C.

1995-01-01

While virtual environment systems are typically thought to consist of a head mounted display and a flex-sensing glove, alternative peripheral devices are beginning to be developed in response to application requirements. Three such alternatives are discussed: fingertip sensing gloves, fixed stereoscopic viewers, and counterbalanced head mounted displays. A subset of commercial examples that highlight each alternative is presented as well as a brief discussion of interesting engineering and implementation issues.

Review of head-worn displays for the Next Generation Air Transportation System

NASA Astrophysics Data System (ADS)

Arthur, Jarvis (Trey) J.; Bailey, Randall E.; Williams, Steven P.; Prinzel, Lawrence J.; Shelton, Kevin J.; Jones, Denise R.; Houston, Vincent E.

2017-05-01

NASA Langley Research Center (LaRC) has conducted research in the area of helmet-mounted display (HMD)/head-worn display (HWD) over the past 30 years. Initially, NASA LaRC's research focused on military applications, but recently NASA has conducted a line of research in the area of HWD for commercial and business aircraft. This work revolved around numerous simulation experiments as well as flight tests to develop technology and data for industry and regulatory guidance. This paper summarizes the results of NASA's HMD/HWD research. Of note, the work tracks progress in wearable collimated optics, head tracking, latency reduction, and weight. The research lends credence to a small, sunglasses-type form factor of the HWD being acceptable to commercial pilots, and this goal is now becoming technologically feasible. The research further suggests that an HWD may serve as an "equivalent" head-up display (HUD) with safety, operational, and cost benefits. "HUD equivalence" appears to be the economic avenue by which HWDs can become mainstream on the commercial and business aircraft flight deck. If this happens, NASA's research suggests that additional operational benefits using the unique capabilities of the HWD can open up new operational paradigms.

Towards Intelligent Environments: An Augmented Reality–Brain–Machine Interface Operated with a See-Through Head-Mount Display

PubMed Central

Takano, Kouji; Hata, Naoki; Kansaku, Kenji

2011-01-01

The brain–machine interface (BMI) or brain–computer interface is a new interface technology that uses neurophysiological signals from the brain to control external machines or computers. This technology is expected to support daily activities, especially for persons with disabilities. To expand the range of activities enabled by this type of interface, here, we added augmented reality (AR) to a P300-based BMI. In this new system, we used a see-through head-mount display (HMD) to create control panels with flicker visual stimuli to support the user in areas close to controllable devices. When the attached camera detects an AR marker, the position and orientation of the marker are calculated, and the control panel for the pre-assigned appliance is created by the AR system and superimposed on the HMD. The participants were required to control system-compatible devices, and they successfully operated them without significant training. Online performance with the HMD was not different from that using an LCD monitor. Posterior and lateral (right or left) channel selections contributed to operation of the AR–BMI with both the HMD and LCD monitor. Our results indicate that AR–BMI systems operated with a see-through HMD may be useful in building advanced intelligent environments. PMID:21541307

Timing considerations of Helmet Mounted Display performance

NASA Technical Reports Server (NTRS)

Tharp, Gregory; Liu, Andrew; French, Lloyd; Lai, Steve; Stark, Lawrence

1992-01-01

The Helmet Mounted Display (HMD) system developed in our lab should be a useful teleoperator systems display if it increases operator performance of the desired task; it can, however, introduce degradation in performance due to display update rate constraints and communication delays. Display update rates are slowed by communication bandwidth and/or computational power limitations. We used simulated 3D tracking and pick-and-place tasks to characterize performance levels for a range of update rates. Initial experiments with 3D tracking indicate that performance levels plateau at an update rate between 10 and 20 Hz. We have found that using the HMD with delay decreases performance as delay increases.

Effects of videogame distraction and a virtual reality type head-mounted display helmet on cold pressor pain in young elementary school-aged children.

PubMed

Dahlquist, Lynnda M; Weiss, Karen E; Law, Emily F; Sil, Soumitri; Herbert, Linda Jones; Horn, Susan Berrin; Wohlheiter, Karen; Ackerman, Claire Sonntag

2010-07-01

This study examined the effects of videogame distraction and a virtual reality (VR) type head-mounted display helmet for children undergoing cold pressor pain. Fifty children between the ages of 6 and 10 years underwent a baseline cold pressor trial followed by two cold pressor trials in which interactive videogame distraction was delivered via a VR helmet or without a VR helmet in counterbalanced order. As expected, children demonstrated significant improvements in pain threshold and pain tolerance during both distraction conditions. However, the two distraction conditions did not differ in effectiveness. Using the VR helmet did not result in improved pain tolerance over and above the effects of interactive videogame distraction without VR technology. Clinical implications and possible developmental differences in elementary school-aged children's ability to use VR technology are discussed.

Monitoring with head-mounted displays: performance and safety in a full-scale simulator and part-task trainer.

PubMed

Liu, David; Jenkins, Simon A; Sanderson, Penelope M; Watson, Marcus O; Leane, Terrence; Kruys, Amanda; Russell, W John

2009-10-01

Head-mounted displays (HMDs) can help anesthesiologists with intraoperative monitoring by keeping patients' vital signs within view at all times, even while the anesthesiologist is busy performing procedures or unable to see the monitor. The anesthesia literature suggests that there are advantages of HMD use, but research into head-up displays in the cockpit suggests that HMDs may exacerbate inattentional blindness (a tendency for users to miss unexpected but salient events in the field of view) and may introduce perceptual issues relating to focal depth. We investigated these issues in two simulator-based experiments. Experiment 1 investigated whether wearing a HMD would affect how quickly anesthesiologists detect events, and whether the focus setting of the HMD (near or far) makes any difference. Twelve anesthesiologists provided anesthesia in three naturalistic scenarios within a simulated operating theater environment. There were 24 different events that occurred either on the patient monitor or in the operating room. Experiment 2 investigated whether anesthesiologists physically constrained by performing a procedure would detect patient-related events faster with a HMD than without. Twelve anesthesiologists performed a complex simulated clinical task on a part-task endoscopic dexterity trainer while monitoring the simulated patient's vital signs. All participants experienced four different events within each of two scenarios. Experiment 1 showed that neither wearing the HMD nor adjusting the focus setting reduced participants' ability to detect events (the number of events detected and time to detect events). In general, participants spent more time looking toward the patient and less time toward the anesthesia machine when they wore the HMD than when they used standard monitoring alone. Participants reported that they preferred the near focus setting. Experiment 2 showed that participants detected two of four events faster with the HMD, but one event more

Helmet-Mounted Display Symbology and Stabilization Concepts

NASA Technical Reports Server (NTRS)

Newman, Richard L.

1995-01-01

The helmet-mounted display (HMD) presents flight, sensor, and weapon information in the pilot's line of sight. The HMD was developed to allow the pilot to retain aircraft and weapon information and to view sensor images while looking off boresight.

Remote vs. head-mounted eye-tracking: a comparison using radiologists reading mammograms

NASA Astrophysics Data System (ADS)

Mello-Thoms, Claudia; Gur, David

2007-03-01

Eye position monitoring has been used for decades in Radiology in order to determine how radiologists interpret medical images. Using these devices several discoveries about the perception/decision making process have been made, such as the importance of comparisons of perceived abnormalities with selected areas of the background, the likelihood that a true lesion will attract visual attention early in the reading process, and the finding that most misses attract prolonged visual dwell, often comparable to dwell in the location of reported lesions. However, eye position tracking is a cumbersome process, which often requires the observer to wear a helmet gear which contains the eye tracker per se and a magnetic head tracker, which allows for the computation of head position. Observers tend to complain of fatigue after wearing the gear for a prolonged time. Recently, with the advances made to remote eye-tracking, the use of head-mounted systems seemed destined to become a thing of the past. In this study we evaluated a remote eye tracking system, and compared it to a head-mounted system, as radiologists read a case set of one-view mammograms on a high-resolution display. We compared visual search parameters between the two systems, such as time to hit the location of the lesion for the first time, amount of dwell time in the location of the lesion, total time analyzing the image, etc. We also evaluated the observers' impressions of both systems, and what their perceptions were of the restrictions of each system.

CUSUM analysis of learning curves for the head-mounted microscope in phonomicrosurgery.

PubMed

Chen, Ting; Vamos, Andrew C; Dailey, Seth H; Jiang, Jack J

2016-10-01

To observe the learning curve of the head-mounted microscope in a phonomicrosurgery simulator using cumulative summation (CUSUM) analysis, which incorporates a magnetic phonomicrosurgery instrument tracking system (MPTS). Retrospective case series. Eight subjects (6 medical students and 2 surgeons inexperienced in phonomicrosurgery) operated on phonomicrosurgical simulation cutting tasks while using the head-mounted microscope for 400 minutes total. Two 20-minute sessions occurred each day for 10 total days, with operation quality (Qs ) and completion time (T) being recorded after each session. Cumulative summation analysis of Qs and T was performed by using subjects' performance data from trials completed using a traditional standing microscope as success criteria. The motion parameters from the head-mounted microscope were significantly better than the standing microscope (P < 0.01), but T was longer than that from the standing microscope (P < 0.01). No subject successfully adapted to the head-mounted microscope, as assessed by CUSUM analysis. Cumulative summation analysis can objectively monitor the learning process associated with a phonomicrosurgical simulator system, ultimately providing a tool to assess learning status. Also, motion parameters determined by our MPTS showed that, although the head-mounted microscope provides better motion control, worse Qs and longer T resulted. This decrease in Qs is likely a result of the relatively unstable visual environment that it provides. Overall, the inexperienced surgeons participating in this study failed to adapt to the head-mounted microscope in our simulated phonomicrosurgery environment. 4 Laryngoscope, 126:2295-2300, 2016. © 2015 The American Laryngological, Rhinological and Otological Society, Inc.

Head-mounted active noise control system with virtual sensing technique

NASA Astrophysics Data System (ADS)

Miyazaki, Nobuhiro; Kajikawa, Yoshinobu

2015-03-01

In this paper, we apply a virtual sensing technique to a head-mounted active noise control (ANC) system we have already proposed. The proposed ANC system can reduce narrowband noise while improving the noise reduction ability at the desired locations. A head-mounted ANC system based on an adaptive feedback structure can reduce noise with periodicity or narrowband components. However, since quiet zones are formed only at the locations of error microphones, an adequate noise reduction cannot be achieved at the locations where error microphones cannot be placed such as near the eardrums. A solution to this problem is to apply a virtual sensing technique. A virtual sensing ANC system can achieve higher noise reduction at the desired locations by measuring the system models from physical sensors to virtual sensors, which will be used in the online operation of the virtual sensing ANC algorithm. Hence, we attempt to achieve the maximum noise reduction near the eardrums by applying the virtual sensing technique to the head-mounted ANC system. However, it is impossible to place the microphone near the eardrums. Therefore, the system models from physical sensors to virtual sensors are estimated using the Head And Torso Simulator (HATS) instead of human ears. Some simulation, experimental, and subjective assessment results demonstrate that the head-mounted ANC system with virtual sensing is superior to that without virtual sensing in terms of the noise reduction ability at the desired locations.

In-flight evaluation of a fiber optic helmet-mounted display

NASA Astrophysics Data System (ADS)

Jennings, Sion A.; Gubbels, Arthur W.; Swail, Carl P.; Craig, Greg

1998-08-01

The National Research Council of Canada (NRC), in conjunction with the Canadian Department of National Defence (DND), is investigating the use of helmet-mounted displays (HMD) to improve pilot situational awareness in all-weather search and rescue helicopter operations. The National Research Council has installed a visually coupled HMD system in the NRC Bell 205 Airborne Simulator. Equipped with a full authority fly-by-wire control system, the Bell 205 has variable stability characteristics, which makes the airborne simulator the ideal platform for the integrated flight testing of HMDs in a simulated operational environment. This paper presents preliminary results from flight test of the NRC HMD. These results are in the form of numerical head tracker data, and subjective handling qualities ratings. Flight test results showed that the HMD degraded handling qualities due to reduced acuity, limited field-of-view, time delays in the sensor platform, and fatigue caused by excessive helmet inertia. Some evidence was found to support the hypothesis of an opto-kinetic cervical reflex whereby a pilot pitches and rolls his head in response to aircraft movements to maintain a level horizon in their field-of- view.

Performance effects of mounting a helmet-mounted display on the ANVIS mount of the HGU-56P helmet

NASA Astrophysics Data System (ADS)

Harding, Thomas H.; Martin, John S.; Rash, Clarence E.

2006-05-01

The U.S. Army, under the auspices of the Air Warrior Product Office, is developing a modular helmet-mounted display (HMD) for four aircraft series within its helicopter fleet. A design consideration is mounting the HMDs to the HGU- 56P Aviator's Night Vision Imaging System (ANVIS) mount. This particular mount is being considered, presumably due to its inherent cost savings, as the mount is already part of the helmet. Mounting the HMD in this position may have consequences for the daylight performance of these HMDs, as well as increasing the forward weight of the HMD. The latter would have consequences for helmet weight and center-of-mass biodynamic issues. Calculations were made of the increased luminance needed as a consequence of mounting the HMD in front of an HGU-56P tinted visor as opposed to mounting it behind the visor. By mounting in front of the helmet's visor, the HMD's light output will be filtered as light coming from the outside world. Special consideration then would have to be given to the HMD's light source selection process, as not to select a source that would differentially reduce luminance by a mounted visor (e.g., laser protection visors) compared to the ambient light in the aviator's field-of-view.

Effects of Videogame Distraction and a Virtual Reality Type Head-Mounted Display Helmet on Cold Pressor Pain in Young Elementary School-Aged Children

PubMed Central

Weiss, Karen E.; Law, Emily F.; Sil, Soumitri; Herbert, Linda Jones; Horn, Susan Berrin; Wohlheiter, Karen; Ackerman, Claire Sonntag

2010-01-01

Objective This study examined the effects of videogame distraction and a virtual reality (VR) type head-mounted display helmet for children undergoing cold pressor pain. Methods Fifty children between the ages of 6 and 10 years underwent a baseline cold pressor trial followed by two cold pressor trials in which interactive videogame distraction was delivered via a VR helmet or without a VR helmet in counterbalanced order. Results As expected, children demonstrated significant improvements in pain threshold and pain tolerance during both distraction conditions. However, the two distraction conditions did not differ in effectiveness. Conclusions Using the VR helmet did not result in improved pain tolerance over and above the effects of interactive videogame distraction without VR technology. Clinical implications and possible developmental differences in elementary school-aged children's ability to use VR technology are discussed. PMID:19786489

Cybersickness provoked by head-mounted display affects cutaneous vascular tone, heart rate and reaction time.

PubMed

Nalivaiko, Eugene; Davis, Simon L; Blackmore, Karen L; Vakulin, Andrew; Nesbitt, Keith V

2015-11-01

Evidence from studies of provocative motion indicates that motion sickness is tightly linked to the disturbances of thermoregulation. The major aim of the current study was to determine whether provocative visual stimuli (immersion into the virtual reality simulating rides on a rollercoaster) affect skin temperature that reflects thermoregulatory cutaneous responses, and to test whether such stimuli alter cognitive functions. In 26 healthy young volunteers wearing head-mounted display (Oculus Rift), simulated rides consistently provoked vection and nausea, with a significant difference between the two versions of simulation software (Parrot Coaster and Helix). Basal finger temperature had bimodal distribution, with low-temperature group (n=8) having values of 23-29 °C, and high-temperature group (n=18) having values of 32-36 °C. Effects of cybersickness on finger temperature depended on the basal level of this variable: in subjects from former group it raised by 3-4 °C, while in most subjects from the latter group it either did not change or transiently reduced by 1.5-2 °C. There was no correlation between the magnitude of changes in the finger temperature and nausea score at the end of simulated ride. Provocative visual stimulation caused prolongation of simple reaction time by 20-50 ms; this increase closely correlated with the subjective rating of nausea. Lastly, in subjects who experienced pronounced nausea, heart rate was elevated. We conclude that cybersickness is associated with changes in cutaneous thermoregulatory vascular tone; this further supports the idea of a tight link between motion sickness and thermoregulation. Cybersickness-induced prolongation of reaction time raises obvious concerns regarding the safety of this technology. Copyright © 2015 Elsevier Inc. All rights reserved.

Instrument-mounted displays for reducing cognitive load during surgical navigation.

PubMed

Herrlich, Marc; Tavakol, Parnian; Black, David; Wenig, Dirk; Rieder, Christian; Malaka, Rainer; Kikinis, Ron

2017-09-01

Surgical navigation systems rely on a monitor placed in the operating room to relay information. Optimal monitor placement can be challenging in crowded rooms, and it is often not possible to place the monitor directly beside the situs. The operator must split attention between the navigation system and the situs. We present an approach for needle-based interventions to provide navigational feedback directly on the instrument and close to the situs by mounting a small display onto the needle. By mounting a small and lightweight smartwatch display directly onto the instrument, we are able to provide navigational guidance close to the situs and directly in the operator's field of view, thereby reducing the need to switch the focus of view between the situs and the navigation system. We devise a specific variant of the established crosshair metaphor suitable for the very limited screen space. We conduct an empirical user study comparing our approach to using a monitor and a combination of both. Results from the empirical user study show significant benefits for cognitive load, user preference, and general usability for the instrument-mounted display, while achieving the same level of performance in terms of time and accuracy compared to using a monitor. We successfully demonstrate the feasibility of our approach and potential benefits. With ongoing technological advancements, instrument-mounted displays might complement standard monitor setups for surgical navigation in order to lower cognitive demands and for improved usability of such systems.

Emergence of solid state helmet-mounted displays in military applications

NASA Astrophysics Data System (ADS)

Casey, Curtis J.

2002-08-01

Helmet Mounted Displays (HMDs) are used to provide pilots with out-the-window capabilities for engaging tactical threats. The first modern system to be employed was the Apache Integrated Helmet Display Sighting System (IHADSS). Using an optical tracker and multiple sensors, the pilot is able to navigate and engage the enemy with his weapons systems cued by the HMD in day and night conditions. Over the next several years HMDs were tested on tactical jet aircraft. The tactical fighter environment - high G maneuvering and the possibility of ejection - created several problems regarding integration and head-borne weight. However, these problems were soon solved by American, British, Israeli, and Russian companies and are employed or in the process of employment aboard the respective countries' tactical aircraft. It is noteworthy that the current configuration employs both the Heads-Up Display (HUD) as well as the HMD. The new Joint Strike Fighter (JSF), however, will become the first tactical jet to employ only a HMD. HMDs have increasingly become part of the avionics and weapons systems of new aircraft and helicopter platforms. Their use however, is migrating to other military applications. They are currently under evaluation on Combat Vehicle platforms for driving tasks to target acquisition and designation tasks under near-all weather, 24-hour conditions. Their use also has penetrated the individual application such as providing data and situational awareness to the individual soldier; the U.S. Army's Land Warrior Program is an example of this technology being applied. Current HMD systems are CRT-based and have many short-comings, including weight, reliability. The emergence of new microelectronics and solid state image sources - Flat Panel Displays (FPDs) - however, has expanded the application of vision devices across all facets of military applications. Some of the greatest contributions are derived from the following Enabling Technologies, and it is upon those

Transparent 3D display for augmented reality

NASA Astrophysics Data System (ADS)

Lee, Byoungho; Hong, Jisoo

2012-11-01

Two types of transparent three-dimensional display systems applicable for the augmented reality are demonstrated. One of them is a head-mounted-display-type implementation which utilizes the principle of the system adopting the concave floating lens to the virtual mode integral imaging. Such configuration has an advantage in that the threedimensional image can be displayed at sufficiently far distance resolving the accommodation conflict with the real world scene. Incorporating the convex half mirror, which shows a partial transparency, instead of the concave floating lens, makes it possible to implement the transparent three-dimensional display system. The other type is the projection-type implementation, which is more appropriate for the general use than the head-mounted-display-type implementation. Its imaging principle is based on the well-known reflection-type integral imaging. We realize the feature of transparent display by imposing the partial transparency to the array of concave mirror which is used for the screen of reflection-type integral imaging. Two types of configurations, relying on incoherent and coherent light sources, are both possible. For the incoherent configuration, we introduce the concave half mirror array, whereas the coherent one adopts the holographic optical element which replicates the functionality of the lenslet array. Though the projection-type implementation is beneficial than the head-mounted-display in principle, the present status of the technical advance of the spatial light modulator still does not provide the satisfactory visual quality of the displayed three-dimensional image. Hence we expect that the head-mounted-display-type and projection-type implementations will come up in the market in sequence.

Comparison of helmet-mounted display designs in support of wayfinding

NASA Astrophysics Data System (ADS)

Kumagai, Jason K.; Massel, Lisa; Tack, David; Bossi, Linda

2003-09-01

The Canadian Soldier Information Requirements Technology Demonstration (SIREQ TD) soldier modernization research and development program has conducted experiments to help determine the types and amount of information needed to support wayfinding across a range of terrain environments, the most effective display modality for providing the information (visual, auditory or tactile) that will minimize conflict with other infantry tasks, and to optimize interface design. In this study, seven different visual helmet-mounted display (HMD) designs were developed based on soldier feedback from previous studies. The displays and an in-service compass condition were contrasted to investigate how the visual HMD interfaces influenced navigation performance. Displays varied with respect to their information content, frame of reference, point of view, and display features. Twelve male infantry soldiers used all eight experimental conditions to locate bearings to waypoints. From a constant location, participants were required to face waypoints presented at offset bearings of 25, 65, and 120 degrees. Performance measures included time to identify waypoints, accuracy, and head misdirection errors. Subjective measures of performance included ratings of ease of use, acceptance for land navigation, and mental demand. Comments were collected to identify likes, dislikes and possible improvements required for HMDs. Results underlined the potential performance enhancement of GPS-based navigation with HMDs, the requirement for explicit directional information, the desirability of both analog and digital information, the performance benefits of an egocentric frame of reference, the merit of a forward field of view, and the desirability of a guide to help landmark. Implications for the information requirements and human factors design of HMDs for land-based navigational tasks are discussed.

Helmet-Mounted Display Of Clouds Of Harmful Gases

NASA Technical Reports Server (NTRS)

Diner, Daniel B.; Barengoltz, Jack B.; Schober, Wayne R.

1995-01-01

Proposed helmet-mounted opto-electronic instrument provides real-time stereoscopic views of clouds of otherwise invisible toxic, explosive, and/or corrosive gas. Display semitransparent: images of clouds superimposed on scene ordinarily visible to wearer. Images give indications on sizes and concentrations of gas clouds and their locations in relation to other objects in scene. Instruments serve as safety devices for astronauts, emergency response crews, fire fighters, people cleaning up chemical spills, or anyone working near invisible hazardous gases. Similar instruments used as sensors in automated emergency response systems that activate safety equipment and emergency procedures. Both helmet-mounted and automated-sensor versions used at industrial sites, chemical plants, or anywhere dangerous and invisible or difficult-to-see gases present. In addition to helmet-mounted and automated-sensor versions, there could be hand-held version. In some industrial applications, desirable to mount instruments and use them similarly to parking-lot surveillance cameras.

Augmented reality 3D display using head-mounted projectors and transparent retro-reflective screen

NASA Astrophysics Data System (ADS)

Soomro, Shoaib R.; Urey, Hakan

2017-02-01

A 3D augmented reality display is proposed that can provide glass-free stereo parallax using a highly transparent projection screen. The proposed display is based on a transparent retro-reflective screen and a pair of laser pico projectors placed close to the viewer's head. The retro-reflective screen directs incident light towards its source with little scattering so that each of the viewer's eyes only perceives the content projected by the associated projector. Each projector displays one of the two components (left or right channel) of stereo content. The retro-reflective nature of screen provides high brightness compared to the regular diffused screens. The partially patterned retro-reflective material on clear substrate introduces optical transparency and facilitates the viewer to see the real-world scene on the other side of screen. The working principle and design of the proposed see-through 3D display are presented. A tabletop prototype consisting of an in-house fabricated 60×40cm2 see-through retro-reflective screen and a pair of 30 lumen pico-projectors with custom 3D printed housings is demonstrated. Geometric calibration between projectors and optimal viewing conditions (eye box size, eye-to-projector distance) are discussed. The display performance is evaluated by measuring the brightness and crosstalk for each eye. The screen provides high brightness (up to 300 cd/m2 per eye) using 30 lumens mobile projectors while maintaining the 75% screen transparency. The crosstalk between left and right views is measured as <10% at the optimum distance of 125-175 cm, which is within acceptable range.

Albertian errors in head-mounted displays: I. Choice of eye-point location for a near- or far-field task visualization.

PubMed

Rolland, Jannick; Ha, Yonggang; Fidopiastis, Cali

2004-06-01

A theoretical investigation of rendered depth and angular errors, or Albertian errors, linked to natural eye movements in binocular head-mounted displays (HMDs) is presented for three possible eye-point locations: the center of the entrance pupil, the nodal point, and the center of rotation of the eye. A numerical quantification was conducted for both the pupil and the center of rotation of the eye under the assumption that the user will operate solely in either the near field under an associated instrumentation setting or the far field under a different setting. Under these conditions, the eyes are taken to gaze in the plane of the stereoscopic images. Across conditions, results show that the center of the entrance pupil minimizes rendered angular errors, while the center of rotation minimizes rendered position errors. Significantly, this investigation quantifies that under proper setting of the HMD and correct choice of the eye points, rendered depth and angular errors can be brought to be either negligible or within specification of even the most stringent applications in performance of tasks in either the near field or the far field.

An analysis of control reversal errors during unusual attitude recoveries using helmet-mounted display symbology.

PubMed

Liggett, Kristen K; Gallimore, Jennie J

2002-02-01

Spatial disorientation (SD) refers to pilots' inability to accurately interpret the attitude of their aircraft with respect to Earth. Unfortunately, SD statistics have held constant for the past few decades, through the transition from the head-down attitude indicator (Al) to the head-up display (HUD) as the attitude instrument. The newest attitude-indicating device to find its way into military cockpits is the helmet-mounted display (HMD). HMDs were initially introduced into the cockpit to enhance target location and weapon-pointing, but there is currently an effort to make HMDs attitude reference displays so pilots need not go head-down to obtain attitude information. However, unintuitive information or inappropriate implementation of on-boresight attitude symbology on the HMD may contribute to the SD problem. The occurrence of control reversal errors (CREs) during unusual attitude recovery tasks when using an HMD to provide attitude information was investigated. The effect of such errors was evaluated in terms of altitude changes during recovery and time to recover. There were 12 pilot-subjects who completed 8 unusual attitude recovery tasks. Results showed that CREs did occur, and there was a significant negative effect of these errors on absolute altitude change, but not on total recovery time. Results failed to show a decrease in the number of CREs occurring when using the HMD as compared with data from other studies that used an Al or a HUD. Results suggest that new HMD attitude symbology needs to be designed to help reduce CREs and, perhaps, SD incidences.

Headphone and Head-Mounted Visual Displays for Virtual Environments

NASA Technical Reports Server (NTRS)

Begault, Duran R.; Ellis, Stephen R.; Wenzel, Elizabeth M.; Trejo, Leonard J. (Technical Monitor)

1998-01-01

A realistic auditory environment can contribute to both the overall subjective sense of presence in a virtual display, and to a quantitative metric predicting human performance. Here, the role of audio in a virtual display and the importance of auditory-visual interaction are examined. Conjectures are proposed regarding the effectiveness of audio compared to visual information for creating a sensation of immersion, the frame of reference within a virtual display, and the compensation of visual fidelity by supplying auditory information. Future areas of research are outlined for improving simulations of virtual visual and acoustic spaces. This paper will describe some of the intersensory phenomena that arise during operator interaction within combined visual and auditory virtual environments. Conjectures regarding audio-visual interaction will be proposed.

Cognitive considerations for helmet-mounted display design

NASA Astrophysics Data System (ADS)

Francis, Gregory; Rash, Clarence E.

2010-04-01

Helmet-mounted displays (HMDs) are designed as a tool to increase performance. To achieve this, there must be an accurate transfer of information from the HMD to the user. Ideally, an HMD would be designed to accommodate the abilities and limitations of users' cognitive processes. It is not enough for the information (whether visual, auditory, or tactual) to be displayed; the information must be perceived, attended, remembered, and organized in a way that guides appropriate decision-making, judgment, and action. Following a general overview, specific subtopics of cognition, including perception, attention, memory, knowledge, decision-making, and problem solving are explored within the context of HMDs.

Head-up and head-down displays integration in automobiles

NASA Astrophysics Data System (ADS)

Betancur, J. Alejandro; Osorio-Gómez, Gilberto; Agudelo, J. David

2014-06-01

In automotive industry, the dashboard has been ergonomically developed in order to keep the driver focused on the horizon while driving, but the possibility to access external electronic devices constraints the driver to turn away his face, generating dangerous situations in spite of the short periods of time. Therefore, this work explores the integration of Head-Up Displays and Head-Down Displays in automobiles, proposing configurations that give to drivers the facility to driving focused. In this way, some of the main ergonomic comments about those configurations are proposed; and also, some technical comments regarding the implemented arrangements are given.

Flight performance using a hyperstereo helmet-mounted display: aircraft handling

NASA Astrophysics Data System (ADS)

Jennings, Sion A.; Craig, Gregory L.; Stuart, Geoffrey W.; Kalich, Melvyn E.; Rash, Clarence E.; Harding, Thomas H.

2009-05-01

A flight study was conducted to assess the impact of hyperstereopsis on helicopter handling proficiency, workload and pilot acceptance. Three pilots with varying levels of night vision goggle and hyperstereo helmet-mounted display experience participated in the test. The pilots carried out a series of flights consisting of low-level maneuvers over a period of two weeks. Four of the test maneuvers, The turn around the tail, the hard surface landing, the hover height estimation and the tree-line following were analysed in detail. At the end of the testing period, no significant difference was observed in the performance data, between maneuvers performed with the TopOwl helmet and maneuvers performed with the standard night vision goggle. This study addressed only the image intensification display aspects of the TopOwl helmet system. The tests did not assess the added benefits of overlaid symbology or head slaved infrared camera imagery. These capabilities need to be taken into account when assessing the overall usefulness of the TopOwl system. Even so, this test showed that pilots can utilize the image intensification imagery displayed on the TopOwl to perform benign night flying tasks to an equivalent level as pilots using ANVIS. The study should be extended to investigate more dynamic and aggressive low level flying, slope landings and ship deck landings. While there may be concerns regarding the effect of hyperstereopsis on piloting, this initial study suggests that pilots can either adapt or compensate for hyperstereo effects with sufficient exposure and training. Further analysis and testing is required to determine the extent of training required.

Helmet-mounted display systems for flight simulation

NASA Technical Reports Server (NTRS)

Haworth, Loren A.; Bucher, Nancy M.

1989-01-01

Simulation scientists are continually improving simulation technology with the goal of more closely replicating the physical environment of the real world. The presentation or display of visual information is one area in which recent technical improvements have been made that are fundamental to conducting simulated operations close to the terrain. Detailed and appropriate visual information is especially critical for nap-of-the-earth helicopter flight simulation where the pilot maintains an 'eyes-out' orientation to avoid obstructions and terrain. This paper describes visually coupled wide field of view helmet-mounted display (WFOVHMD) system technology as a viable visual presentation system for helicopter simulation. Tradeoffs associated with this mode of presentation as well as research and training applications are discussed.

Cybersickness Onset With Reflexive Head Movements During Land and Shipboard Head-Mounted Display Flight Simulation

DTIC Science & Technology

2010-09-09

provoked a predictable OKCR coronal head tilt (p < 0.001) whenever aircraft angle of bank (AOB) increased (Fig. 2). With 90º of simulated AOB, land... head pitch were –3.3 ± 3.8 to 6.8 ± 5.9 on land, and –4.0º ± 5.6 to 7.6º ± 9.7 at sea (Fig. 3). 7 Combined Coronal OKCR ( Head Tilt ) Data for...Land OKCR Figure 2: Coronal OKCR ( head tilt ) vs. angle of bank, during both land based and shipboard HMD/VR flight simulation. Combined

Digital Image Processing Overview For Helmet Mounted Displays

NASA Astrophysics Data System (ADS)

Parise, Michael J.

1989-09-01

Digital image processing provides a means to manipulate an image and presents a user with a variety of display formats that are not available in the analog image processing environment. When performed in real time and presented on a Helmet Mounted Display, system capability and flexibility are greatly enhanced. The information content of a display can be increased by the addition of real time insets and static windows from secondary sensor sources, near real time 3-D imaging from a single sensor can be achieved, graphical information can be added, and enhancement techniques can be employed. Such increased functionality is generating a considerable amount of interest in the military and commercial markets. This paper discusses some of these image processing techniques and their applications.

Image guided percutaneous spine procedures using an optical see-through head mounted display: proof of concept and rationale.

PubMed

Deib, Gerard; Johnson, Alex; Unberath, Mathias; Yu, Kevin; Andress, Sebastian; Qian, Long; Osgood, Gregory; Navab, Nassir; Hui, Ferdinand; Gailloud, Philippe

2018-05-30

Optical see-through head mounted displays (OST-HMDs) offer a mixed reality (MixR) experience with unhindered procedural site visualization during procedures using high resolution radiographic imaging. This technical note describes our preliminary experience with percutaneous spine procedures utilizing OST-HMD as an alternative to traditional angiography suite monitors. MixR visualization was achieved using the Microsoft HoloLens system. Various spine procedures (vertebroplasty, kyphoplasty, and percutaneous discectomy) were performed on a lumbar spine phantom with commercially available devices. The HMD created a real time MixR environment by superimposing virtual posteroanterior and lateral views onto the interventionalist's field of view. The procedures were filmed from the operator's perspective. Videos were reviewed to assess whether key anatomic landmarks and materials were reliably visualized. Dosimetry and procedural times were recorded. The operator completed a questionnaire following each procedure, detailing benefits, limitations, and visualization mode preferences. Percutaneous vertebroplasty, kyphoplasty, and discectomy procedures were successfully performed using OST-HMD image guidance on a lumbar spine phantom. Dosimetry and procedural time compared favorably with typical procedural times. Conventional and MixR visualization modes were equally effective in providing image guidance, with key anatomic landmarks and materials reliably visualized. This preliminary study demonstrates the feasibility of utilizing OST-HMDs for image guidance in interventional spine procedures. This novel visualization approach may serve as a valuable adjunct tool during minimally invasive percutaneous spine treatment. © Article author(s) (or their employer(s) unless otherwise stated in the text of the article) 2018. All rights reserved. No commercial use is permitted unless otherwise expressly granted.

Head-Worn Displays for NextGen

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Shelton, Kevin J.; Arthur, J. J.

2011-01-01

The operating concepts emerging under the Next Generation air transportation system (NextGen) require new technology and procedures - not only on the ground-side - but also on the flight deck. Flight deck display and decision support technologies are specifically targeted to overcome aircraft safety barriers that might otherwise constrain the full realization of NextGen. One such technology is the very lightweight, unobtrusive head-worn display (HWD). HWDs with an integrated head-tracking system are being researched as they offer significant potential benefit under emerging NextGen operational concepts. Two areas of benefit for NextGen are defined. First, the HWD may be designed to be equivalent to the Head-Up Display (HUD) using Virtual HUD concepts. As such, these operational credits may be provided to significantly more aircraft for which HUD installation is neither practical nor possible. Second, the HWD provides unique display capabilities, such as an unlimited field-of-regard. These capabilities may be integral to emerging NextGen operational concepts, eliminating safety issues which might otherwise constrain the full realization of NextGen. The paper details recent research results, current HWD technology limitations, and future technology development needed to realize HWDs as a enabling technology for NextGen.

65. SAC Minuteman Missile "shell", mounted for permanent display in ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

65. SAC Minuteman Missile "shell", mounted for permanent display in front lawn, building 500, looking east - Offutt Air Force Base, Strategic Air Command Headquarters & Command Center, Headquarters Building, 901 SAC Boulevard, Bellevue, Sarpy County, NE

Ultrabright Head Mounted Displays Using LED-Illuminated LCOS

DTIC Science & Technology

2006-01-01

light-piping systems using surface features," in Nonimaging Optics and Efficient Illumination Systems II; Roland Winston , R. John Koshel, eds...Jay Morreale, ed. pp. 1078-1080 (Society for Information Display, San Jose, CA, 2002). 4 Roland Winston , Juan C. Mifiano, and Pablo Benitez, Nonimaging ...ferroelectric liquid-crystal-on-silicon microdisplay and a red-green-blue LED. With an 8x viewing optic giving a 35 degree diagonal field of view, the

Flight performance using a hyperstereo helmet-mounted display: post-flight debriefing questionnaire

NASA Astrophysics Data System (ADS)

Kalich, Melvyn E.; Rash, Clarence E.; Harding, Thomas H.; Jennings, Sion; Craig, Gregory; Stuart, Geoffrey W.

2009-05-01

Helmet-mounted display (HMD) designs have faced persistent head-supported mass and center of mass (CM) problems, especially HMD designs like night vision goggles (NVG) that utilize image intensification (I2) sensors mounted forward in front of the user's eyes. Relocating I2 sensors from the front to the sides of the helmet, at or below the transverse plane through the user's head CM, can resolve most of the CM problems. However, the resulting increase in the separation between the two I2 channels effectively increases the user's interpupillary distance (IPD). This HMD design is referred to as a hyperstero design and introduces the phenomenon of hyperstereopsis, a type of visual distortion where stereoscopic depth perception is exaggerated, particularly at distances under 200 feet (~60 meters). The presence of hyperstereopsis has been a concern regarding implementation of hyperstereo HMDs for rotary-wing aircraft. To address this concern, a flight study was conducted to assess the impact of hyperstereopsis on aircraft handling proficiency and pilot acceptance. Three rated aviators with differing levels of I2 and hyperstereo HMD experience conducted a series of flights that concentrated on low-level maneuvers over a two-week period. Initial and final flights were flown with a standard issue I2 device and a production hyperstereo design HMD. Interim flights were flown only with the hyperstereo HMD. Two aviators accumulated 8 hours of flight time with the hyperstereo HMD, while the third accumulated 6.9 hours. This paper presents data collected via written questionnaires completed by the aviators during the post-flight debriefings. These data are compared to questionnaire data from a previous flight investigation in which aviators in a copilot capacity, hands not on the flight controls, accumulated 8 flight hours of flight time using a hyperstereo HMD.

Evaluation of Helmet Mounted Display Alerting Symbology

NASA Technical Reports Server (NTRS)

DeMaio, Joe; Rutkowski, Michael (Technical Monitor)

2000-01-01

Proposed helicopter helmet mounted displays will be used to alert the pilot to a variety of conditions, from threats to equipment problems. The present research was performed under the NASA Safe All-weather Flight Operations Research (SAFOR) program supported by a joint Army/NASA research agreement. The purpose of the research was to examine ways to optimize the alerting effectiveness of helmet display symbology. The research used two approaches to increasing the effectiveness of alerts. One was to increase the ability of the alert to attract attention by using the entire display surface. The other was to include information about the required response in the alert itself. The investigation was conducted using the NASA Ames Research Center's six-degree-of-freedom vertical motion simulator (VMS) with a rotorcraft cockpit. Helmet display symbology was based on the AH-64's pilot night vision system (PNVS), cruise mode symbology. A standardized mission was developed, that consisted of 11 legs. The mission included four tasks, which allowed variation in the frequency of alerts. The general trend in the data points to a small benefit from both the full-screen alert and the partial information alert.

Heading control and the effects of display characteristics

NASA Technical Reports Server (NTRS)

Hinz, Stephanie J.; Bennett, C. Thomas

1989-01-01

The present study evaluates whether type of display (dot or wire frame) and direction of movement have an effect on a person's ability to actively maintain a specific heading angle. The questions addressed were: (1) does the magnitude of the heading angle errors differ in the two displays, (2) are some heading angles more difficult to maintain than others, and (3) does the magnitude of some errors differ as a function of display type and direction of movement. Differences between the results of this study and previous research are explained by methodological differences across the studies. Another factor that may be responsible for the difference between previous findings and those presented here is the type of graphics used to display the simulated motion. The physical characteristics of the display or the graphics engines that generate the scene have varied greatly across the studies. Analyses and diagrams are presented showing results of the study and the differences generated from previous studies on this subject.

Simulation Test of a Head-Worn Display with Ambient Vision Display for Unusual Attitude Recovery

NASA Technical Reports Server (NTRS)

Arthur, Jarvis (Trey) J., III; Nicholas, Stephanie N.; Shelton, Kevin J.; Ballard, Kathryn; Prinzel, Lawrence J., III; Ellis, Kyle E.; Bailey, Randall E.; Williams, Steven P.

