Ebook: Medicine Meets Virtual Reality 16

We humans are tribal, grouping ourselves by a multitude of criteria: physical, intellectual, political, emotional, etc. Belonging to a tribe comforts us and often we take pride in its exclusivity. Our tribal communities exist in parallel with each other, cooperating and competing. Adam Smith, Charles Darwin, and Henry Ford would see the value in this arrangement—divide according to expertise, perfect your skills, and conquer the marketplace: may the best tribe win.

The Internet and its auxiliary technologies have enabled a novel dimension in tribal behavior during our recent past. New networking tools allow unprecedented global interaction, sweeping aside nation and place. We now freely interact with others, generating new combinations of people and ideas, and creating spontaneous global communities. Our actions increasingly mirror Buckminster Fuller's words: “Our thoughts are inherently radially expansive and contractive, topological systems that are mathematically describable only as four- and six-dimensional systems.”

These new communities are important chiefly because of their rapid, widespread growth. Scattered human attention and intention suddenly align and converge; the power of this collective focus is undeniable. One individual can inform the entire community and even redirect its gaze. Democratic, potent, and sometimes chaotic, Internet-based communities are changing how the world operates.

This growing power and connectivity beg the question: will individuals and their communities come together to solve some very urgent global problems?

In industrialized nations, healthcare is struggling just as baby boomers enter their time of greatest medical need. Insufficient financial preparedness and high expectations exacerbate the gap between aspiration and pocketbook. At MMVR, we explore ways to harness information technology to solve healthcare problems—and we are making progress.

In the developing world, things are more challenging. The United Nations reports that, in 2007 and for the first time ever, the majority of the world's population will live in urban areas, while the number of slum dwellers will surpass one billion. The World Health Organization says 2.6 billion people do not have even a proper toilet. Other sources estimate that two billion children receive little or no education.

A dark and chaotic dystopia makes for an intriguing sci-fi story. In the real world, though, massive urban poverty fuels violence and misery that reach across political borders. Will global networking bring a convergence of individual and tribal problem solving so that, as everyone comes to find everyone else at their doorstep, we encounter allies and not enemies?

A recent exhibition at the Cooper-Hewitt National Design Museum in New York City displayed a barrel-shaped water carrier that easily rolled along the ground, improving daily life in places where water is transported by human labor. The design seems so obvious and simple. The durability and utility of the device, however, rely on plastics developed by the industrialized world.

The One Laptop Per Child project is an even more ambitious attempt to bring rich world know-how to the developing world. Like the water carrier, the laptops are designed for simplicity of use, hardiness, and inexpensive reproduction. They result from the collaborative effort of some of the best minds in the IT industry and academia—affluent individuals who share a vision of knowledge distributed globally and without economic obstacles.

At MMVR, we focus on cutting-edge medical technology—generally, it's expensive stuff. While the benefits of innovation trickle downward, from the privileged few to the broader masses, we should expand this trickle into a flood. Can breakthrough applications in simulation, visualization, robotics, and informatics engender tools as ingeniously straightforward as the barrel water carrier, or be as ubiquitously helpful as these ultra-low-cost laptops? With some extra creativity, we can design better healthcare for the developing world, too.

It is a privilege to be part of the MMVR community, to have colleagues and friends who are so talented, ambitious, and committed to worthy goals. Thank you for including us.

Virtual Reality-based surgical simulators can utilize Collaborative Virtual Environments (C-VEs) to provide team-based training. To support real-time interactions, C-VEs are typically replicated on each user's local computer and a synchronization method helps keep all local copies consistent. This approach does not work well for voxel-based C-VEs since large and frequent volumetric updates make synchronization difficult. This paper describes a method that allows multiple users to interact within a voxel-based C-VE for a craniotomy simulator being developed. Our C-VE method requires smaller update sizes and provides faster synchronization update rates than volumetric-based methods [1,2]. Additionally, we address network bandwidth/latency issues to simulate networked haptic and bone drilling tool interactions with a voxel-based skull C-VE.

A redesigned motion control system for the medical robot Aesop allows automating and programming its movements. An IR eye tracking system has been integrated with this control interface to implement an intelligent, autonomous eye gaze-based laparoscopic positioning system. A laparoscopic camera held by Aesop can be moved based on the data from the eye tracking interface to keep the user's gaze point region at the center of a video feedback monitor. This system setup provides autonomous camera control that works around the surgeon, providing an optimal robotic camera platform.

