Virtual reality applied to hepatic surgery simulation: the next revolution

It has previously been shown that zones of higher electric field form close to the loading end of the gel during denaturing polyacrylamide gel electrophoresis. Here we show that the field can reach up to three times its normal mean value a few cm in front of the loading wells when 44.5 mM Tris-44.5 mM boric acid-1 mM EDTA is used as the gel buffer. We also demonstrate that this electric field gradient is mostly due to the difference in ion transference numbers at the gel/buffer interface caused by the high viscosity of the urea solution contained in the gel. This field gradient leads to increased band widths and forces us to redefine both the electrophoretic mobility and the mean field intensity. We discuss some methods that can be used to minimize the effects of this gradient.     

The virtual hospital: the digital library moves from dream to reality

We examined the effects of passive immunization with a monoclonal antibody (EH3015) that recognizes a 150-kDa surface lectin of Entamoeba histolytica on amebic liver-abscess formation in hamsters. The hamsters were inoculated i.p with 0.1, 1.0, or 10 mg of EH3015 at 24 h prior to an intrahepatic challenge with 10(5) trophozoites of E. histolytica. In hamsters treated with 1.0 and 10 mg of EH3015 the incidence of liver abscesses was significantly reduced. These results demonstrate that monoclonal antibody EH3015 can prevent the development of amebic liver abscesses and that the 150-kDa lectin may be a protective antigen on the surface of E. histolytica.     

可视化与虚拟现实技术及其在矿业中的应用

介绍了可视化及虚拟现实的内涵、特点及关键技术,并就其在矿业中的应用及前景进行了探讨和展望。     

Surgical manpower: past and present reality, estimates for 2000

The growth in the number of board-certified surgeons in the 1970s, projections of the need for surgeons in the year 2000, and possible factors softening the impact of surgical expansion are discussed in detail. The best index for the optimal supply of surgeons in the United States is related to the phenomenon of local community needs.     

Accessing the scientific literature. The reality of virtual scholarship

OBJECTIVE: The purpose of this study was to evaluate HDL-C values and their relationship to high total cholesterol values during childhood. PATIENTS AND METHODS: We have studied 4,547 children and adolescents of both sexes between 4 and 6 years of age. RESULTS: We found HDL-C values > 50, 65 and 75 mg/dl in 66.28%, 26.17% and 7.81%, respectively. Of the cases studied, 44.8% had TC > 174.9 mg/dl and 15.17% higher than 199.9 mg/dl. The positive predictive value (PPV) to detect LDL-C > 129.9 mg/dl was 67.1 and 26.4 for values of TC > 199.9 and 174.9, respectively. The PPV to detect a LDL-C/HDL-C > 2.19 of the TC > 199.9 and 174.9 mg/dl was 54.78 and 23.95, respectively. CONCLUSIONS: The HDL-C of children and adolescents is often high and this could be responsible for the high TC values. Most of the children with TC values between 174.9 and 199.9 mg/dl have neither an increase in LDL-C nor in the LDL-C/HDL-C ratio.     

CD-ROM multimedia. The step before virtual reality

Applications developed using key multimedia elements are finding their way into a number of training and information exchange environments including the laparoscopy training market. Emerging multimedia-based applications range from procedural information for patients to interactive CD-ROM-based applications used to train highly skilled surgeons. These products are designed with a high level of interactivity that allows the surgeon to plan a surgical procedure, review detailed patient information and then merge that information into the surgical planning process. Using this new technology, a surgeon now has the ability to review CD-ROM-based course materials and efficiently meet continuing education requirements. The factor found most limiting in the development of multimedia-based applications for laparoscopy training is generally not the technology, but the limits placed on the technology because of one's reluctance to think beyond what is accepted as the norm. Properly implemented, multimedia applications developed for laparoscopy training reduce the cost and time associated with learning new materials, assist a user in retaining more of the information reviewed, and in many cases make the learning experience much more enjoyable.     

Testing the continuum of delusional beliefs: An experimental study using virtual reality.

A key problem in studying a hypothesized spectrum of severity of delusional ideation is determining that ideas are unfounded. The first objective was to use virtual reality to validate groups of individuals with low, moderate, and high levels of unfounded persecutory ideation. The second objective was to investigate, drawing upon a cognitive model of persecutory delusions, whether clinical and nonclinical paranoia are associated with similar causal factors. Three groups (low paranoia, high nonclinical paranoia, persecutory delusions) of 30 participants were recruited. Levels of paranoia were tested using virtual reality. The groups were compared on assessments of anxiety, worry, interpersonal sensitivity, depression, anomalous perceptual experiences, reasoning, and history of traumatic events. Virtual reality was found to cause no side effects. Persecutory ideation in virtual reality significantly differed across the groups. For the clear majority of the theoretical factors there were dose–response relationships with levels of paranoia. This is consistent with the idea of a spectrum of paranoia in the general population. Persecutory ideation is clearly present outside of clinical groups and there is consistency across the paranoia spectrum in associations with important theoretical variables. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning science in virtual reality multimedia environments: Role of methods and media.