2017-01-01

Head-Worn Displays (HWDs) are envisioned as a possible equivalent to a Head-Up Display (HUD) in commercial and general aviation. A simulation experiment was conducted to evaluate whether the HWD can provide an equivalent or better level of performance to a HUD in terms of unusual attitude recognition and recovery. A prototype HWD was tested with ambient vision capability which were varied (on/off) as an independent variable in the experiment testing for attitude awareness. The simulation experiment was conducted in two parts: 1) short unusual attitude recovery scenarios where the aircraft is placed in an unusual attitude and a single-pilot crew recovered the aircraft; and, 2) a two-pilot crew operating in a realistic flight environment with "off-nominal" events to induce unusual attitudes. The data showed few differences in unusual attitude recognition and recovery performance between the tested head-down, head-up, and head-worn display concepts. The presence and absence of ambient vision stimulation was inconclusive. The ergonomic influences of the head-worn display, necessary to implement the ambient vision experimentation, may have influenced the pilot ratings and acceptance of the concepts.

Conference proceedings of Helmet Mounted Displays and Night Vision Goggles (Visuels Montes sur le Casque et Equipments de Vision Nocturne). Held in Pensacola, Florida, on May 2, 1991

DTIC Science & Technology

1991-12-01

integration. Threc papers considered the ergonomics of helmet design and the snugness of fit to the head and the integration of new helmet mounted devices...with existing equipment. Two papers considered the effects of novel helmet designs on the pilot’s ability to control head position and avoid fatigue. Two...the nature of information displayed, including data fused froml multiple sources and design of abstract symbologics that presernt paramcecis of fight

AMLCD head-down displays for avionic applications

NASA Astrophysics Data System (ADS)

Davis, Alan J.

1997-02-01

Smiths Industries has been involved in the design, manufacture and supply of products used for the presentation of information, in one form or another, from its early pioneering years through to the present day. In the mid 1980s Smiths Industries began to invest in the then emerging active matrix liquid crystal display (AMLCD) technology which the company believed would eventually take over from the cathode ray tube. To date Smiths Industries has made a significant investment in acquiring the enabling technology needed to produce active matrix liquid crystal color head- down displays for fast jet, helicopter and civil aircraft applications. The significant improvement in AMLCD product quality and manufacturing capability over recent years has enabled market penetration of AMLCD technology products to be achieved in military and civil avionic markets. Virtually all new contracts for head-down displays are now demanding the use of AMLCD technology rather than the cathode ray tube. A significant decision to move to AMLCD technology was made by McDonnell Douglas Helicopters in 1995, when a contract to supply over 4000 head-down display products for the Apache Helicopter was let. This has paved the way for the future of AMLCD technology.

Head Up Displays. (Latest Citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1997-01-01

The bibliography contains citations concerning the design, fabrication, and applications of head up displays (HUDs). Applications include military aircraft, helicopters, space shuttle, and commercial aircraft. Functions of the display include instrument approach, target tracking, and navigation. The head up display provides for an integrated avionics system with the pilot in the loop. (Contains 50-250 citations and includes a subject term index and title list.)

Head Up Displays. (Latest citations from the Aerospace Database)

NASA Technical Reports Server (NTRS)

1996-01-01

The bibliography contains citations concerning the design, fabrication, and applications of head up displays (HUDs). Applications include military aircraft, helicopters, space shuttle, and commercial aircraft. Functions of the display include instrument approach, target tracking, and navigation. The head up display provides for an integrated avionics system with the pilot in the loop. (Contains 50-250 citations and includes a subject term index and title list.)

Head-up transition behavior of pilots with and without head-up display in simulated low-visibility approaches

NASA Technical Reports Server (NTRS)

Haines, R. F.; Fischer, E.; Price, T. A.

1980-01-01

To quantify head-up transition behavior with and without a flightpath type head-up display, eight rated B-727 pilots each flew 31 manual and coupled approaches in a simulator with B-727 dynamics and collimated model board external scene. Data were also obtained on the roll played by the head-up display in the coupled-to-manual transition. Various wind shears, low visibilities, and ceilings were tested along with unexpected misalignment between the runway and head-up display symbology. The symbolic format used was a conformal scene. Every pilot except one stayed head-up, flying with the display after descending below the ceiling. Without the display and as altitude decreased, the number of lookups from the instrument panel decreased and the duration of each one increased. No large differences in mean number or duration of transitions up or down were found during the head-up display runs comparing the no-misalignment with the lateral instrument landing system offset misalignment runs. The head-up display led to fewer transitions after the pilot made a decision to land or execute a missed approach. Without the display, pilots generally waited until they had descended below the ceiling to look outside the first time, but with it several pilots looked down at their panel at relatively high altitudes (if they looked down at all). Manual takeover of control was rapid and smooth both with and without the display which permitted smoother engine power changes.

South Fork Latrine, interior showing head with steel tank mounted ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

South Fork Latrine, interior showing head with steel tank mounted to wall; view south - Fort McKinley, South Fork Latrine, West side of East Side Drive, approximately 225 feet south of Weymouth Way, Great Diamond Island, Portland, Cumberland County, ME

Advanced Helmet Mounted Display (AHMD) for simulator applications

NASA Astrophysics Data System (ADS)

Sisodia, Ashok; Riser, Andrew; Bayer, Michael; McGuire, James P.

2006-05-01

The Advanced Helmet Mounted Display (AHMD), augmented reality visual system first presented at last year's Cockpit and Future Displays for Defense and Security conference, has now been evaluated in a number of military simulator applications and by L-3 Link Simulation and Training. This paper presents the preliminary results of these evaluations and describes current and future simulator and training applications for HMD technology. The AHMD blends computer-generated data (symbology, synthetic imagery, enhanced imagery) with the actual and simulated visible environment. The AHMD is designed specifically for highly mobile deployable, minimum resource demanding reconfigurable virtual training systems to satisfy the military's in-theater warrior readiness objective. A description of the innovative AHMD system and future enhancements will be discussed.

Exaggerated displays do not improve mounting success in male seaweed flies Fucellia tergina (Diptera: Anthomyiidae).

PubMed

Memmott, Ruth; Briffa, Mark

2015-11-01

Signals of individual quality are assumed to be difficult to exaggerate, either because they are directly linked to underlying traits (indices) or because they are costly to perform (handicaps). In practise advertisement displays may consist of conventional and costly components, for instance where a morphological structure related to body size is used in visual displays. In this case, there is the potential for dishonest displays, due to the population level variance around the relationship between body size and display structures. We examine the use of wing flicking displays that we observed in situ in a strandline dwelling seaweed fly Fucellia tergina, using overall body size and the size of their eyes as underlying indicators of condition. Males displayed far more frequently than females, and were also observed to frequently mount other flies, a behaviour that was rare in females. The rate of display was greater for males that had positive residual values from relationships between wing length and body length. In other words those males with larger than expected wings for their underlying quality displayed more frequently, indicating that these displays are open to exaggeration. Males with larger than expected wings (for the size of their body or eyes), however, mounted less frequently. We suggest that small bodied males are less successful in terms of mounting, but that those small males with relatively large wings may attempt to compensate for this through increased display effort. Copyright © 2015 Elsevier B.V. All rights reserved.

Performance Comparison Between a Head-Worn Display System and a Head-Up Display for Low Visibility Commercial Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Barnes, James R.; Williams, Steven P.; Jones, Denise R.; Harrison, Stephanie J.; Bailey, Randall E.

2014-01-01

Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in Next Generation Air Transportation System (NextGen). Under the Vehicle Systems Safety Technologies (VSST) project in the Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as an equivalent display to a Head-Up Display (HUD). Title 14 of the US Code of Federal Regulations (CFR) 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent" display combined with Enhanced Vision (EV). If successful, a HWD may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A simulation experiment was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Comparative testing was performed in the Research Flight Deck (RFD) Cockpit Motion Facility (CMF) full mission, motion-based simulator at NASA Langley. Twelve airline crews conducted approach and landing, taxi, and departure operations during low visibility operations (1000' Runway Visual Range (RVR), 300' RVR) at Memphis International Airport (Federal Aviation Administration (FAA) identifier: KMEM). The results showed that there were no statistical differences in the crews performance in terms of touchdown and takeoff. Further, there were no statistical differences between the HUD and HWD in pilots' responses to questionnaires.

Design of integrated eye tracker-display device for head mounted systems

NASA Astrophysics Data System (ADS)

David, Y.; Apter, B.; Thirer, N.; Baal-Zedaka, I.; Efron, U.

2009-08-01

We propose an Eye Tracker/Display system, based on a novel, dual function device termed ETD, which allows sharing the optical paths of the Eye tracker and the display and on-chip processing. The proposed ETD design is based on a CMOS chip combining a Liquid-Crystal-on-Silicon (LCoS) micro-display technology with near infrared (NIR) Active Pixel Sensor imager. The ET operation allows capturing the Near IR (NIR) light, back-reflected from the eye's retina. The retinal image is then used for the detection of the current direction of eye's gaze. The design of the eye tracking imager is based on the "deep p-well" pixel technology, providing low crosstalk while shielding the active pixel circuitry, which serves the imaging and the display drivers, from the photo charges generated in the substrate. The use of the ETD in the HMD Design enables a very compact design suitable for Smart Goggle applications. A preliminary optical, electronic and digital design of the goggle and its associated ETD chip and digital control, are presented.

Color speckle in laser displays

NASA Astrophysics Data System (ADS)

Kuroda, Kazuo

2015-07-01

At the beginning of this century, lighting technology has been shifted from discharge lamps, fluorescent lamps and electric bulbs to solid-state lighting. Current solid-state lighting is based on the light emitting diodes (LED) technology, but the laser lighting technology is developing rapidly, such as, laser cinema projectors, laser TVs, laser head-up displays, laser head mounted displays, and laser headlamps for motor vehicles. One of the main issues of laser displays is the reduction of speckle noise1). For the monochromatic laser light, speckle is random interference pattern on the image plane (retina for human observer). For laser displays, RGB (red-green-blue) lasers form speckle patterns independently, which results in random distribution of chromaticity, called color speckle2).

The Effect of a Monocular Helmet-Mounted Display on Aircrew Health: A Cohort Study of Apache AH Mk 1 Pilots Four-Year Review

DTIC Science & Technology

2009-12-01

forward-looking infrared FOV field-of-view HDU helmet display unit HMD helmet-mounted display IHADSS Integrated Helmet and Display...monocular Integrated Helmet and Display Sighting System (IHADSS) helmet-mounted display ( HMD ) in the British Army’s Apache AH Mk 1 attack helicopter has any...Integrated Helmet and Display Sighting System, IHADSS, Helmet-mounted display, HMD , Apache helicopter, Visual performance UNCLAS UNCLAS UNCLAS SAR 96

Head Worn Display System for Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Cupero, Frank; Valimont, Brian; Wise, John; Best. Carl; DeMers, Bob

2009-01-01

Head-Worn Displays or so-called, near-to-eye displays have potentially significant advantages in terms of cost, overcoming cockpit space constraints, and for the display of spatially-integrated information. However, many technical issues need to be overcome before these technologies can be successfully introduced into commercial aircraft cockpits. The results of three activities are reported. First, the near-to-eye display design, technological, and human factors issues are described and a literature review is presented. Second, the results of a fixed-base piloted simulation, investigating the impact of near to eye displays on both operational and visual performance is reported. Straight-in approaches were flown in simulated visual and instrument conditions while using either a biocular or a monocular display placed on either the dominant or non-dominant eye. The pilot's flight performance, visual acuity, and ability to detect unsafe conditions on the runway were tested. The data generally supports a monocular design with minimal impact due to eye dominance. Finally, a method for head tracker system latency measurement is developed and used to compare two different devices.

Using EMG to anticipate head motion for virtual-environment applications

NASA Technical Reports Server (NTRS)

Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

2005-01-01

In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

Using EMG to anticipate head motion for virtual-environment applications.

PubMed

Barniv, Yair; Aguilar, Mario; Hasanbelliu, Erion

2005-06-01

In virtual environment (VE) applications, where virtual objects are presented in a see-through head-mounted display, virtual images must be continuously stabilized in space in response to user's head motion. Time delays in head-motion compensation cause virtual objects to "swim" around instead of being stable in space which results in misalignment errors when overlaying virtual and real objects. Visual update delays are a critical technical obstacle for implementing head-mounted displays in applications such as battlefield simulation/training, telerobotics, and telemedicine. Head motion is currently measurable by a head-mounted 6-degrees-of-freedom inertial measurement unit. However, even given this information, overall VE-system latencies cannot be reduced under about 25 ms. We present a novel approach to eliminating latencies, which is premised on the fact that myoelectric signals from a muscle precede its exertion of force, thereby limb or head acceleration. We thus suggest utilizing neck-muscles' myoelectric signals to anticipate head motion. We trained a neural network to map such signals onto equivalent time-advanced inertial outputs. The resulting network can achieve time advances of up to 70 ms.

Astronauts Gibson and Pogue at Apollo Telescope Mount display/control panel

NASA Image and Video Library

1973-09-10

S73-32837 (10 Sept. 1973) --- Scientist-astronaut Edward G. Gibson, seated, and astronaut William R. Pogue discuss a mission procedure at the Apollo Telescope Mount (ATM) display and control panel mock-up in the one-G trainer for the Multiple Docking Adapter (MDA) at Johnson Space Center. Photo credit: NASA

Head-Worn Display Concepts for Surface Operations for Commerical Aircraft

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Bailey, Randall E.; Shelton, Kevin J.; Williams, Steven P.; Kramer, Lynda J.; Norman, Robert M.

2008-01-01

Experiments and flight tests have shown that a Head-Up Display (HUD) and a head-down electronic moving map (EMM) can be enhanced with Synthetic Vision for airport surface operations. While great success in ground operations was demonstrated with a HUD, the research noted that two major HUD limitations during ground operations were its monochrome form and limited, fixed field-of-regard. A potential solution to these limitations found with HUDs may be emerging with Head Worn Displays (HWDs). HWDs are small display devices that may be worn without significant encumbrance to the user. By coupling the HWD with a head tracker, unlimited field-of-regard may be realized. The results of three ground simulation experiments conducted at NASA Langley Research Center are summarized. The experiments evaluated the efficacy of head-worn display applications of Synthetic Vision and Enhanced Vision technology to improve transport aircraft surface operations. The results of the experiments showed that the fully integrated HWD provided greater pilot performance with respect to staying on the path compared to using paper charts alone. Further, when comparing the HWD with the HUD concept, there were no differences in path performance. In addition, the HWD and HUD concepts were rated via paired-comparisons the same in terms of situation awareness and workload.

Flight display dynamics and compensatory head movements in pilots.

PubMed

Beer, Jeremy; Freeman, David

2007-06-01

Experiments measured the optokinetic cervical reflex (OKCR), wherein the banking pilot aligns the head with the horizon. In a synthetic cockpit, the flight display was manipulated to test whether changing the visual reference frame would alter OKCR. Eight subjects (five rated pilots) flew a route in simulated visual meteorological conditions that required them to bank the aircraft frequently. Pilots' head tilt was characterized using both the conventional method of regressing against simultaneous aircraft bank, and also an event-based analysis, which identified head movements before, during, and after each turn. Three display configurations were compared to determine whether pilots' orientation would ever migrate from the horizon to the aircraft symbol. The first was a conventional "Inside-Out" condition. A "Frequency-Separated" condition combined Inside-Out horizon geometry with Outside-In dynamics for the aircraft symbol, which depicted joystick bank inputs. In the "Outside-In" condition, the aircraft symbol rolled against a static horizon. Regressions identified an interaction (p < 0.001) between display condition and aircraft bank: head tilt followed horizon tilt in Inside-Out and Frequency-Separated conditions, while remaining mostly level in the Outside-In condition. The event-based analysis identified anticipatory head movements in Inside-Out and Frequency-Separated conditions: 95% CI indicated that before each turn, head tilt favored the direction of the imminent bank. While the conventional analysis confirmed that the horizon comprises a primary spatial reference, the finer-grained event-based analysis indicated that pilots' reference can migrate at least temporarily to the vehicle, and that OKCR can be preceded by anticipatory head movements in the opposite direction.

Three dimensional audio versus head down TCAS displays

NASA Technical Reports Server (NTRS)

Begault, Durand R.; Pittman, Marc T.

1994-01-01

The advantage of a head up auditory display was evaluated in an experiment designed to measure and compare the acquisition time for capturing visual targets under two conditions: Standard head down traffic collision avoidance system (TCAS) display, and three-dimensional (3-D) audio TCAS presentation. Ten commercial airline crews were tested under full mission simulation conditions at the NASA Ames Crew-Vehicle Systems Research Facility Advanced Concepts Flight Simulator. Scenario software generated targets corresponding to aircraft which activated a 3-D aural advisory or a TCAS advisory. Results showed a significant difference in target acquisition time between the two conditions, favoring the 3-D audio TCAS condition by 500 ms.

Effects of head tilt on visual field testing with a head-mounted perimeter imo

PubMed Central

Matsumoto, Chota; Nomoto, Hiroki; Numata, Takuya; Eura, Mariko; Yamashita, Marika; Hashimoto, Shigeki; Okuyama, Sachiko; Kimura, Shinji; Yamanaka, Kenzo; Chiba, Yasutaka; Aihara, Makoto; Shimomura, Yoshikazu

2017-01-01

Purpose A newly developed head-mounted perimeter termed “imo” enables visual field (VF) testing without a fixed head position. Because the positional relationship between the subject’s head and the imo is fixed, the effects of head position changes on the test results are small compared with those obtained using a stationary perimeter. However, only ocular counter-roll (OCR) induced by head tilt might affect VF testing. To quantitatively reveal the effects of head tilt and OCR on the VF test results, we investigated the associations among the head-tilt angle, OCR amplitude and VF testing results. Subjects and methods For 20 healthy subjects, we binocularly recorded static OCR (s-OCR) while tilting the subject’s head at an arbitrary angle ranging from 0° to 60° rightward or leftward in 10° increments. By monitoring iris patterns, we evaluated the s-OCR amplitude. We also performed blind spot detection while tilting the subject’s head by an arbitrary angle ranging from 0° to 50° rightward or leftward in 10° increments to calculate the angle by which the blind spot rotates because of head tilt. Results The association between s-OCR amplitude and head-tilt angle showed a sinusoidal relationship. In blind spot detection, the blind spot rotated to the opposite direction of the head tilt, and the association between the rotation angle of the blind spot and the head-tilt angle also showed a sinusoidal relationship. The rotation angle of the blind spot was strongly correlated with the s-OCR amplitude (R2≥0.94, p<0.0001). A head tilt greater than 20° with imo causes interference between adjacent test areas. Conclusions Both the s-OCR amplitude and the rotation angle of the blind spot were correlated with the head-tilt angle by sinusoidal regression. The rotated VF was correlated with the s-OCR amplitude. During perimetry using imo, the change in the subject’s head tilt should be limited to 20°. PMID:28945777

Recording stereoscopic 3D neurosurgery with a head-mounted 3D camera system.

PubMed

Lee, Brian; Chen, Brian R; Chen, Beverly B; Lu, James Y; Giannotta, Steven L

2015-06-01

Stereoscopic three-dimensional (3D) imaging can present more information to the viewer and further enhance the learning experience over traditional two-dimensional (2D) video. Most 3D surgical videos are recorded from the operating microscope and only feature the crux, or the most important part of the surgery, leaving out other crucial parts of surgery including the opening, approach, and closing of the surgical site. In addition, many other surgeries including complex spine, trauma, and intensive care unit procedures are also rarely recorded. We describe and share our experience with a commercially available head-mounted stereoscopic 3D camera system to obtain stereoscopic 3D recordings of these seldom recorded aspects of neurosurgery. The strengths and limitations of using the GoPro(®) 3D system as a head-mounted stereoscopic 3D camera system in the operating room are reviewed in detail. Over the past several years, we have recorded in stereoscopic 3D over 50 cranial and spinal surgeries and created a library for education purposes. We have found the head-mounted stereoscopic 3D camera system to be a valuable asset to supplement 3D footage from a 3D microscope. We expect that these comprehensive 3D surgical videos will become an important facet of resident education and ultimately lead to improved patient care.

Evaluation of a Head-Worn Display System as an Equivalent Head-Up Display for Low Visibility Commercial Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis (Trey) J., III; Shelton, Kevin J.; Prinzel, Lawrence J.; Nicholas, Stephanie N.; Williams, Steven P.; Ellis, Kyle E.; Jones, Denise R.; Bailey, Randall E.; Harrison, Stephanie J.; Barnes, James R.

2017-01-01

Research, development, test, and evaluation of fight deck interface technologies is being conducted by the National Aeronautics and Space Administration (NASA) to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in the Next Generation Air Transportation System (NextGen). One specific area of research was the use of small Head-Worn Displays (HWDs) to serve as a possible equivalent to a Head-Up Display (HUD). A simulation experiment and a fight test were conducted to evaluate if the HWD can provide an equivalent level of performance to a HUD. For the simulation experiment, airline crews conducted simulated approach and landing, taxi, and departure operations during low visibility operations. In a follow-on fight test, highly experienced test pilots evaluated the same HWD during approach and surface operations. The results for both the simulation and fight tests showed that there were no statistical differences in the crews' performance in terms of approach, touchdown and takeoff; but, there are still technical hurdles to be overcome for complete display equivalence including, most notably, the end-to-end latency of the HWD system.

Head-mounted LED for optogenetic experiments of freely-behaving animal

NASA Astrophysics Data System (ADS)

Kwon, Ki Yong; Gnade, Andrew G.; Rush, Alexander D.; Patten, Craig D.

2016-03-01

Recent developments in optogenetics have demonstrated the ability to target specific types of neurons with sub-millisecond temporal precision via direct optical stimulation of genetically modified neurons in the brain. In most applications, the beam of a laser is coupled to an optical fiber, which guides and delivers the optical power to the region of interest. Light emitting diodes (LEDs) are an alternative light source for optogenetics and they provide many advantages over a laser based system including cost, size, illumination stability, and fast modulation. Their compact size and low power consumption make LEDs suitable light sources for a wireless optogenetic stimulation system. However, the coupling efficiency of an LED's output light into an optical fiber is lower than a laser due to its noncollimated output light. In typical chronic optogenetic experiment, the output of the light source is transmitted to the brain through a patch cable and a fiber stub implant, and this configuration requires two fiber-to-fiber couplings. Attenuation within the patch cable is potential source of optical power loss. In this study, we report and characterize a recently developed light delivery method for freely-behaving animal experiments. We have developed a head-mounted light source that maximizes the coupling efficiency of an LED light source by eliminating the need for a fiber optic cable. This miniaturized LED is designed to couple directly to the fiber stub implant. Depending on the desired optical power output, the head-mounted LED can be controlled by either a tethered (high power) or battery-powered wireless (moderate power) controller. In the tethered system, the LED is controlled through 40 gauge micro coaxial cable which is thinner, more flexible, and more durable than a fiber optic cable. The battery-powered wireless system uses either infrared or radio frequency transmission to achieve real-time control. Optical, electrical, mechanical, and thermal

Pathway concepts experiment for head-down synthetic vision displays

NASA Astrophysics Data System (ADS)

Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Kramer, Lynda J.; Bailey, Randall E.

2004-08-01

Eight 757 commercial airline captains flew 22 approaches using the Reno Sparks 16R Visual Arrival under simulated Category I conditions. Approaches were flown using a head-down synthetic vision display to evaluate four tunnel ("minimal", "box", "dynamic pathway", "dynamic crow's feet") and three guidance ("ball", "tadpole", "follow-me aircraft") concepts and compare their efficacy to a baseline condition (i.e., no tunnel, ball guidance). The results showed that the tunnel concepts significantly improved pilot performance and situation awareness and lowered workload compared to the baseline condition. The dynamic crow's feet tunnel and follow-me aircraft guidance concepts were found to be the best candidates for future synthetic vision head-down displays. These results are discussed with implications for synthetic vision display design and future research.

Non-RF wireless helmet-mounted display and two-way audio connectivity using covert free-space optical communications

NASA Astrophysics Data System (ADS)

Strauss, M.; Volfson, L.

2011-06-01

Providing the warfighter with Head or Helmet Mounted Displays (HMDs) while in tracked vehicles provides a means to visually maintain access to systems information while in a high vibration environment. The high vibration and unique environment of military tracked and turreted vehicles impact the ability to distinctly see certain information on an HMD, especially small font size or graphics and information that requires long fixation (staring), rather than a brief or peripheral glance. The military and commercial use of HMDs was compiled from market research, market trends, and user feedback. Lessons learned from previous military and commercial use of HMD products were derived to determine the feasibility of HMDs use in the high vibration and the unique environments of tracked vehicles. The results are summarized into factors that determine HMD features which must be specified for successful implementation.

Visual Stability of Objects and Environments Viewed through Head-Mounted Displays

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Adelstein, Bernard D.

2015-01-01

Virtual Environments (aka Virtual Reality) is again catching the public imagination and a number of startups (e.g. Oculus) and even not-so-startup companies (e.g. Microsoft) are trying to develop display systems to capitalize on this renewed interest. All acknowledge that this time they will get it right by providing the required dynamic fidelity, visual quality, and interesting content for the concept of VR to take off and change the world in ways it failed to do so in past incarnations. Some of the surprisingly long historical background of the technology that the form of direct simulation that underlies virtual environment and augmented reality displays will be briefly reviewed. An example of a mid 1990's augmented reality display system with good dynamic performance from our lab will be used to illustrate some of the underlying phenomena and technology concerning visual stability of virtual environments and objects during movement. In conclusion some idealized performance characteristics for a reference system will be proposed. Interestingly, many systems more or less on the market now may actually meet many of these proposed technical requirements. This observation leads to the conclusion that the current success of the IT firms trying to commercialize the technology will depend on the hidden costs of using the systems as well as the development of interesting and compelling content.

First Use of Heads-up Display for Astronomy Education

NASA Astrophysics Data System (ADS)

Mumford, Holly; Hintz, E. G.; Jones, M.; Lawler, J.; Fisler, A.

2013-01-01

As part of our work on deaf education in a planetarium environment we are exploring the use of heads-up display systems. This allows us to overlap an ASL interpreter with our educational videos. The overall goal is to allow a student to watch a full-dome planetarium show and have the interpreter tracking to any portion of the video. We will present the first results of using a heads-up display to provide an ASL ‘sound-track’ for a deaf audience. This work is partially funded by an NSF IIS-1124548 grant and funding from the Sorenson Foundation.

Pathway Concepts Experiment for Head-Down Synthetic Vision Displays

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Kramer, Lynda J.; Bailey, Randall E.

2004-01-01

Eight 757 commercial airline captains flew 22 approaches using the Reno Sparks 16R Visual Arrival under simulated Category I conditions. Approaches were flown using a head-down synthetic vision display to evaluate four tunnel ("minimal", "box", "dynamic pathway", "dynamic crow s feet") and three guidance ("ball", "tadpole", "follow-me aircraft") concepts and compare their efficacy to a baseline condition (i.e., no tunnel, ball guidance). The results showed that the tunnel concepts significantly improved pilot performance and situation awareness and lowered workload compared to the baseline condition. The dynamic crow s feet tunnel and follow-me aircraft guidance concepts were found to be the best candidates for future synthetic vision head-down displays. These results are discussed with implications for synthetic vision display design and future research.

Attitude symbology for helmet-mounted displays: lessons learned

NASA Astrophysics Data System (ADS)

Drewery, Chris C.; Davy, Eleanor C.; Dudfield, Helen J.

1997-06-01

This paper will review recent research on attitude symbology on helmet-mounted displays (HMDs) for the air-to-ground mission. General issues concerned with HMDs will be discussed and the lessons learned during the research will be outlined. It is suggested that a sound development approach to HMD symbology is critical since such symbology will constantly follow the pilot's line of sight (LOS). Further, the HMD field-of-view (FOV) is likely to be limited. Hence, if HMDs are to be used operationally for more than weapon aiming a number of human factors issues need to be investigated, such as the optimal method of presenting attitude information. The pitch ladder was designed to be presented along the boresight, directly in the pilot's LOS, at a fixed frame of reference. As pilots are used to and have been trained upon attitude information presented in consistency with the forward LOS, information representative of the pitch ladder may be beneficial on HMDs. None the less, since the pitch ladder was not designed for the HMD, novel formats may be more appropriate. As with all novel attitude symbology, enhanced operational performance must always be demonstrated and substantiated against the conventional existing symbology. Several experiments will be described which compared the pitch ladder to novel symbology, namely: the cylinder display; the arc segmented attitude reference display; and the modified roll-pitch display. These experiments were conducted using a variety of operationally relevant mission tasks and scenarios. The results will be summarized and the lessons learned for prototyping attitude symbology on HMDs will be discussed.

Comanche Helmet-Mounted Display Symbology Simulation

NASA Technical Reports Server (NTRS)

Turpin, Terry S.; Dowell, Susan R.; Szoboszlay, Zoltan

2006-01-01

The Aeroflightdynamics Directorate (AMRDEC) conducted a simulation to examine the performance of the Comanche Contact Analog world-referenced symbology displayed on the Comanche HIDSS when compared with a compressed symbology design similar to that specified by the former MIL-STD 1295. Six experimental test pilots flew one modified ADS-33 maneuver (hover turn, bob-up), an unusual attitude recovery, and two terrain flight tactical tasks in the NASA Vertical Motion Simulator (VMS). Analysis of the pilot objective performance data and subjective data showed the following results. Objective test results showed that 1295 symbology yielded more rapid maneuvering in the hover turn bob-up than Contact Analog symbology. The average margin of difference in the time to complete the maneuver was approximately two seconds, which was statistically significant. There were no significant differences measured between symbology sets with respect to altitude or position performance measures for all other maneuvers. The NOE target ID task data showed improved accuracy in determining heading to target when using Contact Analog over MIL-STD-1295. Subjective test results, including handling qualities ratings (HQRs) and NASA-TLX workload ratings, showed small but consistent advantages of 1295 symbology over Contact Analog for most parameters. For the bob-up maneuver, 1295 symbology handling qualities were rated Desired for lateral position error and time to complete whereas Contact Analog was rated adequate. The average HQRs for all other maneuvers were rated the same for both symbology sets. Pilot comments and the results of an online questionnaire more strongly favored 1295 over Contact Analog. Repeated comments from all six pilots led to a focus on design issues with six Contact Analog symbols. Those symbols were the heading tape, horizon line, radar altitude six-second predictor, the position of the torque symbol, the absence of a hover position cue, and the widespread positioning of

Terrain Portrayal for Head-Down Displays Experiment

NASA Technical Reports Server (NTRS)

Hughes, Monica F.; Takallu, M. A.

2002-01-01

The General Aviation Element of the Aviation Safety Program's Synthetic Vision Systems (SVS) Project is developing technology to eliminate low visibility induced General Aviation (GA) accidents. SVS displays present computer generated 3-dimensional imagery of the surrounding terrain on the Primary Flight Display (PFD) to greatly enhance pilot's situation awareness (SA), reducing or eliminating Controlled Flight into Terrain, as well as Low-Visibility Loss of Control accidents. SVS-conducted research is facilitating development of display concepts that provide the pilot with an unobstructed view of the outside terrain, regardless of weather conditions and time of day. A critical component of SVS displays is the appropriate presentation of terrain to the pilot. An experimental study has been conducted at NASA Langley Research Center (LaRC) to explore and quantify the relationship between the realism of the terrain presentation and resulting enhancements of pilot SA and pilot performance. Composed of complementary simulation and flight test efforts, Terrain Portrayal for Head-Down Displays (TP-HDD) experiments will help researchers evaluate critical terrain portrayal concepts. The experimental effort is to provide data to enable design trades that optimize SVS applications, as well as develop requirements and recommendations to facilitate the certification process. This paper focuses on the experimental set-up and preliminary qualitative results of the TP-HDD simulation experiment. In this experiment a fixed based flight simulator was equipped with various types of Head Down flight displays, ranging from conventional round dials (typical of most GA aircraft) to glass cockpit style PFD's. The variations of the PFD included an assortment of texturing and Digital Elevation Model (DEM) resolution combinations. A test matrix of 10 terrain display configurations (in addition to the baseline displays) were evaluated by 27 pilots of various backgrounds and experience levels

Quick-disconnect harness system for helmet-mounted displays

NASA Astrophysics Data System (ADS)

Bapu, P. T.; Aulds, M. J.; Fuchs, Steven P.; McCormick, David M.

1992-10-01

We have designed a pilot's harness-mounted, high voltage quick-disconnect connectors with 62 pins, to transmit voltages up to 13.5 kV and video signals with 70 MHz bandwidth, for a binocular helmet-mounted display system. It connects and disconnects with power off, and disconnects 'hot' without pilot intervention and without producing external sparks or exposing hot embers to the explosive cockpit environment. We have implemented a procedure in which the high voltage pins disconnect inside a hermetically-sealed unit before the physical separation of the connector. The 'hot' separation triggers a crowbar circuit in the high voltage power supplies for additional protection. Conductor locations and shields are designed to reduce capacitance in the circuit and avoid crosstalk among adjacent circuits. The quick- disconnect connector and wiring harness are human-engineered to ensure pilot safety and mobility. The connector backshell is equipped with two hybrid video amplifiers to improve the clarity of the video signals. Shielded wires and coaxial cables are molded as a multi-layered ribbon for maximum flexibility between the pilot's harness and helmet. Stiff cabling is provided between the quick-disconnect connector and the aircraft console to control behavior during seat ejection. The components of the system have been successfully tested for safety, performance, ergonomic considerations, and reliability.

Contributions of Head-Mounted Cameras to Studying the Visual Environments of Infants and Young Children

ERIC Educational Resources Information Center

Smith, Linda B.; Yu, Chen; Yoshida, Hanako; Fausey, Caitlin M.

2015-01-01

Head-mounted video cameras (with and without an eye camera to track gaze direction) are being increasingly used to study infants' and young children's visual environments and provide new and often unexpected insights about the visual world from a child's point of view. The challenge in using head cameras is principally conceptual and concerns the…

New ultraportable display technology and applications

NASA Astrophysics Data System (ADS)

Alvelda, Phillip; Lewis, Nancy D.

1998-08-01

MicroDisplay devices are based on a combination of technologies rooted in the extreme integration capability of conventionally fabricated CMOS active-matrix liquid crystal display substrates. Customized diffraction grating and optical distortion correction technology for lens-system compensation allow the elimination of many lenses and systems-level components. The MicroDisplay Corporation's miniature integrated information display technology is rapidly leading to many new defense and commercial applications. There are no moving parts in MicroDisplay substrates, and the fabrication of the color generating gratings, already part of the CMOS circuit fabrication process, is effectively cost and manufacturing process-free. The entire suite of the MicroDisplay Corporation's technologies was devised to create a line of application- specific integrated circuit single-chip display systems with integrated computing, memory, and communication circuitry. Next-generation portable communication, computer, and consumer electronic devices such as truly portable monitor and TV projectors, eyeglass and head mounted displays, pagers and Personal Communication Services hand-sets, and wristwatch-mounted video phones are among the may target commercial markets for MicroDisplay technology. Defense applications range from Maintenance and Repair support, to night-vision systems, to portable projectors for mobile command and control centers.

Projection-type see-through holographic three-dimensional display

NASA Astrophysics Data System (ADS)

Wakunami, Koki; Hsieh, Po-Yuan; Oi, Ryutaro; Senoh, Takanori; Sasaki, Hisayuki; Ichihashi, Yasuyuki; Okui, Makoto; Huang, Yi-Pai; Yamamoto, Kenji

2016-10-01

Owing to the limited spatio-temporal resolution of display devices, dynamic holographic three-dimensional displays suffer from a critical trade-off between the display size and the visual angle. Here we show a projection-type holographic three-dimensional display, in which a digitally designed holographic optical element and a digital holographic projection technique are combined to increase both factors at the same time. In the experiment, the enlarged holographic image, which is twice as large as the original display device, projected on the screen of the digitally designed holographic optical element was concentrated at the target observation area so as to increase the visual angle, which is six times as large as that for a general holographic display. Because the display size and the visual angle can be designed independently, the proposed system will accelerate the adoption of holographic three-dimensional displays in industrial applications, such as digital signage, in-car head-up displays, smart-glasses and head-mounted displays.

Evaluation of Head-Worn Display Concepts for Commercial Aircraft Taxi Operations

NASA Technical Reports Server (NTRS)

Bailey, Randall E.; Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Kramer, Lynda J.

2007-01-01

Previous research has demonstrated that a Head-Up Display (HUD) can be used to enable more capacity and safer aircraft surface operations. This previous research also noted that the HUD exhibited two major limitations which hindered the full potential of the display concept: 1) the monochrome HUD format; and, 2) a limited, fixed field of regard. Full-color Head Worn Displays (HWDs) with very small sizes and weights are emerging to the extent that this technology may be practical for commercial and business aircraft operations. By coupling the HWD with a head tracker, full-color, out-the-window display concepts with an unlimited field-of-regard may be realized to improve efficiency and safety in surface operations. A ground simulation experiment was conducted at NASA Langley to evaluate the efficacy of head-worn display applications which may directly address the limitations of the HUD while retaining all of its advantages in surface operations. The simulation experiment used airline crews to evaluate various displays (HUD, HWD) and display concepts in an operationally realistic environment by using a Chicago, O Hare airport database. The results pertaining to the implications of HWDs for commercial business and transport aviation applications are presented herein. Overall HWD system latency was measured and found to be acceptable, but not necessarily optimal. A few occurrences of simulator sickness were noted while wearing the HWD, but overall there appears to be commercial pilot acceptability and usability to the concept. Many issues were identified which need to be addressed in future research including continued reduction in user encumbrance due to the HWD, and improvement in image alignment, accuracy, and boresighting.

Assessment of a visually coupled system (VCS) using a binocular helmet-mounted display (BHMD) and a steerable FLIR

NASA Astrophysics Data System (ADS)

Longman, Peter J.; How, Thomas C.; Hudson, Craig; Clarkson, Geoffrey J. N.

2001-08-01

The Defence Evaluation Research Agency carried out an airborne demonstration and evaluation of a fast-jet Visually Coupled System (VCS) installed in ZD902, the Tornado Integrated Avionics Research Aircraft for the UK MOD. The installed VCS used a Head Steered Forward Looking Infra-Red (HSFLIR) sensor and a Head Tracking system to provide the pilot with an image of the outside world projected onto a Binocular Helmet Mounted Display. In addition to the sensor image, information such as aircraft altitude, attitude, and airspeed were also presented to the pilot through the HMD to eliminate the need to look inside the cockpit for critical flight data. The aim of the VIVIAN trial was to demonstrate by day and night the benefits of a fast-jet integrated HSFLIR and HMD as an aid to low level flight, navigation, target acquisition, take-off and landing. The outcome of this flight test program was very encouraging and, although testing has identified that improvements are necessary, in particular to HSFLIR image quality, Auto Gain Control performance, helmet fit and symbology design, test aircrew endorse the acceptability of a VCS.

Optoelectronic Mounting Structure

DOEpatents

Anderson, Gene R.; Armendariz, Marcelino G.; Baca, Johnny R. F.; Bryan, Robert P.; Carson, Richard F.; Chu, Dahwey; Duckett, III, Edwin B.; McCormick, Frederick B.; Peterson, David W.; Peterson, Gary D.; Reber, Cathleen A.; Reysen, Bill H.

2004-10-05

An optoelectronic mounting structure is provided that may be used in conjunction with an optical transmitter, receiver or transceiver module. The mounting structure may be a flexible printed circuit board. Thermal vias or heat pipes in the head region may transmit heat from the mounting structure to the heat spreader. The heat spreader may provide mechanical rigidity or stiffness to the heat region. In another embodiment, an electrical contact and ground plane may pass along a surface of the head region so as to provide an electrical contact path to the optoelectronic devices and limit electromagnetic interference. In yet another embodiment, a window may be formed in the head region of the mounting structure so as to provide access to the heat spreader. Optoelectronic devices may be adapted to the heat spreader in such a manner that the devices are accessible through the window in the mounting structure.

Toward Head-Up and Head-Worn Displays for Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Arthur, Jarvis J.; Bailey, Randall E.; Shelton, Kevin J.; Kramer, Lynda J.; Jones, Denise R.; Williams, Steven P.; Harrison, Stephanie J.; Ellis, Kyle K.

