What is Virtual Reality? Virtual reality is a new technology that alters the way individuals interact with computers. In fact, it can be defined as a set of computer technologies which, when combined, provide an interface to a computer-generated world. In particular it provides such a convincing interface that the user believes he is actually in a three dimensional computer-generated world. A virtual environment is a virtual reality application that lets users navigate and interact with a three-dimensional, computer generated (and computer-maintained) environment in real time.

A key feature of a virtual environment is that the user believes that he is actually in this different world. This is accomplished by immersing the person's senses using a head-mounted display or some other immersive display device. A second key feature of Virtual Reality is that if the user moves his head, arms or legs, the shift of visual cues must be those he would expect in a real world. In other words, besides immersion, in a virtual world we have navigation and interaction.

Although virtual reality is mature enough to have different medical applications, the common use of this technology outside the surgical field is actually limited due to different problems:

• Many of the available products seems to be “a solution in search of a problem”. As with early computer graphics products, the entry-level costs are relatively prohibitive. Although some attempts have been made to use PC-based virtual reality systems, the majority of the existing systems use RISC platforms whose cost is beyond the means of a normal Hospital or Department. A complete VR environment, including workstations, goggles, body suits, and software, ranges from $40.000 to $1.000.000;

• The hyperbole and sensational press coverage associated with this technology has led many potential users to overestimate the actual capabilities of existing systems. Almost all of the applications in this sector can be considered “one-off” creations tied to their development hardware and software, which have been adjusted in the field by a process of trial and error. This makes them difficult to use in contexts other than those in which they were developed. Unless their expertise includes knowledge of the human-machine interface requirements for their application, their resulting product will rarely get beyond a “conceptual demo” that lacks practical utility;

• Although it is theoretically possible to use a single virtual reality system for many different applications, none of the existing systems can be easily adapted to different tasks. This means that two different wards/departments within the same organization may find themselves having to use two different VR systems because of the impossibility of adapting one single system to their different needs;

• Fundamental questions remain about how people interact within a virtual environment and how they can best be employed for instruction, training, assessment, rehabilitation and other clinical oriented applications.

To create successful health care applications with today's virtual environments, we must begin by asking: what are they good at? This book offers an answer to its possible readers - physicians, psychologists and health care provider - by presenting an overview of the current research in this field. Infact the book, whose idea comes from the work made within the EC funded Virtual Reality Environments for Psycho-neuro-physiological Assessment and Rehabilitation VREPAR - project, (HC 1053 - http://www.etho.be/ht_projects/vrepar/), is a collection of chapters from researchers who have pioneered the ideas and the technology associated with virtual reality. More in particular, the book discuss the clinical principles, human factors, and technological issues associated with the use of virtual reality for assessment and treatment.

It should be noted that technical characteristics of virtual worlds change very rapidly; but what will not change is the user of a virtual environment. Thus, to ensure that the contents of this book is not quickly updated, all the contributors have made a great effort to identify possible constraints in the use of this technology and to indicate how they can be faced and solved. The key issue was to integrate knowledge of clinical therapy and psychological principles related to human factors into the design of virtual environments.

The book is divided in three main sections comprising 13 chapters overall: virtual reality for health care, virtual reality for psychological assessment and rehabilitation and virtual reality for neuro-physiological assessment and rehabilitation.

The first section of the book contains two chapter written to provide a broad introduction to the use of virtual reality in health care. The two chapters provide basic definition and background material which thus sets the stage for future chapters. Specifically, Chapter 1, written by Moline, surveys the current applications of virtual environments for health care: surgical procedures (remote surgery or telepresence, augmented or enhanced surgery, and planning and simulation of procedures before surgery); medical therapy; preventive medicine and patient education; medical education and training; visualization of massive medical databases; skill enhancement and rehabilitation; and architectural design for healthcare facilities. Chapter 2, by Lewis and Griffin, provides an excellent overview of the human factors involved in the virtual experience. The authors also identified specific factors which are likely to affect the incidence of side-effects during and after exposures, and which need to be understood in order to minimize undesirable consequences.

The second section of the book provides information on the possible application of virtual environments for psychological assessment and rehabilitation. Chapter 3 and 4 offer a broad introduction to the research in this field. In Chapter 3 M. North, S. North, and Coble describe the Virtual Reality Therapy (VRT), a new therapeutic approach that can be used to overcome some of the difficulties inherent in the traditional treatment of phobias. The chapter also describes how to use virtual reality in the treatment of specific phobias: fear of flying, fear of heights, fear of being in certain situations, and fear of public speaking. Chapter 4, written by me, describes the context of current psychological assessment and underlines possible advantages of a VR based assessment tool. The chapter also details the characteristics of BIVRS, Body Image Virtual Reality Scale, an assessment tool designed to assess cognitive and affective components of body image. The remaining four chapters discuss specific applications of virtual reality: for the treatment of Autism (Chapter 5 by Strickland), for the palliative care of cancer (Chapter 6 by Oyama), for the treatment of body image disturbances (Chapter 7 by me and Melis) and to diagnose and treat patients with psychological and psychiatrical difficulties (Chapter 8 by Hirose, Kijima, Shirakawa and Nihei).

The last section of the book contains five chapters that focus on the current applications of virtual environments in neuro-physiological assessment and rehabilitation. Chapter 9 and 10 define the rationale for the possible application of virtual reality in this field. Specifically, Chapter 9, written by Rizzo and Buckwalter, provide an introduction to the basic concepts of neuro-psychological assessment and cognitive rehabilitation, along with rationales for virtual reality's applicability in these complimentary fields. The authors review the relevant literature regarding theoretical and pragmatic issues for these applications and provide references for further reading. In Chapter 10 Rose, Attree and Brooks describe the new opportunities offered by virtual reality to pursue several aspects of the rehabilitation process. The value of the technology of virtual environments in this context is that it allows the clinicians to immerse people with brain damage in relatively realistic interactive environments which, because of their patterns of impairment, would otherwise be unavailable to them. Finally, in the last chapters are presented many different applications of virtual reality: for the treatment of hemiparesis, unilateral neglect and cerebral palsy (Chapter 11 by Wann, Rushton, Smyth and Jones), for the quantitative analysis of neuromotor diseases (Chapter 12 by Rovetta, Lorini and Canina) and for the therapy of multiple sclerosis and spinal cord injury (Chapter 13 by Steffin).

In the end I want to thank and Carlo Galimberti, Enrico Molinari and Eugenia Scabini for supporting me right from the early days and for turning a blind eye when it was needed. My thanks also go to Luca Melis who spent with me much time and effort to tune-up our VR system. Thanks also to Paolo Mardegan and Cristina Selis who helped me during the last year.

My gratitude goes to my bosses and colleagues al Istituto Auxologico Italiano, one of the leading health care center in Italy and the most important European in-patients center for the treatment of eating disorders, for believing in the possibility of the clinical use of virtual reality and for supporting me in this exciting adventure. Finally I want to dedicate this book to the memory of Giuseppe Girotti, a great man and my first mentor.

I hope that the contents of this book will stimulate additional research on cognitive and human factors related to the virtual experience and on how best use virtual environments in psychology and medicine. In particular I hope that the European Community, that strongly supported the VREPAR project, will keep on in helping European research in this demanding field.

Giuseppe Riva

Istituto Auxologico Italiano Applied Technology for Psychology Lab. Verbania, Italy

May 1997