Andrew Raij

University of Central Florida | UCF · Institute for Simulation and Training

In recent years, virtual reality (VR) has been become a popular training tool for individuals with Autism Spectrum Disorder (ASD). Although VR was proven to be a promising tool for individuals with ASD, effects of VR properties or attributes of user interfaces designed for VR on user experience is still an unexplored area. In this study, we explore...

Virtual reality (VR) is becoming a more popular and available technology, with the new generation systems and more content specifically developed for this medium. One of the crucial components of VR applications is locomotion, which is used for moving the viewpoint of user in virtual environments. Locomotion in VR is expected to have a direct effec...

This paper presents a system for vocational training and assessment of individuals with severe physical disabilities using immersive virtual reality. The system was developed at the University of South Florida’s Center for Assistive, Rehabilitation, and Robotics Technologies (CARRT). A virtual and physical assistive robot was used for the remote-co...

Virtual reality (VR) systems are seeing growing use for training individuals with Autism Spectrum Disorder (ASD). Although these systems indicate effective use of VR for training, there is little work in the literature evaluating different VR interaction techniques for this audience. In this paper, different VR interaction techniques are explored i...

In this article, state of the art on virtual reality (VR) for individuals with autism spectrum disorder (ASD) with a focus on training/targeted intervention is discussed and reflected upon to explore areas for more future benefits. We present advantages of VR for individuals with ASD. We identify challenges and design issues for future training app...

Technological human surrogates, including robotic and virtual humans, have been popularly used in various scenarios, including training, education, and entertainment. Prior research has investigated the effects of the surrogate’s physicality and gesturing in human perceptions and social influence of the surrogate. However, those studies have been c...

Instructions are an important aspect of virtual reality serious games since they are crucial to understanding what is expected from the user. User friendly instructions can contribute positively to the user experience, while confusing instructions can degrade it. There are various methods of instruction giving. In this study, we examine the effects...

In this article, a virtual reality system for vocational rehabilitation of individuals with disabilities (VR4VR) is presented. VR4VR uses immersive virtual environments to assess and train individuals with cognitive and physical disabilities. This article focuses on the system modules that were designed and developed for the Autism Spectrum Disorde...

The BehaviorSim Modeling Tool, a behavioral-scientist-facing software for development of Computational Human Behavior Models (CHBMs), has been developed in an effort to close the gap between Just-in-Time Adaptive Intervention researchers and dynamical systems modeling. We present a summary of our iterative methodology for creating the BehaviorSim M...

To support the study of effective human-surrogate interaction techniques and modalities, the Office of Naval Research awarded an equipment grant to support the development of a Human-Surrogate Interaction Space (HuSIS) at the University of Central Florida in the Institute for Simulation & Training. The HuSIS consists of a dedicated physical space,...

With the increasing popularity of virtual reality (VR) and new devices getting available with relatively lower costs, more and more video games have been developed recently. Most of these games use first person interaction techniques since it is more natural for Head Mounted Displays (HMDs). One of the most widely used interaction technique in VR v...

Virtual reality (VR) has been used as an effective tool for training individuals with autism spectrum disorder (ASD). Recently there have been an increase in the number of applications developed for this purpose. One of the most important aspects of these applications is locomotion, which is an essential form of human computer interaction. Locomoti...

Virtual reality systems are seeing growing use for training individuals with Autism Spectrum Disorder (ASD). Although the tested systems indicate effective use of virtual reality for training, there is little work in the literature evaluating different virtual reality interaction techniques for this specific group of audience. Individuals with ASD...

In theory, Just-in-Time Adaptive Interventions (JiTAIs) are a persuasive technology which promise to empower personal behavioral goals by optimizing treatments to situational context and user behaviors. This paper outlines open challenges facing the development of JiTAIs and discusses the use of modeling as a common ground between behavioral scient...