2015-01-01

A key capability envisioned for the future air transportation system is the concept of equivalent visual operations (EVO). EVO is the capability to achieve the safety of current-day Visual Flight Rules (VFR) operations and maintain the operational tempos of VFR irrespective of the weather and visibility conditions. Enhanced Flight Vision Systems (EFVS) offer a path to achieve EVO. NASA has successfully tested EFVS for commercial flight operations that has helped establish the technical merits of EFVS, without reliance on natural vision, to runways without category II/III ground-based navigation and lighting requirements. The research has tested EFVS for operations with both Head-Up Displays (HUDs) and "HUD equivalent" Head-Worn Displays (HWDs). The paper describes the EVO concept and representative NASA EFVS research that demonstrate the potential of these technologies to safely conduct operations in visibilities as low as 1000 feet Runway Visual Range (RVR). Future directions are described including efforts to enable low-visibility approach, landing, and roll-outs using EFVS under conditions as low as 300 feet RVR.

Helmet-mounted displays: why haven't they taken off?

NASA Astrophysics Data System (ADS)

Havig, P.; Goff, C.; McIntire, J.; Franck, D.

2009-05-01

Helmet-Mounted Display (HMD) technologies have been developing for over 3 decades and have been studied for multiple applications ranging from military aircraft, to virtual reality, augmented reality, entertainment and a host of other ideas. It would not be unreasonable to assume that after this much time they would be employed in our daily lives as ubiquitously as the common desktop monitor. However, this is simply not the case. How can this be when they can be used in so many ways for so many tasks? Throughout this work we will look at some of the reasons why as well of some of the ways they can be used.

Surgeon point-of-view recording: Using a high-definition head-mounted video camera in the operating room.

PubMed

Nair, Akshay Gopinathan; Kamal, Saurabh; Dave, Tarjani Vivek; Mishra, Kapil; Reddy, Harsha S; Della Rocca, David; Della Rocca, Robert C; Andron, Aleza; Jain, Vandana

2015-10-01

To study the utility of a commercially available small, portable ultra-high definition (HD) camera (GoPro Hero 4) for intraoperative recording. A head mount was used to fix the camera on the operating surgeon's head. Due care was taken to protect the patient's identity. The recorded video was subsequently edited and used as a teaching tool. This retrospective, noncomparative study was conducted at three tertiary eye care centers. The surgeries recorded were ptosis correction, ectropion correction, dacryocystorhinostomy, angular dermoid excision, enucleation, blepharoplasty and lid tear repair surgery (one each). The recorded videos were reviewed, edited, and checked for clarity, resolution, and reproducibility. The recorded videos were found to be high quality, which allowed for zooming and visualization of the surgical anatomy clearly. Minimal distortion is a drawback that can be effectively addressed during postproduction. The camera, owing to its lightweight and small size, can be mounted on the surgeon's head, thus offering a unique surgeon point-of-view. In our experience, the results were of good quality and reproducible. A head-mounted ultra-HD video recording system is a cheap, high quality, and unobtrusive technique to record surgery and can be a useful teaching tool in external facial and ophthalmic plastic surgery.

Surgeon point-of-view recording: Using a high-definition head-mounted video camera in the operating room

PubMed Central

Nair, Akshay Gopinathan; Kamal, Saurabh; Dave, Tarjani Vivek; Mishra, Kapil; Reddy, Harsha S; Rocca, David Della; Rocca, Robert C Della; Andron, Aleza; Jain, Vandana

2015-01-01

Objective: To study the utility of a commercially available small, portable ultra-high definition (HD) camera (GoPro Hero 4) for intraoperative recording. Methods: A head mount was used to fix the camera on the operating surgeon's head. Due care was taken to protect the patient's identity. The recorded video was subsequently edited and used as a teaching tool. This retrospective, noncomparative study was conducted at three tertiary eye care centers. The surgeries recorded were ptosis correction, ectropion correction, dacryocystorhinostomy, angular dermoid excision, enucleation, blepharoplasty and lid tear repair surgery (one each). The recorded videos were reviewed, edited, and checked for clarity, resolution, and reproducibility. Results: The recorded videos were found to be high quality, which allowed for zooming and visualization of the surgical anatomy clearly. Minimal distortion is a drawback that can be effectively addressed during postproduction. The camera, owing to its lightweight and small size, can be mounted on the surgeon's head, thus offering a unique surgeon point-of-view. In our experience, the results were of good quality and reproducible. Conclusions: A head-mounted ultra-HD video recording system is a cheap, high quality, and unobtrusive technique to record surgery and can be a useful teaching tool in external facial and ophthalmic plastic surgery. PMID:26655001

Development and manufacture of visor for helmet-mounted display

NASA Astrophysics Data System (ADS)

Krevor, David H.; McNelly, Gregg; Skubon, John; Speirs, Robert

2004-01-01

The manufacturing design and process development for the Visor for the JHMCS (Joint Helmet Mounted Cueing System) are discussed. The JHMCS system is a Helmet Mounted Display (HMD) system currently flying on the F-15, F-16 and F/A-18 aircraft. The Visor manufacturing processes are essential to both system performance and economy. The Visor functions both as the system optical combiner and personal protective equipment for the pilot. The Visor material is optical polycarbonate. For a military HMD system, the mechanical and environmental properties of the Visor are as necessary as the optical properties. The visor must meet stringent dimensional requirements to assure adequate system optical performance. Injection molding can provide dimensional fidelity to the requirements, if done properly. Concurrent design of the visor and the tool (i.e., the injection mold) is essential. The concurrent design necessarily considers manufacturing operations and the use environment of the Visor. Computer modeling of the molding process is a necessary input to the mold design. With proper attention to product design and tool development, it is possible to improve upon published standard dimensional tolerances for molded polycarbonate articles.

Micromirror-based real image laser automotive head-up display

NASA Astrophysics Data System (ADS)

Fan, Chao; He, Siyuan

2017-01-01

This paper reports a micromirror-based real image laser automotive head-up display (HUD), which overcomes the limitations of the previous designs by: (1) implementing an advanced display approach which is able to display sharp corners while the previous designs can only display curved lines such as to improve the display fidelity and (2) Optimizing the optical configuration to significantly reduce the HUD module size. The optical design in the HUD is simulated to choose the off-the-shelf concave lens. The vibration test is conducted to verify that the micromirror can survive 5 g. The prototype of the HUD system is fabricated and tested.

A green-color portable waveguide eyewear display system

NASA Astrophysics Data System (ADS)

Xia, Lingbo; Xu, Ke; Wu, Zhengming; Hu, Yingtian; Li, Zhenzhen; Wang, Yongtian; Liu, Juan

2013-08-01

Waveguide display systems are widely used in various display fields, especially in head mounted display. Comparing with the traditional head mounted display system, this device dramatically reduce the size and mass. However, there are still several fatal problems such as high scatting, the cumbersome design and chromatic aberration that should be solved. We designed and fabricated a monochromatic portable eyewear display system consist of a comfortable eyewear device and waveguide system with two holographic gratings located on the substrate symmetrically. We record the gratings on the photopolymer medium with high efficiency and wavelength sensitivity. The light emitting from the micro-display is diffracted by the grating and trapped in the glass substrate by total internal reflection. The relationship between the diffraction efficiency and exposure value is studied and analyzed, and we fabricated the gratings with appropriate diffraction efficiency in a optimization condition. To avoid the disturbance of the stray light, we optimize the waveguide system numerically and perform the optical experiments. With this system, people can both see through the waveguide to obtain the information outside and catch the information from the micro display. After considering the human body engineering and industrial production, we design the structure in a compact and portable way. It has the advantage of small-type configuration and economic acceptable. It is believe that this kind of planar waveguide system is a potentially replaceable choice for the portable devices in future mobile communications.

SVGA and XGA active matrix microdisplays for head-mounted applications

NASA Astrophysics Data System (ADS)

Alvelda, Phillip; Bolotski, Michael; Brown, Imani L.

2000-03-01

The MicroDisplay Corporation's liquid crystal on silicon (LCOS) display devices are based on the union of several technologies with the extreme integration capability of conventionally fabricated CMOS substrates. The fast liquid crystal operation modes and new scalable high-performance pixel addressing architectures presented in this paper enable substantially improved color, contrast, and brightness while still satisfying the optical, packaging, and power requirements of portable applications. The entire suite of MicroDisplay's technologies was devised to create a line of mixed-signal application-specific integrated circuits (ASICs) in single-chip display systems. Mixed-signal circuits can integrate computing, memory, and communication circuitry on the same substrate as the display drivers and pixel array for a multifunctional complete system-on-a-chip. System-on-a-chip benefits also include reduced head supported weight requirements through the elimination of off-chip drive electronics.

A Preliminary Design for a Heads-Up Display for Rail Operations

DOT National Transportation Integrated Search

2017-08-01

This research project designed a locomotive Heads-Up Display (HUD), a secondary display that helps the operator locate possible hazards in the surrounding environment while maintaining an awareness of the vehicle's current state. HUDs are widely used...

Head-Up Displays and Attention Capture

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Risser, Matthew

2004-01-01

The primary role of head-up displays (HUDs) is to provide primary flight, navigation, and guidance information to the pilot in a forward field-of-view on a head-up transparent screen. Therefore, this theoretically allows for optimal control of an aircraft through the simultaneous scanning of both instrument data and the out-the-window scene. However, despite significant aviation safety benefits afforded by HUDs, a number of accidents have shown that their use does not come without costs. The human factors community has identified significant issues related to the pilot distribution of near and far domain attentional resources because of the compellingness of symbology elements on the HUD; a concern termed, attention or cognitive capture. The paper describes the phenomena of attention capture and presents a selected survey of the literature on the etiology and potential prescriptions.

A head-up display for low-visibility approach and landing

NASA Technical Reports Server (NTRS)

Bray, R. S.; Scott, B. C.

1981-01-01

An electronic flight-guidance display format was designed for use in evaluations of the collimated head-up display concept in low-visibility landings of transport aircraft. In the design process of iterative evaluation and modification, some general principles, or guidelines, applicable to such flight displays were suggested. The usefulness of an indication of instantaneous inertial flightpath was clearly demonstrated, particularly in low-altitude transition to visual references. Evaluator pilot acceptance of the unfamiliar display concepts was very positive when careful attention was given to indoctrination and training.

Superimposition, symbology, visual attention, and the head-up display

NASA Technical Reports Server (NTRS)

Martin-Emerson, R.; Wickens, C. D.

1997-01-01

In two experiments we examined a number of related factors postulated to influence head-up display (HUD) performance. We addressed the benefit of reduced scanning and the cost of increasing the number of elements in the visual field by comparing a superimposed HUD with an identical display in a head-down position in varying visibility conditions. We explored the extent to which the characteristics of HUD symbology support a division of attention by contrasting conformal symbology (which links elements of the display image to elements of the far domain) with traditional instrument landing system (ILS) symbology. Together the two experiments provide strong evidence that minimizing scanning between flight instruments and the far domain contributes substantially to the observed HUD performance advantage. Experiment 1 provides little evidence for a performance cost attributable to visual clutter. In Experiment 2 the pattern of differences in lateral tracking error between conformal and traditional ILS symbology supports the hypothesis that, to the extent that the symbology forms an object with the far domain, attention may be divided between the superimposed image and its counterpart in the far domain.

Virtual workstation - A multimodal, stereoscopic display environment

NASA Astrophysics Data System (ADS)

Fisher, S. S.; McGreevy, M.; Humphries, J.; Robinett, W.

1987-01-01

A head-mounted, wide-angle, stereoscopic display system controlled by operator position, voice and gesture has been developed for use in a multipurpose interface environment. The system provides a multisensory, interactive display environment in which a user can virtually explore a 360-degree synthesized or remotely sensed environment and can viscerally interact with its components. Primary applications of the system are in telerobotics, management of large-scale integrated information systems, and human factors research. System configuration, application scenarios, and research directions are described.

Consideration of technologies for head-down displays

NASA Astrophysics Data System (ADS)

Bartlett, Christopher T.

1998-09-01

The market for military avionics head down displays for which Active Matrix Liquid Crystal Displays (AMLCD) has been specified is both well established and substantial. Typical major programs such as F-22, V-22 and Joint Strike Fighter (JSF) amount to over 15,000 displays. Nevertheless there is an insecurity about the situation because of the dependency upon Japanese and Korean manufacturers and the vagaries of the commercial market. The U.S. has only 7% of the world's manufacturing capability in AMLCD and is seeking alternative technologies to regain a hold in this lucrative business. The U.S. military manufacturers of AMLCD are capable, but can never achieve the benefits of scale that Commercial Off The Shelf (COTS) equipment can offer. In addition to the commercial and political concerns, there are still performance issues related to AMLCD and there is a view that emissive displays in particular can offer advantages over AMLCD. However, it is beneficial to be able to tailor display sizes and there are doubts about the ability of current flat panel technologies to achieve custom, or indeed large area panels either economically, or reliably. It is in this arena that projection displays may be the optimum solution.

An experimental evaluation of head-up display formats

NASA Technical Reports Server (NTRS)

Naish, J. M.; Miller, D. L.

1980-01-01

Three types of head-up display format are investigated. Type 1 is an unreferenced (conventional) flight director, type 2 is a ground referenced flight path display, and type 3 is a ground referenced director. Formats are generated by computer and presented by reflecting collimation against a simulated forward view in flight. Pilots, holding commercial licenses, fly approaches in the instrument flight mode and in a combined instrument and visual flight mode. The approaches are in wind shear with varied conditions of visibility, offset, and turbulence. The displays are equivalent in pure tracking but there is a slight advantage for the unreferenced director in poor conditions. Flight path displays are better for tracking in the combined flight mode, possibly because of poor director control laws and the division of attention between superimposed fields. Workloads is better for the type 2 displays. The flight path and referenced director displays are criticized for effects of symbol motion and field limiting. In the subjective judgment of pilots familiar with the director displays, they are rated clearly better than path displays, with a preference for the unreferenced director. There is a fair division of attention between superimposed fields.

Helmet-mounted displays in long-range-target visual acquisition

NASA Astrophysics Data System (ADS)

Wilkins, Donald F.

1999-07-01

Aircrews have always sought a tactical advantage within the visual range (WVR) arena -- usually defined as 'see the opponent first.' Even with radar and interrogation foe/friend (IFF) systems, the pilot who visually acquires his opponent first has a significant advantage. The Helmet Mounted Cueing System (HMCS) equipped with a camera offers an opportunity to correct the problems with the previous approaches. By utilizing real-time image enhancement technique and feeding the image to the pilot on the HMD, the target can be visually acquired well beyond the range provided by the unaided eye. This paper will explore the camera and display requirements for such a system and place those requirements within the context of other requirements, such as weight.

Review and analysis of avionic helmet-mounted displays

NASA Astrophysics Data System (ADS)

Li, Hua; Zhang, Xin; Shi, Guangwei; Qu, Hemeng; Wu, Yanxiong; Zhang, Jianping

2013-11-01

With the development of new concepts and principles over the past century, helmet-mounted displays (HMDs) have been widely applied. This paper presents a review of avionic HMDs and shows some areas of active and intensive research. This review is focused on the optical design aspects and is divided into three sections to explore new optical design methods, which include an off-axis design, design with freeform optical surface, and design with holographic optical waveguide technology. Building on the fundamentals of optical design and engineering, the principles section primarily expounds on the five optical system parameters, which include weight, field of view, modulation transfer function, exit pupil size, and eye relief. We summarized the previous design works using new components to achieve compact and lightweight HMDs. Moreover, the paper presents a partial summary of the more notable experimental, prototype, fielded, and future HMD fixed-wing and rotary-wing programs.

Visual Acuity Using Head-fixed Displays During Passive Self and Surround Motion

NASA Technical Reports Server (NTRS)

Wood, Scott J.; Black, F. Owen; Stallings, Valerie; Peters, Brian

2007-01-01

The ability to read head-fixed displays on various motion platforms requires the suppression of vestibulo-ocular reflexes. This study examined dynamic visual acuity while viewing a head-fixed display during different self and surround rotation conditions. Twelve healthy subjects were asked to report the orientation of Landolt C optotypes presented on a micro-display fixed to a rotating chair at 50 cm distance. Acuity thresholds were determined by the lowest size at which the subjects correctly identified 3 of 5 optotype orientations at peak velocity. Visual acuity was compared across four different conditions, each tested at 0.05 and 0.4 Hz (peak amplitude of 57 deg/s). The four conditions included: subject rotated in semi-darkness (i.e., limited to background illumination of the display), subject stationary while visual scene rotated, subject rotated around a stationary visual background, and both subject and visual scene rotated together. Visual acuity performance was greatest when the subject rotated around a stationary visual background; i.e., when both vestibular and visual inputs provided concordant information about the motion. Visual acuity performance was most reduced when the subject and visual scene rotated together; i.e., when the visual scene provided discordant information about the motion. Ranges of 4-5 logMAR step sizes across the conditions indicated the acuity task was sufficient to discriminate visual performance levels. The background visual scene can influence the ability to read head-fixed displays during passive motion disturbances. Dynamic visual acuity using head-fixed displays can provide an operationally relevant screening tool for visual performance during exposure to novel acceleration environments.

Light exposure via a head-mounted device suppresses melatonin and improves vigilant attention without affecting cortisol and comfort.

PubMed

Schmidt, Christina; Xhrouet, Marine; Hamacher, Manon; Delloye, Eric; LeGoff, Caroline; Cavalier, Etienne; Collette, Fabienne; Vandewalle, Gilles

2018-06-26

We aimed at assessing whether a head-mounted light therapy device, enriched in blue wavelengths, suppresses melatonin secretion and improves vigilant attention in the late evening hours. We also assessed whether using such light device is associated with discomfort and physiological stress. Seventeen healthy young participants (eight females) participated in a counterbalanced within-subject design during which they were exposed for 2 hr before habitual sleep time to a blue-enriched light (1500 lx) or to a lower intensity red-light (150 lx) control condition, using a new-generation light emitting diode (LED) head-mounted device. Compared to the red light control condition, blue-enriched light significantly reduced melatonin secretion and reaction times during a psychomotor vigilance task while no significant differences were detected in discomfort and cortisol levels. These results suggest that, compared to a control condition, blue-enriched light, delivered by a new-generation head-mounted device, elicits typical non-visual responses to light without detectable discomfort and physiological stress. They suggest that such devices might constitute an effective alternative to standard light boxes. © 2018 The Institute of Psychology, Chinese Academy of Sciences and John Wiley & Sons Australia, Ltd.

A head-up display format for transport aircraft approach and landing

NASA Technical Reports Server (NTRS)

Bray, R. S.; Scott, B. C.

1981-01-01

An electronic flight-guidance display format was designed for use in evaluations of the collimated head-up display concept applied to transport aircraft landing. In the design process of iterative evaluation and modification, some general principles, or guidelines, applicable to electronic flight displays were suggested. The usefulness of an indication of instantaneous inertial flightpath was clearly demonstrated. Evaluator pilot acceptance of the unfamiliar display concepts was very positive when careful attention was given to indoctrination and training.

Color Helmet Mounted Display System with Real Time Computer Generated and Video Imagery for In-Flight Simulation

NASA Technical Reports Server (NTRS)

Sawyer, Kevin; Jacobsen, Robert; Aiken, Edwin W. (Technical Monitor)

1995-01-01

NASA Ames Research Center and the US Army are developing the Rotorcraft Aircrew Systems Concepts Airborne Laboratory (RASCAL) using a Sikorsky UH-60 helicopter for the purpose of flight systems research. A primary use of the RASCAL is in-flight simulation for which the visual scene will use computer generated imagery and synthetic vision. This research is made possible in part to a full color wide field of view Helmet Mounted Display (HMD) system that provides high performance color imagery suitable for daytime operations in a flight-rated package. This paper describes the design and performance characteristics of the HMD system. Emphasis is placed on the design specifications, testing, and integration into the aircraft of Kaiser Electronics' RASCAL HMD system that was designed and built under contract for NASA. The optical performance and design of the Helmet mounted display unit will be discussed as well as the unique capabilities provided by the system's Programmable Display Generator (PDG).

[A case of hypothyroidism displaying "dropped head" syndrome].

PubMed

Furutani, Rikiya; Ishihara, Kenji; Miyazawa, Yumi; Suzuki, Yoshio; Shiota, Jun-Ichi; Kawamur, Mitsuru

2007-01-01

We describe a patient with hypothyroidism displaying "dropped head" syndrome. A 50-year-old man visited our clinic because he was unable to hold his head in the natural position. He had weakness and hypertrophy of the neck extensor muscles. Tendon reflexes were diminished or absent in all limbs. Mounding phenomena were observed in the bilateral upper extremities. Blood biochemical analysis revealed hypothyroidism, hyperlipidemia, and elevated levels of muscle-derived enzymes. Magnetic resonance imaging (MRI) of the neck demonstrated swelling and hyperintensity of the neck extensor muscles on T2-weighted images. The result of biopsy of the right biceps brachii muscle suggested mild atrophy of type 2 fibers. The diameters of the muscle fibers exhibited mild variation. No inflammatory changes were observed. We diagnosed hin as having "dropped head" syndrome due to hypothyroidism. Administration of thyroid hormone agent gradually improved his condition, and he became able to hold his head in the natural position. Levels of muscle-derived enzymes normalized and his hyperlipidemia remitted. Neck MRI also revealed improvement. Our findings suggest that hypothyroidism should be considered in the differential diagnosis of "dropped head" syndrome, although only a few cases like ours have been reported.

Improvement of Head-Up Display Standards. Volume 5. Head Up Display ILS (Instrument Landing System) Accuracy Flight Tests.

DTIC Science & Technology

1987-09-01

amber system. The front canopy of the NT-33A is cov- ered with an amber plastic sheet; when the front seat pilot low- ers his blue visor, the...tigation of the effect of head-up display symbol dynamic response caracteristics on flying qualities; Task B was an investigation of symbol accuracy...An amber vinyl plastic sheet covered the in- side front half of the NT-33 canopy. Blue snap-on visors were pi ovided to the evaluation pilots. The

Toward Head-Worn Displays for Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence (Lance) J., III; Arthur, Jarvis J. (Trey); Bailey, Randall E.; Jones, Denise R.; Williams, Steven P.; Harrison, Stephanie J.

2015-01-01

The Next Generation Air Transportation System represents an envisioned transformation to the U.S. air transportation system that includes an "equivalent visual operations" (EVO) concept, intended to achieve the safety and operational tempos of Visual Flight Rules (VFR) operations independent of visibility conditions. Today, Federal Aviation Administration regulations provide for the use of an Enhanced Flight Visual System (EFVS) as "operational credit" to conduct approach operations below traditional minima otherwise prohibited. An essential element of an EFVS is the Head-Up Display (HUD). NASA has conducted a substantial amount of research investigating the use of HUDs for operational landing "credit", and current efforts are underway to enable manually flown operations as low as 1000 feet Runway Visual Range (RVR). Title 14 CFR 91.175 describes the use of EFVS and the operational credit that may be obtained with airplane equipage of a HUD combined with Enhanced Vision (EV) while also offering the potential use of an “equivalent” display in lieu of the HUD. A Head-Worn Display (HWD) is postulated to provide the same, or better, safety and operational benefits as current HUD-equipped aircraft but for potentially more aircraft and for lower cost. A high-fidelity simulation was conducted that examined the efficacy of HWDs as "equivalent" displays. Twelve airline flight crews conducted 1000 feet RVR approach and 300 feet RVR departure operations using either a HUD or HWD, both with simulated Forward Looking Infra-Red cameras. The paper shall describe (a) quantitative and qualitative results, (b) a comparative evaluation of these findings with prior NASA HUD studies, and (c) describe current research efforts for EFVS to provide for a comprehensive EVO capability.

Concepts for conformal and body-axis attitude information for spatial awareness presented in a helmet-mounted display

NASA Technical Reports Server (NTRS)

Jones, Denise R.; Abbott, Terence S.; Burley, James R., II

1993-01-01

A piloted simulation study has been conducted to evaluate two methods of presenting attitude information in a helmet-mounted display (HMD) for spatial awareness in a fighter airplane. One method, the body-axis concept, displayed the information relative to the body axis of the airplane. The quantitative results of this study favored the body-axis concept. Although no statistically significant differences were noted for either the pilots' understanding of roll attitude or target position, the pilots made pitch judgment errors three times more often with the conformal display. The subjective results showed the body-axis display did not cause attitude confusion, a prior concern with this display. In the posttest comments, the pilots overwhelmingly selected the body-axis display as the display of choice.

The impact of human factors, crashworthiness and optical performance design requirements on helmet-mounted display development from the 1970s to the present

NASA Astrophysics Data System (ADS)

Harding, Thomas H.; Rash, Clarence E.; McLean, William E.; Martin, John S.

2015-05-01

Driven by the operational needs of modern warfare, the helmet-mounted display (HMD) has matured from a revolutionary, but impractical, World War I era idea for an infantry marksman's helmet-mounted weapon delivery system to a sophisticated and ubiquitous display and targeting system that dominates current night warfighting operations. One of the most demanding applications for HMD designs has been in Army rotary-wing aviation, where HMDs offer greater direct access to visual information and increased situational awareness in an operational environment where information availability is critical on a second-to-second basis. However, over the past 40 years of extensive HMD development, a myriad of crashworthiness, optical, and human factors issues have both frustrated and challenged designers. While it may be difficult to attain a full consensus on which are the most important HMD design factors, certainly head-supported weight (HSW), exit pupil size, field-of-view, image resolution and physical eye relief have been among the most critical. A confounding factor has been the interrelationship between the many design issues, such as early attempts to use non-glass optical elements to lower HSW, but at the cost of image quality, and hence, pilot visual performance. This paper traces how the role of the demanding performance requirements placed on HMDs by the U.S. Army aviation community has impacted the progress of HMD designs towards the Holy Grail of HMD design: a wide field-of-view, high resolution, binocular, full-color, totally crashworthy system.

Effects of mold design of aspheric projector lens for head up display

NASA Astrophysics Data System (ADS)

Chen, Chao-Chang A.; Tang, Jyun-Cing; Teng, Lin-Ming

2010-08-01

This paper investigates the mold design and related effects on an aspheric projector lens for Head Up Display (HUD) with injection molding process. Injection flow analysis with a commercial software, Moldex3D has been used to simulate this projector lens for filling, packing, shrinkage, and flow-induced residual stress. This projector lens contains of variant thickness due to different aspheric design on both surfaces. Defects may be induced as the melt front from the gate into the cavity with jet-flow phenomenon, short shot, weld line, and even shrinkage. Thus, this paper performs a gate design to find the significant parameters including injection velocity, melt temperature, and mold temperature. After simulation by the Moldex3D, gate design for the final assembly of Head Up Display (HUD) has been obtained and then experimental tests have been proceeded for verification of short-shot, weight variation, and flow-induced stress. Moreover, warpage analysis of the Head Up Display (HUD) can be integrated with the optical design specification in future work.

Synthetic Vision Enhanced Surface Operations With Head-Worn Display for Commercial Aircraft

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Shelton, Kevin J.; Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Norman, R. M.

2007-01-01

Experiments and flight tests have shown that airport surface operations can be enhanced by using synthetic vision and associated technologies, employed on a Head-Up Display (HUD) and head-down display electronic moving maps (EMM). Although HUD applications have shown the greatest potential operational improvements, the research noted that two major limitations during ground operations were its monochrome form and limited, fixed field-of-regard. A potential solution to these limitations may be the application of advanced Head Worn Displays (HWDs) particularly during low-visibility operations wherein surface movement is substantially limited because of the impaired vision of pilots and air traffic controllers. The paper describes the results of ground simulation experiments conducted at the NASA Langley Research Center. The results of the experiments showed that the fully integrated HWD concept provided significantly improved path performance compared to using paper charts alone. When comparing the HWD and HUD concepts, there were no statistically-significant differences in path performance or subjective ratings of situation awareness and workload. Implications and directions for future research are described.

Evaluation of control and display configurations for helicopter shipboard operations

NASA Technical Reports Server (NTRS)

Paulk, C. H., Jr.; Donley, S. T.; Hollis, M. K.

1983-01-01

A simulation evaluation of several approach and landing flight-control configurations and of two out-of-the-cockpit display devices (a head-up display and a helmet-mounted display) was performed for the task of landing a helicopter on a destroyer in adverse weather. The results indicated that the ship airwake turbulence was the most significant environmental variable affecting hover performance. In addition, to achieve adequate landing performance, attitude-command control compensation was required for the pilot regardless of the display used. For improved performance with reduced pilot effort, a velocity-command, position-hold control system was desired.

Integrated Display and Environmental Awareness System - System Architecture Definition

NASA Technical Reports Server (NTRS)

Doule, Ondrej; Miranda, David; Hochstadt, Jake

2017-01-01

The Integrated Display and Environmental Awareness System (IDEAS) is an interdisciplinary team project focusing on the development of a wearable computer and Head Mounted Display (HMD) based on Commercial-Off-The-Shelf (COTS) components for the specific application and needs of NASA technicians, engineers and astronauts. Wearable computers are on the verge of utilization trials in daily life as well as industrial environments. The first civil and COTS wearable head mounted display systems were introduced just a few years ago and they probed not only technology readiness in terms of performance, endurance, miniaturization, operability and usefulness but also maturity of practice in perspective of a socio-technical context. Although the main technical hurdles such as mass and power were addressed as improvements on the technical side, the usefulness, practicality and social acceptance were often noted on the side of a broad variety of humans' operations. In other words, although the technology made a giant leap, its use and efficiency still looks for the sweet spot. The first IDEAS project started in January 2015 and was concluded in January 2017. The project identified current COTS systems' capability at minimum cost and maximum applicability and brought about important strategic concepts that will serve further IDEAS-like system development.

Blurring the boundaries between frame-based and frameless stereotaxy: feasibility study for brain biopsies performed with the use of a head-mounted robot.

PubMed

Grimm, Florian; Naros, Georgios; Gutenberg, Angelika; Keric, Naureen; Giese, Alf; Gharabaghi, Alireza

2015-09-01

Frame-based stereotactic interventions are considered the gold standard for brain biopsies, but they have limitations with regard to flexibility and patient comfort because of the bulky head ring attached to the patient. Frameless image guidance systems that use scalp fiducial markers offer more flexibility and patient comfort but provide less stability and accuracy during drilling and biopsy needle positioning. Head-mounted robot-guided biopsies could provide the advantages of these 2 techniques without the downsides. The goal of this study was to evaluate the feasibility and safety of a robotic guidance device, affixed to the patient's skull through a small mounting platform, for use in brain biopsy procedures. This was a retrospective study of 37 consecutive patients who presented with supratentorial lesions and underwent brain biopsy procedures in which a surgical guidance robot was used to determine clinical outcomes and technical procedural operability. The portable head-mounted device was well tolerated by the patients and enabled stable drilling and needle positioning during surgery. Flexible adjustments of predefined paths and selection of new trajectories were successfully performed intraoperatively without the need for manual settings and fixations. The patients experienced no permanent deficits or infections after surgery. The head-mounted robot-guided approach presented here combines the stability of a bone-mounted set-up with the flexibility and tolerability of frameless systems. By reducing human interference (i.e., manual parameter settings, calibrations, and adjustments), this technology might be particularly useful in neurosurgical interventions that necessitate multiple trajectories.

Attentional effects with superimposed symbology : implications for head-up displays (HUD)

DOT National Transportation Integrated Search

1993-01-01

Previous research has shown that the presence of head-up display (HUD) symbology : containing altitude information improves altitude performance at the cost of : terrain path performance, implying that these information sources may not be : available...

Multispectral image-fused head-tracked vision system (HTVS) for driving applications

NASA Astrophysics Data System (ADS)

Reese, Colin E.; Bender, Edward J.

2001-08-01

Current military thermal driver vision systems consist of a single Long Wave Infrared (LWIR) sensor mounted on a manually operated gimbal, which is normally locked forward during driving. The sensor video imagery is presented on a large area flat panel display for direct view. The Night Vision and Electronics Sensors Directorate and Kaiser Electronics are cooperatively working to develop a driver's Head Tracked Vision System (HTVS) which directs dual waveband sensors in a more natural head-slewed imaging mode. The HTVS consists of LWIR and image intensified sensors, a high-speed gimbal, a head mounted display, and a head tracker. The first prototype systems have been delivered and have undergone preliminary field trials to characterize the operational benefits of a head tracked sensor system for tactical military ground applications. This investigation will address the advantages of head tracked vs. fixed sensor systems regarding peripheral sightings of threats, road hazards, and nearby vehicles. An additional thrust will investigate the degree to which additive (A+B) fusion of LWIR and image intensified sensors enhances overall driving performance. Typically, LWIR sensors are better for detecting threats, while image intensified sensors provide more natural scene cues, such as shadows and texture. This investigation will examine the degree to which the fusion of these two sensors enhances the driver's overall situational awareness.

A head-up display for mid-air drone recovery

NASA Technical Reports Server (NTRS)

Augustine, W. L.; Heft, E. L.; Bowen, T. E.; Newman, R. L.

1978-01-01

During mid-air retrieval of parachute packages, the absence of a natural horizon creates serious difficulties for the pilot of the recovery helicopter. A head-up display (HUD) was tested in an attempt to solve this problem. Both a roll-stabilized HUD and a no-roll (pitch only) HUD were tested. The results show that fewer missed passes occurred with the roll-stabilized HUD when the horizon was obscured. The pilots also reported that the workload was greatly reduced. Roll-stabilization was required to prevent vertigo when flying in the absence of a natural horizon. Any HUD intended for mid-air retrieval should display pitch, roll, sideslip, airspeed, and vertical velocity.

Basic Perception in Head-worn Augmented Reality Displays

DTIC Science & Technology

2012-01-01

Basic Perception in Head-worn Augmented Reality Displays Mark A. Livingston, Joseph L. Gabbard , J. Edward Swan II, Ciara M. Sibley, and Jane H...mark.livingston@nrl.navy.mil Joseph L. Gabbard Virginia Polytechnic Institute and State University, Blacksburg, VA 24061, USA e-mail: jgabbard@vt.edu J...Standard Form 298 (Rev. 8-98) Prescribed by ANSI Std Z39-18 2 Livingston, Gabbard , et al. 1 Introduction For many first-time users of augmented reality

MEMS scanned laser head-up display

NASA Astrophysics Data System (ADS)

Freeman, Mark O.

2011-03-01

Head-up displays (HUD) in automobiles and other vehicles have been shown to significantly reduce accident rates by keeping the driver's eyes on the road. The requirements for automotive HUDs are quite demanding especially in terms of brightness, dimming range, supplied power, and size. Scanned laser display technology is particularly well-suited to this application since the lasers can be very efficiently relayed to the driver's eyes. Additionally, the lasers are only turned on where the light is needed in the image. This helps to provide the required brightness while minimizing power and avoiding a background glow that disturbs the see-through experience. Microvision has developed a couple of HUD architectures that are presented herein. One design uses an exit pupil expander and relay optics to produce a high quality virtual image for built-in systems where the image appears to float above the hood of the auto. A second design uses a patented see-through screen technology and pico projector to make automotive HUDs available to anyone with a projector. The presentation will go over the basic designs for the two types of HUD and discuss design tradeoffs.

A miniature shoe-mounted orientation determination system for accurate indoor heading and trajectory tracking.

PubMed

Zhang, Shengzhi; Yu, Shuai; Liu, Chaojun; Liu, Sheng

2016-06-01

Tracking the position of pedestrian is urgently demanded when the most commonly used GPS (Global Position System) is unavailable. Benefited from the small size, low-power consumption, and relatively high reliability, micro-electro-mechanical system sensors are well suited for GPS-denied indoor pedestrian heading estimation. In this paper, a real-time miniature orientation determination system (MODS) was developed for indoor heading and trajectory tracking based on a novel dual-linear Kalman filter. The proposed filter precludes the impact of geomagnetic distortions on pitch and roll that the heading is subjected to. A robust calibration approach was designed to improve the accuracy of sensors measurements based on a unified sensor model. Online tests were performed on the MODS with an improved turntable. The results demonstrate that the average RMSE (root-mean-square error) of heading estimation is less than 1°. Indoor heading experiments were carried out with the MODS mounted on the shoe of pedestrian. Besides, we integrated the existing MODS into an indoor pedestrian dead reckoning application as an example of its utility in realistic actions. A human attitude-based walking model was developed to calculate the walking distance. Test results indicate that mean percentage error of indoor trajectory tracking achieves 2% of the total walking distance. This paper provides a feasible alternative for accurate indoor heading and trajectory tracking.

Flight Simulator Evaluation of Display Media Devices for Synthetic Vision Concepts

NASA Technical Reports Server (NTRS)

Arthur, J. J., III; Williams, Steven P.; Prinzel, Lawrence J., III; Kramer, Lynda J.; Bailey, Randall E.

2004-01-01

The Synthetic Vision Systems (SVS) Project of the National Aeronautics and Space Administration's (NASA) Aviation Safety Program (AvSP) is striving to eliminate poor visibility as a causal factor in aircraft accidents as well as enhance operational capabilities of all aircraft. To accomplish these safety and capacity improvements, the SVS concept is designed to provide a clear view of the world around the aircraft through the display of computer-generated imagery derived from an onboard database of terrain, obstacle, and airport information. Display media devices with which to implement SVS technology that have been evaluated so far within the Project include fixed field of view head up displays and head down Primary Flight Displays with pilot-selectable field of view. A simulation experiment was conducted comparing these display devices to a fixed field of view, unlimited field of regard, full color Helmet-Mounted Display system. Subject pilots flew a visual circling maneuver in IMC at a terrain-challenged airport. The data collected for this experiment is compared to past SVS research studies.

Modeling Of A Monocular, Full-Color, Laser-Scanning, Helmet-Mounted Display for Aviator Situational Awareness

DTIC Science & Technology

2017-03-27

USAARL Report No. 2017-10 Modeling of a Monocular, Full -Color, Laser- Scanning, Helmet-Mounted Display for Aviator Situational Awareness By Thomas...RESPONSIBLE PERSON 19b. TELEPHONE NUMBER (Include area code) 27-03-2017 Final 2002-2003 Modeling of a Monocular, Full -Color, Laser-Scanning, Helmet...was the idea of modeling HMDs by producing computer imagery for an observer to evaluate the quality of symbology. HMD, ANVIS, HGU-56P, Virtual

Flight Test of a Head-Worn Display as an Equivalent-HUD for Terminal Operations

NASA Technical Reports Server (NTRS)

Shelton, K. J.; Arthur, J. J., III; Prinzel, L. J., III; Nicholas, S. N.; Williams, S. P.; Bailey, R. E.

2015-01-01

Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in the Next Generation Air Transportation System (NextGen). Under NASA's Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as a potential equivalent display to a Head-up Display (HUD). Title 14 of the US CFR 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent"' display combined with Enhanced Vision (EV). A successful HWD implementation may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A flight test was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Approach and taxi testing was performed on-board NASA's experimental King Air aircraft in various visual conditions. Preliminary quantitative results indicate the HWD tested provided equivalent HUD performance, however operational issues were uncovered. The HWD showed significant potential as all of the pilots liked the increased situation awareness attributable to the HWD's unique capability of unlimited field-of-regard.

Flight test of a head-worn display as an equivalent-HUD for terminal operations

NASA Astrophysics Data System (ADS)

Shelton, K. J.; Arthur, J. J.; Prinzel, L. J.; Nicholas, S. N.; Williams, S. P.; Bailey, R. E.

2015-05-01

Research, development, test, and evaluation of flight deck interface technologies is being conducted by NASA to proactively identify, develop, and mature tools, methods, and technologies for improving overall aircraft safety of new and legacy vehicles operating in the Next Generation Air Transportation System (NextGen). Under NASA's Aviation Safety Program, one specific area of research is the use of small Head-Worn Displays (HWDs) as a potential equivalent display to a Head-up Display (HUD). Title 14 of the US CFR 91.175 describes a possible operational credit which can be obtained with airplane equipage of a HUD or an "equivalent"' display combined with Enhanced Vision (EV). A successful HWD implementation may provide the same safety and operational benefits as current HUD-equipped aircraft but for significantly more aircraft in which HUD installation is neither practical nor possible. A flight test was conducted to evaluate if the HWD, coupled with a head-tracker, can provide an equivalent display to a HUD. Approach and taxi testing was performed on-board NASA's experimental King Air aircraft in various visual conditions. Preliminary quantitative results indicate the HWD tested provided equivalent HUD performance, however operational issues were uncovered. The HWD showed significant potential as all of the pilots liked the increased situation awareness attributable to the HWD's unique capability of unlimited field-of-regard.

