Affiliate, Stanford Medical Informatics (2001 - Present)
Honors & Awards
SATAVA Award, MMVR Medicine Meets Virtual Reality (Jan 2003)
President's Award, American College of Obstetrics and Gynecology (1975)
Faculty Fellow, Josiah Macy, Jr. Foundation (1966)
Grand Prize, GameTech 2011 Users Conference Federal Consortium of Virtual Worlds (March 24, 2011)
Grand Prize, GameTech 2012 Users Conference, Federal Consortium of Virtual Worlds (March 25, 2012)
M.D., University of Oklahoma, Medicine (1958)
M.S., Ph.D., University of Oregon, Biochemistry (Steroids) (1967)
Current Research and Scholarly Interests
Surgical simulation; team-training in virtual environments;telemedicine for acute & chronic disease management in virtual environments; developing patho-physiological models for acute and chronic diseases, and complications of pregnancy.
Virtual Worlds in Healthcare: Applications and Implications
SERIOUS GAMES FOR HEALTHCARE: APPLICATIONS AND IMPLICATIONS
View details for DOI 10.4018/978-1-4666-1903-6.ch0011
View details for Web of Science ID 000315288600001
Simulators for learning basic skills, tasks, and endoscopic surgical procedures
NEZHAT'S VIDEO-ASSISTED AND ROBOTIC-ASSISTED LAPAROSCOPY AND HYSTEROSCOPY, 4TH EDITION
View details for Web of Science ID 000339685100027
CliniSpace: a multiperson 3D online immersive training environment accessible through a browser.
Studies in health technology and informatics
2011; 163: 173-179
Immersive online medical environments, with dynamic virtual patients, have been shown to be effective for scenario-based learning (1). However, ease of use and ease of access have been barriers to their use. We used feedback from prior evaluation of these projects to design and develop CliniSpace. To improve usability, we retained the richness of prior virtual environments but modified the user interface. To improve access, we used a Software-as-a-Service (SaaS) approach to present a richly immersive 3D environment within a web browser.
View details for PubMedID 21335784
Exploring Virtual Worlds for Scenario-Based Repeated Team Training of Cardiopulmonary Resuscitation in Medical Students
JOURNAL OF MEDICAL INTERNET RESEARCH
2010; 12 (3)
Contemporary learning technologies, such as massively multiplayer virtual worlds (MMVW), create new means for teaching and training. However, knowledge about the effectiveness of such training is incomplete, and there are no data regarding how students experience it. Cardiopulmonary resuscitation (CPR) is a field within medicine in high demand for new and effective training modalities.In addition to finding a feasible way to implement CPR training, our aim was to investigate how a serious game setting in a virtual world using avatars would influence medical students' subjective experiences as well as their retention of knowledge.An MMVW was refined and used in a study to train 12 medical students in CPR in 3-person teams in a repeated fashion 6 months apart. An exit questionnaire solicited reflections over their experiences. As the subjects trained in 4 CPR scenarios, measurements of self-efficacy, concentration, and mental strain were made in addition to measuring knowledge. Engagement modes and coping strategies were also studied. Parametric and nonparametric statistical analyses were carried out according to distribution of the data.The majority of the subjects reported that they had enjoyed the training, had found it to be suitable, and had learned something new, although several asked for more difficult and complex scenarios as well as a richer virtual environment. The mean values for knowledge dropped during the 6 months from 8.0/10 to 6.25/10 (P = .002). Self-efficacy increased from before to after each of the two training sessions, from 5.9/7 to 6.5/7 (P = .01) after the first and from 6.0/7 to 6.7/7 (P = .03) after the second. The mean perceived concentration value increased from 54.2/100 to 66.6/100 (P = .006), and in general the mental strain was found to be low to moderate (mean = 2.6/10).Using scenario-based virtual world team training with avatars to train medical students in multi-person CPR was feasible and showed promising results. Although we found no evidence of stimulated recall of CPR procedures in our test-retest study, the subjects were enthusiastic and reported increased concentration during the training. We also found that subjects' self-efficacy had increased after the training. Despite the need for further studies, these findings imply several possible uses of MMVW technology for future emergency medical training.
