Nikhil Balram

Light field otoscope design for 3D in vivo imaging of the middle ear

We present a light field digital otoscope designed to measure three-dimensional shape of the tympanic membrane. This paper describes the optical and anatomical considerations we used to develop the prototype, along with the simulation and experimental measurements of vignetting, field curvature, and lateral resolution. Using an experimental evaluation procedure, we have determined depth accuracy and depth precision of our system to be 0.05-0.07 mm and 0.21-0.44 mm, respectively. To demonstrate the application of our light field otoscope, we present the first three-dimensional reconstructions of tympanic membranes in normal and otitis media conditions, acquired from children who participated in a feasibility study at the Childrens Hospital of Pittsburgh of the University of Pittsburgh Medical Center.

Design and optimization of a near-eye multifocal display system for augmented reality

We present a binocular, near-eye multifocal display prototype capable of multiplexing 6-focal-plane, flicker-free virtual content into the eyes. The prototype’s hardware design, focal sampling strategy, and rendered multifocal images are presented.

Content-adaptive focus configuration for near-eye multi-focal displays

Near-eye multi-focal (light field) displays are known to be more advantageous than conventional stereoscopic 3D displays, because they can alleviate the vergence-accommodation conflict. While stereoscopic 3D displays are restricted to projecting images on a single focal plane, near-eye light field displays can form multiple focal planes and volumetrically render 3D data. Most existing near-eye light field displays use simplistic, uniformly spaced focal plane configuration (in dioptric space). In this paper, we present a novel technique that optimizes the focal plane configuration based on characteristics of the content to be rendered. We show that this technique can significantly improve the perceived visual quality of content visualized on such displays.

Objective comparisons between gesture and exploration based touchscreen keyboards for the blind

We report the results of a short term experimental study on blind participants to evaluate their performances on two different text typing techniques. BrailleTouch, a gesture based text typing technology, is objectively compared to the TalkBack-enabled Android stock keyboard which requires touch exploration to type. We found that on an average BrailleTouch was almost twice as fast as the Android stock keyboard for typing each character. At the same time, these experiments clearly establish that accuracy of the BrailleTouch technique significantly dwindles as the number of dots in a Braille cell increase due to lesser motor control over the ring finger (or the digitus medicinalis).

Depth-disparity calibration for augmented reality on binocular optical see-through displays

We present a study of depth-disparity calibration for augmented reality applications using binocular optical see-through displays. Two techniques were proposed and compared. The paired-eyes technique leverages the Panums fusional area to help viewer find alignment between the virtual and physical objects. The separate-eyes technique eliminates the need of binocular fusion and involves using both eyes sequentially to check the virtual-physical object alignment on retinal images. We conducted a user study to measure the calibration results and assess the subjective experience of users with the proposed techniques.

Digital health in the age of The Infinite Network

The exponential growth in digital technology is leading us to a future in which all things and all people are connected all the time, something we refer to as The Infinite Network (TIN), which will cause profound changes in every industry. Here, we focus on the impact it will have in healthcare. TIN will change the essence of healthcare to a data-driven continuous approach as opposed to the event-driven discrete approach used today. At a micro or individual level, smart sensing will play a key role, in the form of embedded sensors, wearable sensors, and sensing from smart medical devices. At a macro or aggregate level, healthcare will be provided by Intelligent Telehealth Networks that evolve from the telehealth networks that are available today. Traditional telemedicine has delivered remote care to patients in the area where doctors are not readily available, but has not achieved at large scale. New advanced networks will deliver care at a much larger scale. The long-term future requires intelligent hybrid networks that combine artificial intelligence with human intelligence to provide continuity of care at higher quality and lower cost than is possible today.

33.2: Intelligent Adaptive Color Management Unit For Digital Video

We describe an intelligent adaptive color management unit whose functionality and architecture are well suited for processing digital video in consumer electronics products like media players, TVs, tablets and smart phones. The unit provides intelligent locally adaptive color, contrast and brightness adjustment using an approach that minimizes artifacts and distortions. It can be used for color management, including gamut remapping, and for enhancement of visual image quality. This technology has been incorporated in several video and media processor ICs.