College students learned about botany through an agent-based multimedia game. In Experiment 1, students received either spoken or identical on-screen text explanations; in addition, the lesson was presented either via a desktop display (D), a head-mounted display (HMD) used while sitting, or an HMD used while walking (W). In Experiment 2, we examined the effects of presenting explanations as narration (N), text (T), or both (NT) within the D and W conditions. Students scored higher on retention, transfer, and program ratings in N conditions than in T conditions. The NT condition produced results in between. Students gave higher ratings of presence when learning with HMDs, but media did not affect performance on measures of retention, transfer, or program ratings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Psychological benefits of exercise paired with virtual reality: Outdoor exercise energizes whereas indoor virtual exercise relaxes.

In the present study the authors sought to evaluate the psychological effects of exercise when paired with virtual reality. One-hundred and twelve introductory psychology students (47 male and 65 female) were randomly assigned to one of three 20-min experimental conditions including (a) taking a brisk outdoor walk around a college campus, (b) walking on a laboratory treadmill combined with a virtual reality video presentation of the same college campus walk, or (c) viewing the virtual reality walk without participating in any actual exercise. Several standardized mood and enjoyment measures were administered immediately before and after the experimental conditions. Results suggest that greater energy was experienced while walking outside whereas less energy was reported when viewing the virtual reality walk with no actual exercise. These findings were most pronounced for female participants. Both female and male participants walking in the laboratory with the virtual reality were more relaxed and experienced the least tension of the three conditions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

VR技术在矿工安全培训中的应用研究

传统的矿工培训高成本、低效益,不能适应井下复杂多变特殊环境的要求。本文应用计算机技术,采用基于虚拟现实的方法,构建了井下生产的虚拟环境;在这个虚拟环境中,矿工可以身临其境地去接触、认知、决策和处理各种突变情况,其决策结果会立即反馈给受训者,由此提高矿工的培训效果。     

The application of virtual reality technology in rehabilitation.

Virtual reality (VR) is an emerging technology with a variety of potential benefits for many aspects of rehabilitation assessment, treatment, and research. Through its capacity to allow the creation and control of dynamic 3-dimensional, ecologically valid stimulus environments within which behavioral responding can be recorded and measured, VR offers clinical assessment and rehabilitation options that are not available with traditional methods. Initial applications of VR in other aspects of medicine and psychology have yielded encouraging results, but continued research and understanding of this evolving technology will be crucial for its effective integration into rehabilitation. This article provides a brief introduction to VR technology, examines the specific benefits VR offers consumers and providers of rehabilitation services and discusses potential areas of application and important considerations in applying this technology. Finally, 2 examples of current Vr applications are presented. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Virtual cisternoscopy of intracranial vessels: a novel visualization technique using virtual reality

This paper introduces a different visualization method which we call "virtual cisternoscopy" using 3D MRA data sets. Virtual cisternoscopy uses well known tools, such as perspective volume rendering (pVR), fly-through techniques, and interactive visualization and combines them to a new approach featuring motion to resolve spatial relationships of intracranial vessels and vascular malformations. With a dedicated flight protocol extraluminal topography of intracranial arteries was analyzed using pVR. For evaluation of difficult vascular malformations extraluminal views are necessary. Therefore, movies of pVR views were produced simulating virtual tracks of neurosurgical flexible endoscopes, by flying around the intracranial vessels and vascular malformations within the cisterns. Endoluminal views were acquired additionally for precise evaluation of cases with complex vessel topography. Two healthy volunteers and three patients were examined. Comparing MIP and pVR images relevant advantages of pVR were found, such as depth information, perspective, lighting, and color. In contrast to MIP and source images of the MRA data set, virtual cisternoscopy of an aneurysm of the left middle cerebral artery demonstrated clearly an early origin of an artery in the region of the aneurysm neck/sac. In this case only virtual cisternoscopy led to the correct therapeutical decision. In a newborn, the type of a vein of Galen aneurysmal malformation could only be evaluated reliably by means of virtual cisternoscopy. The third case of a patient with a clipped aneurysm was evaluated more easily with virtual cisternoscopy than with DSA. In conclusion, virtual cisternoscopy may improve the pretherapeutic visualization of intracranial vascular malformations.     

基于可视化虚拟现实技术的炼钢—连铸生产调度系统

采用虚拟现实技术开发了钢铁企业炼钢－连铸调度计划的调度系统。此方法利用虚拟现实技术的反馈设计和可视化的特点,能够使计划编制人员方便而有铲地制定调度计划。提出的调度方法有界面友好、结论直观、模型修改方便等优点。     

Virtual reality for the psychophysiological assessment of phobic fear: Responses during virtual tunnel driving.