View details for DOI 10.2196/jmir.1426
View details for Web of Science ID 000282761500002
View details for PubMedID 20813717
View details for PubMedCentralID PMC2956337
- Training Healthcare Personnel for Mass Casualty Incidents in a Virtual Emergency Department; VED II Pre-hospital and Disaster Medicine 2010; 25 (5): 422-434
Design and Implementation of Rule-based Medical Models: An In Silico Pathophysiological Trauma Model for Hypovolemic Shock
16th Conference on Medicine Meets Virtual Reality
I O S PRESS. 2008: 159–164
Trauma from 'Dirty' Bomb blasts presents complex clinical problems to healthcare providers who must make critical emergency care decisions with incomplete information, usually limited initially only to cursory observations and vital signs. A set of simple, HFSM patho-physiological models of hypovolemic shock based upon blood volume deficits and remedial therapeutic actions has been created for 10 Virtual World scenarios used for training healthcare personnel in the diagnosis and management of 'dirty' bomb victims. Several general rules define the models: * Virtual patients have individual characteristics of gender, age, health status. * An Expanded Organ Injury Scale (EOIS) indicates in descriptive terms the type, severity, and location of the injury. * Traumatic Hemorrhage Classes (THC) determine Blood Volume Deficit. * EOIS/THC Score and Volume Deficit are tightly linked to the Hemorrhage Rate. * Remedial actions include Wound care, Volume Replacement (0.9% saline, packed cells), and a Drug Formulary for Treating Hemorrhagic Shock. The above rules and their logical basis are derived from the literature on emergency medicine (trauma), with modifications for organ injury, and introducing progressive deterioration beyond the body's homeostatic capabilities, into failure of systems and organs, followed by death. The ten unique models and scenarios are designed to run simultaneously in a virtual emergency department to provide training experiences for healthcare personnel with trauma from a 'dirty' bomb blast event.
View details for Web of Science ID 000272668400034
View details for PubMedID 18391278
LAPAROSCOPY SIMULATORS FOR TRAINING BASIC SURGICAL SKILLS, TASKS, AND PROCEDURES
NEZHAT'S OPERATIVE GYNECOLOGIC LAPAROSCOPY AND HYSTEROSCOPY, 3RD EDITION
View details for Web of Science ID 000308328700063
- Simulation for Team Training and Assessment: Case Studies of Online Training with Virtual Worlds World Journal of Surgery; Special Issue 2008; 32 (161): 161-170
- Design, Development and Evaluation of an Online Virtual Emergency Department for Training Trauma Teams. Simulation in Healthcare 2008; 3 (3 Fall): 146-153
Criterion-based training with surgical simulators: proficiency of experienced surgeons.
JSLS : Journal of the Society of Laparoendoscopic Surgeons / Society of Laparoendoscopic Surgeons
2007; 11 (3): 273-302
In our effort to establish criterion-based skills training for surgeons, we assessed the performance of 17 experienced laparoscopic surgeons on basic technical surgical skills recorded electronically in 26 modules selected in 5 commercially available, computer-based simulators.Performance data were derived from selected surgeons randomly assigned to simulator stations, and practicing repetitively during one and one-half day sessions on 5 different simulators. We measured surgeon proficiency defined as efficient, error-free performance and developed proficiency score formulas for each module. Demographic and opinion data were also collected.Surgeons' performance demonstrated a sharp learning curve with the most performance improvement seen in early practice attempts. Median scores and performance levels at the 10th, 25th, 75th, and 90th percentiles are provided for each module. Construct validity was examined for 2 modules by comparing experienced surgeons' performance with that of a convenience sample of less-experienced surgeons.A simple mathematical method for scoring performance is applicable to these simulators. Proficiency levels for training courses can now be specified objectively by residency directors and by professional organizations for different levels of training or post-training assessment of technical performance. But data users should be cautious due to the small sample size in this study and the need for further study into the reliability and validity of the use of surgical simulators as assessment tools.
View details for PubMedID 17931510
Virtual worlds and team training.
2007; 25 (2): 321-336
An important component of all emergency medicine residency programs is managing trauma effectively as a member of an emergency medicine team, but practice on live patients is often impractical and mannequin-based simulators are expensive and require all trainees to be physically present at the same location. This article describes a project to develop and evaluate a computer-based simulator (the Virtual Emergency Department) for distance training in teamwork and leadership in trauma management. The virtual environment provides repeated practice opportunities with life-threatening trauma cases in a safe and reproducible setting.
View details for PubMedID 17574193
Implementing Virtual Worlds for Systematic Training of prehospital CPR in Medical School
IOS PRESS. 2007: 82-+
We report on a study that investigates the relationship between repeated training of teams managing medical emergencies in the Virtual World and affective learning outcomes in a group of 12 medical students. The focus of the training was on individual actions, but also on interaction and behaviour in the team. Current CPR training seems to lack important team training aspects which this type of training is addressing. We found an increase in flow experience and in self efficacy. This type of training could probably be expanded to other groups for a similar purpose because of its easiness to use, adaptability and interactivity.