The effectiveness of simulation-based training has been accepted with great success in many fields including medicine. Most of the simulation research and development in medicine has focused on surgery. There has been some development of hardware based biomechanical models of sections of human anatomy, such as pelvic exam simulators. More recently, with the advances in haptics technology, software and hardware based simulators are being developed for the previously ignored area of palpatory diagnosis. The Virtual Haptic Back (VHB) is a simulator based on virtual reality and haptics that is currently being used to train medical students in palpatory diagnosis. This study examined the effect of repeating the training on the VHB.

One of the great ironies of modern medicine is that the very environments created to heal are the cause of countless injuries, illnesses and death to the vulnerable population they were created to serve. Not since Florence Nightingale visited the pestholes in which wounded and sick British soldiers were housed in the Crimea, has there been a growing international awareness of the harm caused by the healing environment. There is growing recognition that risks and hazards of health care associated injury and harm are a result of systemic design problems rather than poor performance by individual providers. The evidence is overwhelming that current hospital design is not sufficient to prevent medical errors, rates of infection and injuries from falls, and even contributes to slow patient recovery and high nurse turnover.

Today's challenges are even steeper than a half-century ago due to:

a) Rising concern and demand about health care costs and quality

b) Large population increase with an exponentially growing elderly proportion

c) A proliferation of complex and confusing local, state and federal regulations

d) A dramatically evolving technological environment

e) A sicker, more debilitated and compromised patient population, and

f) A workforce with higher expectations of the work environment should be like

The present hospital construction boom provides an opportunity to rethink hospital design, and especially to consider how improved hospital design can help reduce staff stress and fatigue, reduce patient and family stress and improve patient outcomes and quality of care. A key challenge remains how to incorporate technology into the local learning environment and culture in ways that optimize its implementation and use.

An extension to the classical mass-spring model for more realistic simulation of soft tissues for surgery simulation was proposed. The conventional equations of mass-spring model were generalized for non-linear springs, and model parameters were tuned using experimental data. Results show that the proposed model is fast and interactive, and also demonstrate the typical nonlinear and visco-elastic behaviors of soft tissues well.

Serious games are being actively explored as supplements to and, in some cases, replacement for traditional didactic lectures and computer-based instruction in venues ranging from medicine to the military. As part of an intelligent tutoring system (ITS) for nuclear event first responders, we designed and evaluated two serious games that were integrated with adaptive multimedia content. Results reveal that there was no decay in score six weeks following game-based training, which contrasts with results expected with traditional training. This study suggests that adaptive serious games may help integrate didactic content presented though conventional means.

When performing the ABC's of care for the trauma patient, airway management is of paramount importance. Management of the airway is often difficult because medical personnel caring for the patient do not commonly intubate patients or manage airways. To accomplish endotracheal intubation, a direct line of sight must be accomplished through the mouth, pharynx and larynx to the glottic opening. This is anatomically challenging in patients with a small mouth, large tongue, lack of cervical mobility, cervical trauma, protruding incisors or small mandible. This investigation compares indirect laryngoscopy, which allows the laryngoscopist to “see around the corner” during intubation, to standard direct laryngoscopy. This indirect view is a virtual view of the airway accomplished by projecting the view from an image device on the end of the laryngoscope to a monitor viewed by the laryngoscopist. The virtual (indirect) laryngoscopy improved the view of the glottic opening by an average 1.28 (p<0.001) Cormack-Lehane grades, consistant with existing literature. Indirect laryngoscopy results in improved glottic visualization compared to direct laryngoscopy. This difference will prove critically important for medical personnel who infrequently intubate and for students learning intubation skills in a clinical setting. The results of our study confirm the value of videolaryngoscopy as a standard method for hands-on airway management training of medical personnel. Indirect “virtual” laryngoscopy is an advanced technology method which will advance the development of teleanesthesiology practice. Videolaryngoscopy is an enabling technology for development of remote telementoring of trainee intubation skills curricula using video enabled distributed learning systems. This research was conducted following an approved University of Nebraska Medical Center institutional review board protocol.