In this paper, an immersive virtual reality system for vocational rehabilitation of individuals with Autism Spectrum Disorder (VR4VR) is presented. VR4VR uses immersive virtual environments to assess and train individuals with Autism Spectrum Disorder (ASD). This paper discusses lessons learned from the testing sessions with neuro typical individua...

Crowd Sensing (CS) is a sensing paradigm that takes advantage from the increasing use of mobile smart devices and their capabilities for sensing and computation. In this paper, we present an incentive mechanism for encourage user participation in schemes of sensing that requires consecutive and regular sampling. The proposed mechanism uses a recurr...

We investigate needs, challenges, and opportunities in visualizing time-series sensor data on stress to inform the design of just-in-time adaptive interventions (JITAIs). We identify seven key challenges: massive volume and variety of data, complexity in identifying stressors, scalability of space, multifaceted relationship between stress and time,...

This paper examines just-in-time adaptive interventions (JITAIs) for stress, a pervasive and affective computing application with significant implications for long-term health and quality of life. We discuss fundamental components needed to enabling JITAIs based for one kind of affect data stress. Chronic stress has significant long-term behavioral...

Crowd sensing (CS) is an approach to collecting many samples of a phenomena of interest by distributing the sampling across a large number of individuals. While any one individual may not provide sufficient samples, aggregating samples across many individuals provides high-quality, high-coverage measurements of the phenomena. Thus, for participator...

We investigate needs, challenges, and opportunities in visualizing time-series sensor data on stress to inform the design of just-in-time adaptive interventions (JITAIs). We identify seven key challenges: massive volume and variety of data, complexity in identifying stressors, scalability of space, multifaceted relationship between stress and time,...

This paper presents a virtual reality for vocational rehabilitation system (VR4VR) that is currently in development at the University of South Florida's Center for Assistive, Rehabilitation, and Robotics Technologies (CARRT). VR4VR utilizes virtual reality to assess and train individuals with severe cognitive and physical disabilities. Using virtua...

Advances in pervasive computing, machine learning, and human activity recognition are changing preventive health care. Emerging paradigms, such as Mobile Cyber-Physical System (MCPS) and Just-in-time interventions (JITI), allow patients to take health monitoring, diagnosis, therapy and treatments beyond traditional medical settings. These paradigms...

Crowd sensing (CS) is an approach that consists of collecting many samples of a phenomena of interest by distributing the sampling process across a large number of individuals. In this work, we address the effect of cooperation among individuals by modeling a recurrent CS task as a repeated game. In this game, participants are the players of the co...

Advancements in ubiquitous computing are rapidly changing preventative health care these quick changes allow not only to track in real time the heath of an individual, but also to react to any anomalies that may indicate the need of help. This new health care paradigm (i.e., Just-in-time interventions) allows to support treatments and deliver help...

Crowd sensing (CS) is a new sensing paradigm that takes advantage of the availability of mobile devices almost in every place. In this type of system, the mobile phones users are asked to use their resources such as data plan, energy and time, in order to collect and transmit data to a central infrastructure. Since participants usually do not recei...

Chronic stress has significant long-term behavioral and physical health consequences, including an increased risk of cardiovascular disease, cancer, anxiety and depression. This paper conducts post-hoc experiments and simulations to demonstrate feasibility of both real-time stress forecasting and stress intervention adaptation and optimization. Usi...

We present TeamVis, a set of tools for sensing and visualization of objective team performance in a simulated medical scenario. TeamVis helps teams, instructors, and researchers in observation, analysis, and evaluation of team behavior. The current system supports analysis of team movements and verbal communication. The system has potential to prov...

In this paper, a virtual reality for vocational rehabilitation (VR4VR) system for individuals with disabilities is presented. VR4VR aims to enable job coaches to use immersive virtual environments to inexpensively and safely assess and train the job skills of individuals with disabilities. Several key system requirements and challenges are discusse...

