Ebook: Medicine Meets Virtual Reality 21

Since 1992, the NextMed/MMVR conference has gathered researchers who create tools that improve medical care and education. Engineers, clinicians, scientists, educators, industry, military, and students come to share, learn, evaluate, and nurture progress. Their mission is to improve healthcare outcomes and efficiency through computing and networking technologies—products of the IT industry.

These researchers also participate in the healthcare crisis that the United States and, to a lesser extent, other developed countries now face: how to meet the public's high expectations of care when costs are precariously high.

Multiple factors have elevated these expectations. Baby Boomers are entering retirement after a lifetime of viewing ads that promise them “golden years” invigorated by science. Competition for affluent patients means hospital ads never admit a tacit truth: “Yes, our experienced doctors treat people with fancy machines, but some still die or never improve”. The media glowingly report on patients saved by dedicated physicians, and people believe they can buy miracles with sufficient talent and technology. Meanwhile, a convoluted reimbursement system obscures the true cost of care, individually and collectively.

The cost of care is steadily increasing, too. In the United States, the chronically ill of all ages—five percent of the population—consume half of all healthcare spending. Many of these patients suffer from lifestyle diseases that proliferate in synch with modernization. Aging Boomers will exacerbate this increase as they approach the inevitable during the next decade or so. Granted, human nature compels us to fight illness by any means possible—without weighing the financial toll beforehand. (If a TV medical drama included accountants in the ER who tabulated invoices while doctors saved lives, it would morph into a dark comedy that's not too far from reality.) However, when we extend lives with innovative therapies but don't completely heal, the economic burden can accumulate impressively.

And unfortunately, the American public's return on investment—healthier lives per dollars spent—is poor. Again, several factors are at play. Opaque and monopolistic healthcare pricing obstructs comparison between providers, so inefficiencies stand uncorrected. In addition, the insurance industry takes a large cut of healthcare spending without actually providing any care. Furthermore, American culture tends to underrate prevention, but value dramatic interventions. (How many cardiac stents and insulin pumps could we eliminate with better dietary education?) And when the public expresses discontent and asks the government to improve the current system, the methods to effect change become stubbornly politicized. Naturally, players already making a lot of money protect their advantage; political expediency influences how healthcare profits remain private and losses become socialized.

Caregivers, hospitals, drugs, and devices are limited and valuable resources that merit significant investment. In order to protect these resources and improve our investment, though, we need to resolve the key issue at hand: how much more can the public pay for care without damaging the rest of the economy? Clearly, we require greater efficiency.

Scientists and engineers also form part of the relationship between healthcare invention, patient expectations, and increasing expenditure. They tackle healthcare problems focusing chiefly on scientific solutions. But science is also a business, so following successful discovery and regulatory approval, corporations must recoup R&D and fund future research. Their aggressive marketing of new products maximizes sales, and pricing reflects what the market will bear, yet FDA approval doesn't guarantee that a new therapy is the most cost-effective option available. Return on investment—from the public's standpoint—appears to be an afterthought.

Although the technologies shared at NextMed/MMVR capitalize on the increasing capabilities and decreasing costs pioneered by the IT industry, researchers can further help patients by aiming for not just a cure, but a cure patients can afford. No one wants to dampen ingenuity, but could researchers take into account the future costcompetitiveness of the investigated solution?

Can engineers and scientists, for example, collaborate with healthcare providers (including those ER accountants tabulating in the background) to understand what patients need, clinically and economically? Can their differing perspectives reduce misguided efforts and improve the economic viability of the cure? At NextMed/MMVR, we believe they can. In fact, interdisciplinary collaboration has been a conference objective since 1992, and it remains as important as ever.

To the many researchers who contributed papers for this volume, thank you for the tremendous effort and ingenuity you have invested in improving healthcare, and for presenting your work at this conference.

Acknowledgment

Many thanks to Dr. Patrick Cregan, a member of the NextMed/MMVR Organizing Committee, for sharing his enthusiasm for healthcare economics and some useful references on the topic.

James D. Westwood

Aligned Management Associates, Inc.