View details for Web of Science ID 000270613800018
View details for PubMedID 17377239
Avatars Alive! The Integration of Physiology Models and Computer Generated Avatars in a Multiplayer Online Simulation
15th Conference on Medicine Meets Virtual Reality
I O S PRESS. 2007: 256–258
In a mass casualty incident, injured and at-risk patients will pass through a continuum of care from many different providers acting as a team in a clinical environment. As presented at MMVR 14 [Kaufman, et al 2006], formative evaluations have shown that simulation practice is nearly as good as, and in some cases better than, live exercises for stimulating learners to integrate their procedural knowledge in new circumstances through experiential practice. However, to date, multiplayer game technologies have given limited physiological fidelity to their characters, thus limiting the realism and complexity of the scenarios that can be practiced by medical professionals. This paper describes the status of a follow-on program to merge medical and gaming technologies so that computer generated, but human-controlled, avatars used in a simulated, mass casualty training environment will exhibit realistic life signs. This advance introduces a new level of medical fidelity to simulated mass casualty scenarios that can represent thousands of injuries. The program is identifying the critical instructional challenges and related system engineering issues associated with the incorporation of multiple state-of-the-art physiological models into the computer generated synthetic representation of patients. The work is a collaboration between Forterra Systems and the SUMMIT group of Stanford University Medical School, and is sponsored by the US Army Medical Command's Telemedicine and Advanced Technologies Research Center (TATRC).
View details for Web of Science ID 000270613800058
View details for PubMedID 17377279
Virtual Worlds for Teaching the New CPR to High School Students
15th Conference on Medicine Meets Virtual Reality
I O S PRESS. 2007: 515–519
In this study we created a virtual 3D world for learning to manage medical emergencies and evaluated it with 24 high school students in the USA and Sweden. We found that students in both groups felt immersed and found the online simulation easy to use. Scores for flow and self-assessed flow were significantly higher for the RHS group as compared to the HG group (p=.001 and .023 respectively; Mann Whitney U test). Self-efficacy scores for the HG group were significantly higher after training (p=.016 Mann Whitney U test). Males in the RHS group scored significantly higher on flow and self assessed flow than females (p=.006 and p=.023 respectively; Mann Whitney U test). This study demonstrates the potential value of using MMOS for learning to respond to medical emergencies.
View details for Web of Science ID 000270613800119
View details for PubMedID 17377340
Virtual patient model for multi-person virtual medical environments.
AMIA ... Annual Symposium proceedings / AMIA Symposium. AMIA Symposium
We describe the architecture of a virtual patient model, the Virtual ED Patient, for scenarios in emergency medicine. The model is rule-based, and uses four vital signs as a representation of its state. The model is used in a multi-person learning environment based on online gaming technology. The efficacy of the model and the Virtual ED learning environment is evaluated in a study where advanced medical students and first year residents manage six trauma cases. Pre and post-test performance results show significant learning, with results comparable to those obtained in human manikin simulators. Some future directions for development of the model are also presented.
View details for PubMedID 18693822
Comparison of training on two laparoscopic simulators and assessment of skills transfer to surgical performance
JOURNAL OF THE AMERICAN COLLEGE OF SURGEONS
2005; 200 (4): 546-551
Several studies have investigated the transfer of surgical trainees' skills acquired on surgical simulators to the operating room setting. The purpose of this study was to compare the effectiveness of two laparoscopic surgery simulators by assessing the transfer of skills learned on simulators to closely matched surgical tasks in the animal laboratory.In this post-test-only Control group study design, 46 surgically naive medical student volunteers were randomly assigned to one of three groups: Tower Trainer group (n = 16), LapSim group (n = 17), and Control group (n = 13). Outcomes measures included both time and accuracy scores on three laparoscopic tasks (Task 1: Grasp and Place; Task 2: Run the Bowel; Task 3: Clip and Cut) performed on live anesthetized pigs, and a global rating of overall performance as judged by four experienced surgeons.The Tower Trainer group performed significantly better than the Control group on 1 of 7 outcomes measures-Task 3: Time (p < 0.032), although the LapSim group performed significantly better than the Control group on 2 of 7 measures-Task 3: Time (p < 0.008) and Global score (p < 0.005). In comparing the two simulators, the LapSim group performed significantly better than the Tower Trainer group on 3 of 7 outcomes measures-Task 2: Time (p < 0.032), Task 2: Accuracy (p < 0.030) and Global score (p < 0.005), although the Tower Trainer group did not perform significantly better than the LapSim group on any measure.This study demonstrated that naive subjects trained on a virtual-reality part-task trainer performed better on live surgical tasks in a porcine model as compared with those trained with a traditional box trainer. These findings could aid in selection of appropriate training methodologies.