Evaluation of Head Mounted and Head Down Information Displays During Simulated Mine-Countermeasures Dives to 42 msw

DTIC Science & Technology

2008-04-01

visualisation tête basse (VTB) ou d’un visiocasque pour l’exécution de leurs tâches courantes sous l’eau. Neuf plongeurs de lutte contre les mines ont...existe peu d’information empirique sur l’aptitude des plongeurs à utiliser un dispositif multifonction de visualisation tête basse (VTB) ou d’un...experiment, the diver was also linked to the researchers and operations crew via audio communications. 11 Display Screen Chamber Laptop Diver

Volumetric, dashboard-mounted augmented display

NASA Astrophysics Data System (ADS)

Kessler, David; Grabowski, Christopher

2017-11-01

The optical design of a compact volumetric display for drivers is presented. The system displays a true volume image with realistic physical depth cues, such as focal accommodation, parallax and convergence. A large eyebox is achieved with a pupil expander. The windshield is used as the augmented reality combiner. A freeform windshield corrector is placed at the dashboard.

Amplified Head Rotation in Virtual Reality and the Effects on 3D Search, Training Transfer, and Spatial Orientation.

PubMed

Ragan, Eric D; Scerbo, Siroberto; Bacim, Felipe; Bowman, Doug A

2017-08-01

Many types of virtual reality (VR) systems allow users to use natural, physical head movements to view a 3D environment. In some situations, such as when using systems that lack a fully surrounding display or when opting for convenient low-effort interaction, view control can be enabled through a combination of physical and virtual turns to view the environment, but the reduced realism could potentially interfere with the ability to maintain spatial orientation. One solution to this problem is to amplify head rotations such that smaller physical turns are mapped to larger virtual turns, allowing trainees to view the entire surrounding environment with small head movements. This solution is attractive because it allows semi-natural physical view control rather than requiring complete physical rotations or a fully-surrounding display. However, the effects of amplified head rotations on spatial orientation and many practical tasks are not well understood. In this paper, we present an experiment that evaluates the influence of amplified head rotation on 3D search, spatial orientation, and cybersickness. In the study, we varied the amount of amplification and also varied the type of display used (head-mounted display or surround-screen CAVE) for the VR search task. By evaluating participants first with amplification and then without, we were also able to study training transfer effects. The findings demonstrate the feasibility of using amplified head rotation to view 360 degrees of virtual space, but noticeable problems were identified when using high amplification with a head-mounted display. In addition, participants were able to more easily maintain a sense of spatial orientation when using the CAVE version of the application, which suggests that visibility of the user's body and awareness of the CAVE's physical environment may have contributed to the ability to use the amplification technique while keeping track of orientation.

Visual-conformal display format for helicopter guidance

NASA Astrophysics Data System (ADS)

Doehler, H.-U.; Schmerwitz, Sven; Lueken, Thomas

2014-06-01

Helicopter guidance in situations where natural vision is reduced is still a challenging task. Beside new available sensors, which are able to "see" through darkness, fog and dust, display technology remains one of the key issues of pilot assistance systems. As long as we have pilots within aircraft cockpits, we have to keep them informed about the outside situation. "Situational awareness" of humans is mainly powered by their visual channel. Therefore, display systems which are able to cross-fade seamless from natural vision to artificial computer vision and vice versa, are of greatest interest within this context. Helmet-mounted displays (HMD) have this property when they apply a head-tracker for measuring the pilot's head orientation relative to the aircraft reference frame. Together with the aircraft's position and orientation relative to the world's reference frame, the on-board graphics computer can generate images which are perfectly aligned with the outside world. We call image elements which match the outside world, "visual-conformal". Published display formats for helicopter guidance in degraded visual environment apply mostly 2D-symbologies which stay far behind from what is possible. We propose a perspective 3D-symbology for a head-tracked HMD which shows as much as possible visual-conformal elements. We implemented and tested our proposal within our fixed based cockpit simulator as well as in our flying helicopter simulator (FHS). Recently conducted simulation trials with experienced helicopter pilots give some first evaluation results of our proposal.

Design and Testing of an Unlimited Field-of-regard Synthetic Vision Head-worn Display for Commercial Aircraft Surface Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Shelton, Kevin J.; Kramer, Lynda J.; Williams, Steven P.; Bailey, Randall E.; Norman, Robert M.

2007-01-01

Experiments and flight tests have shown that a Head-Up Display (HUD) and a head-down, electronic moving map (EMM) can be enhanced with Synthetic Vision for airport surface operations. While great success in ground operations was demonstrated with a HUD, the research noted that two major HUD limitations during ground operations were their monochrome form and limited, fixed field of regard. A potential solution to these limitations found with HUDs may be emerging Head Worn Displays (HWDs). HWDs are small, lightweight full color display devices that may be worn without significant encumbrance to the user. By coupling the HWD with a head tracker, unlimited field-of-regard may be realized for commercial aviation applications. In the proposed paper, the results of two ground simulation experiments conducted at NASA Langley are summarized. The experiments evaluated the efficacy of head-worn display applications of Synthetic Vision and Enhanced Vision technology to enhance transport aircraft surface operations. The two studies tested a combined six display concepts: (1) paper charts with existing cockpit displays, (2) baseline consisting of existing cockpit displays including a Class III electronic flight bag display of the airport surface; (3) an advanced baseline that also included displayed traffic and routing information, (4) a modified version of a HUD and EMM display demonstrated in previous research; (5) an unlimited field-of-regard, full color, head-tracked HWD with a conformal 3-D synthetic vision surface view; and (6) a fully integrated HWD concept. The fully integrated HWD concept is a head-tracked, color, unlimited field-of-regard concept that provides a 3-D conformal synthetic view of the airport surface integrated with advanced taxi route clearance, taxi precision guidance, and data-link capability. The results of the experiments showed that the fully integrated HWD provided greater path performance compared to using paper charts alone. Further, when

System for providing an integrated display of instantaneous information relative to aircraft attitude, heading, altitude, and horizontal situation

NASA Technical Reports Server (NTRS)

James, R. (Inventor)

1981-01-01

A display device is disclosed which is particularly suited for providing the pilot of an aircraft with combined inflight attitude, heading, altitude, and horizontal situation information previously available only by using two or three devices providing separate displays. The preferred embodiment combines a commonly used and commercially available flight director-type device for providing a display in combination with a miniature aircraft supported for angular displacement from a vertical orientation to indicate heading error, or heading offset, and an extended course deviation indicator bar which projects into juxtaposition with the miniature aircraft for providing a true picture of the aircraft's horizontal situation relative to a selective VOR, ILS, or MLS course.

Collision judgment when using an augmented-vision head-mounted display device

PubMed Central

Luo, Gang; Woods, Russell L; Peli, Eli

2016-01-01

Purpose We have developed a device to provide an expanded visual field to patients with tunnel vision by superimposing minified edge images of the wide scene, in which objects appear closer to the heading direction than they really are. We conducted experiments in a virtual environment to determine if users would overestimate collision risks. Methods Given simulated scenes of walking or standing with intention to walk towards a given direction (intended walking) in a shopping mall corridor, participants (12 normally sighted and 7 with tunnel vision) reported whether they would collide with obstacles appearing at different offsets from variable walking paths (or intended directions), with and without the device. The collision envelope (CE), a personal space based on perceived collision judgments, and judgment uncertainty (variability of response) were measured. When the device was used, combinations of two image scales (5× minified and 1:1) and two image types (grayscale or edge images) were tested. Results Image type did not significantly alter collision judgment (p>0.7). Compared to the without-device baseline, minification did not significantly change the CE of normally sighted subjects for simulated walking (p=0.12), but increased CE by 30% for intended walking (p<0.001). Their uncertainty was not affected by minification (p>0.25). For the patients, neither CE nor uncertainty was affected by minification (p>0.13) in both walking conditions. Baseline CE and uncertainty were greater for patients than normally-sighted subjects in simulated walking (p=0.03), but the two groups were not significantly different in all other conditions. Conclusion Users did not substantially overestimate collision risk, as the 5× minified images had only limited impact on collision judgments either during walking or before starting to walk. PMID:19458339

Collision judgment when using an augmented-vision head-mounted display device.

PubMed

Luo, Gang; Woods, Russell L; Peli, Eli

2009-09-01

A device was developed to provide an expanded visual field to patients with tunnel vision by superimposing minified edge images of the wide scene, in which objects appear closer to the heading direction than they really are. Experiments were conducted in a virtual environment to determine whether users would overestimate collision risks. Given simulated scenes of walking or standing with intention to walk toward a given direction (intended walking) in a shopping mall corridor, participants (12 normally sighted and 7 with tunnel vision) reported whether they would collide with obstacles appearing at different offsets from variable walking paths (or intended directions), with and without the device. The collision envelope (CE), a personal space based on perceived collision judgments, and judgment uncertainty (variability of response) were measured. When the device was used, combinations of two image scales (5x minified and 1:1) and two image types (grayscale or edge images) were tested. Image type did not significantly alter collision judgment (P > 0.7). Compared to the without-device baseline, minification did not significantly change the CE of normally sighted subjects for simulated walking (P = 0.12), but increased CE by 30% for intended walking (P < 0.001). Their uncertainty was not affected by minification (P > 0.25). For the patients, neither CE nor uncertainty was affected by minification (P > 0.13) in both walking conditions. Baseline CE and uncertainty were greater for patients than normally sighted subjects in simulated walking (P = 0.03), but the two groups were not significantly different in all other conditions. Users did not substantially overestimate collision risk, as the x5 minified images had only limited impact on collision judgments either during walking or before starting to walk.

Automatic cell identification and visualization using digital holographic microscopy with head mounted augmented reality devices.

PubMed

O'Connor, Timothy; Rawat, Siddharth; Markman, Adam; Javidi, Bahram

2018-03-01

We propose a compact imaging system that integrates an augmented reality head mounted device with digital holographic microscopy for automated cell identification and visualization. A shearing interferometer is used to produce holograms of biological cells, which are recorded using customized smart glasses containing an external camera. After image acquisition, segmentation is performed to isolate regions of interest containing biological cells in the field-of-view, followed by digital reconstruction of the cells, which is used to generate a three-dimensional (3D) pseudocolor optical path length profile. Morphological features are extracted from the cell's optical path length map, including mean optical path length, coefficient of variation, optical volume, projected area, projected area to optical volume ratio, cell skewness, and cell kurtosis. Classification is performed using the random forest classifier, support vector machines, and K-nearest neighbor, and the results are compared. Finally, the augmented reality device displays the cell's pseudocolor 3D rendering of its optical path length profile, extracted features, and the identified cell's type or class. The proposed system could allow a healthcare worker to quickly visualize cells using augmented reality smart glasses and extract the relevant information for rapid diagnosis. To the best of our knowledge, this is the first report on the integration of digital holographic microscopy with augmented reality devices for automated cell identification and visualization.

Quantification of visual clutter using a computation model of human perception : an application for head-up displays

DOT National Transportation Integrated Search

2004-03-20

A means of quantifying the cluttering effects of symbols is needed to evaluate the impact of displaying an increasing volume of information on aviation displays such as head-up displays. Human visual perception has been successfully modeled by algori...

Human interaction with wearable computer systems: a look at glasses-mounted displays

NASA Astrophysics Data System (ADS)

Revels, Allen R.; Quill, Laurie L.; Kancler, David E.; Masquelier, Barbara L.

1998-09-01

With the advancement of technology and the information explosion, integration of the two into performance aiding systems can have a significant impact on operational and maintenance environments. The Department of Defense and commercial industry have made great strides in digitizing and automating technical manuals and data to be presented on performance aiding systems. These performance aides are computerized interactive systems that provide procedures on how to operate and maintain fielded systems. The idea is to provide the end-user a system which is compatible with their work environment. The purpose of this paper is to show, historically, the progression of wearable computer aiding systems for maintenance environments, and then highlight the work accomplished in the design and development of glasses- mounted displays (GMD). The paper reviews work performed over the last seven years, then highlights, through review of a usability study, the advances made with GMDs. The use of portable computing systems, such as laptop and notebook, computers, does not necessarily increase the accessibility of the displayed information while accomplishing a given task in a hands-busy, mobile work environment. The use of a GMD increases accessibility of the information by placing it in eye sight of the user without obstructing the surrounding environment. Although the potential utility for this type of display is great, hardware and human integration must be refined. Results from the usability study show the usefulness and usability of the GMD in a mobile, hands-free environment.

Simulator evaluation of display concepts for pilot monitoring and control of space shuttle approach and landing. Phase 2: Manual flight control

NASA Technical Reports Server (NTRS)

Gartner, W. B.; Baldwin, K. M.

1973-01-01

A study of the display requirements for final approach management of the space shuttle orbiter vehicle is presented. An experimental display concept, providing a more direct, pictorial representation of the vehicle's movement relative to the selected approach path and aiming points, was developed and assessed as an aid to manual flight path control. Both head-up, windshield projections and head-down, panel mounted presentations of the experimental display were evaluated in a series of simulated orbiter approach sequence. Data obtained indicate that the experimental display would enable orbiter pilots to exercise greater flexibility in implementing alternative final approach control strategies. Touchdown position and airspeed dispersion criteria were satisfied on 91 percent of the approach sequences, representing various profile and wind effect conditions. Flight path control and airspeed management satisfied operationally-relevant criteria for the two-segment, power-off orbiter approach and were consistently more accurate and less variable when the full set of experimental display elements was available to the pilot. Approach control tended to be more precise when the head-up display was used; however, the data also indicate that the head-down display would provide adequate support for the manual control task.

Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results

NASA Technical Reports Server (NTRS)

Hughes, Monica F.; Glaab, Louis J.

2007-01-01

A critical component of SVS displays is the appropriate presentation of terrain to the pilot. At the time of this study, the relationship between the complexity of the terrain presentation and resulting enhancements of pilot SA and pilot performance had been largely undefined. The terrain portrayal for SVS head-down displays (TP-HDD) simulation examined the effects of two primary elements of terrain portrayal on the primary flight display (PFD): variations of digital elevation model (DEM) resolution and terrain texturing. Variations in DEM resolution ranged from sparsely spaced (30 arc-sec) to very closely spaced data (1 arc-sec). Variations in texture involved three primary methods: constant color, elevation-based generic, and photo-realistic, along with a secondary depth cue enhancer in the form of a fishnet grid overlay.

Study for verification testing of the helmet-mounted display in the Japanese Experimental Module.

PubMed

Nakajima, I; Yamamoto, I; Kato, H; Inokuchi, S; Nemoto, M

2000-02-01

Our purpose is to propose a research and development project in the field of telemedicine. The proposed Multimedia Telemedicine Experiment for Extra-Vehicular Activity will entail experiments designed to support astronaut health management during Extra-Vehicular Activity (EVA). Experiments will have relevant applications to the Japanese Experimental Module (JEM) operated by National Space Development Agency of Japan (NASDA) for the International Space Station (ISS). In essence, this is a proposal for verification testing of the Helmet-Mounted Display (HMD), which enables astronauts to verify their own blood pressures and electrocardiograms, and to view a display of instructions from the ground station and listings of work procedures. Specifically, HMD is a device designed to project images and data inside the astronaut's helmet. We consider this R&D proposal to be one of the most suitable projects under consideration in response to NASDA's open invitation calling for medical experiments to be conducted on JEM.

Head-mounted eye tracking: a new method to describe infant looking.

PubMed

Franchak, John M; Kretch, Kari S; Soska, Kasey C; Adolph, Karen E

2011-01-01

Despite hundreds of studies describing infants' visual exploration of experimental stimuli, researchers know little about where infants look during everyday interactions. The current study describes the first method for studying visual behavior during natural interactions in mobile infants. Six 14-month-old infants wore a head-mounted eye-tracker that recorded gaze during free play with mothers. Results revealed that infants' visual exploration is opportunistic and depends on the availability of information and the constraints of infants' own bodies. Looks to mothers' faces were rare following infant-directed utterances but more likely if mothers were sitting at infants' eye level. Gaze toward the destination of infants' hand movements was common during manual actions and crawling, but looks toward obstacles during leg movements were less frequent. © 2011 The Authors. Child Development © 2011 Society for Research in Child Development, Inc.

Issues and Knowledge Concerning the Use of Heads-Up Displays in Air Transports

DOT National Transportation Integrated Search

2003-03-01

This document provides a literature review of design issues encountered by the Federal Aviation Administration (FAA) during the : certification of head-up displays (HUDs) for use in air transports. This review extracts certification advice from the l...

Head-Up Auditory Displays for Traffic Collision Avoidance System Advisories: A Preliminary Investigation

NASA Technical Reports Server (NTRS)

Begault, Durand R.

1993-01-01

The advantage of a head-up auditory display was evaluated in a preliminary experiment designed to measure and compare the acquisition time for capturing visual targets under two auditory conditions: standard one-earpiece presentation and two-earpiece three-dimensional (3D) audio presentation. Twelve commercial airline crews were tested under full mission simulation conditions at the NASA-Ames Man-Vehicle Systems Research Facility advanced concepts flight simulator. Scenario software generated visual targets corresponding to aircraft that would activate a traffic collision avoidance system (TCAS) aural advisory; the spatial auditory position was linked to the visual position with 3D audio presentation. Results showed that crew members using a 3D auditory display acquired targets approximately 2.2 s faster than did crew members who used one-earpiece head- sets, but there was no significant difference in the number of targets acquired.

Exploring Virtual Worlds with Head-Mounted Displays

DTIC Science & Technology

1989-02-01

docking problem is important both to biochemists attempting to understand how proteins and nucleic acids work, and to chemists doing analytic drug design...then depressing the mouse button he is able to manipulate the methotrexate. A. long as the mouse button is depressed the methotrexate will follow the... depressing the mouse button outside of the drug’s "grabbing" volume. In this mode, both molecules move in concert. When the active site is positioned to

A novel active heads-up display for driver assistance.

PubMed

Doshi, Anup; Cheng, Shinko Yuanhsien; Trivedi, Mohan Manubhai

2009-02-01

In this paper, we introduce a novel laser-based wide-area heads-up windshield display which is capable of actively interfacing with a human as part of a driver assistance system. The dynamic active display (DAD) is a unique prototype interface that presents safety-critical visual icons to the driver in a manner that minimizes the deviation of his or her gaze direction without adding to unnecessary visual clutter. As part of an automotive safety system, the DAD presents alerts in the field of view of the driver only if necessary, which is based upon the state and pose of the driver, vehicle, and environment. This paper examines the effectiveness of DAD through a comprehensive comparative experimental evaluation of a speed compliance driver assistance system, which is implemented on a vehicular test bed. Three different types of display protocols for assisting a driver to comply with speed limits are tested on actual roadways, and these are compared with a conventional dashboard display. Given the inclination, drivers who are given an overspeed warning alert reduced the time required to slow down to the speed limit by 38% (p < 0.01) as compared with the drivers not given the alert. Additionally, certain alerts decreased distraction levels by reducing the time spent looking away from the road by 63% (p < 0.01). Ultimately, these alerts demonstrate the utility and promise of the DAD system.

An intelligent system and a relational data base for codifying helmet-mounted display symbology design requirements

NASA Astrophysics Data System (ADS)

Rogers, Steven P.; Hamilton, David B.

1994-06-01

To employ the most readily comprehensible presentation methods and symbology with helmet-mounted displays (HMDs), it is critical to identify the information elements needed to perform each pilot function and to analytically determine the attributes of these elements. The extensive analyses of mission requirements currently performed for pilot-vehicle interface design can be aided and improved by the new capabilities of intelligent systems and relational databases. An intelligent system, named ACIDTEST, has been developed specifically for organizing and applying rules to identify the best display modalities, locations, and formats. The primary objectives of the ACIDTEST system are to provide rapid accessibility to pertinent display research data, to integrate guidelines from many disciplines and identify conflicts among these guidelines, to force a consistent display approach among the design team members, and to serve as an 'audit trail' of design decisions and justifications. A powerful relational database called TAWL ORDIR has been developed to document information requirements and attributes for use by ACIDTEST as well as to greatly augment the applicability of mission analysis data. TAWL ORDIR can be used to rapidly reorganize mission analysis data components for study, perform commonality analyses for groups of tasks, determine the information content requirement for tailored display modes, and identify symbology integration opportunities.

Enhanced/synthetic vision and head-worn display technologies for terminal maneuvering area NextGen operations

NASA Astrophysics Data System (ADS)

Arthur, Jarvis J., III; Prinzel, Lawrence J., III; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

2011-06-01

NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field

Enhanced/Synthetic Vision and Head-Worn Display Technologies for Terminal Maneuvering Area NextGen Operations

NASA Technical Reports Server (NTRS)

Arthur, Jarvis J., III; Prinzell, Lawrence J.; Williams, Steven P.; Bailey, Randall E.; Shelton, Kevin J.; Norman, R. Mike

2011-01-01

NASA is researching innovative technologies for the Next Generation Air Transportation System (NextGen) to provide a "Better-Than-Visual" (BTV) capability as adjunct to "Equivalent Visual Operations" (EVO); that is, airport throughputs equivalent to that normally achieved during Visual Flight Rules (VFR) operations rates with equivalent and better safety in all weather and visibility conditions including Instrument Meteorological Conditions (IMC). These new technologies build on proven flight deck systems and leverage synthetic and enhanced vision systems. Two piloted simulation studies were conducted to access the use of a Head-Worn Display (HWD) with head tracking for synthetic and enhanced vision systems concepts. The first experiment evaluated the use a HWD for equivalent visual operations to San Francisco International Airport (airport identifier: KSFO) compared to a visual concept and a head-down display concept. A second experiment evaluated symbology variations under different visibility conditions using a HWD during taxi operations at Chicago O'Hare airport (airport identifier: KORD). Two experiments were conducted, one in a simulated San Francisco airport (KSFO) approach operation and the other, in simulated Chicago O'Hare surface operations, evaluating enhanced/synthetic vision and head-worn display technologies for NextGen operations. While flying a closely-spaced parallel approach to KSFO, pilots rated the HWD, under low-visibility conditions, equivalent to the out-the-window condition, under unlimited visibility, in terms of situational awareness (SA) and mental workload compared to a head-down enhanced vision system. There were no differences between the 3 display concepts in terms of traffic spacing and distance and the pilot decision-making to land or go-around. For the KORD experiment, the visibility condition was not a factor in pilot's rating of clutter effects from symbology. Several concepts for enhanced implementations of an unlimited field

Tracking a Head-Mounted Display in a Room-Sized Environment with Head-Mounted Cameras

DTIC Science & Technology

1990-04-01

poor resolution and a very limited working volume [Wan90]. 4 OPTOTRAK [Nor88] uses one camera with two dual-axis CCD infrared position sensors. Each...Nor88] Northern Digital. Trade literature on Optotrak - Northern Digital’s Three Dimensional Optical Motion Tracking and Analysis System. Northern Digital

Evaluation of stereoscopic video cameras synchronized with the movement of an operator's head on the teleoperation of the actual backhoe shovel

NASA Astrophysics Data System (ADS)

Minamoto, Masahiko; Matsunaga, Katsuya

1999-05-01

Operator performance while using a remote controlled backhoe shovel is described for three different stereoscopic viewing conditions: direct view, fixed stereoscopic cameras connected to a helmet mounted display (HMD), and rotating stereo camera connected and slaved to the head orientation of a free moving stereo HMD. Results showed that the head- slaved system provided the best performance.

Dismembering bodies for display: a bioarchaeological study of trophy heads from the Wari site of Conchopata, Peru.

PubMed

Tung, Tiffiny A

2008-07-01

Human trophy heads from the Wari site of Conchopata (AD 600-1000) are examined to evaluate if recently deceased persons or old corpses were used to make trophy heads and determine if the modifications are standardized. Similarly styled trophy heads may suggest state oversight that ensured uniform modifications, while different styles may suggest that various factions or kin groups prepared them to their own specifications. Other studies often interpret trophy heads as either enemies or ancestors; so, this study addresses that debate by documenting aspects of their identity as revealed through demographic, paleopathological, and trauma data. Results show that "fresh" bodies, not old corpses, were used to make trophies, as evidenced by cutmarks indicating intentional removal of soft tissues. Trophy heads are remarkably standardized; 89% display a hole on the superior of the cranium, apparently a design feature that displays the trophy head upright and facing forward when suspended by a cord. Of the 31 trophy heads, 24 are adolescents/adults and 7 are children, and of the 17 sexed adults, 15 are male and 2 are female. This suggests that adult men and children were favored as trophies. Among 19 observable adult trophy heads, 42% exhibit cranial trauma, suggesting that violence was common among this group. Complementary data on Wari iconography shows warriors wearing trophy heads and Wari deities holding captives and trophy heads. Thus, it is likely that captives (or just their heads) were taken in battles and raids-either secular or ritual-and eventually transformed into trophy heads. (c) 2008 Wiley-Liss, Inc.

gPhysics--Using Smart Glasses for Head-Centered, Context-Aware Learning in Physics Experiments

ERIC Educational Resources Information Center

Kuhn, Jochen; Lukowicz, Paul; Hirth, Michael; Poxrucker, Andreas; Weppner, Jens; Younas, Junaid

2016-01-01

Smart Glasses such as Google Glass are mobile computers combining classical Head-Mounted Displays (HMD) with several sensors. Therefore, contact-free, sensor-based experiments can be linked with relating, near-eye presented multiple representations. We will present a first approach on how Smart Glasses can be used as an experimental tool for…

Near field magnetic communications for helmet-mounted display applications

NASA Astrophysics Data System (ADS)

Field, Mark; Sailer, Alan

2005-05-01

Helmet-mounted displays need a data feed that is typically provided by a cable or RF wireless data link to an external computer. In defense applications these solutions are problematic: a cable gets in the way and restricts use and emergency egress, while an RF wireless link can be detected at some distance giving away position and is susceptible to jamming. What is required is an alternative wireless technology that is low power, extremely localized and difficult to detect or jam. Near field magnetic communications is one possible alternative to RF communications that may fulfill these needs. This technology uses a time varying magnetic field to carry information, and is only useable over small distances of order six feet. This is expected to have significant advantages for particular applications: notably power requirements and security compared with RF wireless links. The power stored in a magnetic field falls off as 1/r6, compared with 1/r2 for RF, which means that all the power is localized around the transmitter. By having a physically small communications region around each platform or user, a large bandwidth can be guaranteed by allowing the reuse of the frequency spectrum outside the immediate vicinity. It also confers security on the data-link, as the signal is undetectable beyond the short range of the system.

Pathway Design Effects on Synthetic Vision Head-Up Displays

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

2004-01-01

NASA s Synthetic Vision Systems (SVS) project is developing technologies with practical applications that will eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced pathway guidance for transport aircraft. This experiment evaluated the influence of different tunnel and guidance concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two tunnel formats (dynamic, minimal) were evaluated against a baseline condition (no tunnel) during simulated IMC approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence on the tunnel formats. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

Suppression of biodynamic interference in head-tracked teleoperation

NASA Technical Reports Server (NTRS)

Lifshitz, S.; Merhav, S. J.; Grunwald, A. J.; Tucker, G. E.; Tischler, M. B.

1991-01-01

The utility of helmet-tracked sights to provide pointing commands for teleoperation of cameras, lasers, or antennas in aircraft is degraded by the presence of uncommanded, involuntary heat motion, referred to as biodynamic interference. This interference limits the achievable precision required in pointing tasks. The noise contributions due to biodynamic interference consists of an additive component which is correlated with aircraft vibration and an uncorrelated, nonadditive component, referred to as remnant. An experimental simulation study is described which investigated the improvements achievable in pointing and tracking precision using dynamic display shifting in the helmet-mounted display. The experiment was conducted in a six degree of freedom motion base simulator with an emulated helmet-mounted display. Highly experienced pilot subjects performed precision head-pointing tasks while manually flying a visual flight-path tracking task. Four schemes using adaptive and low-pass filtering of the head motion were evaluated to determine their effects on task performance and pilot workload in the presence of whole-body vibration characteristic of helicopter flight. The results indicate that, for tracking tasks involving continuously moving targets, improvements of up to 70 percent can be achieved in percent on-target dwelling time and of up to 35 percent in rms tracking error, with the adaptive plus low-pass filter configuration. The results with the same filter configuration for the task of capturing randomly-positioned, stationary targets show an increase of up to 340 percent in the number of targets captured and an improvement of up to 24 percent in the average capture time. The adaptive plus low-pass filter combination was considered to exhibit the best overall display dynamics by each of the subjects.

Cognitive issues in head-up displays

NASA Technical Reports Server (NTRS)

Fischer, E.; Haines, R. F.

1980-01-01

The ability of pilots to recognize and act upon unexpected information, presented in either the outside world or in a head-up display (HUD), was evaluated. Eight commercial airline pilots flew 18 approaches with a flightpath-type HUD and 13 approaches with conventional instruments in a fixed-base 727 simulator. The approaches were flown under conditions of low visibility, turbulence, and wind shear. Vertical and lateral flight performance was measured for five cognitive variables: an unexpected obstacle on runway; vertical and lateral boresight-type offset of the HUD; lateral ILS beam bend-type offset; and no anomaly. Mean response time to the runway obstacle was longer with HUD than without it (4.13 vs 1.75 sec.), and two of the pilots did not see the obstacle at all with the HUD. None of the offsets caused any deterioration in lateral flight performance, but all caused some change in vertical tracking; all offsets seemed to magnify the environmental effects. In all conditions, both vertical and lateral tracking was better with the HUD than with the conventional instruments.

High color fidelity thin film multilayer systems for head-up display use

NASA Astrophysics Data System (ADS)

Tsou, Yi-Jen D.; Ho, Fang C.

1996-09-01

Head-up display is gaining increasing access in automotive vehicles for indication and position/navigation purposes. An optical combiner, which allows the driver to receive image information from outside and inside of the automobile, is the essential part of this display device. Two multilayer thin film combiner coating systems with distinctive polarization selectivity and broad band spectral neutrality are discussed. One of the coating systems was designed to be located at the lower portion of the windshield. The coating reduced the exterior glare by approximately 45% and provided about 70% average see-through transmittance in addition to the interior information display. The other coating system was designed to be integrated with the sunshield located at the upper portion of the windshield. The coating reflected the interior information display while reducing direct sunlight penetration to 25%. Color fidelity for both interior and exterior images were maintained in both systems. This facilitated the display of full-color maps. Both coating systems were absorptionless and environmentally durable. Designs, fabrication, and performance of these coating systems are addressed.

Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results: Compilation of Pilot Transcripts

NASA Technical Reports Server (NTRS)

Hughes, Monica F.; Glaab, Louis J.

2007-01-01

The Terrain Portrayal for Head-Down Displays (TP-HDD) simulation experiment addressed multiple objectives involving twelve display concepts (two baseline concepts without terrain and ten synthetic vision system (SVS) variations), four evaluation maneuvers (two en route and one approach maneuver, plus a rare-event scenario), and three pilot group classifications. The TP-HDD SVS simulation was conducted in the NASA Langley Research Center's (LaRC's) General Aviation WorkStation (GAWS) facility. The results from this simulation establish the relationship between terrain portrayal fidelity and pilot situation awareness, workload, stress, and performance and are published in the NASA TP entitled Terrain Portrayal for Synthetic Vision Systems Head-Down Displays Evaluation Results. This is a collection of pilot comments during each run of the TP-HDD simulation experiment. These comments are not the full transcripts, but a condensed version where only the salient remarks that applied to the scenario, the maneuver, or the actual research itself were compiled.

Lightweight helmet-mounted eye movement measurement system

NASA Technical Reports Server (NTRS)

Barnes, J. A.

1978-01-01

The helmet-mounted eye movement measuring system, weighs 1,530 grams; the weight of the present aviators' helmet in standard form with the visor is 1,545 grams. The optical head is standard NAC Eye-Mark. This optical head was mounted on a magnesium yoke which in turn was attached to a slide cam mounted on the flight helmet. The slide cam allows one to adjust the eye-to-optics system distance quite easily and to secure it so that the system will remain in calibration. The design of the yoke and slide cam is such that the subject can, in an emergency, move the optical head forward and upward to the stowed and locked position atop the helmet. This feature was necessary for flight safety. The television camera that is used in the system is a solid state General Electric TN-2000 with a charged induced device imager used as the vidicon.

PTSD in Limb Trauma and Recovery

DTIC Science & Technology

2008-10-16

field of view, much greater image fidelity and more comfortable viewing than the Emagin head-mounted display, and is well-suited to deployment in a...run on display platforms other than the eMagin Head-Mounted Display (HMD). This will include Brown University’s Cave, an eight- foot immersive VR...Samsung display provides wider field of view, much greater image fidelity and more comfortable viewing than the Emagin head-mounted display, and is

Initial flight and simulator evaluation of a head up display for standard and noise abatement visual approaches

NASA Technical Reports Server (NTRS)

Bourquin, K.; Palmer, E. A.; Cooper, G.; Gerdes, R. M.

1973-01-01

A preliminary assessment was made of the adequacy of a simple head up display (HUD) for providing vertical guidance for flying noise abatement and standard visual approaches in a jet transport. The HUD featured gyro-stabilized approach angle scales which display the angle of declination to any point on the ground and a horizontal flight path bar which aids the pilot in his control of the aircraft flight path angle. Thirty-three standard and noise abatement approaches were flown in a Boeing 747 aircraft equipped with a head up display. The HUD was also simulated in a research simulator. The simulator was used to familiarize the pilots with the display and to determine the most suitable way to use the HUD for making high capture noise abatement approaches. Preliminary flight and simulator data are presented and problem areas that require further investigation are identified.

Brain state-dependence of electrically evoked potentials monitored with head-mounted electronics.

PubMed

Richardson, Andrew G; Fetz, Eberhard E

2012-11-01

Inferring changes in brain connectivity is critical to studies of learning-related plasticity and stimulus-induced conditioning of neural circuits. In addition, monitoring spontaneous fluctuations in connectivity can provide insight into information processing during different brain states. Here, we quantified state-dependent connectivity changes throughout the 24-h sleep-wake cycle in freely behaving monkeys. A novel, head-mounted electronic device was used to electrically stimulate at one site and record evoked potentials at other sites. Electrically evoked potentials (EEPs) revealed the connectivity pattern between several cortical sites and the basal forebrain. We quantified state-dependent changes in the EEPs. Cortico-cortical EEP amplitude increased during slow-wave sleep, compared to wakefulness, while basal-cortical EEP amplitude decreased. The results demonstrate the utility of using portable electronics to document state-dependent connectivity changes in freely behaving primates.

Skin suturing and cortical surface viral infusion improves imaging of neuronal ensemble activity with head-mounted miniature microscopes.

PubMed

Li, Xinjian; Cao, Vania Y; Zhang, Wenyu; Mastwal, Surjeet S; Liu, Qing; Otte, Stephani; Wang, Kuan Hong

2017-11-01

In vivo optical imaging of neural activity provides important insights into brain functions at the single-cell level. Cranial windows and virally delivered calcium indicators are commonly used for imaging cortical activity through two-photon microscopes in head-fixed animals. Recently, head-mounted one-photon microscopes have been developed for freely behaving animals. However, minimizing tissue damage from the virus injection procedure and maintaining window clarity for imaging can be technically challenging. We used a wide-diameter glass pipette at the cortical surface for infusing the viral calcium reporter AAV-GCaMP6 into the cortex. After infusion, the scalp skin over the implanted optical window was sutured to facilitate postoperative recovery. The sutured scalp was removed approximately two weeks later and a miniature microscope was attached above the window to image neuronal activity in freely moving mice. We found that cortical surface virus infusion efficiently labeled neurons in superficial layers, and scalp skin suturing helped to maintain the long-term clarity of optical windows. As a result, several hundred neurons could be recorded in freely moving animals. Compared to intracortical virus injection and open-scalp postoperative recovery, our methods minimized tissue damage and dura overgrowth underneath the optical window, and significantly increased the experimental success rate and the yield of identified neurons. Our improved cranial surgery technique allows for high-yield calcium imaging of cortical neurons with head-mounted microscopes in freely behaving animals. This technique may be beneficial for other optical applications such as two-photon microscopy, multi-site imaging, and optogenetic modulation. Published by Elsevier B.V.

Integrated head package for top mounted nuclear instrumentation

DOEpatents

Malandra, Louis J.; Hornak, Leonard P.; Meuschke, Robert E.

1993-01-01

A nuclear reactor such as a pressurized water reactor has an integrated head package providing structural support and increasing shielding leading toward the vessel head. A reactor vessel head engages the reactor vessel, and a control rod guide mechanism over the vessel head raises and lowers control rods in certain of the thimble tubes, traversing penetrations in the reactor vessel head, and being coupled to the control rods. An instrumentation tube structure includes instrumentation tubes with sensors movable into certain thimble tubes disposed in the fuel assemblies. Couplings for the sensors also traverse penetrations in the reactor vessel head. A shroud is attached over the reactor vessel head and encloses the control rod guide mechanism and at least a portion of the instrumentation tubes when retracted. The shroud forms a structural element of sufficient strength to support the vessel head, the control rod guide mechanism and the instrumentation tube structure, and includes radiation shielding material for limiting passage of radiation from retracted instrumentation tubes. The shroud is thicker at the bottom adjacent the vessel head, where the more irradiated lower ends of retracted sensors reside. The vessel head, shroud and contents thus can be removed from the reactor as a unit and rested safely and securely on a support.

Evaluation of helmet-mounted display targeting symbology based on eye tracking technology

NASA Astrophysics Data System (ADS)

Wang, Lijing; Wen, Fuzhen; Ma, Caixin; Zhao, Shengchu; Liu, Xiaodong

2014-06-01

The purpose of this paper is to find the Target Locator Lines (TLLs) which perform best by contrasting and comparing experiment based on three kinds of TTLs of fighter HMD. 10 university students, male, with an average age of 21-23, corrected visual acuity 1.5, participated in the experiment. In the experiment, head movement data was obtained by TrackIR. The geometric relationship between the coordinates of the real world and coordinates of the visual display was obtained by calculating the distance from viewpoint to midpoint of both eyes and the head movement data. Virtual helmet system simulation experiment environment was created by drawing TLLs of fighter HMD in the flight simulator visual scene. In the experiment, eye tracker was used to record the time and saccade trajectory. The results were evaluated by the duration of the time and saccade trajectory. The results showed that the symbol"locator line with digital vector length indication" cost most time and had the longest length of the saccade trajectory. It is the most ineffective and most unacceptable way. "Locator line with extending head vector length symbol" cost less time and had less length of the saccade trajectory. It is effective and acceptable;"Locator line with reflected vector length symbol" cost the least time and had the least length of the saccade trajectory. It is the most effective and most acceptable way. "Locator line with reflected vector length symbol" performs best. The results will provide reference value for the research of TTLs in future.

Issues and research needs concerning the use of head-up displays in air transports

DOT National Transportation Integrated Search

2001-10-14

Head-up Displays (HUDs) are being installed in air transports in order to allow manual approaches, landings, and takeoffs in poor visibility. HUDs make it possible to overlay and augment the real-world image with conformal symbols such as a flight pa...

Terrain Portrayal for Head-Down Displays Flight Test

NASA Technical Reports Server (NTRS)

Hughes, Monica F.; Glaab, Louis J.

2003-01-01

The Synthetic Vision Systems General Aviation (SVS-GA) element of NASA's Aviation Safety Program is developing technology to eliminate low visibility induced General Aviation (GA) accidents through the application of synthetic vision techniques. SVS displays present computer generated 3-dimensional imagery of the surrounding terrain to greatly enhance pilot's situation awareness (SA), reducing or eliminating Controlled Flight into Terrain (CFIT), as well as Low-Visibility Loss of Control (LVLOC) accidents. In addition to substantial safety benefits, SVS displays have many potential operational benefits that can lead to flight in instrument meteorological conditions (IMC) resembling those conducted in visual meteorological conditions (VMC). Potential benefits could include lower landing minimums, more approach options, reduced training time, etc. SVS conducted research will develop display concepts providing the pilot with an unobstructed view of the outside terrain, regardless of weather conditions and time of day. A critical component of SVS displays is the appropriate presentation of terrain to the pilot. The relationship between the realism of the terrain presentation and resulting enhancements of pilot SA and pilot performance has been largely undefined. Comprised of coordinated simulation and flight test efforts, the terrain portrayal for head-down displays (TP-HDD) test series examined the effects of two primary elements of terrain portrayal: variations of digital elevation model (DEM) resolution and terrain texturing. Variations in DEM resolution ranged from sparsely spaced (30 arc-sec/2,953ft) to very closely spaced data (1 arc-sec/98 ft). Variations in texture involved three primary methods: constant color, elevation-based generic, and photo-realistic, along with a secondary depth cue enhancer in the form of a fishnet grid overlay. The TP-HDD test series was designed to provide comprehensive data to enable design trades to optimize all SVS applications, as

Binocular Rivalry in Helmet-Mounted Display Applications

DTIC Science & Technology

1975-06-01

research apparatus. 31 ., simple magnifying ophthalmic lenses were used, mounted in eyeglass frames. These were 2. 5 diopter lenses for both eyes to...wear eyeglasses with 2. 5 diopter lenses. The focal length of these lenses was 15. 5 inches and the eye waa accommodated at infinity when objects were...HMD luminance is positively related to I-I•D visibility, while ambient scene luminance bears an inverse relation- ship to HMD visibility. Scene

Stereoscopic display technologies, interaction paradigms, and rendering approaches for neurosurgical visualization

NASA Astrophysics Data System (ADS)

Cooperstock, Jeremy R.; Wang, Guangyu

2009-02-01

We conducted a comparative study of different stereoscopic display modalities (head-mounted display, polarized projection, and multiview lenticular display) to evaluate their efficacy in supporting manipulation and understanding of 3D content, specifically, in the context of neurosurgical visualization. Our study was intended to quantify the differences in resulting task performance between these choices of display technology. The experimental configuration involved a segmented brain vasculature and a simulated tumor. Subjects were asked to manipulate the vasculature and a pen-like virtual probe in order to define a vessel-free path from cortical surface to the targeted tumor. Because of the anatomical complexity, defining such a path can be a challenging task. To evaluate the system, we quantified performance differences under three different stereoscopic viewing conditions. Our results indicate that, on average, participants achieved best performance using polarized projection, and worst with the multiview lenticular display. These quantitative measurements were further reinforced by the subjects' responses to our post-test questionnaire regarding personal preferences.