This paper considers the design and development of a virtual reality system that aids in vocational rehabilitation of individuals with disabilities. The system focuses on three types of disabilities: autism spectrum disorder, traumatic brain injury, and severe mobility impairment. The system allows job trainers to rapidly assess the capabilities of...

We present a mobile avatar system designed to provide a constant user-avatar interface for health behavior change therapy. The presented Android application replaces the user's phone background with an animated avatar. The avatar's level of physical activity is made to match the physical activity level of the user. This activity level is inferred u...

The combination of inexpensive wearable sensors, powerful mobile phones, and always-connected cloud computing are enabling new, real-time feedback and coaching via mobile technologies. This paper explores the use of avatars - digital representations of the self - as an ideal user interface for mobile health application. Specifically, a justificatio...

Personal Informatics (PI) systems help individuals collect and reflect on personal physiological, behavioral and/or contextual data. Typically, these systems offer users interactive visualizations that allow meaningful exploration of the data. Through this exploration, PI systems have great potential to facilitate self-reflection and encourage beha...

A convergence between consumer electronics and virtual reality is occurring. We present an immersive head-mounted-display-based, wearable D user interface that is inexpensive (less than $900 USD), robust (sourceless tracking), and portable (lightweight and untethered). While the current display has known deficiencies, the user tracking quality is w...

We introduce a new paradigm of collaborative computing called the Ubiquitous Collaborative Activity Virtual Environment (UCAVE). UCAVEs are portable immersive virtual environments that leverage mobile communication platforms, motion trackers and displays to facilitate ad-hoc virtual collaboration. We discuss design criteria and research challenges...

Effect of psychosocial stress on health has been a central focus area of public health research. This demonstration features a wireless sensor suite called AutoSense that collects and processes cardiovascular, respiratory, and thermoregularity measurements that can inform about the general stress state of test subjects in their natural environment....

The effect of psychosocial stress on health has been a central focus area of public health research. However, progress has been limited due a to lack of wearable sensors that can provide robust measures of stress in the field. In this paper, we present a wireless sensor suite called AutoSense that collects and processes cardiovascular, respiratory,...

Micro-incentives represent a new but little-studied trend in participant compensation for user studies. In this paper, we use a combination of statistical analysis and models from labor economics to evaluate three canonical micro-payment schemes in the context of high-burden user studies, where participants wear sensors for extended durations. We l...

Mobile devices (e.g., smartphones, personal digital assistants, and tablets) are evolving rapidly and growing exponentially in multiple facets around the globe. Specifically, mobile devices can be used as audio and video chat, reference guide, training tool, handoff facilitation, and decision support. Undoubtedly, there are clear advantages of leve...

Wearable sensors are revolutionizing healthcare and science by enabling capture of physiological, psychological, and behavioral measurements in natural environments. However, these seemingly innocuous measurements can be used to infer potentially private behaviors such as stress, conversation, smoking, drinking, illicit drug usage, and others. We c...

We present a novel method to detect when a person is speaking using respiratory measurements collected in the natural environment. A speaker’s respiration pattern is sampled from a respiratory inductive plethysmograph (RIP) band worn around the speaker’s chest. Ratio of inhalation duration to exhalation duration (IE ratio) has traditionally been us...

Repeated exposures to psychological stress can lead to or worsen diseases of slow accumulation such as heart diseases and cancer. The main challenge in addressing the growing epidemic of stress is a lack of robust methods to measure a person's exposure to stress in the natural environment. Periodic self-reports collect only subjective aspects, ofte...

Body area sensor networks measure biomedical signals from subjects continuously, as they go about their daily lives. Signals measured in these conditions are affected by anomalies, such as artifacts and noise. Some anomalies can be corrected, if detected in real-time, for example, ECG electrode detachment. We present energy and computationally effi...

This paper proposes virtual social perspective-taking (VSP). In VSP, users are immersed in an experience of another person to aid in understanding the person's perspective. Users are immersed by 1) providing input to user senses from logs of the target person's senses, 2) instructing users to act and interact like the target, and 3) reminding users...

