Head-worn display design is inherently an interdisciplinary subject fusing optical engineering, electronics, user interface design, new optical materials and manufacturing techniques, human perception and physiology for assessing these displays. Various optical design forms are investigated. In order to achieve compact, light-weight systems, aspheric, diffractive or holographic elements are being used in our designs. Various applications drive the HWDs with various requirements and our research in HWDs is conducted in close collaboration with end users from various domains of applications and closed loop with human perception assessments. Some of our designs include a 60deg FOV, full color off axis design, various types of ultra-compact (6g per eye) head-mounted projections optics with external or internal projection screens, eyetracking integration, conformal head tracking, and recently eyeglasses displays. Main collaborators on this project include MSU, Optimax Corporation, Nvis Corporation, and Linz University in Austria.

Additional References
Larry Davis, Conformal Tracking for Virtual Environments, Ph.D. Dissertation, University of Central Florida (2004).

Cali Fidopiastis, User-Centered Virtual Environment Assessment and Design for Cognitive Rehabilitation Applications, Ph.D. Dissertation, University of Central Florida (2006).

This project started with the development of the Virtual Reality Dynamic Anatomy (VRDA) Tool initiated in 1997 which combined research in augmented reality, optical tracking, head-worn displays, and computer vision developed in our laboratory to perform dynamic optical superimposition of internal organs on the human body. The VRDA project first investigated the optical superimposition of bony knee joint on a human knee in motion, research featured in Scientific American in an article by Steve Feiner and also CNN-online. Videos of this work can be found under images&movies on our site.

Since 2002, the project extended to the visualization of the upper airways on a human patient simulator for medical training. As part of this project, we are developing a dynamic model of breathing lung that builds on the biomechanics of deformation, physiology of breathing, neural controls, and the science of real time simulation. Our main collaborators on this project include METI Corporation, Columbia University Medical School, John Hopkins Medical School, the University of Florida, Washington University Medical School in Saint Louis, the MD Anderson Cancer Center in Orlando, Ocala Regional Hospital, the Medical Imaging Group of the Ecole National Superieure des Telecommunications in Paris.

Additional References
Yohan Baillot, First Implementation of the Virtual Reality Dynamic Anatomy Tool, Master Thesis, University of Central Florida (1998)

Anand Santhanam, Modeling and Simulation of 3D lung Dynamics, Ph.D. Dissertation, University of Central Florida (2006).

This project investigated means to create distributed collaborative environments in which the distribution of information at remote locations allows efficient communication. Particularly challenging were distributed interactive Virtual Environments that allow knowledge sharing through 3D information. As part of the outcome of this research, a distributed interactive Augmented Reality testbed and assocaited algorithms where developed and implementated. This project overlaps with Head-worn Displays. This project is currently continued in collaboration with Amstrong Atlantic State University where Dr. Hamza-Lup was offered a tenure earning position in 2005.

Additional References
Felix Hamza-Lup, Dynamic Shared State Maintenance in Dirstributed Virtual Environments, Ph.D. Dissertation, University of Central Florida (2004).

As part of the quest for brighter microdisplays for use in head-worn displays, this project investigates LED based illumination schemes for reflective LCDs. Other applications are since also being investigated beyond that of head-worn displays.

Our main collaborators on this project include VDC Corporation.

This project innovates in technology for microscopic imaging using the low temporal coherence properties of broad band light sources. Such technology allows imaging up to a few millimeters inside biological tissues up to about 1 micron resolution. Innovative solutions to handle the trade-offs in imaging speed, invariant resolution across the sample, and sample size constitute the focus of our research, together with quantitative image quality assessment in close loop with technology optimization. Main results from this project include optical spectra shaping, less than 2mm in diameter catheter for lung imaging using Bessel beam optics, dynamic focusing optics with no moving parts for skin imaging, portable compact electronics, novel instrument for OCT combined two photons absorption spectroscopy, and a framework for task-based image quality assessment. Main collaborators on this projects include the University of Arizona and the University of Florida.

Additional reference
C.A. Akcay, System Design and Optimization of Optical Coherence Tomography, Ph.D. Dissertation, University of Central Florida (2005)

This project involves the development of a new wavefront sensor that is based on curvature measurements. The Shack-Hartmann wavefront sensor, current very popular in optical testing, adaptive / active optics and ophthalmology, is based on slope measurements. A method to measure the differentials of the slopes at each grid point to obtain the curvatures proposed. Importantly, the techniques allows to measure the principal curvatures and directions, from which other curvatures mean and Gaussian may be computed as desired. Because we measure the curvature of the wavefront, the measurement is insensitive to vibrations, tip/tilt and whole body movement between the sensor and the wavefront under test. Like the Shack-Hartmann sensor, the measurements are real-time, inherently two-dimensional and parallel, and it can be applied across various wavelength bands. Finally, this project is investigating zonal wavefront reconstruction and how to optimize accuracy as a function of the reconstruction geometry, the amount of noise in the mesurements, and means to handle boundary conditions. Main collaborators on this project include Bauer Corporation.

Additional References
Weiyao Zou, GRADIENT AND CURVATURE-BASED WAVE FRONT SENSING AND ZONAL RECONSTRUCTION, Ph.D. Dissertation, University of Central Florida (2006)

In this project, the computation of a multi-absorbing layers system is applied to the specific case of surface plasmon resonance (SPR) sensors. Specifically, the impact of the properties of a metallic layer on the shape of the reflectivity and sensitivity curve is investigated in the case of a Kretschmann configuration. This theoretical study permits to establish the best optical properties of the metal in order to obtain a localized SPR given the illuminating beam properties. Towards the development of a sensitive biosensor based on SPR, we quantify the changes in reflectivity of such optical biosensor induced by the deposition of a nanometric biochemical film as a function of the metal film characteristics and the illumination operating conditions. The sensitivity of the system points out the potential of such biophotonic technology using metallic multi-layer configurations and especially making use of envisioned metamaterials. Our main collaborators on this project is the Institut d'Optique Theorique et Appliqee near Paris.