An evaluation of head-up displays in civil transport operations

NASA Technical Reports Server (NTRS)

Lauber, J. K.; Bray, R. S.; Scott, B. C.

1981-01-01

To determine the advantages and disadvantages of head-up displays (HUD) in civil transport approach and landing operations, an operational evaluation was conducted on the flight simulator for advanced aircraft at Ames. A non-conformal HUD concept which contained raw data and Flight Director command information, and a conformal, flight path HUD concept was designed to permit terminal area maneuvering, intercept, final approach, flare, and landing operations. Twelve B-727 line pilots (Captains) flew a series of precision and non-precision approaches under a variety of environmental and operational conditions, including wind shear, turbulence and low ceilings and visibilities. A preliminary comparison of various system and pilot performance measures as a function of display type (Flight Director HUD, Flight Path HUD, or No HUD) indicates improvements in precision and accuracy of aircraft flight path control when using the HUDs. The results also demonstrated some potentially unique advantages of a flight path HUD during non-precision approaches.

Study of a direct visualization display tool for space applications

NASA Astrophysics Data System (ADS)

Pereira do Carmo, J.; Gordo, P. R.; Martins, M.; Rodrigues, F.; Teodoro, P.

2017-11-01

The study of a Direct Visualization Display Tool (DVDT) for space applications is reported. The review of novel technologies for a compact display tool is described. Several applications for this tool have been identified with the support of ESA astronauts and are presented. A baseline design is proposed. It consists mainly of OLEDs as image source; a specially designed optical prism as relay optics; a Personal Digital Assistant (PDA), with data acquisition card, as control unit; and voice control and simplified keyboard as interfaces. Optical analysis and the final estimated performance are reported. The system is able to display information (text, pictures or/and video) with SVGA resolution directly to the astronaut using a Field of View (FOV) of 20x14.5 degrees. The image delivery system is a monocular Head Mounted Display (HMD) that weights less than 100g. The HMD optical system has an eye pupil of 7mm and an eye relief distance of 30mm.

Human-machine interface issues in the use of helmet-mounted displays in short conjugate simulators

NASA Astrophysics Data System (ADS)

Melzer, James E.

2011-06-01

With the introduction of helmet-mounted displays (HMD) into modern aircraft, there is a desire on the part of pilot trainees to achieve a "look and feel" for the simulation environment similar to the real flight hardware. Given this requirement for high fidelity, it may be necessary to configure - or to perhaps re-configure - the HMD for a short conjugate viewing distance and to do so without causing eye strain or other adverse physiological effects. This paper will survey the human factors literature and provide an analysis on the visual construct issues of focus and vergence which - if not properly configured for the short conjugate simulator - could cause adverse effects, which can negatively affect training.

Enhanced flight symbology for wide-field-of-view helmet-mounted displays

NASA Astrophysics Data System (ADS)

Rogers, Steven P.; Asbury, Charles N.; Szoboszlay, Zoltan P.

2003-09-01

A series of studies was conducted to improve the Army aviator's ability to perform night missions by developing innovative symbols that capitalize on the advantages of new wide field-of-view (WFOV) helmet-mounted displays (HMDs). The most important outcomes of the research were two new symbol types called the Cylinder and the Flight Path Predictor. The Cylinder provides a large symbolic representation of real-world orientation that enables pilots to maintain the world frame of reference even if the visibility of the world is lost due to dust, smoke, snow, or inadvertent instrument meteorological conditions (IMC). Furthermore, the Cylinder is peripherally presented, supporting the "ambient" visual mode so that it does not require the conscious attention of the viewer. The Flight Path Predictor was developed to show the predicted flight path of a maneuvering aircraft using earth-referenced HMD symbology. The experimental evidence and the pilot interview results show that the new HMD symbology sets are capable of preventing spatial disorientation, improving flight safety, enhancing flight maneuver precision, and reducing workload so that the pilot can more effectively perform the critical mission tasks.

Advanced Pathway Guidance Evaluations on a Synthetic Vision Head-Up Display

NASA Technical Reports Server (NTRS)

Kramer, Lynda J.; Prinzel, Lawrence J., III; Arthur, Jarvis J., III; Bailey, Randall E.

2005-01-01

NASA's Synthetic Vision Systems (SVS) project is developing technologies with practical applications to potentially eliminate low visibility conditions as a causal factor to civil aircraft accidents while replicating the operational benefits of clear day flight operations, regardless of the actual outside visibility condition. A major thrust of the SVS project involves the development/demonstration of affordable, certifiable display configurations that provide intuitive out-the-window terrain and obstacle information with advanced guidance for commercial and business aircraft. This experiment evaluated the influence of different pathway and guidance display concepts upon pilot situation awareness (SA), mental workload, and flight path tracking performance for Synthetic Vision display concepts using a Head-Up Display (HUD). Two pathway formats (dynamic and minimal tunnel presentations) were evaluated against a baseline condition (no tunnel) during simulated instrument meteorological conditions approaches to Reno-Tahoe International airport. Two guidance cues (tadpole, follow-me aircraft) were also evaluated to assess their influence. Results indicated that the presence of a tunnel on an SVS HUD had no effect on flight path performance but that it did have significant effects on pilot SA and mental workload. The dynamic tunnel concept with the follow-me aircraft guidance symbol produced the lowest workload and provided the highest SA among the tunnel concepts evaluated.

Rotation and direction judgment from visual images head-slaved in two and three degrees-of-freedom.

PubMed

Adelstein, B D; Ellis, S R

2000-03-01

The contribution to spatial awareness of adding a roll degree-of-freedom (DOF) to telepresence camera platform yaw and pitch was examined in an experiment where subjects judged direction and rotation of stationary target markers in a remote scene. Subjects viewed the scene via head-slaved camera images in a head-mounted display. Elimination of the roll DOF affected rotation judgment, but only at extreme yaw and pitch combinations, and did not affect azimuth and elevation judgement. Systematic azimuth overshoot occurred regardless of roll condition. Observed rotation misjudgments are explained by kinematic models for eye-head direction of gaze.

Effect of Display Technology on Perceived Scale of Space.

PubMed

Geuss, Michael N; Stefanucci, Jeanine K; Creem-Regehr, Sarah H; Thompson, William B; Mohler, Betty J

2015-11-01

Our goal was to evaluate the degree to which display technologies influence the perception of size in an image. Research suggests that factors such as whether an image is displayed stereoscopically, whether a user's viewpoint is tracked, and the field of view of a given display can affect users' perception of scale in the displayed image. Participants directly estimated the size of a gap by matching the distance between their hands to the gap width and judged their ability to pass unimpeded through the gap in one of five common implementations of three display technologies (two head-mounted displays [HMD] and a back-projection screen). Both measures of gap width were similar for the two HMD conditions and the back projection with stereo and tracking. For the displays without tracking, stereo and monocular conditions differed from each other, with monocular viewing showing underestimation of size. Display technologies that are capable of stereoscopic display and tracking of the user's viewpoint are beneficial as perceived size does not differ from real-world estimates. Evaluations of different display technologies are necessary as display conditions vary and the availability of different display technologies continues to grow. The findings are important to those using display technologies for research, commercial, and training purposes when it is important for the displayed image to be perceived at an intended scale. © 2015, Human Factors and Ergonomics Society.

Man-in-the-loop study of filtering in airborne head tracking tasks

NASA Technical Reports Server (NTRS)

Lifshitz, S.; Merhav, S. J.

1992-01-01

A human-factors study is conducted of problems due to vibrations during the use of a helmet-mounted display (HMD) in tracking tasks whose major factors are target motion and head vibration. A method is proposed for improving aiming accuracy in such tracking tasks on the basis of (1) head-motion measurement and (2) the shifting of the reticle in the HMD in ways that inhibit much of the involuntary apparent motion of the reticle, relative to the target, and the nonvoluntary motion of the teleoperated device. The HMD inherently furnishes the visual feedback required by this scheme.

Reduce volume of head-up display by image stitching

NASA Astrophysics Data System (ADS)

Chiu, Yi-Feng; Su, Guo-Dung J.

2016-09-01

Head-up Display (HUD) is a safety feature for automobile drivers. Although there have been some HUD systems in commercial product already, their images are too small to show assistance information. Another problem, the volume of HUD is too large. We proposed a HUD including micro-projectors, rear-projection screen, microlens array (MLA) and the light source is 28 mm x 14 mm realized a 200 mm x 100 mm image in 3 meters from drivers. We want to use the MLA to reduce the volume by virtual image stitching. We design the HUD's package dimensions is 12 cm x 12 cm x 9 cm. It is able to show speed, map-navigation and night vision information. We used Liquid Crystal Display (LCD) as our image source due to its brighter image output required and the minimum volume occupancy. The MLA is a multi aperture system. The proposed MLA consists of many optical channels each transmitting a segment of the whole field of view. The design of the system provides the stitching of the partial images, so that we can see the whole virtual image.

Auditory, visual, and bimodal data link displays and how they support pilot performance.

PubMed

Steelman, Kelly S; Talleur, Donald; Carbonari, Ronald; Yamani, Yusuke; Nunes, Ashley; McCarley, Jason S

2013-06-01

The design of data link messaging systems to ensure optimal pilot performance requires empirical guidance. The current study examined the effects of display format (auditory, visual, or bimodal) and visual display position (adjacent to instrument panel or mounted on console) on pilot performance. Subjects performed five 20-min simulated single-pilot flights. During each flight, subjects received messages from a simulated air traffic controller. Messages were delivered visually, auditorily, or bimodally. Subjects were asked to read back each message aloud and then perform the instructed maneuver. Visual and bimodal displays engendered lower subjective workload and better altitude tracking than auditory displays. Readback times were shorter with the two unimodal visual formats than with any of the other three formats. Advantages for the unimodal visual format ranged in size from 2.8 s to 3.8 s relative to the bimodal upper left and auditory formats, respectively. Auditory displays allowed slightly more head-up time (3 to 3.5 seconds per minute) than either visual or bimodal displays. Position of the visual display had only modest effects on any measure. Combined with the results from previous studies by Helleberg and Wickens and Lancaster and Casali the current data favor visual and bimodal displays over auditory displays; unimodal auditory displays were favored by only one measure, head-up time, and only very modestly. Data evinced no statistically significant effects of visual display position on performance, suggesting that, contrary to expectations, the placement of a visual data link display may be of relatively little consequence to performance.

Field emitter displays for future avionics applications

NASA Astrophysics Data System (ADS)

Jones, Susan K.; Jones, Gary W.; Zimmerman, Steven M.; Blazejewski, Edward R.

1995-06-01

Field emitter array-based display technology offers CRT-like characteristics in a thin flat-panel display with many potential applications for vehicle-mounted, crew workstation, and helmet-mounted displays, as well as many other military and commercial applications. In addition to thinness, high brightness, wide viewing angle, wide temperature range, and low weight, field emitter array displays also offer potential advantages such as row-at-a-time matrix addressability and the ability to be segmented.

An evaluation of flight path formats head-up and head-down

NASA Technical Reports Server (NTRS)

Sexton, George A.; Moody, Laura E.; Evans, Joanne; Williams, Kenneth E.

1988-01-01

Flight path primary flight display formats were incorporated on head-up and head-down electronic displays and integrated into an Advanced Concepts Flight Simulator. Objective and subjective data were collected while ten airline pilots evaluated the formats by flying an approach and landing task under various ceiling, visibility and wind conditions. Deviations from referenced/commanded airspeed, horizontal track, vertical track and touchdown point were smaller using the head-up display (HUD) format than the head-down display (HDD) format, but not significantly smaller. Subjectively, the pilots overwhelmingly preferred (1) flight path formats over attitude formats used in current aircraft, and (2) the head-up presentation over the head-down, primarily because it eliminated the head-down to head-up transition during low visibility landing approaches. This report describes the simulator, the flight displays, the format evaluation, and the results of the objective and subjective data.

Three methods of presenting flight vector information in a head-up display during simulated STOL approaches

NASA Technical Reports Server (NTRS)

Dwyer, J. H., III; Palmer, E. A., III

1975-01-01

A simulator study was conducted to determine the usefulness of adding flight path vector symbology to a head-up display designed to improve glide-slope tracking performance during steep 7.5 deg visual approaches in STOL aircraft. All displays included a fixed attitude symbol, a pitch- and roll-stabilized horizon bar, and a glide-slope reference bar parallel to and 7.5 deg below the horizon bar. The displays differed with respect to the flight-path marker (FPM) symbol: display 1 had no FPM symbol; display 2 had an air-referenced FPM, and display 3 had a ground-referenced FPM. No differences between displays 1 and 2 were found on any of the performance measures. Display 3 was found to decrease height error in the early part of the approach and to reduce descent rate variation over the entire approach. Two measures of workload did not indicate any differences between the displays.

When less is best: female brown-headed cowbirds prefer less intense male displays.

PubMed

O'Loghlen, Adrian L; Rothstein, Stephen I

2012-01-01

Sexual selection theory predicts that females should prefer males with the most intense courtship displays. However, wing-spread song displays that male brown-headed cowbirds (Molothrus ater) direct at females are generally less intense than versions of this display that are directed at other males. Because male-directed displays are used in aggressive signaling, we hypothesized that females should prefer lower intensity performances of this display. To test this hypothesis, we played audiovisual recordings showing the same males performing both high intensity male-directed and low intensity female-directed displays to females (N = 8) and recorded the females' copulation solicitation display (CSD) responses. All eight females responded strongly to both categories of playbacks but were more sexually stimulated by the low intensity female-directed displays. Because each pair of high and low intensity playback videos had the exact same audio track, the divergent responses of females must have been based on differences in the visual content of the displays shown in the videos. Preferences female cowbirds show in acoustic CSD studies are correlated with mate choice in field and captivity studies and this is also likely to be true for preferences elucidated by playback of audiovisual displays. Female preferences for low intensity female-directed displays may explain why male cowbirds rarely use high intensity displays when signaling to females. Repetitive high intensity displays may demonstrate a male's current condition and explain why these displays are used in male-male interactions which can escalate into physical fights in which males in poorer condition could be injured or killed. This is the first study in songbirds to use audiovisual playbacks to assess how female sexual behavior varies in response to variation in a male visual display.

Visuomotor adaptation in head-mounted virtual reality versus conventional training

PubMed Central

Anglin, J. M.; Sugiyama, T.; Liew, S.-L.

2017-01-01

Immersive, head-mounted virtual reality (HMD-VR) provides a unique opportunity to understand how changes in sensory environments affect motor learning. However, potential differences in mechanisms of motor learning and adaptation in HMD-VR versus a conventional training (CT) environment have not been extensively explored. Here, we investigated whether adaptation on a visuomotor rotation task in HMD-VR yields similar adaptation effects in CT and whether these effects are achieved through similar mechanisms. Specifically, recent work has shown that visuomotor adaptation may occur via both an implicit, error-based internal model and a more cognitive, explicit strategic component. We sought to measure both overall adaptation and balance between implicit and explicit mechanisms in HMD-VR versus CT. Twenty-four healthy individuals were placed in either HMD-VR or CT and trained on an identical visuomotor adaptation task that measured both implicit and explicit components. Our results showed that the overall timecourse of adaption was similar in both HMD-VR and CT. However, HMD-VR participants utilized a greater cognitive strategy than CT, while CT participants engaged in greater implicit learning. These results suggest that while both conditions produce similar results in overall adaptation, the mechanisms by which visuomotor adaption occurs in HMD-VR appear to be more reliant on cognitive strategies. PMID:28374808

Some VTOL head-up display drive-law problems and solutions

NASA Technical Reports Server (NTRS)

Merrick, Vernon K.

1993-01-01

A piloted simulation test was conducted on the Ames Research Center's vertical motion simulator (VMS) in support of the Phase 2A flight test of NASA's V/STOL systems research aircraft (VSRA). During the simulation several problems were found with the head-up display (HUD) symbol drive laws and the flightpath synthesis. These problems and the solutions devised to solve them are described. Most of the resulting HUD drive-law changes were implemented during the simulation and their effectiveness was verified. Subsequently both the HUD symbol drive-law and flightpath-synthesis changes were implemented in the VSRA and tested successfully in the Phase 2A flight tests.

Comparison of two head-up displays in simulated standard and noise abatement night visual approaches

NASA Technical Reports Server (NTRS)

Cronn, F.; Palmer, E. A., III

1975-01-01

Situation and command head-up displays were evaluated for both standard and two segment noise abatement night visual approaches in a fixed base simulation of a DC-8 transport aircraft. The situation display provided glide slope and pitch attitude information. The command display provided glide slope information and flight path commands to capture a 3 deg glide slope. Landing approaches were flown in both zero wind and wind shear conditions. For both standard and noise abatement approaches, the situation display provided greater glidepath accuracy in the initial phase of the landing approaches, whereas the command display was more effective in the final approach phase. Glidepath accuracy was greater for the standard approaches than for the noise abatement approaches in all phases of the landing approach. Most of the pilots preferred the command display and the standard approach. Substantial agreement was found between each pilot's judgment of his performance and his actual performance.

OPO-based compact laser projection display

NASA Astrophysics Data System (ADS)

Lee, Dicky; Moulton, Peter F.; Bergstedt, Robert; Flint, Graham W.

2001-09-01

In this paper we discuss our red, green, and blue (RGB) optical parametric oscillator (OPO) based laser projection display. The complete project display consists of two subsystems, the RGB-OPO laser head and the light modulation unit. The RGB lights from rack-mounted laser head are fibers coupled to the projection unit for independent placement. The light source consists of a diode-pumped pump laser and a LBO-based OPO. Based on our Nd:YLF gain module design, the pump laser is frequency doubled to serve as the pump source for the OPO. The unconverted pump power is recycled as the green light for projection. The singly resonant, non- critically phase-matched (NCPM) OPO has, to date, generated 13 W of 898-nm signal power and an estimated 9.3 W of intra- cavity idler power at 1256 nm. With approximately 76% of pump depletion, the power of the residual green light for projection is about 5.8 W. We have extra-cavity doubled the signal to produce approximately 3.5 W of 449-nm blue light and intra-cavity doubled the idler to produce approximately 6 W of 628-nm red light. The OPO-based RGB source generates about 4000 lumens of D65-balanced white light. The overall electrical power on a commercially available JVC's three- panel D-ILA (reflective LCD) projector with the arc-lamp removed and extensive modifications. The projector has a native resolution of 1365 x 1024 and the expected on screen lumens from our laser display is about 1200 lumens.

Development of a Flyable Acousto-Optic Laser Beam Deflection System for a Head Up Display of the Future.

DTIC Science & Technology

Rayleigh criteria). The system was designed for stroke writing but was demonstrated with lissajous writing. The acousto - optic deflectors employed...The report describes a laser display which is to be used in a Head-Up Display of the future. The uniqueness of the display is that it uses acousto ... optic components for the modulation and deflection of the laser beam. As a result, there are no moving parts, which increases the reliability and life

A fully automated calibration method for an optical see-through head-mounted operating microscope with variable zoom and focus.

PubMed

Figl, Michael; Ede, Christopher; Hummel, Johann; Wanschitz, Felix; Ewers, Rolf; Bergmann, Helmar; Birkfellner, Wolfgang

2005-11-01

Ever since the development of the first applications in image-guided therapy (IGT), the use of head-mounted displays (HMDs) was considered an important extension of existing IGT technologies. Several approaches to utilizing HMDs and modified medical devices for augmented reality (AR) visualization were implemented. These approaches include video-see through systems, semitransparent mirrors, modified endoscopes, and modified operating microscopes. Common to all these devices is the fact that a precise calibration between the display and three-dimensional coordinates in the patient's frame of reference is compulsory. In optical see-through devices based on complex optical systems such as operating microscopes or operating binoculars-as in the case of the system presented in this paper-this procedure can become increasingly difficult since precise camera calibration for every focus and zoom position is required. We present a method for fully automatic calibration of the operating binocular Varioscope M5 AR for the full range of zoom and focus settings available. Our method uses a special calibration pattern, a linear guide driven by a stepping motor, and special calibration software. The overlay error in the calibration plane was found to be 0.14-0.91 mm, which is less than 1% of the field of view. Using the motorized calibration rig as presented in the paper, we were also able to assess the dynamic latency when viewing augmentation graphics on a mobile target; spatial displacement due to latency was found to be in the range of 1.1-2.8 mm maximum, the disparity between the true object and its computed overlay represented latency of 0.1 s. We conclude that the automatic calibration method presented in this paper is sufficient in terms of accuracy and time requirements for standard uses of optical see-through systems in a clinical environment.

Three-dimensional visualization and display technologies; Proceedings of the Meeting, Los Angeles, CA, Jan. 18-20, 1989

NASA Technical Reports Server (NTRS)

Robbins, Woodrow E. (Editor); Fisher, Scott S. (Editor)

1989-01-01

Special attention was given to problems of stereoscopic display devices, such as CAD for enhancement of the design process in visual arts, stereo-TV improvement of remote manipulator performance, a voice-controlled stereographic video camera system, and head-mounted displays and their low-cost design alternatives. Also discussed was a novel approach to chromostereoscopic microscopy, computer-generated barrier-strip autostereography and lenticular stereograms, and parallax barrier three-dimensional TV. Additional topics include processing and user interface isssues and visualization applications, including automated analysis and fliud flow topology, optical tomographic measusrements of mixing fluids, visualization of complex data, visualization environments, and visualization management systems.

Effects of head-up display airspeed indicator and altimeter formats on pilot scanning and attention switching

DOT National Transportation Integrated Search

2004-03-20

The effects of the rotating pointers and gradation marks of head-up display (HUD) airspeed : indicator (ASI) and altimeter symbology formats were examined. The effects of the gradation : marks were of special interest, as being able to remove them wo...

Distance Perception of Stereoscopically Presented Virtual Objects Optically Superimposed on Physical Objects by a Head-Mounted See-Through Display

NASA Technical Reports Server (NTRS)

Ellis, Stephen R.; Bucher, Urs J.; Statler, Irving C. (Technical Monitor)

1994-01-01

The influence of physically presented background stimuli on the perceived depth of optically overlaid, stereoscopic virtual images has been studied using headmounted stereoscopic, virtual image displays. These displays allow presentation of physically unrealizable stimulus combinations. Positioning of an opaque physical object either at the initial perceived depth of the virtual image or at a position substantially in front of the virtual image, causes the virtual image to perceptually move closer to the observer. In the case of objects positioned substantially in front of the virtual image, subjects often perceive the opaque object to become transparent. Evidence is presented that the apparent change of position caused by interposition of the physical object is not due to occlusion cues. According, it may have an alternative cause such as variation in the binocular vengeance position of the eyes caused by introduction of the physical object. This effect may complicate design of overlaid virtual image displays for near objects and appears to be related to the relative conspicuousness of the overlaid virtual image and the background. Consequently, it may be related to earlier analyses of John Foley which modeled open-loop pointing errors to stereoscopically presented points of light in terms of errors in determination of a reference point for interpretation of observed retinal disparities. Implications for the design of see-through displays for manufacturing will be discussed.

Pressure vessel bottle mount

NASA Technical Reports Server (NTRS)

Wingett, Paul (Inventor)

2001-01-01

A mounting assembly for mounting a composite pressure vessel to a vehicle includes a saddle having a curved surface extending between two pillars for receiving the vessel. The saddle also has flanged portions which can be bolted to the vehicle. Each of the pillars has hole in which is mounted the shaft portion of an attachment member. A resilient member is disposed between each of the shaft portions and the holes and loaded by a tightening nut. External to the holes, each of the attachment members has a head portion to which a steel band is attached. The steel band circumscribes the vessel and translates the load on the springs into a clamping force on the vessel. As the vessel expands and contracts, the resilient members expand and contract so that the clamping force applied by the band to the vessel remains constant.

Information presentation through a head-worn display (“smart glasses”) has a smaller influence on the temporal structure of gait variability during dual-task gait compared to handheld displays (paper-based system and smartphone)

PubMed Central

Sedighi, Alireza; Ulman, Sophia M.

2018-01-01

The need to complete multiple tasks concurrently is a common occurrence both daily life and in occupational activities, which can often include simultaneous cognitive and physical demands. As one example, there is increasing availability of head-worn display technologies that can be employed when a user is mobile (e.g., while walking). This new method of information presentation may, however, introduce risks of adverse outcomes such as a decrement to gait performance. The goal of this study was thus to quantify the effects of a head-worn display (i.e., smart glasses) on motor variability during gait and to compare these effects with those of other common information displays (i.e., smartphone and paper-based system). Twenty participants completed four walking conditions, as a single task and in three dual-task conditions (three information displays). In the dual-task conditions, the information display was used to present several cognitive tasks. Three different measures were used to quantify variability in gait parameters for each walking condition (using the cycle-to-cycle standard deviation, sample entropy, and the “goal-equivalent manifold” approach). Our results indicated that participants used less adaptable gait strategies in dual-task walking using the paper-based system and smartphone conditions compared with single-task walking. Gait performance, however, was less affected during dual-task walking with the smart glasses. We conclude that the risk of an adverse gait event (e.g., a fall) in head-down walking conditions (i.e., the paper-based system and smartphone conditions) were higher than in single-task walking, and that head-worn displays might help reduce the risk of such events during dual-task gait conditions. PMID:29630614

Magnitude of visual accommodation to a head-up display

NASA Technical Reports Server (NTRS)

Leitner, E. F.; Haines, R. F.

1981-01-01

The virtual image symbology of head-up displays (HUDs) is presented at optical infinity to the pilot. This design feature is intended to help pilots maintain visual focus distance at optical infinity. However, the accommodation response could be nearer than optical infinity, due to an individual's dark focus response. Accommodation responses were measured of two age groups of airline pilots to: (1) static symbology on a HUD; (2) a landing site background at optical infinity; (3) the combination of the HUD symbology and the landing site background; and (4) complete darkness. Results indicate that magnitude of accommodation to HUD symbology, with and without the background, is not significantly different from an infinity focus response for either age group. The dark focus response is significantly closer than optical infinity for the younger pilots, but not the older pilots, a finding consistent with previous research.

Common software and interface for different helmet-mounted display (HMD) aircraft symbology sets

NASA Astrophysics Data System (ADS)

Mulholland, Fred F.

2000-06-01

Different aircraft in different services and countries have their own set of symbology they want displayed on their HMD. Even as flight symbolgy is standardized, there will still be some differences for types of aircraft, different weapons, different sensors, and different countries. As an HMD supplier, we want to provide a system that can be used across all these applications with no changes in the system, including no changes in the software. This HMD system must also provide the flexibility to accommodate new symbology as it is developed over the years, again, with no change in the HMD software. VSI has developed their HMD software to accommodate F-15, F- 16, F-18, and F-22 symbology sets for the Joint Helmet Mounted Cueing System. It also has the flexibility to accommodate the aircraft types and services of the Joint Strike Fighter: Conventional Takeoff and Landing variant for the USAF, Carrier-based Variant for the USN, and the Short Takeoff and Vertical Landing variant for the USMC and U.K. Royal Navy and Air Force. The key to this flexibility is the interface definition. The interface parameters are established at power-on with the download of an interface definition data set. This data set is used to interpret symbology commands from the aircraft OFP during operation and provide graphic commands to the HMD software. This presentation will define the graphics commands, provide an example of how the interface definition data set is defined, and then show how symbology commands produce a display.

Optical engineering challenges of the virtual retinal display

NASA Astrophysics Data System (ADS)

Kollin, Joel S.; Tidwell, Michael R.

1995-08-01

The Virtual Retinal Display (VRD) is a unique approach to developing a high-resolution head- mounted display currently under development at the University of Washington's Human Interface Technology (HIT) Laboratory. Rather than looking at a screen though a magnifier or optical relay system, the viewer of the VRD has a scanned beam of light enter the pupil of the eye and focused to a spot on the retina. This type of optical system is subject to different design constraints than a typical HMD. With the VRD it may be possible to realize higher resolution, greater color saturation, higher brightness and larger field-of-view than a traditional LCD or CRT screen-based system. In this paper the author will present the VRD approach and how it can provide these advantages. Issues to be resolved for the VRD to reach its full potential and some of the solutions developed at the HIT lab will also be discussed.

Symbology requirements in head-up and head-down displays for helicopters in NOE flight

NASA Astrophysics Data System (ADS)

Haidn, Hermann; Odendahl, Goetz

1993-12-01

In modern warfare scenarios military helicopters have to be able to operate in NoE envelopes under all meteorological conditions. Under daytime good weather conditions this poses no problem for well-trained aircrews. In nighttime or bad weather conditions however the use of electronic sensors like IIT or TI is necessary. The aircrew use these devices for obstacle detection and avoidance and flight attitude perception. Flight below tree top level is only feasible when both of these tasks can be accomplished safely throughout the whole flight. For this reason the pilots must fly visual at all times. Relying on instruments for flight attitude control when flying between the trees would surely result in the striking of obstacles. These facts and the necessity for the aircrew to view greater azimuth angles than fixed wing pilots imply differing equipment and symbology packages for the two aircraft species. As a matter of fact only helmet mounted displays are really useful for helicopter flight control symbology. The following are results of experience from a number of trials with symbology in helicopters in low level flight down to 10 feet at night with IITs.

Voluntary presetting of the vestibular ocular reflex permits gaze stabilization despite perturbation of fast head movements

NASA Technical Reports Server (NTRS)

Zangemeister, Wolfgang H.

1989-01-01

Normal subjects are able to change voluntarily and continuously their head-eye latency together with their compensatory eye movement gain. A continuous spectrum of intent-latency modes of the subject's coordinated gaze through verbal feedback could be demonstrated. It was also demonstrated that the intent to counteract any perturbation of head-eye movement, i.e., the mental set, permitted the subjects to manipulate consciously their vestibular ocular reflex (VOR) gain. From the data, it is inferred that the VOR is always on. It may be, however, variably suppressed by higher cortical control. With appropriate training, head-mounted displays should permit an easy VOR presetting that leads to image stabilization, perhaps together with a decrease of possible misjudgements.

Attentional limitations with Head-Up Displays

NASA Technical Reports Server (NTRS)

Mccann, Robert S.; Foyle, David C.; Johnston, James C.

1993-01-01

Recent models of visual information processing suggest that visual attention can be focussed on either Head-Up Displays (HUD) or on the world beyond them, but not on both simultaneously. This hypothesis was tested in a part-task simulation in which subjects viewed a simulated approach to a runway with a HUD superimposed. An alphanumeric cue ('IFR' or 'VFR') appeared on either the HUD or the runway and was followed by two sets of three geometric forms; one set on the HUD and one set on the runway. Each set contained one potential target, either a stop sign or a diamond. If the cue spelled 'IFR', subjects made a speeded response based on the identity of the HUD target; if the cue spelled 'VFR', subjects made a speeded response based on the identity of the runway target. Regardless of cue location (HUD or Runway), responses were faster when the cue and the relevant target were part of the same perceptual group (i.e., both on the HUD or both on the runway) than when they were part of different perceptual groups. These results, as well as others, suggest that attentional constraints place severe limits on the ability of pilots to process HUD-referenced information and world-referenced information simultaneously. In addition, they provide direct evidence that transitioning from processing HUD information to processing world information requires an attention shift. Implications for HUD design are considered.

Evaluation of display and control concepts for a terminal configured vehicle in final approach in a windshear environment

NASA Technical Reports Server (NTRS)

Levison, W. H.

1978-01-01

A revised treatment of nonrandom inputs was incorporated in the model. Response behavior was observed for two display configurations (a pictorial EADI presentation and a flight-director configuration requiring use of a panel-mounted airspeed indicator), two control configurations (attitude and velocity control wheel steering), and two shear environments, each of which contained a head-to-tail shear and a vertical component. In general, performance trends predicted by the model were confirmed experimentally. Experimental and analytical results both indicated superiority to the EADI display with respect to regulation of height and airspeed errors. Velocity steering allowed tighter regulation of height errors, but control parameters had little influence on airspeed regulation. Model analysis indicated that display-related differences could be ascribed to differences in the quality of speed-related information provided by the two displays.

Adapter for mounting a microphone flush with the external surface of the skin of a pressurized aircraft

NASA Technical Reports Server (NTRS)

Cohn, R. B. (Inventor)

1983-01-01

A mounting device for securing a microphone pick up head flush with respect to the external surfaces of the skin of an aircraft for detecting shock waves passing thereover is described. The mount includes a sleeve mounted internally of the aircraft for capturing and supporting an electronics package having the microphone pick up head attached thereto in a manner such that the head is flush with the external surface of the aircraft skin and a pressure seal is established between the internal and external surfaces of the aircraft skin.

MINIMAL ENDOILLUMINATION LEVELS AND DISPLAY LUMINOUS EMITTANCE DURING THREE-DIMENSIONAL HEADS-UP VITREORETINAL SURGERY.

PubMed

Adam, Murtaza K; Thornton, Sarah; Regillo, Carl D; Park, Carl; Ho, Allen C; Hsu, Jason

2017-09-01

To determine minimal endoillumination levels required to perform 3-dimensional heads-up vitreoretinal surgery and to correlate endoillumination levels used for measurements of heads-up display (HUD) luminous emittance. Prospective, observational surgical case series of 10 patients undergoing vitreoretinal surgery. Endoillumination levels were set to 40% of maximum output and were decreased at set intervals until the illumination level was 0%. Corresponding luminous emittance (lux) of the HUD was measured 40 cm from the display using a luxmeter (Dr. Meter, Model #LX1010BS). In 9 of 10 cases, the surgeon felt that they could operate comfortably at an endoillumination level of 10% of maximum output with corresponding HUD emittance of 14.3 ± 9.5 lux. In the remaining case, the surgeon felt comfortable at a 3% endoillumination level with corresponding HUD emittance of 15 lux. Below this threshold, subjective image dimness and digital noise limited visibility. Endoillumination levels were correlated with luminous emittance from the 3-dimensional HUD (P < 0.01). The average coefficient of variation of HUD luminance was 0.546. There were no intraoperative complications. With real-time digital processing and automated brightness control, 3-dimensional HUD platforms may allow for reduced intraoperative endoillumination levels and a theoretically reduced risk of retinal phototoxicity during vitreoretinal surgery.

Novel microscope-integrated stereoscopic heads-up display for intrasurgical optical coherence tomography

PubMed Central

Shen, Liangbo; Carrasco-Zevallos, Oscar; Keller, Brenton; Viehland, Christian; Waterman, Gar; Hahn, Paul S.; Kuo, Anthony N.; Toth, Cynthia A.; Izatt, Joseph A.

2016-01-01

Intra-operative optical coherence tomography (OCT) requires a display technology which allows surgeons to visualize OCT data without disrupting surgery. Previous research and commercial intrasurgical OCT systems have integrated heads-up display (HUD) systems into surgical microscopes to provide monoscopic viewing of OCT data through one microscope ocular. To take full advantage of our previously reported real-time volumetric microscope-integrated OCT (4D MIOCT) system, we describe a stereoscopic HUD which projects a stereo pair of OCT volume renderings into both oculars simultaneously. The stereoscopic HUD uses a novel optical design employing spatial multiplexing to project dual OCT volume renderings utilizing a single micro-display. The optical performance of the surgical microscope with the HUD was quantitatively characterized and the addition of the HUD was found not to substantially effect the resolution, field of view, or pincushion distortion of the operating microscope. In a pilot depth perception subject study, five ophthalmic surgeons completed a pre-set dexterity task with 50.0% (SD = 37.3%) higher success rate and in 35.0% (SD = 24.8%) less time on average with stereoscopic OCT vision compared to monoscopic OCT vision. Preliminary experience using the HUD in 40 vitreo-retinal human surgeries by five ophthalmic surgeons is reported, in which all surgeons reported that the HUD did not alter their normal view of surgery and that live surgical maneuvers were readily visible in displayed stereoscopic OCT volumes. PMID:27231616

Simulator Study of Helmet-Mounted Symbology System Concepts in Degraded Visual Environments.

PubMed

Cheung, Bob; McKinley, Richard A; Steels, Brad; Sceviour, Robert; Cosman, Vaughn; Holst, Peter

2015-07-01

A sudden loss of external visual cues during critical phases of flight results in spatial disorientation. This is due to undetected horizontal and vertical drift when there is little tolerance for error and correction delay as the helicopter is close to the ground. Three helmet-mounted symbology system concepts were investigated in the simulator as potential solutions for the legacy Griffon helicopters. Thirteen Royal Canadian Air Force (RCAF) Griffon pilots were exposed to the Helmet Display Tracking System for Degraded Visual Environments (HDTS), the BrownOut Symbology System (BOSS), and the current RCAF AVS7 symbology system. For each symbology system, the pilot performed a two-stage departure and a single-stage approach. The presentation order of the symbology systems was randomized. Objective performance metrics included aircraft speed, altitude, attitude, and distance from the landing point. Subjective measurements included situation awareness, mental effort, perceived performance, perceptual cue rating, and NASA Task Load Index. Repeated measures analysis of variance and subsequent planned comparison for all the objective and subjective measurements were performed between the AVS7, HDTS, and BOSS. Our results demonstrated that HDTS and BOSS showed general improvement over AVS7 in two-stage departure. However, only HDTS performed significantly better in heading error than AVS7. During the single-stage approach, BOSS performed worse than AVS7 in heading root mean square error, and only HDTS performed significantly better in distance to landing point and approach heading than the others. Both the HDTS and BOSS possess their own limitations; however, HDTS is the pilots' preferred flight display.

Mount Kilimanjaro, Tanzania

NASA Image and Video Library

1996-01-20

STS072-722-004 (11-20 Jan. 1996) --- Mount Kilimanjaro in Tanzania is featured in this 70mm frame exposed from the Earth-orbiting Space Shuttle Endeavour. Orient with the clouds trailing to the left; then the view is southwest from Kenya past Kilimanjaro to Mount Meru, in Tanzania. Mount Kilimanjaro is about three degrees south of the Equator, but at nearly 6,000 meters has a permanent snowfield. The mountain displays a classic zonation of vegetation types from seasonally dry savannah on the plains at 1,000 meters, to the cloud forest near the top. The mountain is being managed experimentally as an international biosphere reserve. A buffer zone of "traditional" agriculture and pastoral land use is designated around the closed-canopy forest reserve. Specialists familiar with this area say management is partially successful so far, but cleared areas of the forest can be seen on this photograph as light green "nibbles" or "cookie cuts" extending into the dark forest region.

Computerized system for translating a torch head

NASA Technical Reports Server (NTRS)

Wall, W. A., Jr.; Ives, R. E.; Bruce, M. M., Jr.; Pryor, P. P., Jr.; Gard, L. H. (Inventor)

1978-01-01

The system provides a constant travel speed along a contoured workpiece. It has a driven skate characterized by an elongated bed, with a pair of independently pivoted trucks connected to the bed for support. The trucks are mounted on a contoured track of arbitrary configuration in a mutually spaced relation. An axially extensible torch head manipulator arm is mounted on the bed of the carriage and projects perpendicular from the midportion. The torch head is mounted at its distal end. A real-time computerized control drive subsystem is used to advance the skate along the track of a variable rate for maintaining a constant speed for the torch head tip, and to position the torch axis relative to a preset angle to the workpiece.

A head up display format for application to V/STOL aircraft approach and landing

NASA Technical Reports Server (NTRS)

Merrick, Vernon K.; Farris, Glenn G.; Vanags, Andrejs A.