View details for DOI 10.1016/j.jamcollsurg.2004.11.011
View details for PubMedID 15804468
The fundamental manipulations of surgery: A structural vocabulary for designing surgical curricula and simulators
JOURNAL OF THE AMERICAN ASSOCIATION OF GYNECOLOGIC LAPAROSCOPISTS
2004; 11 (4): 450-456
A structured vocabulary is proposed for supporting the design and development of advanced surgical simulators. Nine fundamental surgical instrument-tissue actions or manipulations are defined and common synonyms provided. The vocabulary focuses on "target skills" that are familiar to surgeons, in comparison with "enabling skills" from the lexicon of instructional designers and psychometricians. The adoption of this vocabulary can facilitate communication among surgeons and bioengineers developing "high-fidelity" surgical simulators.
View details for Web of Science ID 000225326500004
View details for PubMedID 15701184
Initial evaluation of a shoulder arthroscopy simulator: Establishing construct validity
JOURNAL OF SHOULDER AND ELBOW SURGERY
2004; 13 (2): 196-205
Formal evaluation of surgical simulators is essential before their introduction into training programs. We report our assessment of the Mentice Corp Procedicus shoulder arthroscopy simulator. This study tests the hypothesis of construct validity that experienced surgeons will score better on the simulator than individuals with minimal to no experience with the technique. Thirty-five subjects were stratified into three groups (novice, intermediate, and expert) based on their past 5 years' experience with shoulder arthroscopies. Each subject had an identical session on the simulator and completed anatomic identification, hook manipulations, and scope navigation exercises. We found statistically significant differences among the three groups in hook manipulation and scope navigation exercises, with the expert group performing the exercises more quickly (P =.013) and more accurately (P =.002) than the other two groups. No statistically significant differences were found among the groups in the identification of anatomic landmarks. Experts rated the simulator as an effective teaching tool, giving it a mean score of 4.22 and 4.44 (maximum, 5) for teaching instrument control and triangulation, respectively.
View details for DOI 10.1016/j.jse.2003.12.009
View details for PubMedID 14997099
- LUCY,v2.6: A 3D pelvic model for surgical simulation. Journal of the Amercian Association of Gynecologic Laparoscopists 2004; 11 (No. 3): 326-331
Simulated medical learning environments on the Internet
JOURNAL OF THE AMERICAN MEDICAL INFORMATICS ASSOCIATION
2002; 9 (5): 437-447
Learning anatomy and surgical procedures requires both a conceptual understanding of three-dimensional anatomy and a hands-on manipulation of tools and tissue. Such virtual resources are not available widely, are expensive, and may be culturally disallowed. Simulation technology, using high-performance computers and graphics, permits realistic real-time display of anatomy. Haptics technology supports the ability to probe and feel this virtual anatomy through the use of virtual tools. The Internet permits world-wide access to resources. We have brought together high-performance servers and high-bandwidth communication using the Next Generation Internet and complex bimanual haptics to simulate a tool-based learning environment for wide use. This article presents the technologic basis of this environment and some evaluation of its use in the gross anatomy course at Stanford University.
View details for DOI 10.1197/jamia.M1089
View details for Web of Science ID 000178205000002
View details for PubMedID 12223496
View details for PubMedCentralID PMC346631
Visual representations of physical abilities: Reverse haptic technology?
10th Annual Medicine Meets Virtual Reality Conference
I O S PRESS. 2002: 380–381
View details for Web of Science ID 000176591900068
View details for PubMedID 15458118
The effect of simulator use on learning and self-assessment: The case of Stanford University's E-Pelvis simulator
Conference on Medicine Meets Virtual Reality 2001
I O S PRESS. 2001: 396–400
View details for Web of Science ID 000169103300074
View details for PubMedID 11317776
Simulated learning environments in anatomy and surgery delivered via the Next Generation Internet
10th World Congress on Medical Informatics (MEDINFO 2001)
I O S PRESS. 2001: 1014–1018
The Next Generation Internet (NGI) will provide high bandwidth, guaranteed Quality of Service, collaboration and security, features that are not available in today's Internet. Applications that take advantage of these features will need to build them into their pedagogic requirements. We present the Anatomy Workbench and the Surgery Workbench, two applications that require most of these features of the NGI. We used pedagogic need and NGI features to define a set of applications that would be difficult to operate on the current Internet, and that would require the features of the NGI. These applications require rich graphics and visualization, and extensive haptic interaction with biomechanical models that represent bony and soft tissue. We are in the process of implementing these applications, and some examples are presented here. An additional feature that we required was that the applications be scalable such that they could run on either on a low-end desktop device with minimal manipulation tools or on a fully outfitted high-end graphic computer with a realistic set of surgical tools. The Anatomy and Surgery Workbenches will be used to test the features of the NGI, and to show the importance of these new features for innovative educational applications.
View details for Web of Science ID 000172901700272
View details for PubMedID 11604884
- "Surgical Simulator for Diagnostic and Operative Hysteroscopy", in Proc.15th Annual Int'l Computer- Assisted Radiology & Surgery (CARS) H. Lemke ed:) Elsevier Science Press, Amsterdam, The Netherlands 2001
Virtual body structures: a 3D structure development tool from visible human data.