The first virtual-reality-based simulator for Natural Orifice Translumenal Endoscopic Surgery (NOTES) is developed called the Virtual Translumenal Endoscopic Surgery Trainer (VTEST^TM). VTEST^TM aims to simulate hybrid NOTES cholecystectomy procedure using a rigid scope inserted through the vaginal port. The hardware interface is designed for accurate motion tracking of the scope and laparoscopic instruments to reproduce the unique hand-eye coordination. The haptic-enabled multimodal interactive simulation includes exposing the Calot's triangle and detaching the gall bladder while performing electrosurgery. The developed VTEST^TM was demonstrated and validated at NOSCAR 2013.

Mandibular reconstruction is typically performed for traumatic or postsurgical conditions, and may involve the use of autologous osteocutaneous fibula free flaps for large defects. Recreating the native contour of the mandible during reconstructive surgery is challenging. Existed pre-operative planning software has limitations. In this paper we present a novel pre-operative planning system that helps to optimize the number and location of bony osteotomies, and the orientation of the harvested bone segments by specifically prioritizing the position and number of the cutanteous perforators to the osteocutaneous fibula free flap, in order to improve the reliability of the osteocutaneous fibula free flap.

We propose a principled approach to the design of a computer-based, virtual reality simulator specifically for electrosurgical training. The design builds on the Fundamental Use of Surgical Energy (FUSE) program's didactic curriculum and the results of a survey of domain experts on the roles of cognitive knowledge and hands-on training for a selection of electrosurgery tasks. The resulting design focuses narrowly on the tissue effects caused during electrosurgery and the identified physician-controllable factors causing those effects.

Graphically realistic, haptics-enabled, virtual reality surgical simulations are becoming increasingly popular training tools for neurosurgical procedures and surgical skills. Compared with traditional training models, virtual simulations are safe, versatile, consistent, and are relatively cost effective. Most simulations are deficient, however, in representing the diverse anatomical variations that occur clinically. In this work, we describe the design and implementation of a pipeline to create patient-specific surgical scenarios for simulator-based training of the endoscopic third ventriculostomy: the procedure of choice for treating obstructive hydrocephalus.

Embedded microcontroller hardware has matured to the point that organ- and system-specific modules that can be assembled in various configurations are practical. Our work developing and interconnecting organ and system modules in the cardiovascular and pulmonary systems illustrates the signaling requirements necessary to fully leverage the technology. It also highlights the need for standard signaling protocols that parallel those under development for software-centric physiology simulation systems.

In the context of cognitive competencies, we are defined by our memories. As such, experiential data in various forms of Electronic Competency Records (ECRs), including the Learning Record Store (LRS), can be used as the basis for an Intelligent Tutoring System (ITS), scheduling medical recertification preparation and other forms of educational intervention. However, the experiential data infrastructure provided by an ECR is necessary but insufficient for realizing the full potential of competency tracking and prediction technology. To this end, we are exploring competency degradation models based on time and interference, using retrospective data from our ECR-based work in ITS.

Deep Brain Stimulation is aneurosurgical approach for the treatment of pathologies such as Parkinson's disease. The basic principle consists in placing a thin electrode in a deep part of the brain. To safely reach the target of interest, careful planning must be performed to ensure that no vital structure (e.g. blood vessel) will be damaged during the insertion of the electrode. Currently this planning phase is done without considering the brain shift, which occurs during the surgery once the skull is open, leading to increased risks of complications. In this paper, we propose a method to compute the motion of anatomical structures induced by the brain shift. This computation is based on a biomechanical model of the brain and the cerebro-spinal fluid. We then visualize in a intuitive way the risk of damaging vital structures with the electrode.

Future minimally invasive neck surgery requires a navigation system adapted to the actual intra-operative bedding of the patient. The detection of the bedding-caused tissue shift is essential for a safe orientation for the surgeon new endoscopic operation procedures in neck surgery. It is essential to visualize the relation between important anatomic landmarks and operation instruments at any time. Within the scientific project SACAS we focus on developing an ultrasound supported navigation system based on preoperative imaging which considers the intra-operative tissue shift. A rotatable, flexible neck-model provides the basis for our analysis to evaluate the tissue shift and to invent the new navigation system for endoscopic neck surgery. The total registration error of the system was 2 mm.

Laparoscopic Adjustable Gastric Banding (LAGB) is a common surgery method used to help obese patients to lose weight. However, even if LAGB is able to produce a durable and relevant weight loss, it is less effective in improving body image: as demonstrated by a recent study, obese patients with a body image disorder in the pre-operative stage continue to show this even 13 months after the operation. In this presentation we will discuss the possible role of virtual reality (VR) in addressing this problem within an integrated cognitive behavioral approach. To test this approach, a case series of three LAGB patient who experienced body dissatisfaction even after a >30/40% excess body weight loss, is presented and discussed. At the end of the 6-week protocol the patients experienced a 15%–20% further reduction of their weight. This reduction was also matched by a general improvement of the psychological state. Both the weight loss and the level of well-being were further improved after a three-month follow-up.