An overall assessment of phobic fear requires not only a verbal self-report of fear but also an assessment of behavioral and physiological responses. Virtual reality can be used to simulate realistic (phobic) situations and therefore should be useful for inducing emotions in a controlled, standardized way. Verbal and physiological fear reactions were examined in 15 highly tunnel-fearful and 15 matched control participants in 3 virtual driving scenarios: an open environment, a partially open tunnel (gallery), and a closed tunnel. Highly tunnel-fearful participants were characterized by elevated fear responses specifically during tunnel drives as reflected in verbal fear ratings, heart rate reactions, and startle responses. Heart rate and fear ratings differentiated highly tunnel-fearful from control participants with an accuracy of 88% and 93%, respectively. Results indicate that virtual environments are valuable tools for the assessment of fear reactions and should be used in future experimental research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Age effect on components of episodic memory and feature binding: A virtual reality study.

Objective: The aims were (1) to explore the effects of normal aging on the main aspects of episodic memory—what, where, and when,—and on feature binding in a virtual environment; (2) to explore the influence of the mode of learning, intentional versus incidental; and (3) to benchmark virtual environment findings collected with older adults against data recorded in classical neuropsychological tests. Method: We tested a population of 82 young adults and 78 older adults without dementia (they participated in a short battery of neuropsychological tests). All the participants drove a car in an urban virtual environment composing of 9 turns and specific areas. Half of the participants were told to drive through the virtual town; the other half were asked to drive and to memorize the environment (itinerary, elements, etc.). All aspects of episodic memory were then assessed (what, where, when, and binding). Results: The older participants had less recollection of the spatiotemporal context of events than the younger with intentional encoding (p p p p     

Twelve-month follow-up of virtual reality and standard exposure therapies for the fear of flying.

This study reports the 12-mo follow-up from patients with the fear of flying who were treated in a controlled study and randomly assigned (n=49) to virtual reality exposure (VRE) therapy, standard exposure (SE) therapy, or to a wait-list control (WL). VRE and SE were equally superior to WL. At 12 mo posttreatment, data were gathered on 24 of the 30 (80%) patients who were assigned to VRE or SE. Patients maintained their treatment gains, and 92% of VRE participants and 91% of SE participants had flown on a real airplane since the graduation flight. This is the 1st year-long follow-up of patients having been treated with VRE and indicates that short-term treatment can have lasting effects. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analgesic effects of posthypnotic suggestions and virtual reality distraction on thermal pain.

The individual and combined effects of posthypnotic suggestion (PHS) and virtual reality distraction (VRD) on experimentally induced thermal pain were examined using a 2 × 2, between-groups design. After receiving baseline thermal pain, each participant received hypnosis or no hypnosis, followed by VRD or no VRD during another pain stimulus. Consistent with the hypothesis that hypnosis and VRD work via different mechanisms, results show that posthypnotic analgesia was moderated by hypnotizability but VRD analgesia was not. The impact of PHSs for analgesia was specific to high hypnotizables, whereas VRD was effective independent of hypnotizability. Results also show a nonsignificant but predicted pattern for high hypnotizables: Audio hypnosis combined with VRD reduced worst pain 22% more and pain unpleasantness 25% more than did VRD alone. Theoretical and clinical implications are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Transference: Psychic reality and material reality.

This article explores the impact of material reality in the form of the analyst's unrecognized and enacted countertransference on a patient's psychic reality (PR) as it presents in the transference. PR refers to a patient's experience in the transference and to an organization of unconscious fantasies, encoded as compromise formations, that actively structures the present and can be inferred from the data of psychoanalysis. Clinical material is presented in support of the author's belief that PR plays the central role in the construction of the transference and that material reality can influence both the nature and form of the transference through the activation or inhibition of different sets of fantasies in the analyst and the patient. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

A controlled study of virtual reality exposure therapy for the fear of flying.

Fear of flying (FOF) affects an estimated 10–25% of the population. Patients with FOF (N?=?49) were randomly assigned to virtual reality exposure (VRE) therapy, standard exposure (SE) therapy, or a wait-list (WL) control. Treatment consisted of 8 sessions over 6 weeks, with 4 sessions of anxiety management training followed by either exposure to a virtual airplane (VRE) or exposure to an actual airplane at the airport (SE). A posttreatment flight on a commercial airline measured participants' willingness to fly and anxiety during flight immediately after treatment. The results indicated that VRE and SE were both superior to WL, with no differences between VRE and SE. The gains observed in treatment were maintained at a 6-month follow up. By 6 months posttreatment, 93% of VRE participants and 93% of SE participants had flown. VRE therapy and SE therapy for treatment of FOF were unequivocally supported in this controlled study. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Brief report: two case studies using virtual reality as a learning tool for autistic children

The objective of this study was to evaluate the osteogenic capacities of a vascularized periosteal flap reinforced by a bone substitute, coral, to validate the possibility of creating prefabricated bone flaps with shapes adapted to a recipient zone, while limiting the donor site sequelae. 24 periosteal flaps, with preserved vascular pedicles, were raised from the medial femoral epiphyses of 12 ewes. In the same animal, these flaps were reinforced with a cylinder of coral and a cylinder of autologous graft. After implantation for 2 or 8 weeks depending on the animal, the flaps were submitted to histopathological and histomorphometric examination. The results of this examination demonstrated a similar course of the flaps regardless of the type of reinforcement, both in terms of implant resorption and the quantity of newly formed bone.