Studies in health technology and informatics
2000; 70: 323-326
Understanding the visiospatial aspects of anatomic structures is one of the most important aspects of studying gross anatomy. In this paper we are describing a tool that self-constructs 3D virtual body structures (VBS) 'right in-front-of your-eyes'. Furthermore, manipulation capabilities, such as translucent visualization, interactive rotation, translation, and scaling, incorporated into VBS facilitate fundamental learning experience that leads one to 'build 3D models in the mind', providing a validation of computer-assisted individual learning. Creating 3-D virtual body structures from actual human data has long been a dream of many computer scientists and Medical doctors. Now, with the advances in computer hardware and software technologies, our Virtual Body Structure technique, and the Visible Human project, that dream is becoming a reality.
View details for PubMedID 10977564
Visual language to interface users of educational surgical simulators for fundamental surgical manipulations
14th International Congress and Exhibition on Computer Assisted Radiology and Surgery (CARS 2000)
ELSEVIER SCIENCE BV. 2000: 29–34
View details for Web of Science ID 000165685600005
G2H--graphics-to-haptic virtual environment development tool for PC's.
Studies in health technology and informatics
2000; 70: 1-3
For surgical training and preparations, the existing surgical virtual environments have shown great improvement. However, these improvements are more in the visual aspect. The incorporation of haptics into virtual reality base surgical simulations would enhance the sense of realism greatly. To aid in the development of the haptic surgical virtual environment we have created a graphics to haptic, G2H, virtual environment developer tool. G2H transforms graphical virtual environments (created or imported) to haptic virtual environments without programming. The G2H capability has been demonstrated using the complex 3D pelvic model of Lucy 2.0, the Stanford Visible Female. The pelvis was made haptic using G2H without any further programming effort.
View details for PubMedID 10977518
Human issues and medical economics of endometriosis - Three- vs. six-month GnRH-agonist therapy
JOURNAL OF REPRODUCTIVE MEDICINE
1998; 43 (3): 299-308
To project the efficacy and economic consequence of short-term intranasal gonadotropin-releasing hormone agonist (GnRH-a) for diagnosis of and therapy for endometriosis.Multicenter, placebo-controlled clinical trials of GnRH-a comparing three vs. six months of treatment, three months of retreatment and three months of postoperative treatment for the symptoms and signs of laparoscopically diagnosed endometriosis.The reduction in symptoms and signs of endometriosis was similar at the end of three months to the relief at six months. Retreatment was as effective as initial treatment, and the return of symptoms after laparoscopic surgery plus postoperative treatment for three months was delayed by approximately 18 months as compared to surgery alone. The projected charges for the surgical approaches (laparoscopy or minilaparoscopy) to diagnosis and therapy were 50-60% greater than those for the medical approach.GnRH-a administration for three months could be a cost-effective approach to the presumptive diagnosis and treatment of endometriosis among women with chronic pelvic pain.
View details for Web of Science ID 000073086200010
View details for PubMedID 9564665
Formative design of a virtual learning environment
Conference on Medicine Meets Virtual Reality 6
I O S PRESS. 1998: 392–398
Current technology for 3D visualization, modeling and interaction allows the construction of attractive virtual environments for study of anatomy, surgery and other biomedical fields. The formative methodology for designing such environments is uncharted, but necessary before committing to large scale development. We present one such methodology undertaken during the design of a learning environment for biology for high school and middle school students. We expect to extend this design methodology to the development of environments for the teaching of medical subjects.
View details for Web of Science ID 000073689000073
View details for PubMedID 10180582
The design of Frog Island: A VRML world for biology
Virtual Worlds and Simulation Conference (VWSIM 98) at the 1998 Western MultiConference
SOC MODELING SIMULATION INT-SCS. 1998: 31–36
View details for Web of Science ID 000082157900008
Information Frames: A new multimedia approach to web-based learning of biology and medicine
Conference on Medicine Meets Virtual Reality 6
I O S PRESS. 1998: 370–372
Presentation of content in hyperlinked multimedia formats for teaching has failed using the computer's power of navigation through rich visual and auditory information. We have developed "Information Frames", an authoring tool in hypertext markup language (html) format, that allows easy utilization by technology-challenged teachers and professors, and attracts students because of interactive, design-based learning. An Information Frame contains a definition, explanation and illustration of a single concept. Topics are provided with hyperlinks to other Information Frames having related concepts that may provide prerequisite knowledge, or may raise the concept to a more integrative level. A graphical view of the linked-Information Frames presents a Concept Map of the overall topic.