A significant amount of research has been conducted regarding the design of Internet applications for the elderly. Concomitantly, researchers have been applying online technologies to healthcare for older adults. The oldest old (for our purposes, defined as older adults aged 80+) are increasingly adopting the use of the Internet and likely have different needs than those who are between 55 and 80 years old. The main results from a literature review on the existing research in human factors and design for older adults is presented. These results highlight the need for more research in human factors and design in the much neglected population group, the oldest old.

Surgical simulators can avail minimizing the risk of surgery and help achieving a better outcome. This is also the case for the Nuss procedure, a minimally invasive surgery for correcting pectus excavatum (PE) – a congenital chest wall deformity. A simulator can be of great benefit if it provides realistic behavior and representation of the actual surgery. In this paper, we address various clinical aspects of the procedure for a training simulation, reproducing a virtual model of the patient's thoracic cavity and internal organs with realistic textures, as well as physical behaviors. In addition, a high fidelity haptic force feedback system is constructed to provide the surgeon with a close-to-real sensation while interacting with the virtual model.

We present a navigated simulator for ultrasound-guided spine needle interventions, comprising of an ultrasound scanner, tracking system, surgical instruments, tissue-mimicking spine phantom, and augmented virtuality navigation platform. The ultrasound transducer, spine needle, and spine phantom are magnetically tracked and spatially calibrated, allowing the navigation software to render the surgical scene with streaming ultrasound video in 3D. The spine phantom provides sonoanatomically correct images, with realistic tactile sensation from needle advancement through tissues layers. The combination of a physical phantom and navigation software provides a realistic, inexpensive, and interactive environment for teaching and learning, the latter also having potential as an interventional tool for real-time ultrasound-guided spine needle insertion.

The inferior alveolar nerve canal is an important nerve canal in the jaw bone, and any damage to this canal can cause pain or fatal complications. Since such damage can be caused by a wrong surgical procedure or surgery plan, accurate surgery planning is necessary. Cone-beam computed tomography (CBCT) is a three-dimensional medical imaging method that is mainly used in dental treatment; however, identifying the nerve canal is difficult in CBCT images as compared to conventional CT images. This paper proposes a new concept of a panoramic curve for nerve canal detection and a detection algorithm that is usually applied to facial recognition was introduced in this study for the automatic detection of nerve canal in CBCT images.

Unilateral Spatial Neglect (USN) is normally assessed with paper-and-pencil tests. Virtual reality can be an effective neuropsychological tool for a more ecological and functional assessment and rehabilitation of neglect. We developed a 3D Virtual Reality platform – NeuroVirtual 3D – for the assessment and rehabilitation of cognitive deficits, in particular for USN. Within the virtual environments it is possible to interact with virtual objects and execute specific exercises using a Microsoft Kinect. Through the analysis of different grasping tasks it is possible to evaluate in an ecological way the patients' ability to find and handle objects in both sides of the virtual space.

Traditional surgical teaching requires an expert trainer to be present during training. This training model allows an expert to observe a novice's performance and provide corrective feedback as errors are made. Virtual simulations offer a much needed alternative to learning through error and allow the trainee to hone skills without the presence of a skilled surgical trainer. However, current simulations limit the scope of training to tool directed learning, focusing training around instrumented simulated tool tips. This paper identifies a need for trainee centered virtual training to complement current approaches. The Outside Observer training methodology provides training feedback based on the observation of surgical tool tip manipulations in conjunction with the external movements a trainee performs during a procedure. It is thought that integrating movement and posture training with current tool tracking methods will provide more effective and accelerated learning.

In this paper we propose a method to address the problem of non-rigid registration in real-time. We use Lagrange multipliers and soft sliding constraints to combine data acquired from dynamic image sequence and a biomechanical model of the structure of interest. The biomechanical model plays a role of regularization to improve the robustness and the flexibility of the registration. We apply our method to a pre-operative 3D CT scan of a porcine liver that is registered to a sequence of 2D dynamic MRI slices during the respiratory motion. The finite element simulation provides a full 3D representation (including heterogeneities such as vessels, tumor,...) of the anatomical structure in real-time.