This study describes our experience with using a virtual reality simulator, CricSim, to enhance the training of combat medics to perform a cricothyroidotomy (surgical airway) while in Iraq. Over a six month period, 65 medics used the simulator as part of a Combat Medic Advanced Skills Training class while in Iraq and were asked to evaluate it. Students self-assessed comfort level with the procedure improved dramatically from baseline (p<5.6×10⁻¹⁷). The CricSim was rated highly on realism but only moderately on ease of use. The use of this simulator in a far forward setting was feasible, enhanced training, and provided necessary end-user feedback for future development of this training platform.

Stereoscopic imaging during clinical evaluation can provide utility to physicians and medical educators by extending clinical photography with the provision of depth. A digital SLR camera body fitted with a stereoscopic lens and an autostereoscopic display are evaluated. This paper describes the image acquisition workflow and post-processing methods required to incorporate stereoscopic images into an electronic medical record for physician review.

The purpose of this study was to validate a complex robotic surgical task, mesh alignment, in virtual reality. Nine subjects unrolled and aligned a mesh onto an inanimate template for the mesh alignment task in both an actual (the da Vinci Robotic Surgical System) and a virtual environment. Data analysis included time to task completion, distance traveled, and speed, of the surgical instrument, as well as electromyography of the extensors and flexors of the dominant arm of the subject. Paired t-tests were used to compare the dependent variables between the actual and virtual environments. The virtual mesh alignment task was statistically similar for all variables except the flexor activity as compared to the actual task. In conclusion, virtual reality could be used as an effective environment to train the next generation of robot-assisted laparoscopic surgeons.

We hypothesized that simulation based practice will results in skill improvement on trocar insertion task. Novices, junior trainees and surgeons inserted a trocar into a simulated abdomen. The depth of penetration (plunge) was the similar for novice and junior trainees (p=.98), and exceeded that observed for practicing surgeons (p<.05). Trocar insertion may be an important variable to consider for surgical skill training. To date, no virtual reality (VR) trainers allow for practice of this skill. We will present a prototype of a VR trainer designed.

As the power of personal computing increases, there is a greater demand for high fidelity virtual environments for medical training simulators. However, it is still a challenge to provide realistic soft tissue deformation especially when haptic feedback is also required. This paper presents a new approach to soft tissue deformation using a novel Charged Particle method to efficiently model both the structure and haptic properties of anatomy in real time.

In our approach, we first specify a 3D model of the image structure by segmenting a CT dataset into the respective tissues followed by assigning the acoustic properties (velocity, impedance, scattering mean and standard deviation, damping factor and packing factor). Given that model, we simulate the ray propagation, beam forming, and finally the backscattering. Due to the inhomogenities of tissue, different physical models for ultrasound simulation are required: Rayleigh scattering is applied for homogenous regions and ray tracing techniques handle abrupt changes in acoustic impedance on tissue boundaries. The latter leads to different phenomena like refraction (Snell's law), reflection and transmission (Fresnel equation). The gradients needed for these methods are precomputed for each model using a central-difference method with multiple neighbours. Absorption is calculated by the Beer-Lambert law.

Very little medical virtual reality systems which are developed are applied in real surgical scenarios. One reason for this is that the system solutions resulting from research projects often address a single research question and are not embedded in an overall design. This paper presents a DICOM based approach on standardizing data structures, i.e. surface meshes, which are required for supporting surgical workflows by virtual reality applications.

The advent of small footprint stereo-lithographic printers and the ready availability of segmentation and surface modeling software provide a unique opportunity to create patient-specific physical models of anatomy, validation of image guided intervention applications against phantoms that exhibit naturally occurring anatomic variation. Because these models can incorporate all structures relevant to a procedure, this allows validation to occur under realistic conditions using the same or similar techniques as would be used in a clinical application. This in turn reduces the number of trials and time spent performing in-vivo validation experiments. In this paper, we describe our general approach for the creation of both non-tissue and tissue-mimicking patient-specific models as part of a general-purpose patient emulation system used to validate image guided intervention applications.

We discuss the goal and a design of an immersive and interactive virtual fairview peri-operative environment for patient education for surgery. We further discuss a pipeline for building 3D models of peri-operative environment for usage in VR. Specifically, we capitalize on the recent advancement on laser scanning technology to perform such modeling for both efficiency and accuracy.