View details for Web of Science ID 000073689000065
View details for PubMedID 10180575
Therapeutic efficacy and bone mineral density response during and following a three-month re-treatment of endometriosis with nafarelin (Synarel)
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
1997; 177 (6): 1413-1418
Our goal was to determine the effects of a repeated course of the gonadotropin-releasing hormone agonist nafarelin on symptoms and signs of endometriosis and lumbar and distal radius bone mineral density.Forty-five women previously treated for 6 months with nafarelin, who had recurrent symptoms and signs of endometriosis, received 400 mcg/day of nafarelin intranasally for 3 months. Efficacy was evaluated by changes in severity of symptoms and signs. Lumbar bone mineral density was measured by dual-energy x-ray absorptiometry and distal radius bone mineral density by single-photon absorptiometry. Bone mineral density was also measured in 10 control volunteers.Repeated 3-month treatment significantly alleviated recurrent symptoms and signs of endometriosis. Lumbar bone mineral density decreased significantly by a mean of 2% at the end of treatment; this loss was restored within 3 to 6 months after treatment completion. No bone mineral density decline occurred in the radius. Bone mineral density changes in the control group were statistically insignificant.A repeated 3-month course of nafarelin treatment significantly relieved recurrent endometriotic symptoms and signs without sustained loss of bone mineral density.
View details for Web of Science ID 000071254900028
View details for PubMedID 9423744
Use of nafarelin versus placebo after reductive laparoscopic surgery for endometriosis
52nd Annual Meeting of the American-Society-for-Reproductive-Medicine
ELSEVIER SCIENCE INC. 1997: 860–64
To evaluate the efficacy of the GnRH agonist (GnRH-a) nafarelin compared with placebo administered for 6 months after reductive laparoscopic surgery for symptomatic endometriosis.Randomized, prospective, placebo-controlled, multicenter clinical trial.Thirteen clinics including private practice and university centers.One hundred nine women aged 18-47 with laparoscopically proven endometriosis and pelvic pain who had undergone reductive laparoscopic surgery for endometriosis.Patients were randomized to receive either the GnRH-a nafarelin (200 micrograms twice daily) or placebo for 6 months.Time to initiation of alternative treatment (the length of time from beginning study medication to receiving alternative therapy or to deeming that the study drug was ineffective) and patient-reported and physician-assessed pelvic pain scores.The median time to initiation of alternative treatment was > 24 months in the nafarelin group versus 11.7 months in the placebo group. Fifteen (31%) of 49 nafarelin-treated patients required alternative therapy, compared with 25 (57%) of 44 placebo-treated patients. The patients' pelvic pain scores dropped significantly in the nafarelin and placebo groups after 6 months of treatment. Physician summary ratings showed significant improvement in the nafarelin group and no significant changes in the placebo group after 6 months of treatment.Compared with placebo, nafarelin administered after reductive laparoscopic surgery for endometriosis significantly delays the return of endometriosis symptoms requiring further treatment.
View details for Web of Science ID A1997YH05300018
View details for PubMedID 9389816
Acquisition of Eye-hand Coordination Skills for Videoendoscopic Surgery
The Journal of the American Association of Gynecologic Laparoscopists
1994; 1 (4, Part 2): S37
Evaluation of eye-hand coordination skills in relation to experiential human factors may lead to improved instruction for videoendoscopic surgical skills acquisition. Twenty-nine subjects (medical students or residents in surgical specialties) volunteered to perform three exercises of increasing complexity in an "inanimate" trainer system that simulated the eye-hand coordination tasks inherent in a laboratory videoendoscopic surgical environment. Fourteen subjects participated in a biweekly practice program of 4 weeks duration using an inanimate trainer. Fifteen subjects had no practice on the laparoscopic trainer during the 4 weeks. Both groups were tested after demonstration on three exercises at the beginning and end of a 4 week period and all performed the procedures in solitude. Both groups of subjects increased performance levels (time and accuracy) over the four weeks, but improvement was significantly greater for the practicing subjects. After eight sessions, convergence of performance levels was observed, but plateauing of performance levels was not evident, even with the simple paradigms evaluated. To investigate what factors contribute to learning, subjects were assessed with respect to their surgical experiences, personality, and self-evaluated motor skills. Subjects with prior endoscopic surgical experience, interest in mechanical activities (as measured by the Strong Interest Inventory), or regular engagement in video game play tended to be more skillful initially, but demonstrated less improvement in performance levels after practice than subjects who had lower levels of experience, interest, or video game play. Manual dexterity (as measured by the Purdue Pegboard Manual Dexterity Test) was positively related to the degree of observed improvement. We conclude that "inanimate" videoendoscopic paradigms offer relatively inexpensive and useful training exercises for acquiring basic eye-hand coordination skills. Relevance for animate laboratory skills requirements are probable but can only be inferred. Subjects with manual dexterity skills used in video games may perform better initially in the inanimate videoendoscopic situation but this advantage is shortlived.