Virtual patients (VPs) have the potential to augment existing medical school curricula to teach history-taking and communication skills. A goal of our current efforts to study virtual characters in health professions education is to develop a system that can be independently accessed and thus user satisfaction is an important factor in how readily...

This paper proposes after-action review (AAR) with human-virtual human (H-VH) experiences. H-VH experiences are seeing increased use in training for real-world, H-H experiences. To improve training, the users of H-VH experiences need to review, evaluate, and get feedback on them. AAR enables users to review their H- VH interaction, evaluate their a...

Background: Significant information exchange occurs between a doctor and patient through nonverbal communication such as gestures, body position, and eye gaze. In addition, empathy is an important trust-building element in a physician: patient relationship. Previous work validates the use of virtual patients (VP) to teach and assess content items...

This paper provides key insights into the construction and evaluation of interpersonal simulators--systems that enable interpersonal interaction with virtual humans. Using an interpersonal simulator, two studies were conducted that compare interactions with a virtual human to interactions with a similar real human. The specific interpersonal scenar...

Any new tool introduced for education needs to be validated. We developed a virtual human experience called the Virtual Objective Structured Clinical Examination (VOSCE). In the VOSCE, a medical student examines a life-size virtual human who is presenting symptoms of an illness. The student is then graded on interview skills. As part of a medical s...

The purpose of this paper is, first, to summarize a theoretical perspective toward the development of a virtual reality innovation in education. Next, we will describe a virtual character project that is impacting the training of medical students in two institutions. In doing so, we will present a summary of three studies completed over the last 2...

At most institutions, medical students learn communication skills through the use of standardized patients (SPs), but SPs are time and resource expensive. Virtual patients (VPs) may offer several advantages over SPs, but little data exist regarding the use of VPs in teaching communication skills. Therefore, we report our initial efforts to create a...

This paper reports on a study to examine the similarities and differences in experiencing an interpersonal scenario with real and virtual humans. A system that allows medical students to interview a life-size virtual patient using natural speech and gestures was used as a platform for this comparison. Study participants interviewed either a virtual...

This paper presents our experiences in evolving the Virtual Objective Structured Clinical Exam (VOSCE) system. This system allows medical students to experience the interaction between a patient and a medical doctor using natural methods of interaction with a high level of immersion. These features enable the system to provide training on medical c...

Virtual patients have great potential for training patient-doctor communication skills. There are two approaches to producing the virtual human speech: synthesized speech or recorded speech. The tradeoffs in flexibility, fidelity, and cost raise an interesting development decision: which speech approach is most appropriate for virtual patients? Two...

This paper presents our experiences in evolving the Virtual Objective Structured Clinical Exam (VOSCE) system. This system allows medical students to experience the interaction between a patient and a medical doctor using natural methods of interaction with a high level of immersion. These features enable the system to provide training on medical c...

This paper presents a system which allows medical students to experience the interaction between a patient and a medical doctor using natural methods of interaction with a high level of immersion. We also present our experiences with a pilot group of medical and physician assistant students at various levels of training. They interacted with projec...

By treating projectors as pin-hole cameras, we show it is possible to calibrate the projectors of a casually-aligned, multi-projector display wall using the principles of planar auto-calibration. We also use a pose estimation technique for planar scenes to reconstruct the relative pose of a calibration camera, the projectors and the plane they proj...

We introduce PixelFlex2, our newest scalable wall-sized, multi-projector display system. For it, we had to solve most of the difficult problems left open by its predecessor, PixelFlex, a proof-of-concept demonstration driven by a large, multi-headed SGI graphics system. PixelFlex2 retains the achievements of PixelFlex (high-performance through sing...

Excessive, chronic, and repeated exposure to psychological stress can lead to significant health problems. However, new methods for better coping with stress that could significantly improve health and quality of life, cannot be developed and evaluated without scientifically valid datasets describing the experience of stress in everyday life. In pr...