Finite element methods (FEM) have been used extensively within the field of surgical simulation to describe physically realistic interactions with soft-tissue organs. However, FEMs require researchers to balance computational costs against approximation techniques to maintain adequate performance. We aim to extend previous work in nonlinear FEM implementation with extensions which improve the performance of accurate modelling of multiple organs undergoing deformations.

Medical modeling and simulation literature has undergone significant changes from 2000 until 2007. The MMVR Conference and the MMSD provide two avenues for observing trends in medical modeling and simulation literature. The literature submitted to MMVR and MMSD from 2000 to 2007 were placed into 8 categories and assessed through meta-analysis.

We report on a study that investigates the relationship between repeated training of teams managing a medical emergency (CPR) in a Virtual World and performance outcome measures in a group of 12 medical students. The focus of the training was on individual actions, but also on interaction and behavior in the team. Current CPR training seems to lack important team training aspects which this type of training is addressing. Although a pilot study, we found clear indications of improved performance related to reduced number of errors and an increased CPR efficiency. This type of educational technology could be expanded to other groups for a similar purpose because of its easiness to use, adaptability and interactivity.

An ultrasound imaging system is under development that features a flexible transducer that can be wrapped conformally around curved surfaces of the body. The device is intended to deliver high image quality without the need for mechanical scanning, and will benefit medical personnel with limited ultrasound training. A 2 x 8 element piezoelectric transducer prototype and 15.5 MHz imaging system have been built, and the system concept has been demonstrated by imaging a soft tissue phantom. The transducer design, imaging procedure, and preliminary image processing techniques are presented.

This paper presents, for the first time, a physics-based modeling technique for the Lap-band® (Inamed Health) used in laparoscopic gastric banding (LAGB) operations for treating the morbidly obese. A virtual LAGB simulator can help train medical students as well as surgeons who embark at learning this relatively new operation. The Lap-band® has different thickness and curvature along the centerline, and therefore leads to different deformation behaviors. A hybrid modeling strategy is therefore adopted to successfully replicate its dynamics. A mass-spring model, used to model the less stiff part, is coupled to a quasi-static articulated link model for the more stiff and inextensible part. The virtual Lap-band® model has been implemented into a complete graphics-haptics-physics-based system with two PHANToM Omni devices (from Sensible Technologies) being used for real-time bimanual interaction with force feedback.

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 technology will be adopted. Twenty-three medical students participated in a study in which they interviewed a virtual patient and were asked to rate the educational value of the experience. Despite some of the limitations in this developing technology, students were generally receptive to its use as an educational tool. Further enhancements to the system, including increased fidelity of the interaction and novel feedback mechanisms, should improve learner satisfaction with and adoption of the virtual patient system.

Phacoemulsification cataract surgery, a minimally invasive technique to remove a cloudy lens from the eye, is one of the most commonly performed surgical procedures in the western world. Conventional training for this procedure involves didactic lectures and practice on pig and human cadaver eyes, none of which allow trainees to form an accurate predictive model of human tissue behavior during surgery. A virtual environment simulator for capsulorrhexis, one of the first steps in cataract surgery, has been developed that allows a trainee to use surgical instruments to excise a circle of tissue on the anterior side of the lens capsule through tearing. The simulator invokes a deformable mass-spring-damper mesh model of the tissue that can be grasped and torn via shearing. A novel algorithm for mesh division and maintenance enables realistic tearing behavior. The trainee controls tool motion using a 3-degree-of-freedom haptic device, and haptic feedback is provided from the virtual tissue. Although the haptic feedback in a real capsulorrhexis procedure is below the human threshold of haptic sensing, this simulator enables an experiment to determine the effectiveness of “haptic training wheels” – the idea of haptic training for a task without haptic feedback.

A virtual reality system for the training of the lumbar puncture intervention is presented. We use a haptic device with six degrees of freedom (6DOF) to feedback forces that resist needle insertion and rotation. An improved haptic volume rendering approach is used to calculate the forces and an evaluation component has been developed to rate the success of virtual lumbar punctures to trace the training process of the user and to give feedback about failures.