View details for PubMedID 9073766
INTERLEUKIN-1 TYPE-I RECEPTOR MESSENGER-RIBONUCLEIC-ACID EXPRESSION IN HUMAN ENDOMETRIUM THROUGHOUT THE MENSTRUAL-CYCLE
FERTILITY AND STERILITY
1993; 59 (4): 791-796
To investigate the messenger ribonucleic acid (mRNA) expression of interleukin-1 (IL-1) type I receptor in the endometrial tissue of normal patients during the menstrual cycle.Prospective longitudinal study.Department of Obstetrics and Gynecology, Stanford University Medical Center, Stanford, California.Twenty fertile women between 19 and 41 years of age underwent hysterectomy for benign reasons (n = 9) and laparoscopy for tubal ligation (n = 11). In all cases, endometriosis was not visualized.Endometrial biopsy using the Novak curette was obtained at the time of surgery.Total RNA extracted from unfractioned endometrial tissue was analyzed on Northern blots by using specific complementary deoxyribonucleic acid probes.We found IL-1 type I receptor mRNA expression in endometrial tissue throughout the entire menstrual cycle. However, IL-1 type I receptor mRNA levels were significantly higher during both early and late luteal phases than follicular and midluteal phases.Our results demonstrate the presence of the IL-1 system in the human endometrium and that the receptor is regulated throughout the menstrual cycle with a 4.1-fold increased expression of the IL-1 receptor gene in the early luteal phase compared with preovulatory endometrium.
View details for PubMedID 8458498
NONINVASIVE DETERMINATION OF ULNAR STIFFNESS FROM MECHANICAL RESPONSE - INVIVO COMPARISON OF STIFFNESS AND BONE-MINERAL CONTENT IN HUMANS
JOURNAL OF BIOMECHANICAL ENGINEERING-TRANSACTIONS OF THE ASME
1988; 110 (2): 87-96
An approach referred to as Mechanical Response Tissue Analysis (MRTA) has been developed for the noninvasive determination of mechanical properties of the constituents of the intact limb. Of specific interest in the present study is the bending stiffness of the ulna. The point mechanical impedance properties in the low frequency regime, between 60 and 1,600 Hz are used. The procedure requires a proper design of the probe for good contact of the skin at midshaft and proper support of the proximal and distal ends of the forearm to obtain an approximation to "simple support" of the ulna. A seven-parameter model for the mechanical response is then valid, which includes the first mode of anterior-posterior beam bending of the ulna, the damping and spring effect of the soft tissue between probe and bone, and the damping of musculature. A dynamic analyzer (HP3562A) provides in seconds the impedance curve and the pole-zero curve fit. The physical parameters are obtained from a closed-form solution in terms of the curve-fit parameters. The procedure is automated and is robust and analytically reliable at about the five percent level. Some 80 human subjects have been evaluated by this mechanical response system and by the Norland single photon absorptiometer, providing for the first time in vivo, a comparison of elastic bending stiffness (ulna) and bone mineral content (radius). Three functional parameters of potential clinical value are the cross-sectional bending stiffness EI, the axial load capability Pcr (Euler buckling load) and the bone "sufficiency" S, defined as the ratio of Pcr to body weight. The correlation between EI and bone mineral (r = 0.81) is only slightly less than previous in vitro results with both measurements on the same bone (r = 0.89). When sufficiency is taken into consideration, the correlation of Pcr and bone mineral content is improved (r = 0.89). An implication is that "quality" of bone is a factor which is not indicated by bone mineral content but which is indicated by stiffness. Bone mineral is necessary for proper stiffness but not sufficient. Therefore mechanical measurement should provide a new dimension to be used toward a better understanding of the factors related to bone health and disease.
View details for Web of Science ID A1988N541000001
View details for PubMedID 3379938
MIDGESTATIONAL EXPOSURE OF PREGNANT BALB/C MICE TO MAGNETIC-RESONANCE IMAGING CONDITIONS
MAGNETIC RESONANCE IMAGING
1988; 6 (3): 305-313
The potential for producing reproductive toxicity or teratogenesis in mice by exposure to magnetic resonance imaging (MRI) conditions was evaluated by means of reproduction studies and the homeotic shift test. Embryos from pregnant BALB/c mice were exposed in vivo for 16 hours beginning on gestation day 8.75 to MRI conditions of modest field strength (static field, 0.35 tesla (T); pulsed gradients, 2.3 X 10(-4) T/cm for 2.5 to 10 msec; and radio frequency, 15 MHz at an average of 61.2 mW). Unexposed, sham-exposed (both MRI and X-ray) and X-irradiated (0.5 Gy) animals were the control groups. Neither placental resorptions nor stillbirths were increased by MRI. Fetal weight at birth and crown-rump length were proportional; however, crown-rump length was significantly less (p less than 0.001) in the MRI-exposed fetuses (respective mean values for MRI-exposed fetuses were 21.8 +/- 0.2 mm compared to 22.4 +/- 0.1 for sham-exposed fetuses). Both crown-rump length and fetal weight were significantly reduced after X-irradiation. The percentage of homeotic skeletal shifts was scored for each of eight anatomic sites. Only X-radiation produced significant increases in skeletal shifts. Prolonged midgestational exposure of mice to MRI conditions currently used for human clinical imaging, therefore, failed to reveal overt embryotoxicity (resorptions, stillbirths) or teratogenicity (homeotic shifts), consistent with the non-ionizing properties of MR. However, the slight but significant reduction in fetal crown-rump length after prolonged exposure justifies further study of higher MRI energy levels and consideration of other endpoints for establishing with greater confidence the safety of MRI during pregnancy.