1990-01-01

A head up display (HUD) format developed at NASA Ames Research Center to provide pilots of V/STOL aircraft with complete flight guidance and control information for category-3C terminal-area flight operations, is described in detail. These flight operations cover a large spectrum, from STOL operations on land-based runways to VTOL operations on small ships in high seas. Included in this description is a complete geometrical specification of the HUD elements and their drive laws. The principal features of this display format are the integration of the flightpath and pursuit guidance information into a narrow field of view, easily assimilated by the pilot with a single glance, and the superposition of vertical and horizontal situation information. The display is a derivative of a successful design developed for conventional transport aircraft. The design is the outcome of many piloted simulations conducted over a four-year period. Whereas the concepts on which the display format rests could not be fully exploited because of field-of-view restrictions, and some reservations remain about the acceptability of superimposing vertical and horizontal situation information, the design successfully fulfilled its intended objectives.

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2010 CFR

2010-10-01

... 49 Transportation 7 2010-10-01 2010-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

49 CFR 572.112 - Head assembly.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly. 572.112 Section 572.112... 50th Percentile Male § 572.112 Head assembly. The head assembly consists of the head (drawing 78051-61X...) accelerometers that are mounted in conformance to § 572.36 (c). (a) Test procedure. (1) Soak the head assembly in...

Compact and wide-field-of-view head-mounted display

NASA Astrophysics Data System (ADS)

Uchiyama, Shoichi; Kamakura, Hiroshi; Karasawa, Joji; Sakaguchi, Masafumi; Furihata, Takeshi; Itoh, Yoshitaka

1997-05-01

A compact and wide field of view HMD having 1.32-in full color VGA poly-Si TFT LCDs and simple eyepieces much like LEEP optics has been developed. The total field of view is 80 deg with a 40 deg overlap in its central area. Each optical unit which includes an LCD and eyepiece is 46 mm in diameter and 42 mm in length. The total number of pixels is equivalent to (864 times 3) times 480. This HMD realizes its wide field of view and compact size by having a narrower binocular area (overlap area) than that of commercialized HMDs. For this reason, it is expected that the frequency of monocular vision will be more than that of commercialized HMDs and human natural vision. Therefore, we researched the convergent state of eyes while observing the monocular areas of this HMD by employing an EOG and considered the suitability of this HMD to human vision. As a result, it was found that the convergent state of the monocular vision was nearly equal to that of binocular vision. That is, it can be said that this HMD has the possibility of being well suited to human vision in terms of the convergence.

A new phase encoding approach for a compact head-up display

NASA Astrophysics Data System (ADS)

Suszek, Jaroslaw; Makowski, Michal; Sypek, Maciej; Siemion, Andrzej; Kolodziejczyk, Andrzej; Bartosz, Andrzej

2008-12-01

The possibility of encoding multiple asymmetric symbols into a single thin binary Fourier hologram would have a practical application in the design of simple translucent holographic head-up displays. A Fourier hologram displays the encoded images at the infinity so this enables an observation without a time-consuming eye accommodation. Presenting a set of the most crucial signs for a driver in this way is desired, especially by older people with various eyesight disabilities. In this paper a method of holographic design is presented that assumes a combination of a spatial segmentation and carrier frequencies. It allows to achieve multiple reconstructed images selectable by the angle of the incident laser beam. In order to encode several binary symbols into a single Fourier hologram, the chessboard shaped segmentation function is used. An optimized sequence of phase encoding steps and a final direct phase binarization enables recording of asymmetric symbols into a binary hologram. The theoretical analysis is presented, verified numerically and confirmed in the optical experiment. We suggest and describe a practical and highly useful application of such holograms in an inexpensive HUD device for the use of the automotive industry. We present two alternative propositions of car viewing setups.

Performance characterization of a single bi-axial scanning MEMS mirror-based head-worn display

NASA Astrophysics Data System (ADS)

Liang, Minhua

2002-06-01

The NomadTM Personal Display System is a head-worn display (HWD) with a see-through, high-resolution, high-luminance display capability. It is based on a single bi-axial scanning MEMS mirror. In the Nomad HWD system, a red laser diode emits a beam of light that is scanned bi-axially by a single MEMS mirror. A diffractive beam diffuser and an ocular expand the beam to form a 12mm exit pupil for comfortable viewing. The Nomad display has an SVGA (800x600) resolution, 60Hz frame rate, 23-degree horizontal field of view (FOV) and 3:4 vertical to horizontal aspect ratio, a luminance of 800~900 foot-Lamberts, see-through capability, 30mm eye-relief distance, and 1-foot to infinity focusing adjustment. We have characterized the performance parameters, such as field of view, distortion, contrast ratio (4x4 black and white checker board), modulation depth, exit pupil size, eye relief distance, maximum luminance, dynamic range ratio (full-on-to-full-off ratio), dimming ratio, and luminance uniformity at image plane. The Class-1 eye-safety requirements per IEC 60825-1 Amendment 2 (CDRH Laser Notice No. 50) are analyzed and verified by experiments. The paper describes all of the testing methods and set-ups as well as the representative test results. The test results demonstrate that the Nomad display is an eye-safe display product with good image quality and good user ergonomics.

Display Techniques for Advanced Crew Stations (DTACS). Phase 1. Display Techniques Study.

DTIC Science & Technology

1984-03-01

26 3.1.3 Off Screen Displays .. ................... 27 3.1.4 Flat Panel Displays. .. ................. 27 3.2 FORMAT REQUIREMENTS...Head-Up Display ....... .................... ... 96 4.5.2 Display Panel .... ................. 98 4.5.3 RGB Calligraphic Display ................ 99...117 3.4 VOICE WARNING/RESPONSE TECHNOLOGY .............. . i.117 5.5 TOUCH PANEL TECHNOLOGY ..... ................ ... 118 5.6

Restocking the optical designers' toolbox for next-generation wearable displays (Presentation Recording)

NASA Astrophysics Data System (ADS)

Kress, Bernard C.

2015-09-01

Three years ago, industry and consumers learned that there was more to Head Mounted Displays (HMDs) than the long-lasting but steady market for defense or the market for gadget video player headsets: the first versions of Smart Glasses were introduced to the public. Since then, most major consumer electronics companies unveiled their own versions of Connected Glasses, Smart Glasses or Smart Eyewear, AR (Augmented Reality) and VR (Virtual Reality) headsets. This rush resulted in the build-up of a formidable zoo of optical technologies, each claiming to be best suited for the task on hand. Today, the question is not so much anymore "will the Smart Glass market happen?" but rather "which optical technologies will be best fitted for the various declinations of the existing wearable display market," one of the main declination being the Smart Glasses market.

Cross-axis adaptation improves 3D vestibulo-ocular reflex alignment during chronic stimulation via a head-mounted multichannel vestibular prosthesis

PubMed Central

Dai, Chenkai; Fridman, Gene Y.; Chiang, Bryce; Davidovics, Natan; Melvin, Thuy-Anh; Cullen, Kathleen E.; Della Santina, Charles C.

2012-01-01

By sensing three-dimensional (3D) head rotation and electrically stimulating the three ampullary branches of a vestibular nerve to encode head angular velocity, a multichannel vestibular prosthesis (MVP) can restore vestibular sensation to individuals disabled by loss of vestibular hair cell function. However, current spread to afferent fibers innervating non-targeted canals and otolith endorgans can distort the vestibular nerve activation pattern, causing misalignment between the perceived and actual axis of head rotation. We hypothesized that over time, central neural mechanisms can adapt to correct this misalignment. To test this, we rendered five chinchillas vestibular-deficient via bilateral gentamicin treatment and unilaterally implanted them with a head mounted MVP. Comparison of 3D angular vestibulo-ocular reflex (aVOR) responses during 2 Hz, 50°/s peak horizontal sinusoidal head rotations in darkness on the first, third and seventh days of continual MVP use revealed that eye responses about the intended axis remained stable (at about 70% of the normal gain) while misalignment improved significantly by the end of one week of prosthetic stimulation. A comparable time course of improvement was also observed for head rotations about the other two semicircular canal axes and at every stimulus frequency examined (0.2–5 Hz). In addition, the extent of disconjugacy between the two eyes progressively improved during the same time window. These results indicate that the central nervous system rapidly adapts to multichannel prosthetic vestibular stimulation to markedly improve 3D aVOR alignment within the first week after activation. Similar adaptive improvements are likely to occur in other species, including humans. PMID:21374081

Use of display technologies for augmented reality enhancement

NASA Astrophysics Data System (ADS)

Harding, Kevin

2016-06-01

Augmented reality (AR) is seen as an important tool for the future of user interfaces as well as training applications. An important application area for AR is expected to be in the digitization of training and worker instructions used in the Brilliant Factory environment. The transition of work instructions methods from printed pages in a book or taped to a machine to virtual simulations is a long step with many challenges along the way. A variety of augmented reality tools are being explored today for industrial applications that range from simple programmable projections in the work space to 3D displays and head mounted gear. This paper will review where some of these tool are today and some of the pros and cons being considered for the future worker environment.

Measurement and reduction of system latency in see-through helmet mounted display (HMD) systems

NASA Astrophysics Data System (ADS)

Vincenzi, Dennis A.; Deaton, John E.; Blickenderfer, Elizabeth L.; Pray, Rick; Williams, Barry; Buker, Timothy J.

2010-04-01

Future military aviation platforms such as the proposed Joint Strike Fighter F-35 will integrate helmet mounted displays (HMDs) with the avionics and weapon systems to the degree that the HMDs will become the aircraft's primary display system. In turn, training of pilot flight skills using HMDs will be essential in future training systems. In order to train these skills using simulation based training, improvements must be made in the integration of HMDs with out-thewindow (OTW) simulations. Currently, problems such as latency contribute to the onset of simulator sickness and provide distractions during training with HMD simulator systems that degrade the training experience. Previous research has used Kalman predictive filters as a means of mitigating the system latency present in these systems. While this approach has yielded some success, more work is needed to develop innovative and improved strategies that reduce system latency as well as to include data collected from the user perspective as a measured variable during test and evaluation of latency reduction strategies. The purpose of this paper is twofold. First, the paper describes a new method to measure and assess system latency from the user perspective. Second, the paper describes use of the testbed to examine the efficacy of an innovative strategy that combines a customized Kalman filter with a neural network approach to mitigate system latency. Results indicate that the combined approach reduced system latency significantly when compared to baseline data and the traditional Kalman filter. Reduced latency errors should mitigate the onset of simulator sickness and ease simulator sickness symptomology. Implications for training systems will be discussed.

Oscillating fluid lens in coherent retinal projection displays for extending depth of focus

NASA Astrophysics Data System (ADS)

von Waldkirch, extending depth of focus M.; Lukowicz, P.; Troster, G.

2005-09-01

See-through head-mounted displays, which allow to overlay virtual information over the user's real view, suffer normally from a limited depth of focus (DOF). To overcome this problem we discuss in this paper the use of a fast oscillating, variable-focus lens in a retinal projection display. The evaluation is based on a schematic eye model and on the partial coherence simulation tool SPLAT which allows us to calculate the projected retinal images of a text target. Objective image quality criteria demonstrate that the use of an oscillating lens is promising provided that partially coherent illumination light is used. In this case, psychometric measurements reveal that the depth of focus for reading text can be extended by a factor of up to 2.2. For fully coherent and incoherent illumination, however, the retinal images suffer from structural and contrast degradation effects, respectively.

Ocular Tolerance of Contemporary Electronic Display Devices.

PubMed

Clark, Andrew J; Yang, Paul; Khaderi, Khizer R; Moshfeghi, Andrew A

2018-05-01

Electronic displays have become an integral part of life in the developed world since the revolution of mobile computing a decade ago. With the release of multiple consumer-grade virtual reality (VR) and augmented reality (AR) products in the past 2 years utilizing head-mounted displays (HMDs), as well as the development of low-cost, smartphone-based HMDs, the ability to intimately interact with electronic screens is greater than ever. VR/AR HMDs also place the display at much closer ocular proximity than traditional electronic devices while also isolating the user from the ambient environment to create a "closed" system between the user's eyes and the display. Whether the increased interaction with these devices places the user's retina at higher risk of damage is currently unclear. Herein, the authors review the discovery of photochemical damage of the retina from visible light as well as summarize relevant clinical and preclinical data regarding the influence of modern display devices on retinal health. Multiple preclinical studies have been performed with modern light-emitting diode technology demonstrating damage to the retina at modest exposure levels, particularly from blue-light wavelengths. Unfortunately, high-quality in-human studies are lacking, and the small clinical investigations performed to date have failed to keep pace with the rapid evolutions in display technology. Clinical investigations assessing the effect of HMDs on human retinal function are also yet to be performed. From the available data, modern consumer electronic displays do not appear to pose any acute risk to vision with average use; however, future studies with well-defined clinical outcomes and illuminance metrics are needed to better understand the long-term risks of cumulative exposure to electronic displays in general and with "closed" VR/AR HMDs in particular. [Ophthalmic Surg Lasers Imaging Retina. 2018;49:346-354.]. Copyright 2018, SLACK Incorporated.

A clinical technique for virtual articulator mounting with natural head position by using calibrated stereophotogrammetry.

PubMed

Lam, Walter Y H; Hsung, Richard T C; Choi, Winnie W S; Luk, Henry W K; Cheng, Leo Y Y; Pow, Edmond H N

2017-09-29

Accurate articulator-mounted casts are essential for occlusion analysis and for fabrication of dental prostheses. Although the axis orbital plane has been commonly used as the reference horizontal plane, some clinicians prefer to register the horizontal plane with a spirit level when the patient is in the natural head position (NHP) to avoid anatomic landmark variations. This article presents a digital workflow for registering the patient's horizontal plane in NHP on a virtual articulator. An orientation reference board is used to calibrate a stereophotogrammetry device and a 3-dimensional facial photograph with the patient in NHP. The horizontal plane can then be automatically registered to the patient's virtual model and aligned to the virtual articulator at the transverse horizontal axis level. This technique showed good repeatability with positional differences of less than 1 degree and 1 mm in 5 repeated measurements in 1 patient. Copyright © 2017 Editorial Council for the Journal of Prosthetic Dentistry. Published by Elsevier Inc. All rights reserved.

78 FR 35756 - Special Local Regulations; Recurring Marine Events in the Seventh Coast Guard District

Federal Register 2010, 2011, 2012, 2013, 2014

2013-06-14

... Fireworks Display regulations on certain navigable waterways in Hilton Head Island, Mount Pleasant, and... Fireworks'' in Mount Pleasant, the ``Skull Creek Fireworks'' in Hilton Head, and the ``City of North...

Head-up displays: Effect of information location on the processing of superimposed symbology

NASA Technical Reports Server (NTRS)

Sanford, Beverly D.; Foyle, David C.; Mccann, Robert S.; Jordan, Kevin

1993-01-01

Head-up display (HUD) symbology superimposes vehicle status information onto the external terrain, providing simultaneous visual access to both sources of information. Relative to a baseline condition in which the superimposed altitude indicator was omitted, altitude maintenance was improved by the presence of the altitude indicator, and this improvement was the same magnitude regardless of the position of the altitude indicator on the screen. However, a concurrent decifit in heading maintenance was observed only when the altitude indicator was proximal to the path information. These results did not support a model of the concurrent processing deficit based on an inability to attend to multiple locations in parallel. They are consistent with previous claims that the deficit is the product of attentional limits on subjects' ability to process two separate objects (HUD symbology and terrain information) concurrently. The absence of a performance tradeoff when the HUD and the path information were less proximal is attributed to a breaking of attentional tunneling on the HUD, possibly due to eye movements.

Female-female mounting among goats stimulates sexual performance in males.

PubMed

Shearer, Meagan K; Katz, Larry S

2006-06-01

The hypothesis that female-female mounting is proceptivity in goats, in that male goats are aroused by the visual cues of this mounting behavior, was tested. Once a week, male goats were randomly selected and placed in a test pen in which they were allowed to observe one of six selected social or sexual stimulus conditions. The stimulus conditions were one familiar male with two estrous females (MEE); three estrous females that displayed female-female mounting (E(m)); three estrous females that did not mount (E(nm)); three non-estrous females (N(E)); three familiar males (M); and no animals in the pen (Empty). After 10 min, the stimulus animals were removed, and an estrous female was placed in the test pen with the male for a 20-min sexual performance test. During sexual performance tests, the frequencies and latencies of all sexual behaviors were recorded. This procedure was repeated so all males (n = 6) were tested once each test day, and all the stimulus conditions were presented each test day. This was repeated weekly until all males had been exposed to each stimulus condition. Viewing mounting behavior, whether male-female or female-female, increased the total number of sexual behaviors displayed, increased ejaculation frequency, and decreased latency to first mount and ejaculation, post-ejaculatory interval, and the interval between ejaculations. We conclude that male goats are aroused by the visual cues of mounting behavior, and that female-female mounting is proceptivity in goats.

Simulation evaluation of a low-altitude helicopter flight guidance system adapted for a helmet-mounted display

NASA Technical Reports Server (NTRS)

Swenson, Harry N.; Zelenka, Richard E.; Hardy, Gordon H.; Dearing, Munro G.

1992-01-01

A computer aiding concept for low-altitude helicopter flight was developed and evaluated in a real-time piloted simulation. The concept included an optimal control trajectory-generation algorithm based upon dynamic programming and a helmet-mounted display (HMD) presentation of a pathway-in-the-sky, a phantom aircraft, and flight-path vector/predictor guidance symbology. The trajectory-generation algorithm uses knowledge of the global mission requirements, a digital terrain map, aircraft performance capabilities, and advanced navigation information to determine a trajectory between mission way points that seeks valleys to minimize threat exposure. The pilot evaluation was conducted at NASA ARC moving base Vertical Motion Simulator (VMS) by pilots representing NASA, the U.S. Army, the Air Force, and the helicopter industry. The pilots manually tracked the trajectory generated by the algorithm utilizing the HMD symbology. The pilots were able to satisfactorily perform the tracking tasks while maintaining a high degree of awareness of the outside world.

A novel device for head gesture measurement system in combination with eye-controlled human machine interface

NASA Astrophysics Data System (ADS)

Lin, Chern-Sheng; Ho, Chien-Wa; Chang, Kai-Chieh; Hung, San-Shan; Shei, Hung-Jung; Yeh, Mau-Shiun

2006-06-01

This study describes the design and combination of an eye-controlled and a head-controlled human-machine interface system. This system is a highly effective human-machine interface, detecting head movement by changing positions and numbers of light sources on the head. When the users utilize the head-mounted display to browse a computer screen, the system will catch the images of the user's eyes with CCD cameras, which can also measure the angle and position of the light sources. In the eye-tracking system, the program in the computer will locate each center point of the pupils in the images, and record the information on moving traces and pupil diameters. In the head gesture measurement system, the user wears a double-source eyeglass frame, so the system catches images of the user's head by using a CCD camera in front of the user. The computer program will locate the center point of the head, transferring it to the screen coordinates, and then the user can control the cursor by head motions. We combine the eye-controlled and head-controlled human-machine interface system for the virtual reality applications.

Virtual reality helmet display quality influences the magnitude of virtual reality analgesia.

PubMed

Hoffman, Hunter G; Seibel, Eric J; Richards, Todd L; Furness, Thomas A; Patterson, David R; Sharar, Sam R

2006-11-01

Immersive Virtual Reality (VR) distraction can be used in addition to traditional opioids to reduce procedural pain. The current study explored whether a High-Tech-VR helmet (ie, a 60-degree field-of-view head-mounted display) reduces pain more effectively than a Low-Tech-VR helmet (a 35-degree field-of-view head-mounted display). Using a double-blind between-groups design, 77 healthy volunteers (no patients) aged 18-23 were randomly assigned to 1 of 3 groups. Each subject received a brief baseline thermal pain stimulus, and the same stimulus again minutes later while in SnowWorld using a Low-Tech-VR helmet (Group 1), using a High-Tech-VR helmet (Group 2), or receiving no distraction (Group 3, control group). Each participant provided subjective 0-10 ratings of cognitive, sensory, and affective components of pain, and amount of fun during the pain stimulus. Compared to the Low-Tech-VR helmet group, subjects in the High-Tech-VR helmet group reported 34% more reduction in worst pain (P < .05), 46% more reduction in pain unpleasantness (P = .001), 29% more reduction in "time spent thinking about pain" (P < .05), and 32% more fun during the pain stimulus in VR (P < .05). Only 29% of participants in the Low-Tech helmet group, as opposed to 65% of participants in the High-Tech-VR helmet group, showed a clinically significant reduction in pain intensity during virtual reality. These results highlight the importance of using an appropriately designed VR helmet to achieve effective VR analgesia (see ). Pain during medical procedures (eg, burn wound care) is often excessive. Adjunctive virtual reality distraction can substantially reduce procedural pain. The results of the present study show that a higher quality VR helmet was more effective at reducing pain than a lower quality VR helmet.

Head-up display (HUD) utility. II - Runway to HUD transitions monitoring eye focus and decision times

NASA Technical Reports Server (NTRS)

Weintraub, D. J.; Haines, R. F.; Randle, R. J.

1985-01-01

An experiment conducted using a head-up display (HUD) suggests that the demonstrated superiority of the HUD over a conventional instrument panel stems from its superior layout of information. A HUD display presents instrument-panel information to pilots in such a way that the symbols appear as a virtual image at optical infinity superimposed on the landscape. In the experiment conducted, the luminance of the display symbology and its angle subtended at the eye remained fixed, while optical distance and gaze angle were varied. Concomitant measures of eye movements, eye accommodative state, and decision-making time concerning airspeed, altitude and runway condition were obtained. It is found that, while looking straight ahead, at zero diopters, the HUD shortens decision time by 80 to 90 msec, not statistically significant at the 0.05 (slope of diopter/gaze interaction) level. The question of a cognitive overload induced by the luminous symbols of the HUD is subsequently addressed.

High brightness MEMS mirror based head-up display (HUD) modules with wireless data streaming capability

NASA Astrophysics Data System (ADS)

Milanovic, Veljko; Kasturi, Abhishek; Hachtel, Volker

2015-02-01

A high brightness Head-Up Display (HUD) module was demonstrated with a fast, dual-axis MEMS mirror that displays vector images and text, utilizing its ~8kHz bandwidth on both axes. Two methodologies were evaluated: in one, the mirror steers a laser at wide angles of <48° on transparent multi-color fluorescent emissive film and displays content directly on the windshield, and in the other the mirror displays content on reflective multi-color emissive phosphor plates reflected off the windshield to create a virtual image for the driver. The display module is compact, consisting of a single laser diode, off-the-shelf lenses and a MEMS mirror in combination with a MEMS controller to enable precise movement of the mirror's X- and Y-axis. The MEMS controller offers both USB and wireless streaming capability and we utilize a library of functions on a host computer for creating content and controlling the mirror. Integration with smart phone applications is demonstrated, utilizing the mobile device both for content generation based on various messages or data, and for content streaming to the MEMS controller via Bluetooth interface. The display unit is highly resistant to vibrations and shock, and requires only ~1.5W to operate, even with content readable in sunlit outdoor conditions. The low power requirement is in part due to a vector graphics approach, allowing the efficient use of laser power, and also due to the use of a single, relatively high efficiency laser and simple optics.

A virtual reality oriented clinical experiment on post-stroke rehabilitation: performance and preference comparison among different stereoscopic displays­

NASA Astrophysics Data System (ADS)

Yeh, Shih-Ching; Rizzo, Albert; Sawchuk, Alexander A.

2007-02-01

We have developed a novel VR task: the Dynamic Reaching Test, that measures human forearm movement in 3D space. In this task, three different stereoscopic displays: autostereoscopic (AS), shutter glasses (SG) and head mounted display (HMD), are used in tests in which subjects must catch a virtual ball thrown at them. Parameters such as percentage of successful catches, movement efficiency (subject path length compared to minimal path length), and reaction time are measured to evaluate differences in 3D perception among the three stereoscopic displays. The SG produces the highest percentage of successful catches, though the difference between the three displays is small, implying that users can perform the VR task with any of the displays. The SG and HMD produced the best movement efficiency, while the AS was slightly less efficient. Finally, the AS and HMD produced similar reaction times that were slightly higher (by 0.1 s) than the SG. We conclude that SG and HMD displays were the most effective, but only slightly better than the AS display.

An Operational evaluation of head up displays for civil transport operations. NASA/FAA phase 3 report

NASA Technical Reports Server (NTRS)

Lauber, J. K.; Bray, R. S.; Harrison, R. L.; Hemingway, J. C.; Scott, B. C.

1982-01-01

The advantages and disadvantages of head-up displays (HUDs) in commercial jet transport approach and landing operations was evaluated. Ten airline captains currently qualified in the B-727 aircraft flew a series of instrument landing system (ILS) and nonprecision approaches in a motion base simulator using both a flight director HUD concept and a flightpath HUD concept as well as conventional head-down instruments under a variety of environmental and operational conditions to assess: (1) the potential benefits of these HUDs in airline operations; (2) problems which might be associated with their use; and (3) flight crew training requirements and flight crew operating procedures suitable for use with the HUDs. Results are presented in terms of objective simulator based performance measures, subject pilot opinion and rating data, and observer data.

Helmet-Mounted Displays: Sensation, Perception and Cognition Issues

DTIC Science & Technology

2009-01-01

Inc., web site: http://www.metavr.com/ technology/ papers /syntheticvision.html Helmetag, A., Halbig, C., Kubbat, W., and Schmidt, R. (1999...system-of-systems.” One integral system is a “head-borne vision enhancement” system (an HMD) that provides fused I2/ IR sensor imagery (U.S. Army Natick...Using microwave, radar, I2, infrared ( IR ), and other technology-based imaging sensors, the “seeing” range of the human eye is extended into the

Missing depth cues in virtual reality limit performance and quality of three dimensional reaching movements

PubMed Central

Mayo, Johnathan; Baur, Kilian; Wittmann, Frieder; Riener, Robert; Wolf, Peter

2018-01-01

Background Goal-directed reaching for real-world objects by humans is enabled through visual depth cues. In virtual environments, the number and quality of available visual depth cues is limited, which may affect reaching performance and quality of reaching movements. Methods We assessed three-dimensional reaching movements in five experimental groups each with ten healthy volunteers. Three groups used a two-dimensional computer screen and two groups used a head-mounted display. The first screen group received the typically recreated visual depth cues, such as aerial and linear perspective, occlusion, shadows, and texture gradients. The second screen group received an abstract minimal rendering lacking those. The third screen group received the cues of the first screen group and absolute depth cues enabled by retinal image size of a known object, which realized with visual renderings of the handheld device and a ghost handheld at the target location. The two head-mounted display groups received the same virtually recreated visual depth cues as the second or the third screen group respectively. Additionally, they could rely on stereopsis and motion parallax due to head-movements. Results and conclusion All groups using the screen performed significantly worse than both groups using the head-mounted display in terms of completion time normalized by the straight-line distance to the target. Both groups using the head-mounted display achieved the optimal minimum in number of speed peaks and in hand path ratio, indicating that our subjects performed natural movements when using a head-mounted display. Virtually recreated visual depth cues had a minor impact on reaching performance. Only the screen group with rendered handhelds could outperform the other screen groups. Thus, if reaching performance in virtual environments is in the main scope of a study, we suggest applying a head-mounted display. Otherwise, when two-dimensional screens are used, achievable performance

Attitude symbology issues for helmet-mounted displays

NASA Astrophysics Data System (ADS)

Davy, Eleanor C.; Dudfield, Helen J.; Hardiman, Thomas D.; Doyle, Anthony J. R.

1996-06-01

One of the major advantages of HMDs is the display of information wherever the pilot is looking. These displays, however, raise important human factor issues for the optimal method of presenting attitude information. For example, problems may occur when the pilot looks off- boresight and is provided with information that is based upon the forward view of the aircraft (i.e. aircraft-referenced) and is thus incongruent. An experiment was conducted to examine this issue in which a traditional pitch ladder format was compared against the novel 'cylinder' format in an off-boresight attitude control task on a simulated HMD. This task involved recovery from unusual positions (UPs) which were presented at various off-boresight angles. Subjects' initial response times were faster for the pitch ladder format than for the two formats for total recovery times, error rates, height deviations, situational awareness rating technique or the questionnaire data. It was concluded that the performance on the cylinder format may be explained by the subjects' past experience using the pitch ladder or by the lack of information available when the aircraft was slightly nose-up or nose-down. It was suggested that improvements should be made to the cylinder if it is to be further examined in future research. Finally, the implications of this research for future work are discussed.

Display technology - Human factors concepts

NASA Astrophysics Data System (ADS)

Stokes, Alan; Wickens, Christopher; Kite, Kirsten

1990-03-01

Recent advances in the design of aircraft cockpit displays are reviewed, with an emphasis on their applicability to automobiles. The fundamental principles of display technology are introduced, and individual chapters are devoted to selective visual attention, command and status displays, foveal and peripheral displays, navigational displays, auditory displays, color and pictorial displays, head-up displays, automated systems, and dual-task performance and pilot workload. Diagrams, drawings, and photographs of typical displays are provided.

Change Blindness Phenomena for Virtual Reality Display Systems.

PubMed

Steinicke, Frank; Bruder, Gerd; Hinrichs, Klaus; Willemsen, Pete

2011-09-01

In visual perception, change blindness describes the phenomenon that persons viewing a visual scene may apparently fail to detect significant changes in that scene. These phenomena have been observed in both computer-generated imagery and real-world scenes. Several studies have demonstrated that change blindness effects occur primarily during visual disruptions such as blinks or saccadic eye movements. However, until now the influence of stereoscopic vision on change blindness has not been studied thoroughly in the context of visual perception research. In this paper, we introduce change blindness techniques for stereoscopic virtual reality (VR) systems, providing the ability to substantially modify a virtual scene in a manner that is difficult for observers to perceive. We evaluate techniques for semiimmersive VR systems, i.e., a passive and active stereoscopic projection system as well as an immersive VR system, i.e., a head-mounted display, and compare the results to those of monoscopic viewing conditions. For stereoscopic viewing conditions, we found that change blindness phenomena occur with the same magnitude as in monoscopic viewing conditions. Furthermore, we have evaluated the potential of the presented techniques for allowing abrupt, and yet significant, changes of a stereoscopically displayed virtual reality environment.

Definition of display/control requirements for assault transport night/adverse weather capability

NASA Technical Reports Server (NTRS)

Milelli, R. J.; Mowery, G. W.; Pontelandolfo, C.

1982-01-01

A Helicopter Night Vision System was developed to improve low-altitude night and/or adverse weather assult transport capabilities. Man-in-the-loop simulation experiments were performed to define the minimum display and control requirements for the assult transport mission and investigate forward looking infrared sensor requirements, along with alternative displays such as panel mounted displays (PMD) helmet mounted displays (HMD), and integrated control display units. Also explored were navigation requirements, pilot/copilot interaction, and overall cockpit arrangement. Pilot use of an HMD and copilot use of a PMD appear as both the preferred and most effective night navigation combination.

Motion parallax in immersive cylindrical display systems

NASA Astrophysics Data System (ADS)

Filliard, N.; Reymond, G.; Kemeny, A.; Berthoz, A.

2012-03-01

Motion parallax is a crucial visual cue produced by translations of the observer for the perception of depth and selfmotion. Therefore, tracking the observer viewpoint has become inevitable in immersive virtual (VR) reality systems (cylindrical screens, CAVE, head mounted displays) used e.g. in automotive industry (style reviews, architecture design, ergonomics studies) or in scientific studies of visual perception. The perception of a stable and rigid world requires that this visual cue be coherent with other extra-retinal (e.g. vestibular, kinesthetic) cues signaling ego-motion. Although world stability is never questioned in real world, rendering head coupled viewpoint in VR can lead to the perception of an illusory perception of unstable environments, unless a non-unity scale factor is applied on recorded head movements. Besides, cylindrical screens are usually used with static observers due to image distortions when rendering image for viewpoints different from a sweet spot. We developed a technique to compensate in real-time these non-linear visual distortions, in an industrial VR setup, based on a cylindrical screen projection system. Additionally, to evaluate the amount of discrepancies tolerated without perceptual distortions between visual and extraretinal cues, a "motion parallax gain" between the velocity of the observer's head and that of the virtual camera was introduced in this system. The influence of this artificial gain was measured on the gait stability of free-standing participants. Results indicate that, below unity, gains significantly alter postural control. Conversely, the influence of higher gains remains limited, suggesting a certain tolerance of observers to these conditions. Parallax gain amplification is therefore proposed as a possible solution to provide a wider exploration of space to users of immersive virtual reality systems.

Ergonomic evaluation of ubiquitous computing with monocular head-mounted display

NASA Astrophysics Data System (ADS)

Kawai, Takashi; Häkkinen, Jukka; Yamazoe, Takashi; Saito, Hiroko; Kishi, Shinsuke; Morikawa, Hiroyuki; Mustonen, Terhi; Kaistinen, Jyrki; Nyman, Göte

2010-01-01

In this paper, the authors conducted an experiment to evaluate the UX in an actual outdoor environment, assuming the casual use of monocular HMD to view video content while short walking. In conducting the experiment, eight subjects were asked to view news videos on a monocular HMD while walking through a large shopping mall. Two types of monocular HMDs and a hand-held media player were used, and the psycho-physiological responses of the subjects were measured before, during, and after the experiment. The VSQ, SSQ and NASA-TLX were used to assess the subjective workloads and symptoms. The objective indexes were heart rate and stride and a video recording of the environment in front of the subject's face. The results revealed differences between the two types of monocular HMDs as well as between the monocular HMDs and other conditions. Differences between the types of monocular HMDs may have been due to screen vibration during walking, and it was considered as a major factor in the UX in terms of the workload. Future experiments to be conducted in other locations will have higher cognitive loads in order to study the performance and the situation awareness to actual and media environments.

A tactual display aid for primary flight training

NASA Technical Reports Server (NTRS)

Gilson, R. D.

1979-01-01

A means of flight instruction is discussed. In addition to verbal assistance, control feedback was continously presented via a nonvisual means utilizing touch. A kinesthetic-tactile (KT) display was used as a readout and tracking device for a computer generated signal of desired angle of attack during the approach and landing. Airspeed and glide path information was presented via KT or visual heads up display techniques. Performance with the heads up display of pitch information was shown to be significantly better than performance with the KT pitch display. Testing without the displays showed that novice pilots who had received tactile pitch error information performed both pitch and throttle control tasks significantly better than those who had received the same information from the visual heads up display of pitch during the test series of approaches to landing.

76 FR 14841 - Head Start Program

Federal Register 2010, 2011, 2012, 2013, 2014

2011-03-18

... based on that information, the person has determined the pregnant woman or child to be eligible for... pregnant women who are ineligible for participation in Head Start or Early Head Start programs are enrolled... women from such families in recognition of the mounting evidence that the earliest years matter a great...

Biomechanics of head injury in olympic taekwondo and boxing.

PubMed

Fife, G P; O'Sullivan, D; Pieter, W

2013-12-01

The purpose was to examine differences between taekwondo kicks and boxing punches in resultant linear head acceleration (RLA), head injury criterion (HIC15), peak head velocity, and peak foot and fist velocities. Data from two existing publications on boxing punches and taekwondo kicks were compared. For taekwondo head impacts a Hybrid II Crash Dummy (Hybrid II) head was instrumented with a tri-axial accelerometer mounted inside the Hybrid II head. The Hybrid II was fixed to a height-adjustable frame and fitted with a protective taekwondo helmet. For boxing testing, a Hybrid III Crash Dummy head was instrumented with an array of tri-axial accelerometers mounted at the head centre of gravity. Differences in RLA between the roundhouse kick (130.11±51.67 g) and hook punch (71.23±32.19 g, d = 1.39) and in HIC15 (clench axe kick: 162.63±104.10; uppercut: 24.10±12.54, d = 2.29) were observed. Taekwondo kicks demonstrated significantly larger magnitudes than boxing punches for both RLA and HIC.

BIOMECHANICS OF HEAD INJURY IN OLYMPIC TAEKWONDO AND BOXING

PubMed Central

Fife, G.P.; Pieter, W.

2013-01-01

Objective The purpose was to examine differences between taekwondo kicks and boxing punches in resultant linear head acceleration (RLA), head injury criterion (HIC15), peak head velocity, and peak foot and fist velocities. Data from two existing publications on boxing punches and taekwondo kicks were compared. Methods For taekwondo head impacts a Hybrid II Crash Dummy (Hybrid II) head was instrumented with a tri-axial accelerometer mounted inside the Hybrid II head. The Hybrid II was fixed to a height-adjustable frame and fitted with a protective taekwondo helmet. For boxing testing, a Hybrid III Crash Dummy head was instrumented with an array of tri-axial accelerometers mounted at the head centre of gravity. Results Differences in RLA between the roundhouse kick (130.11±51.67 g) and hook punch (71.23±32.19 g, d = 1.39) and in HIC15 (clench axe kick: 162.63±104.10; uppercut: 24.10±12.54, d = 2.29) were observed. Conclusions Taekwondo kicks demonstrated significantly larger magnitudes than boxing punches for both RLA and HIC. PMID:24744497

Pixels, people, perception, pet peeves, and possibilities: a look at displays

NASA Astrophysics Data System (ADS)

Task, H. Lee

2007-04-01

This year marks the 35 th anniversary of the Visually Coupled Systems symposium held at Brooks Air Force Base, San Antonio, Texas in November of 1972. This paper uses the proceedings of the 1972 VCS symposium as a guide to address several topics associated primarily with helmet-mounted displays, systems integration and the human-machine interface. Specific topics addressed include monocular and binocular helmet-mounted displays (HMDs), visor projection HMDs, color HMDs, system integration with aircraft windscreens, visual interface issues and others. In addition, this paper also addresses a few mysteries and irritations (pet peeves) collected over the past 35+ years of experience in the display and display related areas.

An externally head-mounted wireless neural recording device for laboratory animal research and possible human clinical use.

PubMed

Yin, Ming; Li, Hao; Bull, Christopher; Borton, David A; Aceros, Juan; Larson, Lawrence; Nurmikko, Arto V

2013-01-01

In this paper we present a new type of head-mounted wireless neural recording device in a highly compact package, dedicated for untethered laboratory animal research and designed for future mobile human clinical use. The device, which takes its input from an array of intracortical microelectrode arrays (MEA) has ninety-seven broadband parallel neural recording channels and was integrated on to two custom designed printed circuit boards. These house several low power, custom integrated circuits, including a preamplifier ASIC, a controller ASIC, plus two SAR ADCs, a 3-axis accelerometer, a 48MHz clock source, and a Manchester encoder. Another ultralow power RF chip supports an OOK transmitter with the center frequency tunable from 3GHz to 4GHz, mounted on a separate low loss dielectric board together with a 3V LDO, with output fed to a UWB chip antenna. The IC boards were interconnected and packaged in a polyether ether ketone (PEEK) enclosure which is compatible with both animal and human use (e.g. sterilizable). The entire system consumes 17mA from a 1.2Ahr 3.6V Li-SOCl2 1/2AA battery, which operates the device for more than 2 days. The overall system includes a custom RF receiver electronics which are designed to directly interface with any number of commercial (or custom) neural signal processors for multi-channel broadband neural recording. Bench-top measurements and in vivo testing of the device in rhesus macaques are presented to demonstrate the performance of the wireless neural interface.

Ergonomic design considerations for an optical data link between a warfighter's head and body-worn technologies

NASA Astrophysics Data System (ADS)

Trew, Noel; Linn, Aaron; Nelson, Zac; Burnett, Greg; Sedillo, Mike

2012-06-01

Today, warfighters are burdened by a web of cables linking technologies that span the head and torso regions of the body. These cables help to provide interoperability between helmet-worn peripherals such as head mounted displays (HMDs), cameras, and communication equipment with chest-worn computers and radios. Although promoting enhanced capabilities, this cabling also poses snag hazards and makes it difficult for the warfighter to extricate himself from his kit when necessary. A newly developed wireless personal area network (WPAN), one that uses optical transceivers, may prove to be an acceptable alternative to traditional cabling. Researchers at the Air Force Research Laboratory's 711th Human Performance Wing are exploring how best to mount the WPAN transceivers to the body in order to facilitate unimpeded data transfer while also maintaining the operator's natural range of motion. This report describes the two-step research process used to identify the performance limitations and usability of a body-worn optical wireless system. Firstly, researchers characterized the field of view for the current generation of optical WPAN transceivers. Then, this field of view was compared with anthropometric data describing the range of motion of the cervical vertebrae to see if the data link would be lost at the extremes of an operator's head movement. Finally, this report includes an additional discussion of other possible military applications for an optical WPAN.

Effects of Different Types of Virtual Reality Display on Presence and Learning in a Safety Training Scenario.