Situation awareness (SA) is a critical non-technical skill which affects outcome during emergency medical endeavors. Using a modified self-report instrument a significant increase of SA was found during multiplayer virtual world CPR team training among 12 medical students. Further a correlation between SA and attention was noted. Being a vital factor during the process of video-game play, we argue that this skill is suitably practiced using this training method.

Natural orifice translumenal endoscopic surgery (NOTES) is a minimally invasive procedure which utilizes the body's natural orifices to gain access to the peritoneal cavity. The VTEST is a virtual reality NOTES cholecystectomy simulator being built at the CeMSIM at RPI. We have developed a 2 DOF decoupled haptic device, which can provide translational and rotational haptic feedback to the user handling the flexible endoscope. Preliminary results indicate the device is capable of providing realistic feedback to the user while operating the device.

As advanced minimally invasive techniques have become more prevalent, there has been an increase in the number of pediatric surgeons performing thoracoscopic repair of congenital diaphragmatic hernia (CDH). Opportunities to learn and practice this procedure are few. The use of a simulation model for thoracoscopic CDH repair may help reduce errors in the operating room. Prototypes for low and high fidelity CDH repair simulators were designed and built. These prototypes allow pediatric surgery trainees the opportunity to learn and practice thoracoscopic CDH repair before performing this operation on infants.

Although cadaveric specimens that have been fresh-frozen then thawed are considered the gold standard for biomechanics research, because they most closely represent in vivo tissues, potential problems include a relatively short useful time-span and risk of infection. A recently reported new method of phenol-based “soft” embalming has been found to preserve tissues in a fresh-like state over an extended period of time and simultaneously reduced infection risks. This study presents radio-ulnar deviation end-range data from 4 soft-embalmed and refrigerated human cadaveric forearm specimens over 12 months. All end-range comparisons were found to be statistically equivalent to within a clinically acceptable range of ±5 degrees of radio-ulnar deviation with a 95% con. dence measure of p < 0.01 in every case. These soft-embalmed specimens provide promising results for further use in biomechanical studies.

Two hundred forty-five thousand patients seek care at Landstuhl Regional Medical Center. They battle lengthy commutes, costly procedures, and limited specialty care in order to consult their physicians. Implementing telemedical procedures at hospitals such at LRMC is believed to reduce travel time, decrease costs, and increase specialization. Healthcare providers who were trained in Tele ENT procedures unanimously accepted the technology as an alternative way to care for patients. Expansion of telemedical procedures in hospitals is deemed to reduce health care costs and to be accepted by providers.

Palpation is the first step for many medical interventions. To provide an immersive virtual training and planning environment, the palpation step has to be successfully modeled and simulated. Here, we present a multiproxy approach that calculates friction and surface resistance forces for multiple contact points on finger tips or virtual tools like ultrasound probes and displays the resulting force and torque on a 6DOF haptic device. No manual or time intensive segmentation of patient image data is needed to create a simulation based on CT data and thus our approach is usable for patient-specific simulation of palpation.

Virtual Reality (VR) is increasingly being used in combination with psycho-physiological measures to improve assessment of distress in mental health research and therapy. However, the analysis and interpretation of multiple physiological measures is time consuming and requires specific skills, which are not available to most clinicians. To address this issue, we designed and developed a Decision Support System (DSS) for automatic classification of stress levels during exposure to VR environments. The DSS integrates different biosensor data (ECG, breathing rate, EEG) and behavioral data (body gestures correlated with stress), following a training process in which self-rated and clinical-rated stress levels are used as ground truth. Detected stress events for each VR session are reported to the therapist as an aggregated value (ranging from 0 to 1) and graphically displayed on a diagram accessible by the therapist through a web-based interface.

The PATIENT manikin (Physical Anatomical Trainer Instrumented for Education and Non-subjective Testing) is designed with the conflicting needs of a highly modular system for ultimate scenario flexibility and cost containment, and a highly realistic system. PATIENT provides a unique combination of capital and disposable components, with each organ treated as a limited-reuse component. The organs contain unobtrusive instrumentation which informs the PATIENT control unit of the organ status. The control unit can adjust whole-body parameters to reflect the local physiology. PATIENT enables tailored simulations, from Point of Injury training of basic life support, through hospital training including surgical interventions.