PubMed

Buttussi, Fabio; Chittaro, Luca

2018-02-01

The increasing availability of head-mounted displays (HMDs) for home use motivates the study of the possible effects that adopting this new hardware might have on users. Moreover, while the impact of display type has been studied for different kinds of tasks, it has been scarcely explored in procedural training. Our study considered three different types of displays used by participants for training in aviation safety procedures with a serious game. The three displays were respectively representative of: (i) desktop VR (a standard desktop monitor), (ii) many setups for immersive VR used in the literature (an HMD with narrow field of view and a 3-DOF tracker), and (iii) new setups for immersive home VR (an HMD with wide field of view and 6-DOF tracker). We assessed effects on knowledge gain, and different self-reported measures (self-efficacy, engagement, presence). Unlike previous studies of display type that measured effects only immediately after the VR experience, we considered also a longer time span (2 weeks). Results indicated that the display type played a significant role in engagement and presence. The training benefits (increased knowledge and self-efficacy) were instead obtained, and maintained at two weeks, regardless of the display used. The paper discusses the implications of these results.

Adapted head- and eye-movement responses to added-head inertia

NASA Technical Reports Server (NTRS)

Gauthier, G. M.; Martin, B. J.; Stark, L. W.

1986-01-01

Adaptation to inertia added to the head was studied in men by mounting masses on a rigidly attached helmet until two- to ten-fold increases of inertia were produced, while an overhead suspension compensated for the weights. The observed changes in the eye and head movement coordination included increased head movement latencies, as well as changes in the eye movement amplitude, and later stabilizing alternate contractions of the neck muscles. Oscillopsia, or continual displacement or instability of the visual world, which is a symptom of a breakdown of space constancy, was prominent and consistent in the perceptual reports of the subjects. Although adaptation resulting from adding inertia to the head occurred much faster than that induced by adding prisms or lenses, it has similar perceptual and motor components that may be objectively studied in detail.

Flight simulator evaluation of a novel flight instrument display to minimize the risks of spatial disorientation.

PubMed

Braithwaite, M G; Durnford, S J; Groh, S L; Jones, H D; Higdon, A A; Estrada, A; Alvarez, E A

1998-08-01

Spatial disorientation (SD) in flight remains a major source of attrition. Many SD accidents would occur regardless of the instrument display in use, since the aircrew are simply not looking at the instruments. However, there are a number of accidents which might be amenable to improved instrument displays. In an attempt to improve maintenance and reattainment of correct orientation with a reduced cognitive workload, a novel instrument display has been developed. This paper describes an assessment of the display in a UH-60 helicopter flight simulator. This study tested the hypothesis that during instrument flight and recovery from unusual attitudes, the novel display permits a more accurate maintenance and reestablishment of flight parameters than the standard flight instruments. There were 16 male aviators who flew a simulated instrument flight profile and recovery from unusual attitudes using both the standard flight instruments and the novel display. The two display formats were tested both with and without a secondary task. When compared with the standard instruments, both control of flight parameters and recovery from unusual attitudes were significantly improved when using the novel display. Analysis of the secondary task scores showed that cognitive workload was reduced when using the novel display compared with the standard instruments. Results from all aspects of the assessment indicated benefits of the new display. Future testing should be carried out during real flight, and the display should be further developed to be used in a head-up or helmet-mounted device.

Cylinder head for internal combustion engine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bell, D.W.

1992-10-06

This patent describes a cylinder head for attachment to a block assembly having at least one cylinder bore therein. It comprises: a cylinder head body adapted for attachment to the block assembly and having at least one side-entry fluid intake opening in communication with the cylinder bore, and having at least one side-exit exhaust fluid opening in communication with the cylinderbore; an intake spool mounted for axial rotation within the intake spool cavity; an exhaust spool mounted for axial rotation within the exhaust spool cavity; timing means for rotating the intake spool and the exhaust spool; and at least onemore » intake port and at least one exhaust port.« less

Driving While Interacting With Google Glass: Investigating the Combined Effect of Head-Up Display and Hands-Free Input on Driving Safety and Multitask Performance.

PubMed

Tippey, Kathryn G; Sivaraj, Elayaraj; Ferris, Thomas K

2017-06-01

This study evaluated the individual and combined effects of voice (vs. manual) input and head-up (vs. head-down) display in a driving and device interaction task. Advances in wearable technology offer new possibilities for in-vehicle interaction but also present new challenges for managing driver attention and regulating device usage in vehicles. This research investigated how driving performance is affected by interface characteristics of devices used for concurrent secondary tasks. A positive impact on driving performance was expected when devices included voice-to-text functionality (reducing demand for visual and manual resources) and a head-up display (HUD) (supporting greater visibility of the driving environment). Driver behavior and performance was compared in a texting-while-driving task set during a driving simulation. The texting task was completed with and without voice-to-text using a smartphone and with voice-to-text using Google Glass's HUD. Driving task performance degraded with the addition of the secondary texting task. However, voice-to-text input supported relatively better performance in both driving and texting tasks compared to using manual entry. HUD functionality further improved driving performance compared to conditions using a smartphone and often was not significantly worse than performance without the texting task. This study suggests that despite the performance costs of texting-while-driving, voice input methods improve performance over manual entry, and head-up displays may further extend those performance benefits. This study can inform designers and potential users of wearable technologies as well as policymakers tasked with regulating the use of these technologies while driving.

Circular displays: control/display arrangements and stereotype strength with eight different display locations.

PubMed

Chan, Alan H S; Hoffmann, Errol R

2015-01-01

Two experiments are reported that were designed to investigate control/display arrangements having high stereotype strengths when using circular displays. Eight display locations relative to the operator and control were tested with rotational and translational controls situated on different planes according to the Frame of Reference Transformation Tool (FORT) model of Wickens et al. (2010). (Left. No, Right! Development of the Frame of Reference Transformation Tool (FORT), Proceedings of the Human Factors and Ergonomics Society 54th Annual Meeting, 54: 1022-1026). In many cases, there was little effect of display locations, indicating the importance of the Worringham and Beringer (1998. Directional stimulus-response compatibility: a test of three alternative principles. Ergonomics, 41(6), 864-880) Visual Field principle and an extension of this principle for rotary controls (Hoffmann and Chan (2013). The Worringham and Beringer 'visual field' principle for rotary controls. Ergonomics, 56(10), 1620-1624). The initial indicator position (12, 3, 6 and 9 o'clock) had a major effect on control/display stereotype strength for many of the six controls tested. Best display/control arrangements are listed for each of the different control types (rotational and translational) and for the planes on which they are mounted. Data have application where a circular display is used due to limited display panel space and applies to space-craft, robotics operators, hospital equipment and home appliances. Practitioner Summary: Circular displays are often used when there is limited space available on a control panel. Display/control arrangements having high stereotype strength are listed for four initial indicator positions. These arrangements are best for design purposes.

Maneuvering impact boring head

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zollinger, W.T.; Reutzel, E.W.

An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

Maneuvering impact boring head

DOEpatents

Zollinger, W.T.; Reutzel, E.W.

1998-08-18

An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure. 8 figs.

Maneuvering impact boring head

DOEpatents

Zollinger, W. Thor; Reutzel, Edward W.

1998-01-01

An impact boring head may comprise a main body having an internal cavity with a front end and a rear end. A striker having a head end and a tail end is slidably mounted in the internal cavity of the main body so that the striker can be reciprocated between a forward position and an aft position in response to hydraulic pressure. A compressible gas contained in the internal cavity between the head end of the striker and the front end of the internal cavity returns the striker to the aft position upon removal of the hydraulic pressure.

Advancement of thyroid surgery video recording: A comparison between two full HD head mounted video cameras.

PubMed

Ortensi, Andrea; Panunzi, Andrea; Trombetta, Silvia; Cattaneo, Alberto; Sorrenti, Salvatore; D'Orazi, Valerio

2017-05-01

The aim of this study was to test two different video cameras and recording systems used in thyroid surgery in our Department. This is meant to be an attempt to record the real point of view of the magnified vision of surgeon, so as to make the viewer aware of the difference with the naked eye vision. In this retrospective study, we recorded and compared twenty thyroidectomies performed using loupes magnification and microsurgical technique: ten were recorded with GoPro ® 4 Session action cam (commercially available) and ten with our new prototype of head mounted video camera. Settings were selected before surgery for both cameras. The recording time is about from 1 to 2 h for GoPro ® and from 3 to 5 h for our prototype. The average time of preparation to fit the camera on the surgeon's head and set the functionality is about 5 min for GoPro ® and 7-8 min for the prototype, mostly due to HDMI wiring cable. Videos recorded with the prototype require no further editing, which is mandatory for videos recorded with GoPro ® to highlight the surgical details. the present study showed that our prototype of video camera, compared with GoPro ® 4 Session, guarantees best results in terms of surgical video recording quality, provides to the viewer the exact perspective of the microsurgeon and shows accurately his magnified view through the loupes in thyroid surgery. These recordings are surgical aids for teaching and education and might be a method of self-analysis of surgical technique. Copyright © 2017 IJS Publishing Group Ltd. Published by Elsevier Ltd. All rights reserved.

A preliminary study of head-up display assessment techniques. 2: HUD symbology and panel information search time

NASA Technical Reports Server (NTRS)

Guercio, J. G.; Haines, R. F.

1978-01-01

Twelve commercial pilots were shown 50 high-fidelity slides of a standard aircraft instrument panel with the airspeed, altitude, ADI, VSI, and RMI needles in various realistic orientations. Fifty slides showing an integrated head-up display (HUD) symbology containing an equivalent number of flight parameters as above (with flight path replacing VSI) were also shown. Each subject was told what flight parameter to search for just before each slide was exposed and was given as long as needed (12 sec maximum) to respond by verbalizing the parameter's displayed value. The results for the 100-percent correct data indicated that: there was no significant difference in mean reaction time (averaged across all five flight parameters) between the instrument panel and HUD slides; and a statistically significant difference in mean reaction time was found in responding to different flight parameters.

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2013 CFR

2013-10-01

... 49 Transportation 7 2013-10-01 2013-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2011 CFR

2011-10-01

... 49 Transportation 7 2011-10-01 2011-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2014 CFR

2014-10-01

... 49 Transportation 7 2014-10-01 2014-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

49 CFR 572.152 - Head assembly and test procedure.

Code of Federal Regulations, 2012 CFR

2012-10-01

... 49 Transportation 7 2012-10-01 2012-10-01 false Head assembly and test procedure. 572.152 Section... 12-Month-Old Infant, Alpha Version § 572.152 Head assembly and test procedure. (a) The head assembly (refer to § 572.150(a)(1)(i)) for this test consists of the assembly (drawing 921022-001), triaxial mount...

Advanced Traveler Information Systems and Commercial Vehicle Operations Components of the Intelligent Transportation Systems: Head-up Displays and Driver Attention for Navigation Information

DOT National Transportation Integrated Search

1998-03-01

Since the initial development of prototype automotive head-up displays (HUDs), there has been a concern that the presence of the HUD image may interfere with the driving task and negatively impact driving performance. The overall goal of this experim...

Thin optical display panel

DOEpatents

Veligdan, James Thomas

1997-01-01

An optical display includes a plurality of optical waveguides each including a cladding bound core for guiding internal display light between first and second opposite ends by total internal reflection. The waveguides are stacked together to define a collective display thickness. Each of the cores includes a heterogeneous portion defining a light scattering site disposed longitudinally between the first and second ends. Adjacent ones of the sites are longitudinally offset from each other for forming a longitudinal internal image display over the display thickness upon scattering of internal display light thereagainst for generating a display image. In a preferred embodiment, the waveguides and scattering sites are transparent for transmitting therethrough an external image in superposition with the display image formed by scattering the internal light off the scattering sites for defining a heads up display.

Accelerometer Method and Apparatus for Integral Display and Control Functions

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr. (Inventor)

1996-01-01

Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto. Art accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

Accelerometer Method and Apparatus for Integral Display and Control Functions

NASA Technical Reports Server (NTRS)

Bozeman, Richard J., Jr. (Inventor)

1998-01-01

Method and apparatus for detecting mechanical vibrations and outputting a signal in response thereto is discussed. An accelerometer package having integral display and control functions is suitable for mounting upon the machinery to be monitored. Display circuitry provides signals to a bar graph display which may be used to monitor machine conditions over a period of time. Control switches may be set which correspond to elements in the bar graph to provide an alert if vibration signals increase in amplitude over a selected trip point. The circuitry is shock mounted within the accelerometer housing. The method provides for outputting a broadband analog accelerometer signal, integrating this signal to produce a velocity signal, integrating and calibrating the velocity signal before application to a display driver, and selecting a trip point at which a digitally compatible output signal is generated.

Simulator evaluation of displays for a revised takeoff performance monitoring system

NASA Technical Reports Server (NTRS)

Middleton, David B.; Srivatsan, Raghavachari; Person, Lee H., Jr

1992-01-01

Cockpit displays for a Takeoff Performance Monitoring System (TOPMS) to provide pilots with graphic and alphanumeric information pertinent to their decision to continue or abort a takeoff are evaluated. Revised head-down and newly developed head-up displays were implemented on electronic screens in the real-time Transport Systems Research Vehicle (TSRV) Simulator for the Boeing 737 airplane at the Langley Research Center and evaluated by 17 NASA, U.S. Air Force, airline, and industry pilots. Both types of displays were in color, but they were not dependent upon it. The TOPMS head-down display is composed of a runway graphic overlaid with symbolic status and advisory information related to both the expected takeoff point and the predicted stop point (in the event an abort becomes necessary). In addition, an overall Situation Advisory Flag indicates a preferred course of action based on analysis of the various elements of airplane performance and system status. A simpler head-up display conveys most of this same information and relates it to the visual scene. The evaluation pilots found the displays to be credible, easy to monitor, and appropriate for the task. In particular, the pilots said the head-up display was monitored with very little effort and did not obstruct or distract them from monitoring the simulated out-the-window runway scene. This report augments NASA TP-2908, 1989.

An Evaluation of Signal Annoyance for a Head-Mounted Tactile Display

DTIC Science & Technology

2015-03-01

the burden, to Department of Defense , Washington Headquarters Services, Directorate for Information Operations and Reports (0704-0188), 1215... the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing the ...be used on the finger, torso, and arm, and currently, vibrotactile signals are optimized for use on those areas. Thus, integrating BC

Jedi training: playful evaluation of head-mounted augmented reality display systems

NASA Astrophysics Data System (ADS)

Ozbek, Christopher S.; Giesler, Bjorn; Dillmann, Ruediger

2004-05-01

A fundamental decision in building augmented reality (AR) systems is how to accomplish the combining of the real and virtual worlds. Nowadays this key-question boils down to the two alternatives video-see-through (VST) vs. optical-see-through (OST). Both systems have advantages and disadvantages in areas like production-simplicity, resolution, flexibility in composition strategies, field of view etc. To provide additional decision criteria for high dexterity, accuracy tasks and subjective user-acceptance a gaming environment was programmed that allowed good evaluation of hand-eye coordination, and that was inspired by the Star Wars movies. During an experimentation session with more than thirty participants a preference for optical-see-through glasses in conjunction with infra-red-tracking was found. Especially the high-computational demand for video-capture, processing and the resulting drop in frame rate emerged as a key-weakness of the VST-system.

Game-Based Evacuation Drill Using Augmented Reality and Head-Mounted Display

ERIC Educational Resources Information Center

Kawai, Junya; Mitsuhara, Hiroyuki; Shishibori, Masami

2016-01-01

Purpose: Evacuation drills should be more realistic and interactive. Focusing on situational and audio-visual realities and scenario-based interactivity, the authors have developed a game-based evacuation drill (GBED) system that presents augmented reality (AR) materials on tablet computers. The paper's current research purpose is to improve…

Mount Everest region as seen from the STS-66 orbiter Atlantis

NASA Image and Video Library

1994-11-14

STS066-124-059 (3-14 Nov. 1994) --- Mount Everest region, Nepal and China. Low morning Sun highlights Mount Everest (the highest mountain in the world at 8,848 meters), Cho Oyu (8,153 meters) to the northwest, and other peaks of "The Roof of the World". New snow seems to be confined to the highest peaks. Abundant details of glacier surfaces, including moraines, crevasse fields, and ice falls are displayed for study.

Using wintergreen oil for mounting mosquito larvae: a safer alternative to xylene.

PubMed

Koay, J B; Natasya, N N; Nashithatul, Mag; Ihsanuddin, R; Salleh, F M; Azil, A H

2016-01-01

Permanent mounting of fourth instar mosquito larvae is essential for identifying Aedes spp. This procedure requires extensive exposure to xylene, a clearing agent in the mounting process. We investigated wintergreen oil as a substitute for xylene. Five hundred larvae were mounted on slides to evaluate shrinkage or expansion of specimens after clearing using xylene or wintergreen oil. We examined the ventral brush and siphonal hair tufts for species identification and for preservation of morphological characteristics after clearing specimens in xylene or wintergreen oil. Shrinkage of the length of whole larvae and width of the head, thorax and abdomen after mounting was significantly greater after clearing with xylene than with wintergreen oil. The length of the comb scale nearest the ventral brush was similar for both clearing agents. The clarity of the specimens after mounting was improved by clearing with wintergreen oil, but the integrity of the ventral brush and siphonal hair tufts were similar for both clearing agents.

Cyborg mini-trainer.

PubMed

Mosso, José L; Nieto, Jesus J; Carbajal, Manuel F; Marmolejo, Jorge; Ochoa, Enrique; De La Fuente, Mireya; Almazan, Andrew; Obrador, Tomas

2009-01-01

We present the smallest surgical trainer with a total weight of 400 gr, built in aluminum of 25 cm large and 24 cm wide, and 23 cm high. It's a system integrated by a small and open module, a lamp and a microcamera connected to a Head Mounted display. It holds two endoscopic instruments, and items to make knots or sutures and enhance visual-motor coordination. The vision we got is by a small microcamera displayed to a Head Mounted Display HMD. This surgical trainer is the smallest in the worldwide, easy to install, and easy to carry.

Virtual environment display for a 3D audio room simulation

NASA Astrophysics Data System (ADS)

Chapin, William L.; Foster, Scott

1992-06-01

Recent developments in virtual 3D audio and synthetic aural environments have produced a complex acoustical room simulation. The acoustical simulation models a room with walls, ceiling, and floor of selected sound reflecting/absorbing characteristics and unlimited independent localizable sound sources. This non-visual acoustic simulation, implemented with 4 audio ConvolvotronsTM by Crystal River Engineering and coupled to the listener with a Poihemus IsotrakTM, tracking the listener's head position and orientation, and stereo headphones returning binaural sound, is quite compelling to most listeners with eyes closed. This immersive effect should be reinforced when properly integrated into a full, multi-sensory virtual environment presentation. This paper discusses the design of an interactive, visual virtual environment, complementing the acoustic model and specified to: 1) allow the listener to freely move about the space, a room of manipulable size, shape, and audio character, while interactively relocating the sound sources; 2) reinforce the listener's feeling of telepresence into the acoustical environment with visual and proprioceptive sensations; 3) enhance the audio with the graphic and interactive components, rather than overwhelm or reduce it; and 4) serve as a research testbed and technology transfer demonstration. The hardware/software design of two demonstration systems, one installed and one portable, are discussed through the development of four iterative configurations. The installed system implements a head-coupled, wide-angle, stereo-optic tracker/viewer and multi-computer simulation control. The portable demonstration system implements a head-mounted wide-angle, stereo-optic display, separate head and pointer electro-magnetic position trackers, a heterogeneous parallel graphics processing system, and object oriented C++ program code.

Investigation of truck mounted attenuator (TMA) crashes in work zones in Virginia.

DOT National Transportation Integrated Search

2015-10-01

Truck mounted attenuators (TMAs) are deployed on shadow vehicles in work zones to mitigate the effects of errant : vehicles that strike the shadow vehicle, either by smoothly decelerating the vehicle to a stop when hit head-on or by redirecting : the...

Color Breakup In Sequentially-Scanned LC Displays

NASA Technical Reports Server (NTRS)

Arend, L.; Lubin, J.; Gille, J.; Larimer, J.; Statler, Irving C. (Technical Monitor)

1994-01-01

In sequentially-scanned liquid-crystal displays the chromatic components of color pixels are distributed in time. For such displays eye, head, display, and image-object movements can cause the individual color elements to be visible. We analyze conditions (scan designs, types of eye movement) likely to produce color breakup.

Obstacles encountered in the development of the low vision enhancement system.

PubMed

Massof, R W; Rickman, D L

1992-01-01

The Johns Hopkins Wilmer Eye Institute and the NASA Stennis Space Center are collaborating on the development of a new high technology low vision aid called the Low Vision Enhancement System (LVES). The LVES consists of a binocular head-mounted video display system, video cameras mounted on the head-mounted display, and real-time video image processing in a system package that is battery powered and portable. Through a phased development approach, several generations of the LVES can be made available to the patient in a timely fashion. This paper describes the LVES project with major emphasis on technical problems encountered or anticipated during the development process.

A review of wearable technology in medicine.

PubMed

Iqbal, Mohammed H; Aydin, Abdullatif; Brunckhorst, Oliver; Dasgupta, Prokar; Ahmed, Kamran

2016-10-01

With rapid advances in technology, wearable devices have evolved and been adopted for various uses, ranging from simple devices used in aiding fitness to more complex devices used in assisting surgery. Wearable technology is broadly divided into head-mounted displays and body sensors. A broad search of the current literature revealed a total of 13 different body sensors and 11 head-mounted display devices. The latter have been reported for use in surgery (n = 7), imaging (n = 3), simulation and education (n = 2) and as navigation tools (n = 1). Body sensors have been used as vital signs monitors (n = 9) and for posture-related devices for posture and fitness (n = 4). Body sensors were found to have excellent functionality in aiding patient posture and rehabilitation while head-mounted displays can provide information to surgeons to while maintaining sterility during operative procedures. There is a potential role for head-mounted wearable technology and body sensors in medicine and patient care. However, there is little scientific evidence available proving that the application of such technologies improves patient satisfaction or care. Further studies need to be conducted prior to a clear conclusion. © The Royal Society of Medicine.

Globular Head-Displayed Conserved Influenza H1 Hemagglutinin Stalk Epitopes Confer Protection against Heterologous H1N1 Virus.

PubMed

Klausberger, Miriam; Tscheliessnig, Rupert; Neff, Silke; Nachbagauer, Raffael; Wohlbold, Teddy John; Wilde, Monika; Palmberger, Dieter; Krammer, Florian; Jungbauer, Alois; Grabherr, Reingard

2016-01-01

Significant genetic variability in the head region of the influenza A hemagglutinin, the main target of current vaccines, makes it challenging to develop a long-lived seasonal influenza prophylaxis. Vaccines based on the conserved hemagglutinin stalk domain might provide broader cross-reactive immunity. However, this region of the hemagglutinin is immunosubdominant to the head region. Peptide-based vaccines have gained much interest as they allow the immune system to focus on relevant but less immunogenic epitopes. We developed a novel influenza A hemagglutinin-based display platform for H1 hemagglutinin stalk peptides that we identified in an epitope mapping assay using human immune sera and synthetic HA peptides. Flow cytometry and competition assays suggest that the identified stalk sequences do not recapitulate the epitopes of already described broadly neutralizing stalk antibodies. Vaccine constructs displaying 25-mer stalk sequences provided up to 75% protection from lethal heterologous virus challenge in BALB/c mice and induced antibody responses against the H1 hemagglutinin. The developed platform based on a vaccine antigen has the potential to be either used as stand-alone or as prime-vaccine in combination with conventional seasonal or pandemic vaccines for the amplification of stalk-based cross-reactive immunity in humans or as platform to evaluate the relevance of viral peptides/epitopes for protection against influenza virus infection.

Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats.

PubMed

Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

2016-10-12

Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal's retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals.

Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

PubMed Central

Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

2016-01-01

Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals. PMID:27731346

Head mounted DMD based projection system for natural and prosthetic visual stimulation in freely moving rats

NASA Astrophysics Data System (ADS)

Arens-Arad, Tamar; Farah, Nairouz; Ben-Yaish, Shai; Zlotnik, Alex; Zalevsky, Zeev; Mandel, Yossi

2016-10-01

Novel technologies are constantly under development for vision restoration in blind patients. Many of these emerging technologies are based on the projection of high intensity light patterns at specific wavelengths, raising the need for the development of specialized projection systems. Here we present and characterize a novel projection system that meets the requirements for artificial retinal stimulation in rats and enables the recording of cortical responses. The system is based on a customized miniature Digital Mirror Device (DMD) for pattern projection, in both visible (525 nm) and NIR (915 nm) wavelengths, and a lens periscope for relaying the pattern directly onto the animal’s retina. Thorough system characterization and the investigation of the effect of various parameters on obtained image quality were performed using ZEMAX. Simulation results revealed that images with an MTF higher than 0.8 were obtained with little effect of the vertex distance. Increased image quality was obtained at an optimal pupil diameter and smaller field of view. Visual cortex activity data was recorded simultaneously with pattern projection, further highlighting the importance of the system for prosthetic vision studies. This novel head mounted projection system may prove to be a vital tool in studying natural and artificial vision in behaving animals.

Heading perception in patients with advanced retinitis pigmentosa

NASA Technical Reports Server (NTRS)

Li, Li; Peli, Eli; Warren, William H.

2002-01-01

PURPOSE: We investigated whether retinis pigmentosa (RP) patients with residual visual field of < 100 degrees could perceive heading from optic flow. METHODS: Four RP patients and four age-matched normally sighted control subjects viewed displays simulating an observer walking over a ground. In experiment 1, subjects viewed either the entire display with free fixation (full-field condition) or through an aperture with a fixation point at the center (aperture condition). In experiment 2, patients viewed displays of different durations. RESULTS: RP patients' performance was comparable to that of the age-matched control subjects: heading judgment was better in the full-field condition than in the aperture condition. Increasing display duration from 0.5 s to 1 s improved patients' heading performance, but giving them more time (3 s) to gather more visual information did not consistently further improve their performance. CONCLUSIONS: RP patients use active scanning eye movements to compensate for their visual field loss in heading perception; they might be able to gather sufficient optic flow information for heading perception in about 1 s.

Heading perception in patients with advanced retinitis pigmentosa.

PubMed

Li, Li; Peli, Eli; Warren, William H

2002-09-01

We investigated whether retinis pigmentosa (RP) patients with residual visual field of < 100 degrees could perceive heading from optic flow. Four RP patients and four age-matched normally sighted control subjects viewed displays simulating an observer walking over a ground. In experiment 1, subjects viewed either the entire display with free fixation (full-field condition) or through an aperture with a fixation point at the center (aperture condition). In experiment 2, patients viewed displays of different durations. RP patients' performance was comparable to that of the age-matched control subjects: heading judgment was better in the full-field condition than in the aperture condition. Increasing display duration from 0.5 s to 1 s improved patients' heading performance, but giving them more time (3 s) to gather more visual information did not consistently further improve their performance. RP patients use active scanning eye movements to compensate for their visual field loss in heading perception; they might be able to gather sufficient optic flow information for heading perception in about 1 s.

The Human Retrosplenial Cortex and Thalamus Code Head Direction in a Global Reference Frame.

PubMed

Shine, Jonathan P; Valdés-Herrera, José P; Hegarty, Mary; Wolbers, Thomas

2016-06-15

Spatial navigation is a multisensory process involving integration of visual and body-based cues. In rodents, head direction (HD) cells, which are most abundant in the thalamus, integrate these cues to code facing direction. Human fMRI studies examining HD coding in virtual environments (VE) have reported effects in retrosplenial complex and (pre-)subiculum, but not the thalamus. Furthermore, HD coding appeared insensitive to global landmarks. These tasks, however, provided only visual cues for orientation, and attending to global landmarks did not benefit task performance. In the present study, participants explored a VE comprising four separate locales, surrounded by four global landmarks. To provide body-based cues, participants wore a head-mounted display so that physical rotations changed facing direction in the VE. During subsequent MRI scanning, subjects saw stationary views of the environment and judged whether their orientation was the same as in the preceding trial. Parameter estimates extracted from retrosplenial cortex and the thalamus revealed significantly reduced BOLD responses when HD was repeated. Moreover, consistent with rodent findings, the signal did not continue to adapt over repetitions of the same HD. These results were supported by a whole-brain analysis showing additional repetition suppression in the precuneus. Together, our findings suggest that: (1) consistent with the rodent literature, the human thalamus may integrate visual and body-based, orientation cues; (2) global reference frame cues can be used to integrate HD across separate individual locales; and (3) immersive training procedures providing full body-based cues may help to elucidate the neural mechanisms supporting spatial navigation. In rodents, head direction (HD) cells signal facing direction in the environment via increased firing when the animal assumes a certain orientation. Distinct brain regions, the retrosplenial cortex (RSC) and thalamus, code for visual and

Methods and apparatus for transparent display using scattering nanoparticles

DOEpatents

Hsu, Chia Wei; Qiu, Wenjun; Zhen, Bo; Shapira, Ofer; Soljacic, Marin

2017-06-14

Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

Methods and apparatus for transparent display using scattering nanoparticles

DOEpatents

Hsu, Chia Wei; Qiu, Wenjun; Zhen, Bo; Shapira, Ofer; Soljacic, Marin

2016-05-10

Transparent displays enable many useful applications, including heads-up displays for cars and aircraft as well as displays on eyeglasses and glass windows. Unfortunately, transparent displays made of organic light-emitting diodes are typically expensive and opaque. Heads-up displays often require fixed light sources and have limited viewing angles. And transparent displays that use frequency conversion are typically energy inefficient. Conversely, the present transparent displays operate by scattering visible light from resonant nanoparticles with narrowband scattering cross sections and small absorption cross sections. More specifically, projecting an image onto a transparent screen doped with nanoparticles that selectively scatter light at the image wavelength(s) yields an image on the screen visible to an observer. Because the nanoparticles scatter light at only certain wavelengths, the screen is practically transparent under ambient light. Exemplary transparent scattering displays can be simple, inexpensive, scalable to large sizes, viewable over wide angular ranges, energy efficient, and transparent simultaneously.

Gas cushion control of OVJP print head position

DOE Office of Scientific and Technical Information (OSTI.GOV)

Forrest, Stephen R

An OVJP apparatus and method for applying organic vapor or other flowable material to a substrate using a printing head mechanism in which the print head spacing from the substrate is controllable using a cushion of air or other gas applied between the print head and substrate. The print head is mounted for translational movement towards and away from the substrate and is biased toward the substrate by springs or other means. A gas cushion feed assembly supplies a gas under pressure between the print head and substrate which opposes the biasing of the print head toward the substrate somore » as to form a space between the print head and substrate. By controlling the pressure of gas supplied, the print head separation from the substrate can be precisely controlled.« less

Illusion in reality: visual perception in displays

NASA Astrophysics Data System (ADS)

Kaufman, Lloyd; Kaufman, James H.

2001-06-01

Research into visual perception ultimately affects display design. Advance in display technology affects, in turn, our study of perception. Although this statement is too general to provide controversy, this paper present a real-life example that may prompt display engineers to make greater use of basic knowledge of visual perception, and encourage those who study perception to track more closely leading edge display technology. Our real-life example deals with an ancient problem, the moon illusion: why does the horizon moon appear so large while the elevated moon look so small. This was a puzzle for many centuries. Physical explanations, such as refraction by the atmosphere, are incorrect. The difference in apparent size may be classified as a misperception, so the answer must lie in the general principles of visual perception. The factors underlying the moon illusion must be the same factors as those that enable us to perceive the sizes of ordinary objects in visual space. Progress toward solving the problem has been irregular, since methods for actually measuring the illusion under a wide range of conditions were lacking. An advance in display technology made possible a serious and methodologically controlled study of the illusion. This technology was the first heads-up display. In this paper we will describe how the heads-up display concept made it possible to test several competing theories of the moon illusion, and how it led to an explanation that stood for nearly 40 years. We also consider the criticisms of that explanation and how the optics of the heads-up display also played a role in providing data for the critics. Finally, we will describe our own advance on the original methodology. This advance was motivated by previously unrelated principles of space perception. We used a stereoscopic heads up display to test alternative hypothesis about the illusion and to discrimate between two classes of mutually contradictory theories. At its core, the

Experimental procedure for measuring and comparing head-neck-trunk posture and movements caused by different progressive addition lens designs.

PubMed

Mateo, B; Porcar-Seder, R; Solaz, J S; Dürsteler, J C

2010-07-01

This study demonstrates that appropriate measurement procedures can detect differences in head movement in a near reading task when using three different progressive addition lenses (PALs). The movements were measured using an anatomical reference system with a biomechanical rationale. This reference system was capable of representing rotations for comparing head flexion relative to trunk, head flexion relative to neck, head rotation relative to trunk and trunk flexion. The subject sample comprised 31 volunteers and three PAL designs with different viewing zones were selected. Significant differences were found between the lenses for three of the seven movement parameters examined. The differences occurred for both vertical and horizontal head movements and could be attributed to aspects of the PAL design. The measurement of the complete kinematic trunk-neck-head chain improved the number of differences that were found over those in previous studies. STATEMENT OF RELEVANCE: The study proposes a methodology based on a biomechanical rationale able to differentiate head-neck-trunk posture and movements caused by different progressive addition lens designs with minimum invasiveness. This methodology could also be applied to analyse the ergonomics of other devices that restrict the user's field of view, such as helmets, personal protective equipment or helmet-mounted displays for pilots. This analysis will allow designers to optimise designs offering higher comfort and performance.

Retired NASA F-18 being mounted on pedestal mount at Lancaster California Municipal Baseball Stadium

NASA Technical Reports Server (NTRS)

1997-01-01

Workers carefully align a mounting bracket attached to an F/A-18 Hornet aircraft with the top of a pedestal in front of the municipal baseball stadium in the city of Lancaster, California. The Blue-and-white twin-jet aircraft, formerly flown as a safety chase and support aircraft by NASA's Dryden Flight Research Center, Edwards, California, was loaned to the city for display following its recent retirement. Known as 'The Hangar,' the stadium is the home field of the Lancaster Jethawks, a Class-A farm team of the Seattle Mariners.

TRISTAR 1: Evaluation methods for testing head-up display (HUD) flight symbology

NASA Technical Reports Server (NTRS)

Newman, R. L.; Haworth, L. A.; Kessler, G. K.; Eksuzian, D. J.; Ercoline, W. R.; Evans, R. H.; Hughes, T. C.; Weinstein, L. F.

1995-01-01

The first in a series of piloted head-up display (HUD) flight symbology studies (TRISTAR) measuring pilot task performance was conducted at the NASA Ames Research Center by the Tri-Service Flight Symbology Working Group (FSWG). Sponsored by the U.S. Army Aeroflightdynamics Directorate, this study served as a focal point for the FSWG to examine HUD test methodology and flight symbology presentations. HUD climb-dive marker dynamics and climb-dive ladder presentations were examined as pilots performed air-to-air (A/A), air-to-ground (A/G), instrument landing system (ILS), and unusual attitude (UA) recover tasks. Symbolic presentations resembled pitch ladder variations used by the U.S. Air Force (USAF), U.S. Navy (USN), and Royal Air Force (RAF). The study was initiated by the FSWG to address HUD flight symbology deficiencies, standardization, issue identification, and test methodologies. It provided the mechanism by which the USAF, USN, RAF, and USA could integrate organizational ideas and reduce differences for comparisons. Specifically it examined flight symbology issues collectively identified by each organization and the use of objective and subjective text methodology and flight tasking proposed by the FSWG.

Head-Up Display (HUD) Technology Demonstration.

DTIC Science & Technology

1983-07-01

changrd, if you wish to be removed from our mailing list, or if the addressee is no longer employed by your organization please notify AFWAL/AA T, W-PAFB...S. E. Shields ’ 9. PERFORMING ORGANIZATION NAME ANO ADORESS 10. PROGRAM LEMENT. PROJECT TASK Display Technology Staff AREA P O ORK UNIT N.UME.RS...stains, it did indicate that the stains contained organic structures that could not be explained by exposure to atmosphere. The results of the surface

62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

62. SIXTEEN INCH GUN MOUNTED ON THE MACHINING LATHE; LOOKING WSW. THE GUN ITSELF EXTENDS BEYOND THE BRICK ARCHES OF THE MAIN SHOP FLOOR'S W WALL AND INTO THE W AISLE. THE LATHE'S CUTTING HEAD CAN BE SEEN AT THE RIGHT CENTER OF THE VIEW. (Ryan) - Watervliet Arsenal, Building No. 110, Hagner Road between Schull & Whittemore Roads, Watervliet, Albany County, NY

LED display for solo aircraft instrument navigation

NASA Technical Reports Server (NTRS)

Crouch, R. K.; Kelly, W. L., VI; Lina, L. J.; Meredith, B. D.

1979-01-01

Solo pilot's task is made easier through convenient display of landing and navigation data. Use of display shows promise as more efficient means of presenting sequential instructions and data, such as course heading, altitude, and radio frequency, to minimize pilot's workload during solo instrument flight.

Influence of visual path information on human heading perception during rotation.

PubMed

Li, Li; Chen, Jing; Peng, Xiaozhe

2009-03-31

How does visual path information influence people's perception of their instantaneous direction of self-motion (heading)? We have previously shown that humans can perceive heading without direct access to visual path information. Here we vary two key parameters for estimating heading from optic flow, the field of view (FOV) and the depth range of environmental points, to investigate the conditions under which visual path information influences human heading perception. The display simulated an observer traveling on a circular path. Observers used a joystick to rotate their line of sight until deemed aligned with true heading. Four FOV sizes (110 x 94 degrees, 48 x 41 degrees, 16 x 14 degrees, 8 x 7 degrees) and depth ranges (6-50 m, 6-25 m, 6-12.5 m, 6-9 m) were tested. Consistent with our computational modeling results, heading bias increased with the reduction of FOV or depth range when the display provided a sequence of velocity fields but no direct path information. When the display provided path information, heading bias was not influenced as much by the reduction of FOV or depth range. We conclude that human heading and path perception involve separate visual processes. Path helps heading perception when the display does not contain enough optic-flow information for heading estimation during rotation.

Mounted Combat System Crew Shock Loading: Head and Neck Injury Potential Evaluation

DTIC Science & Technology

2007-07-01

including the time for reviewing instructions, searching existing data sources, gathering and maintaining the data needed, and completing and reviewing...degrees. The raw data for this project were collected by the Motion Base Technologies Team of TARDEC and their contractors. The data were sent to the...relating the neck force and torque and head accelerations to establish injury criteria for the neck and head. Data from the Hybrid III manikin were

Pilot Errors Involving Head-Up Displays (HUDs), Helmet-Mounted Displays (HMDs), and Night Vision Goggles (NVGs)

DTIC Science & Technology

1992-01-01

results in stimulation of spatial-motion-location visual processes, which are known to take precedence over any other sensor or cognitive stimuli. In...or version he is flying. This was initially an observation that stimulated the birth of the human-factors engineering discipline during World War H...collisions with the surface, the pilot needs inputs to sensory channels other than the focal visual system. Properly designed auditory and

A method for estimating mount isolations of powertrain mounting systems

NASA Astrophysics Data System (ADS)

Qin, Wu; Shangguan, Wen-Bin; Luo, Guohai; Xie, Zhengchao

2018-07-01

A method for calculating isolation ratios of mounts at a powertrain mounting systems (PMS) is proposed assuming a powertrain as a rigid body and using the identified powertrain excitation forces and the measured IPI (input point inertance) of mounting points at the body side. With measured accelerations of mounts at powertrain and body sides of one Vehicle (Vehicle A), the excitation forces of a powertrain are identified using conversational method firstly. Another Vehicle (Vehicle B) has the same powertrain as that of Vehicle A, but with different body and mount configuration. The accelerations of mounts at powertrain side of a PMS on Vehicle B are calculated using the powertrain excitation forces identified from Vehicle A. The identified forces of the powertrain are validated by comparing the calculated and the measured accelerations of mounts at the powertrain side of the powertrain on Vehicle B. A method for calculating acceleration of mounting point at body side for Vehicle B is presented using the identified powertrain excitation forces and the measured IPI at a connecting point between car body and mount. Using the calculated accelerations of mounts at powertrain side and body side at different directions, the isolation ratios of a mount are then estimated. The isolation ratios are validated using the experiment, which verified the proposed methods for estimating isolation ratios of mounts. The developed method is beneficial for optimizing mount stiffness to meet mount isolation requirements before prototype.

Heads-Up Display with Virtual Precision Approach Path Indicator as Implemented in a Real-Time Piloted Lifting-Body Simulation

NASA Technical Reports Server (NTRS)

Neuhaus, Jason R.

2018-01-01

This document describes the heads-up display (HUD) used in a piloted lifting-body entry, approach and landing simulation developed for the simulator facilities of the Simulation Development and Analysis Branch (SDAB) at NASA Langley Research Center. The HUD symbology originated with the piloted simulation evaluations of the HL-20 lifting body concept conducted in 1989 at NASA Langley. The original symbology was roughly based on Shuttle HUD symbology, as interpreted by Langley researchers. This document focuses on the addition of the precision approach path indicator (PAPI) lights to the HUD overlay.

Correction techniques for depth errors with stereo three-dimensional graphic displays

NASA Technical Reports Server (NTRS)

Parrish, Russell V.; Holden, Anthony; Williams, Steven P.

1992-01-01

Three-dimensional (3-D), 'real-world' pictorial displays that incorporate 'true' depth cues via stereopsis techniques have proved effective for displaying complex information in a natural way to enhance situational awareness and to improve pilot/vehicle performance. In such displays, the display designer must map the depths in the real world to the depths available with the stereo display system. However, empirical data have shown that the human subject does not perceive the information at exactly the depth at which it is mathematically placed. Head movements can also seriously distort the depth information that is embedded in stereo 3-D displays because the transformations used in mapping the visual scene to the depth-viewing volume (DVV) depend intrinsically on the viewer location. The goal of this research was to provide two correction techniques; the first technique corrects the original visual scene to the DVV mapping based on human perception errors, and the second (which is based on head-positioning sensor input data) corrects for errors induced by head movements. Empirical data are presented to validate both correction techniques. A combination of the two correction techniques effectively eliminates the distortions of depth information embedded in stereo 3-D displays.

A Versatile Mounting Method for Long Term Imaging of Zebrafish Development.

PubMed

Hirsinger, Estelle; Steventon, Ben

2017-01-26

Zebrafish embryos offer an ideal experimental system to study complex morphogenetic processes due to their ease of accessibility and optical transparency. In particular, posterior body elongation is an essential process in embryonic development by which multiple tissue deformations act together to direct the formation of a large part of the body axis. In order to observe this process by long-term time-lapse imaging it is necessary to utilize a mounting technique that allows sufficient support to maintain samples in the correct orientation during transfer to the microscope and acquisition. In addition, the mounting must also provide sufficient freedom of movement for the outgrowth of the posterior body region without affecting its normal development. Finally, there must be a certain degree in versatility of the mounting method to allow imaging on diverse imaging set-ups. Here, we present a mounting technique for imaging the development of posterior body elongation in the zebrafish D. rerio. This technique involves mounting embryos such that the head and yolk sac regions are almost entirely included in agarose, while leaving out the posterior body region to elongate and develop normally. We will show how this can be adapted for upright, inverted and vertical light-sheet microscopy set-ups. While this protocol focuses on mounting embryos for imaging for the posterior body, it could easily be adapted for the live imaging of multiple aspects of zebrafish development.

Chronic monitoring of cortical hemodynamics in behaving, freely-moving rats using a miniaturized head-mounted optical microscope

NASA Astrophysics Data System (ADS)

Sigal, Iliya; Gad, Raanan; Koletar, Margaret; Ringuette, Dene; Stefanovic, Bojana; Levi, Ofer

2016-03-01

Growing interest within the neurophysiology community in assessing healthy and pathological brain activity in animals that are awake and freely-behaving has triggered the need for optical systems that are suitable for such longitudinal studies. In this work we report label-free multi-modal imaging of cortical hemodynamics in the somatosensory cortex of awake, freely-behaving rats, using a novel head-mounted miniature optical microscope. The microscope employs vertical cavity surface emitting lasers (VCSELs) at three distinct wavelengths (680 nm, 795 nm, and 850 nm) to provide measurements of four hemodynamic markers: blood flow speeds, HbO, HbR, and total Hb concentration, across a > 2 mm field of view. Blood flow speeds are extracted using Laser Speckle Contrast Imaging (LSCI), while oxygenation measurements are performed using Intrinsic Optical Signal Imaging (IOSI). Longitudinal measurements on the same animal are made possible over the course of > 6 weeks using a chronic window that is surgically implanted into the skull. We use the device to examine changes in blood flow and blood oxygenation in superficial cortical blood vessels and tissue in response to drug-induced absence-like seizures, correlating motor behavior with changes in blood flow and blood oxygenation in the brain.

PV module mounting method and mounting assembly

DOEpatents

Lenox, Carl J.S.; Johnson, Kurt M.

2013-04-23

A method for mounting PV modules to a deck includes selecting PV module layout pattern so that adjacent PV module edges are spaced apart. PV mounting and support assemblies are secured to the deck according to the layout pattern using fasteners extending into the deck. The PV modules are placed on the PV mounting and support assemblies. Retaining elements are located over and secured against the upper peripheral edge surfaces of the PV modules so to secure them to the deck with the peripheral edges of the PV modules spaced apart from the deck. In some examples a PV module mounting assembly, for use on a shingled deck, comprises flashing, a base mountable on the flashing, a deck-penetrating fastener engageable with the base and securable to the deck so to secure the flashing and the base to the shingled deck, and PV module mounting hardware securable to the base.

A Real-Time Optical 6D Tracker for Head-Mounted Display Systems

DTIC Science & Technology

1990-03-01

provides a limited working volumne an(J do not sense orientation directly. OPTOTRAK [Nor88] is a new system which claims to be much more accurate than...1987. [Nor88] Northern Digital. Trade literature on Optotrak - Nor’hern Digital’- Three Di- mensional Optical Motion Tracking and Analysis System

Advanced helmet tracking technology developments for naval aviation

NASA Astrophysics Data System (ADS)

Brindle, James H.

1996-06-01

There is a critical need across the Services to improve the effectiveness of aircrew within the crewstation by capitalizing on the natural psycho-motor skills of the pilot through the use of a variety of helmet-mounted visual display and control techniques. This has resulted in considerable interest and significant ongoing research and development efforts on the part of the Navy, as well as the Army and the Air Force, in the technology building blocks associated with this area, such as advanced head position sensing or head tracking technologies, helmet- mounted display optics and electronics, and advanced night vision or image intensification technologies.

14. AERIAL VIEW OF ENGINE DISPLAY INSIDE PASSENGER CAR SHOP ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

14. AERIAL VIEW OF ENGINE DISPLAY INSIDE PASSENGER CAR SHOP (NOW A TRANSPORTATION MUSEUM) - Baltimore & Ohio Railroad, Mount Clare Passenger Car Shop, Southwest corner of Pratt & Poppleton Streets, Baltimore, Independent City, MD

Psychophysical Evaluation of Three-Dimensional Auditory Displays

NASA Technical Reports Server (NTRS)

Wightman, Frederic L. (Principal Investigator)

1995-01-01

This report describes the process made during the first year of a three-year Cooperative Research Agreement (CRA NCC2-542). The CRA proposed a program of applied of psychophysical research designed to determine the requirements and limitations of three-dimensional (3-D) auditory display systems. These displays present synthesized stimuli to a pilot or virtual workstation operator that evoke auditory images at predetermined positions in space. The images can be either stationary or moving. In previous years. we completed a number of studies that provided data on listeners' abilities to localize stationary sound sources with 3-D displays. The current focus is on the use of 3-D displays in 'natural' listening conditions, which include listeners' head movements, moving sources, multiple sources and 'echoic' sources. The results of our research on two of these topics, the role of head movements and the role of echoes and reflections, were reported in the most recent Semi-Annual Pro-ress Report (Appendix A). In the period since the last Progress Report we have been studying a third topic, the localizability of moving sources. The results of this research are described. The fidelity of a virtual auditory display is critically dependent on precise measurement of the listener''s Head-Related Transfer Functions (HRTFs), which are used to produce the virtual auditory images. We continue to explore methods for improving our HRTF measurement technique. During this reporting period we compared HRTFs measured using our standard open-canal probe tube technique and HRTFs measured with the closed-canal insert microphones from the Crystal River Engineering Snapshot system.

Method To Display Data On A Face Mask

NASA Technical Reports Server (NTRS)

Moore, Kevin-Duron

1995-01-01

Proposed electronic instrument displays information on diver's or firefighter's face mask. Includes mask, prism, electronic readouts, transceiver and control electronics. Mounted at periphery of diver's field of view to provide data on elapsed time, depth, pressure, and temperature. Provides greater safety and convenience to user.

Flight Tests of the Head-Up Display (HUD) in DC-9-20 Ship 382, November 1968 - January 1969. IRAD Line Item Description Number D36-69-033f

DTIC Science & Technology

1970-09-14

in this report was carried out as part of an Independent Research and Development program on the contribution of the Head-Up Display to an All...through windshield. W, by partial mirror, M. and imaged at infinity by lens. L. ] 1 »hMWMMMMMHi^^Hik«ni l TABLE I. ORGANIZATIONAL PRINCIPLES USED...movement of the equipment or its components. Translational movements are unlikely to give trouble because the display format is imaged at infinity

Joint helmet-mounted cueing system (JHMCS) helmet qualification testing requirements

NASA Astrophysics Data System (ADS)

Orf, Garry W.

1998-08-01

The Joint Helmet-Mounted Cueing System (JHMCS) program will provide capability to cue high off-boresight (HOBS) weapons to the operator's line of sight and to confirm weapon sensor LOS for the US Air Force and US Navy (USN) aircrew. This capability will ensure the USAF and USN pilots a first shot opportunity. The JHMCS incorporates an ejection-compatible helmet-mounted display system that will be installed on F- 15, F-16, F/A-18, and F-22 aircraft. The JHMCS includes a flight helmet with display optics, miniature cathode ray tube, magnetic receiver unit, miniature camera, automatic brightness control sensor, and microcontroller. The flight helmet for JHMCS is based on the new lightweight HGU-55A/P. This paper describes the requirements for the helmet qualification tests including: windblast, ejection tower, hanging harness, centrifuge, mass properties, energy attenuation and penetration resistance, noise attenuation, visor characteristics, compatibility demonstration, sled/in- flight ejection, water survival, standard conditions and environment. The test objective, success criteria, equipment configuration, and data collection requirements for each test is discussed.

Preliminary Assessment of Primary Flight Display Symbology for Electro- Optic Head-Down Displays

DTIC Science & Technology

1991-06-01

information :elated to pitch and power; the vertica! line provides information related to bank and heading. As a result of this geometrica ...steering bar are centered over the aircraft symbol. -n -1-- If the bars are centered, the aircraft is either correcting properly or is flying the desired...a•Isd bas,:ý muve to provide a new pitch command. Roll theading correction ) commands are seen as unbalanced line width, the low command bar side

Modern Display Technologies for Airborne Applications.

DTIC Science & Technology

1983-04-01

the case of LED head-down direct view displays, this requires that special attention be paid to the optical filtering , the electrical drive/address...effectively attenuates the LED specular reflectance component, the colour and neutral density filtering attentuate the diffuse component and the... filter techniques are planned for use with video, multi- colour and advanced versions of numeric, alphanumeric and graphic displays; this technique

Concurrent 3-D sonifications enable the head-up monitoring of two interrelated aircraft navigation instruments.

PubMed

Towers, John; Burgess-Limerick, Robin; Riek, Stephan

2014-12-01

The aim of this study was to enable the head-up monitoring of two interrelated aircraft navigation instruments by developing a 3-D auditory display that encodes this navigation information within two spatially discrete sonifications. Head-up monitoring of aircraft navigation information utilizing 3-D audio displays, particularly involving concurrently presented sonifications, requires additional research. A flight simulator's head-down waypoint bearing and course deviation instrument readouts were conveyed to participants via a 3-D auditory display. Both readouts were separately represented by a colocated pair of continuous sounds, one fixed and the other varying in pitch, which together encoded the instrument value's deviation from the norm. Each sound pair's position in the listening space indicated the left/right parameter of its instrument's readout. Participants' accuracy in navigating a predetermined flight plan was evaluated while performing a head-up task involving the detection of visual flares in the out-of-cockpit scene. The auditory display significantly improved aircraft heading and course deviation accuracy, head-up time, and flare detections. Head tracking did not improve performance by providing participants with the ability to orient potentially conflicting sounds, suggesting that the use of integrated localizing cues was successful. Conclusion: A supplementary 3-D auditory display enabled effective head-up monitoring of interrelated navigation information normally attended to through a head-down display. Pilots operating aircraft, such as helicopters and unmanned aerial vehicles, may benefit from a supplementary auditory display because they navigate in two dimensions while performing head-up, out-of-aircraft, visual tasks.

Miniaturized, on-head, invasive electrode connector integrated EEG data acquisition system.

PubMed

Ives, John R; Mirsattari, Seyed M; Jones, D

2007-07-01

Intracranial electroencephalogram (EEG) monitoring involves recording multi-contact electrodes. The current systems require separate wires from each recording contact to the data acquisition unit resulting in many connectors and cables. To overcome limitations of such systems such as noise, restrictions in patient mobility and compliance, we developed a miniaturized EEG monitoring system with the amplifiers and multiplexers integrated into the electrode connectors and mounted on the head. Small, surface-mounted instrumentation amplifiers, coupled with 8:1 analog multiplexers, were assembled into 8-channel modular units to connect to 16:1 analog multiplexer manifold to create a small (55 cm(3)) head-mounted 128-channel system. A 6-conductor, 30 m long cable was used to transmit the EEG signals from the patient to the remote data acquisition system. Miniaturized EEG amplifiers and analog multiplexers were integrated directly into the electrode connectors. Up to 128-channels of EEG were amplified and analog multiplexed directly on the patient's head. The amplified EEG data were obtained over one long wire. A miniaturized system of invasive EEG recording has the potential to reduce artefact, simplify trouble-shooting, lower nursing care and increase patient compliance. Miniaturization technology improves intracranial EEG monitoring and leads to >128-channel capacity.

In Vivo Evaluation of Wearable Head Impact Sensors.

PubMed

Wu, Lyndia C; Nangia, Vaibhav; Bui, Kevin; Hammoor, Bradley; Kurt, Mehmet; Hernandez, Fidel; Kuo, Calvin; Camarillo, David B

2016-04-01

Inertial sensors are commonly used to measure human head motion. Some sensors have been tested with dummy or cadaver experiments with mixed results, and methods to evaluate sensors in vivo are lacking. Here we present an in vivo method using high speed video to test teeth-mounted (mouthguard), soft tissue-mounted (skin patch), and headgear-mounted (skull cap) sensors during 6-13 g sagittal soccer head impacts. Sensor coupling to the skull was quantified by displacement from an ear-canal reference. Mouthguard displacements were within video measurement error (<1 mm), while the skin patch and skull cap displaced up to 4 and 13 mm from the ear-canal reference, respectively. We used the mouthguard, which had the least displacement from skull, as the reference to assess 6-degree-of-freedom skin patch and skull cap measurements. Linear and rotational acceleration magnitudes were over-predicted by both the skin patch (with 120% NRMS error for a(mag), 290% for α(mag)) and the skull cap (320% NRMS error for a(mag), 500% for α(mag)). Such over-predictions were largely due to out-of-plane motion. To model sensor error, we found that in-plane skin patch linear acceleration in the anterior-posterior direction could be modeled by an underdamped viscoelastic system. In summary, the mouthguard showed tighter skull coupling than the other sensor mounting approaches. Furthermore, the in vivo methods presented are valuable for investigating skull acceleration sensor technologies.

A Portable Shoulder-Mounted Camera System for Surgical Education in Spine Surgery.

PubMed

Pham, Martin H; Ohiorhenuan, Ifije E; Patel, Neil N; Jakoi, Andre M; Hsieh, Patrick C; Acosta, Frank L; Wang, Jeffrey C; Liu, John C

2017-02-07

The past several years have demonstrated an increased recognition of operative videos as an important adjunct for resident education. Currently lacking, however, are effective methods to record video for the purposes of illustrating the techniques of minimally invasive (MIS) and complex spine surgery. We describe here our experiences developing and using a shoulder-mounted camera system for recording surgical video. Our requirements for an effective camera system included wireless portability to allow for movement around the operating room, camera mount location for comfort and loupes/headlight usage, battery life for long operative days, and sterile control of on/off recording. With this in mind, we created a shoulder-mounted camera system utilizing a GoPro™ HERO3+, its Smart Remote (GoPro, Inc., San Mateo, California), a high-capacity external battery pack, and a commercially available shoulder-mount harness. This shoulder-mounted system was more comfortable to wear for long periods of time in comparison to existing head-mounted and loupe-mounted systems. Without requiring any wired connections, the surgeon was free to move around the room as needed. Over the past several years, we have recorded numerous MIS and complex spine surgeries for the purposes of surgical video creation for resident education. Surgical videos serve as a platform to distribute important operative nuances in rich multimedia. Effective and practical camera system setups are needed to encourage the continued creation of videos to illustrate the surgical maneuvers in minimally invasive and complex spinal surgery. We describe here a novel portable shoulder-mounted camera system setup specifically designed to be worn and used for long periods of time in the operating room.

Design and fabrication of semi-transparent screen based on micro-patterns for direct-view type head-up display in automobiles

NASA Astrophysics Data System (ADS)

Lee, Jae-Yong; Kim, Hyo-Jun; Kim, Young-Joo

2016-02-01

A semi-transparent screen with hemisphere micro-patterns was proposed and designed to enhance the brightness uniformity of the display image toward the driver for a direct-view type head-up display. The hemisphere micro-patterns were designed to consider the inclined angle of the windshield for efficient reflection and scattering toward to the driver. The density and radius of the hemisphere micro-patterns were adjusted as a function of position on the screen based on the geometrical calculation and analyzed by the commercial optical simulation tool based on a ray-tracing method. The designed hemisphere micro-patterns was fabricated by the thermal reflow method and evaluated to confirm the uniform illumination. From the results, the semi-transparent screen with variable micro-patterns shows the 91.9 % of brightness uniformity with the enhanced luminance compare to a screen without micro-patterns. A luminance of fabricated screen also shows good agreement with the simulation result to reflect the clear and bright driving information to the driver.

Enhancing the reproducibility of ocular vestibular evoked myogenic potentials by use of a visual target originating from a head-mounted laser.

PubMed

Jerin, Claudia; Bartl, Klaus; Schneider, Erich; Gürkov, Robert

2015-10-01

Ocular vestibular evoked myogenic potentials (oVEMPs) represent extraocular muscle activity in response to vestibular stimulation. oVEMP amplitudes are known to increase with increasing upward gaze angle, while the patient fixates a visual target. We investigated two different methods of presenting a visual target during oVEMP recordings. 57 healthy subjects were enrolled in this study. oVEMPs were elicited by 500 Hz air-conducted tone bursts while the subjects were looking upward at a marking which was either fixed on the wall or originated from a head-mounted laser attached to a headband, in either case corresponding to a 35° upward gaze angle. oVEMP amplitudes and latencies did not differ between the subjects looking at the fixed marking and the ones looking at the laser marking. The intra-individual standard deviation of amplitudes obtained by two separate measurements for each subject, however, as a measure of test-retest reliability, was significantly smaller for the laser headband group (0.60) in comparison to the group looking at the fixed marking (0.96; p = 0.007). The intraclass correlation coefficient revealed better test-retest reliability for oVEMP amplitudes when using the laser headband (0.957) than using the fixed marking (0.908). Hence, the use of a visual target originating from a headband enhances the reproducibility of oVEMPs. This might be due to the fact that the laser headband ensures a constant gaze angle and rules out the influence of small involuntary head movements on the gaze angle.

Re-engineering the stereoscope for the 21st Century

NASA Astrophysics Data System (ADS)

Kollin, Joel S.; Hollander, Ari J.

2007-02-01

While discussing the current state of stereo head-mounted and 3D projection displays, the authors came to the realization that flat-panel LCD displays offer higher resolution than projection for stereo display at a low (and continually dropping) cost. More specifically, where head-mounted displays of moderate resolution and field-of-view cost tens of thousands of dollars, we can achieve an angular resolution approaching that of the human eye with a field-of-view (FOV) greater than 90° for less than $1500. For many immersive applications head tracking is unnecessary and sometimes even undesirable, and a low cost/high quality wide FOV display may significantly increase the application space for 3D display. After outlining the problem and potential of this solution we describe the initial construction of a simple Wheatstone stereoscope using 24" LCD displays and then show engineering improvements that increase the FOV and usability of the system. The applicability of a high-immersion, high-resolution display for art, entertainment, and simulation is presented along with a content production system that utilizes the capabilities of the system. We then discuss the potential use of the system for VR pain control therapy, treatment of post-traumatic stress disorders and other serious games applications.

Effects of Visual Display on Joint Excursions Used to Play Virtual Dodgeball

PubMed Central

France, Christopher R; Applegate, Megan E; Leitkam, Samuel T; Pidcoe, Peter E; Walkowski, Stevan

2016-01-01

Background Virtual reality (VR) interventions hold great potential for rehabilitation as commercial systems are becoming more affordable and can be easily applied to both clinical and home settings. Objective In this study, we sought to determine how differences in the VR display type can influence motor behavior, cognitive load, and participant engagement. Methods Movement patterns of 17 healthy young adults (8 female, 9 male) were examined during games of Virtual Dodgeball presented on a three-dimensional television (3DTV) and a head-mounted display (HMD). The participant’s avatar was presented from a third-person perspective on a 3DTV and from a first-person perspective on an HMD. Results Examination of motor behavior revealed significantly greater excursions of the knee (P=.003), hip (P<.001), spine (P<.001), shoulder (P=.001), and elbow (P=.026) during HMD versus 3DTV gameplay, resulting in significant differences in forward (P=.003) and downward (P<.001) displacement of the whole-body center of mass. Analyses of cognitive load and engagement revealed that relative to 3DTV, participants indicated that HMD gameplay resulted in greater satisfaction with overall performance and was less frustrating (P<.001). There were no significant differences noted for mental demand. Conclusions Differences in visual display type and participant perspective influence how participants perform in Virtual Dodgeball. Because VR use within rehabilitation settings is often designed to help restore movement following orthopedic or neurologic injury, these findings provide an important caveat regarding the need to consider the potential influence of presentation format and perspective on motor behavior. PMID:27634561

Real-time simulation of combined short-wave and long-wave infrared vision on a head-up display

NASA Astrophysics Data System (ADS)

Peinecke, Niklas; Schmerwitz, Sven

2014-05-01

Landing under adverse weather conditions can be challenging, even if the airfields are well known to the pilots. This is true for civil as well as military aviation. Within the scope of this paper we concentrate especially on fog conditions. The work has been conducted within the project ALICIA. ALICIA is a research and development project co-funded by European Commission under the Seventh Framework Programme. ALICIA aims at developing new and scalable cockpit applications which can extend operations of aircraft in degraded conditions: All Conditions Operations. One of the systems developed is a head-up display that can display a generated symbology together with a raster-mode infrared image. We will detail how we implemented a real-time enabled simulation of a combined short-wave and long-wave infrared image for landing. A major challenge was to integrate several already existing simulation solutions, e.g., for visual simulation and sensors with the required data-bases. For the simulations DLRs in-house sensor simulation framework F3S was used, together with a commercially available airport model that had to be heavily modified in order to provide realistic infrared data. Special effort was invested for a realistic impression of runway lighting under foggy conditions. We will present results and sketch further improvements for future simulations.

Mount St. Helens Rebirth

NASA Technical Reports Server (NTRS)

2002-01-01

could be seen falling from the sky over the Great Plains, more than 1500 km distant. This image was acquired by Landsat 7 on Aug. 22, 1999. It was produced at 30-m resolution using bands 3, 2, and 1 to display red, green, and blue, respectively ('true color'). Some of the effects of the massive eruption on May 18, 1980, can still be seen clearly, especially on the northern and eastern flanks of Mount St. Helens, which are still mostly barren (shades of white and gray). The crater is in the center of the image. Note the streaking from the crater (gray on the image). These are the remnants of pyroclastic flows (superheated avalanches of gas, ash and pieces of rock) that carved deep channels down the slopes and onto the relatively flat areas near the base of the mountain. The partially-filled Spirit Lake can be seen just to the northeast of the crater (blue-black on the image), and the where most of the energy was directed during the blast is the gray area immediately to the northwest of the crater. However, on other parts of the mountain, the rejuvenation process is obvious. Ash deposits have supplied minerals which have accelerated vegetation growth (various shades of green). Though far from what it looked like 20 years ago, Mount St Helens is actively recovering. Data courtesy Landsat 7 project and EROS Data Center. Caption by James Foster, NASA Goddard Space Flight Center.

75 FR 1080 - Certain Automotive Multimedia Display and Navigation Systems, Components Thereof, and Products...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-01-08

... its products accused of infringement include factory-installed GPS units in certain automobiles and certain after-market ``head-unit'' GPS devices that are mounted in automobile dashboards. On September 22... (202) [[Page 1081

Displays. [three dimensional analog visual system for aiding pilot space perception

NASA Technical Reports Server (NTRS)

1974-01-01

An experimental investigation made to determine the depth cue of a head movement perspective and image intensity as a function of depth is summarized. The experiment was based on the use of a hybrid computer generated contact analog visual display in which various perceptual depth cues are included on a two dimensional CRT screen. The system's purpose was to impart information, in an integrated and visually compelling fashion, about the vehicle's position and orientation in space. Results show head movement gives a 40% improvement in depth discrimination when the display is between 40 and 100 cm from the subject; intensity variation resulted in as much improvement as head movement.

Debris flow initiation in proglacial gullies on Mount Rainier, Washington

NASA Astrophysics Data System (ADS)

Legg, Nicholas T.; Meigs, Andrew J.; Grant, Gordon E.; Kennard, Paul

2014-12-01

Effects of climate change, retreating glaciers, and changing storm patterns on debris flow hazards concern managers in the Cascade Range (USA) and mountainous areas worldwide. During an intense rainstorm in November 2006, seven debris flows initiated from proglacial gullies of separate basins on the flanks of Mount Rainier. Gully heads at glacier termini and widespread failure of gully walls imply that overland flow was transformed into debris flow along gullies. We characterized gully change and morphology, and assessed spatial distributions of debris flows to infer the processes and conditions for debris flow initiation. Slopes at gully heads were greater than ~ 0.35 m m- 1 (19°) and exhibited a significant negative relationship with drainage area. A break in slope-drainage area trends among debris flow gullies also occurs at ~ 0.35 m m- 1, representing a possible transition to fluvial sediment transport and erosion. An interpreted hybrid model of debris flow initiation involves bed failure near gully heads followed by sediment recruitment from gully walls along gully lengths. Estimates of sediment volume loss from gully walls demonstrate the importance of sediment inputs along gullies for increasing debris flow volumes. Basin comparisons revealed significantly steeper drainage networks and higher elevations in debris flow-producing than non-debris flow-producing proglacial areas. The high slopes and elevations of debris flow-producing proglacial areas reflect positive slope-elevation trends for the Mount Rainier volcano. Glacier extent therefore controls the slope distribution in proglacial areas, and thus potential for debris flow generation. As a result, debris flow activity may increase as glacier termini retreat onto slopes inclined at angles above debris flow initiation thresholds.

Controlling motion sickness and spatial disorientation and enhancing vestibular rehabilitation with a user-worn see-through display.

PubMed

Krueger, Wesley W O

2011-01-01

An eyewear mounted visual display ("User-worn see-through display") projecting an artificial horizon aligned with the user's head and body position in space can prevent or lessen motion sickness in susceptible individuals when in a motion provocative environment as well as aid patients undergoing vestibular rehabilitation. In this project, a wearable display device, including software technology and hardware, was developed and a phase I feasibility study and phase II clinical trial for safety and efficacy were performed. Both phase I and phase II were prospective studies funded by the NIH. The phase II study used repeated measures for motion intolerant subjects and a randomized control group (display device/no display device) pre-posttest design for patients in vestibular rehabilitation. Following technology and display device development, 75 patients were evaluated by test and rating scales in the phase II study; 25 subjects with motion intolerance used the technology in the display device in provocative environments and completed subjective rating scales, whereas 50 patients were evaluated before and after vestibular rehabilitation (25 using the display device and 25 in a control group) using established test measures. All patients with motion intolerance rated the technology as helpful for nine symptoms assessed, and 96% rated the display device as simple and easy to use. Duration of symptoms significantly decreased with use of the technology displayed. In patients undergoing vestibular rehabilitation, there were no significant differences in amount of change from pre- to posttherapy on objective balance tests between display device users and controls. However, those using the technology required significantly fewer rehabilitation sessions to achieve those outcomes than the control group. A user-worn see-through display, utilizing a visual fixation target coupled with a stable artificial horizon and aligned with user movement, has demonstrated substantial

Analysis of linear head accelerations from collegiate football impacts.

PubMed

Brolinson, P Gunnar; Manoogian, Sarah; McNeely, David; Goforth, Mike; Greenwald, Richard; Duma, Stefan

2006-02-01

Sports-related concussions result in 300,000 brain injuries in the United States each year. We conducted a study utilizing an in-helmet system that measures and records linear head accelerations to analyze head impacts in collegiate football. The Head Impact Telemetry (HIT) System is an in-helmet system with six spring-mounted accelerometers and an antenna that transmits data via radio frequency to a sideline receiver and laptop computer system. A total of 11,604 head impacts were recorded from the Virginia Tech football team throughout the 2003 and 2004 football seasons during 22 games and 62 practices from a total of 52 players. Although the incidence of injury data are limited, this study presents an extremely large data set from human head impacts that provides valuable insight into the lower limits of head acceleration that cause mild traumatic brain injuries.

Centaur Engine Display Installation

NASA Image and Video Library

2016-04-14

The 6,600 pound Centaur test article is a rare artifact recently transported from the U.S. Space and Rocket Center in Alabama. Centaur, developed at NASA Glenn Research Center in the late 1950s, was the world's first high-energy upper stage, burning liquid hydrogen (LH2) and liquid oxygen (LOX), and has enabled the launch of some of NASA's most important scientific missions over its 50-year history. In this image, technicians prepare to mount the hardware on a permanent display stand close to the main entrance at NASA Glenn Research Center.

Head assembly for multiposition borehole extensometer

DOEpatents

Frank, Donald N.

1983-01-01

A head assembly for a borehole extensometer and an improved extensometer for measuring subsurface subsidence. A plurality of inflatable anchors provide discrete measurement points. A metering rod is fixed to each of the anchors which are displaced when subsidence occurs, thereby translating the attached rod. The head assembly includes a sprocket wheel rotatably mounted on a standpipe and engaged by a chain which is connected at one end to the metering rod and at the other end to a counterweight. A second sprocket wheel connected to the standpipe also engages the chain and drives a connected potentiometer. The head assembly converts the linear displacement of the metering rod to the rotary motion of the second sprocket wheel, which is measured by the potentiometer, producing a continuous electrical output.

Digital Data for Volcano Hazards of the Mount Hood Region, Oregon

USGS Publications Warehouse

Schilling, S.P.; Doelger, S.; Scott, W.E.; Pierson, T.C.; Costa, J.E.; Gardner, C.A.; Vallance, J.W.; Major, J.J.

2008-01-01

Snow-clad Mount Hood dominates the Cascade skyline from the Portland metropolitan area to the wheat fields of Wasco and Sherman Counties. The mountain contributes valuable water, scenic, and recreational resources that help sustain the agricultural and tourist segments of the economies of surrounding cities and counties. Mount Hood is also one of the major volcanoes of the Cascade Range, having erupted repeatedly for hundreds of thousands of years, most recently during two episodes in the past 1,500 yr. The last episode ended shortly before the arrival of Lewis and Clark in 1805. When Mount Hood erupts again, it will severely affect areas on its flanks and far downstream in the major river valleys that head on the volcano. Volcanic ash may fall on areas up to several hundred kilometers downwind. The purpose of the volcano hazard report USGS Open-File Report 97-89 (Scott and others, 1997) is to describe the kinds of hazardous geologic events that have happened at Mount Hood in the past and to show which areas will be at risk when such events occur in the future. This data release contains the geographic information system (GIS) data layers used to produce the Mount Hood volcano hazard map in USGS Open-File Report 97-89. Both proximal and distal hazard zones were delineated by scientists at the Cascades Volcano Observatory and depict various volcano hazard areas around the mountain. A second data layer contains points that indicate estimated travel times of lahars.

Head Rotation Movement Times.

PubMed

Hoffmann, Errol R; Chan, Alan H S; Heung, P T

2017-09-01

The aim of this study was to measure head rotation movement times in a Fitts' paradigm and to investigate the transition region from ballistic movements to visually controlled movements as the task index of difficulty (ID) increases. For head rotation, there are gaps in the knowledge of the effects of movement amplitude and task difficulty around the critical transition region from ballistic movements to visually controlled movements. Under the conditions of 11 ID values (from 1.0 to 6.0) and five movement amplitudes (20° to 60°), participants performed a head rotation task, and movement times were measured. Both the movement amplitude and task difficulty have effects on movement times at low IDs, but movement times are dependent only on ID at higher ID values. Movement times of participants are higher than for arm/hand movements, for both ballistic and visually controlled movements. The information-processing rate of head rotational movements, at high ID values, is about half that of arm movements. As an input mode, head rotations are not as efficient as the arm system either in ability to use rapid ballistic movements or in the rate at which information may be processed. The data of this study add to those in the review of Hoffmann for the critical IDs of different body motions. The data also allow design for the best arrangement of display that is under the design constraints of limited display area and difficulty of head-controlled movements in a data-inputting task.

Results from tests, with van-mounted sensor, of magnetic leader cable for aircraft guidance during roll-out and turnoff

NASA Technical Reports Server (NTRS)

Young, J. C.; Bundick, W. T.; Irwin, S. H.

1983-01-01

Tests were conducted with a van mounted experimental magnetic leader cable sensor to evaluate its potential for measuring aircraft displacement and heading with respect to the leader cable during roll out and turnoff. Test results show that the system may be usable in measuring displacement but the heading measurement contains errors introduced by distortion of the magnetic field by the metal van or aircraft.

Effect of short-term exposure to stereoscopic three-dimensional flight displays on real-world depth perception

NASA Technical Reports Server (NTRS)

Busquets, Anthony M.; Parrish, Russell V.; Williams, Steven P.

1991-01-01

High-fidelity color pictorial displays that incorporate depth cues in the display elements are currently available. Depth cuing applied to advanced head-down flight display concepts potentially enhances the pilot's situational awareness and improves task performance. Depth cues provided by stereopsis exhibit constraints that must be fully understood so depth cuing enhancements can be adequately realized and exploited. A fundamental issue (the goal of this investigation) is whether the use of head-down stereoscopic displays in flight applications degrade the real-world depth perception of pilots using such displays. Stereoacuity tests are used in this study as the measure of interest. Eight pilots flew repeated simulated landing approaches using both nonstereo and stereo 3-D head-down pathway-in-the-sky displays. At this decision height of each approach (where the pilot changes to an out-the-window view to obtain real-world visual references) the pilots changed to a stereoacuity test that used real objects. Statistical analysis of stereoacuity measures (data for a control condition of no exposure to any electronic flight display compared with data for changes from nonstereo and from stereo displays) reveals no significant differences for any of the conditions. Therefore, changing from short-term exposure to a head-down stereo display has no more effect on real-world relative depth perception than does changing from a nonstereo display. However, depth perception effects based on sized and distance judgements and on long-term exposure remain issues to be investigated.

Advances in the Dynallax solid-state dynamic parallax barrier autostereoscopic visualization display system.

PubMed

Peterka, Tom; Kooima, Robert L; Sandin, Daniel J; Johnson, Andrew; Leigh, Jason; DeFanti, Thomas A

2008-01-01

A solid-state dynamic parallax barrier autostereoscopic display mitigates some of the restrictions present in static barrier systems, such as fixed view-distance range, slow response to head movements, and fixed stereo operating mode. By dynamically varying barrier parameters in real time, viewers may move closer to the display and move faster laterally than with a static barrier system, and the display can switch between 3D and 2D modes by disabling the barrier on a per-pixel basis. Moreover, Dynallax can output four independent eye channels when two viewers are present, and both head-tracked viewers receive an independent pair of left-eye and right-eye perspective views based on their position in 3D space. The display device is constructed by using a dual-stacked LCD monitor where a dynamic barrier is rendered on the front display and a modulated virtual environment composed of two or four channels is rendered on the rear display. Dynallax was recently demonstrated in a small-scale head-tracked prototype system. This paper summarizes the concepts presented earlier, extends the discussion of various topics, and presents recent improvements to the system.

Controlling Motion Sickness and Spatial Disorientation and Enhancing Vestibular Rehabilitation with a User-Worn See-Through Display

PubMed Central

Krueger, Wesley W.O.

2010-01-01

Objectives/Hypotheses An eyewear mounted visual display (“User-worn see-through display”) projecting an artificial horizon aligned with the user's head and body position in space can prevent or lessen motion sickness in susceptible individuals when in a motion provocative environment as well as aid patients undergoing vestibular rehabilitation. In this project, a wearable display device, including software technology and hardware, was developed and a phase I feasibility study and phase II clinical trial for safety and efficacy were performed. Study Design Both phase I and phase II were prospective studies funded by the NIH. The phase II study used repeated measures for motion intolerant subjects and a randomized control group (display device/no display device) pre-post test design for patients in vestibular rehabilitation. Methods Following technology and display device development, 75 patients were evaluated by test and rating scales in the phase II study; 25 subjects with motion intolerance used the technology in the display device in provocative environments and completed subjective rating scales while 50 patients were evaluated before and after vestibular rehabilitation (25 using the display device and 25 in a control group) using established test measures. Results All patients with motion intolerance rated the technology as helpful for nine symptoms assessed, and 96% rated the display device as simple and easy to use. Duration of symptoms significantly decreased with use of the technology displayed. In patients undergoing vestibular rehabilitation, there were no significant differences in amount of change from pre- to post-therapy on objective balance tests between display device users and controls. However, those using the technology required significantly fewer rehabilitation sessions to achieve those outcomes than the control group. Conclusions A user-worn see-through display, utilizing a visual fixation target coupled with a stable artificial horizon

Flight Deck Display Technologies for 4DT and Surface Equivalent Visual Operations

NASA Technical Reports Server (NTRS)

Prinzel, Lawrence J., III; Jones, Denis R.; Shelton, Kevin J.; Arthur, Jarvis J., III; Bailey, Randall E.; Allamandola, Angela S.; Foyle, David C.; Hooey, Becky L.

2009-01-01

NASA research is focused on flight deck display technologies that may significantly enhance situation awareness, enable new operating concepts, and reduce the potential for incidents/accidents for terminal area and surface operations. The display technologies include surface map, head-up, and head-worn displays; 4DT guidance algorithms; synthetic and enhanced vision technologies; and terminal maneuvering area traffic conflict detection and alerting systems. This work is critical to ensure that the flight deck interface technologies and the role of the human participants can support the full realization of the Next Generation Air Transportation System (NextGen) and its novel operating concepts.

Amplified Pilot Head Vibration and the Effects of Vibration Mitigation on Neck Muscle Strain.

PubMed

Wright Beatty, Heather E; Law, Andrew J; Thomas, J Russell; Wickramasinghe, Viresh

2018-06-01

Rotary wing pilot neck strain is increasing in prevalence due to the combined effects of head supported mass (e.g., Night Vision Goggles, head mounted displays) and whole-body vibration. This study examined the physiological responses of pilots during exposure to whole-body vibration (WBV) representative of the National Research Council's Bell 412 helicopter in forward flight. WBV levels were measured and evaluated using the ISO-2631-1-1997 WBV standards. Twelve pilots (aged 20-59 yr, 7 of the 12 with 20+ years flight experience) underwent six 15-min vibration trials on a human rated shaker platform. Participants were exposed to three vibration levels (-25%, normal, and +25% amplitude; Levels 1-3, respectively) while seated on an Original Equipment Manufacturer (OEM) or vibration mitigating (MIT) cushion. Upper back and neck electromyography (EMG) and acceleration were continuously recorded. Normalized EMG amplitude was higher using the OEM compared to the MIT during Level 2 (0.18 vs. -0.27) and Level 3 (0.24 vs. -0.14) for the anterior neck muscles. Health weighted vibration amplitude at the head (Mean of 3 levels: OEM = 1.19 and MIT = 1.11 m · s-2) was larger than the vibration amplitude at the seat (Mean of 3 levels: OEM = 0.77 and MIT = 0.70 m · s-2). The amplification of head vibration relative to the seat, and the significant effects of vibration level, as well as the vibration mitigation cushion, on neck EMG amplitude support the need for revisions to the ISO-2631-1 standard to account for the head and neck response to whole-body vibration.Wright Beatty HE, Law AJ, Thomas JR, Wickramasinghe V. Amplified pilot head vibration and the effects of vibration mitigation on neck muscle strain. Aerosp Med Hum Perform. 2018; 89(6):510-519.