View details for Web of Science ID A1988N803000013
View details for PubMedID 2899832
SUCCESSFUL TREATMENT OF PULMONARY LYMPHANGIOMYOMATOSIS WITH OOPHORECTOMY AND PROGESTERONE
AMERICAN REVIEW OF RESPIRATORY DISEASE
1985; 132 (4): 916-921
A 35-yr-old woman, with profound dyspnea at rest and failure to thrive, asked to be evaluated at Stanford Medical Center. She requested a second opinion after entering death counseling in another institution because of an unrelenting, deteriorating course caused by pulmonary lymphangiomyomatosis. Her recurring right chylous pleural effusion was drained by chest tube, a LaVeen shunt was placed to decompress her severe chylous ascites, an oophorectomy was performed, large dose progesterone (medroxyprogesterone acetate) was initiated intramuscularly, and during her hospitalization she was fed by total parenteral nutrition. She was discharged mildly improved after 2 months. Now, 3 yr later, her pulmonary function tests and chest radiographs are improved, and she walks 2 miles per day and teaches school full time. Extensive hormonal analysis did not reveal an endocrinologic abnormality that could explain the pathophysiology of her disease. However, the patient had multiple human chorionic gonadotropin injections before becoming ill, as have a number of other patients who have developed this disease. This report is an example of successful treatment of severe pulmonary lymphangiomyomatosis.
View details for Web of Science ID A1985ARY4800038
View details for PubMedID 2932045
PLACENTAL STEROID SULFATASE DEFICIENCY - ASSOCIATION WITH ARYLSULFATASE-A DEFICIENCY
AMERICAN JOURNAL OF HUMAN GENETICS
1982; 34 (3): 434-443
A family with an obstetric history consistent with placental sulfatase deficiency has X-linked ichthyosis. Steroid sulfatase deficiency was confirmed in placenta, leukocytes, and cultured skin fibroblasts of affected males; arylsulfatase A diminution was also observed in these tissues of both affected males and 2 generations of related females. No symptoms of metachromatic leukodystrophy are present in any family members. In this family, placental sulfatase deficiency, and arylsulfatase A pseudodeficiency are nonallelic.
View details for Web of Science ID A1982NR13300008
View details for PubMedID 6123259
A PRACTICAL APPROACH TO THE PATIENT WITH DYSMENORRHEA
JOURNAL OF REPRODUCTIVE MEDICINE
1980; 25 (4): 236-242
Pelvic pain associated with the menses may be a result of physiologic problems, premenstrual tension syndrome, primary dysmenorrhea or secondary dysmenorrhea. All of these conditions may be caused by both physiologic and psychologic factors. An accurate diagnosis requies a complete history and physical examination and astute assessment of predisposing or aggravating conditions. Diagnosis has been improved through the use of laparoscopy, hysteroscopy, hysterosalpingography and dilatation and curettage. Treatment has been revolutionized with the use of oral contraceptives and prostaglandin synthesis inhibitors. These diagnostic and therapeutic advances now enable the sympathetic physician to effectively evaluate and treat almost all patients with menstrually related pelvic pain. When all of these approaches fail, the physician should consider psychiatric consultation or referral to pain clinic or gynecologist with special interest in this field.
View details for Web of Science ID A1980KQ84200009
View details for PubMedID 7001023
DIFFERENTIATION AND REGULATION OF PERIPHERAL ANDROGEN METABOLISM IN RATS AND RHESUS-MONKEYS
AMERICAN JOURNAL OF OBSTETRICS AND GYNECOLOGY
1979; 135 (7): 974-983
The sex-unique metabolic network for steroids is induced neonatally in male rats. The metabolic clearance rates (MCR) of dehydroepiandrosterone and testosterone are similar for both sexes of rats despite quantitatively significant sex differences in individual enzyme activities of adults; neonatally androgenized females had a 2-to 3-fold increase in MCR but cyproterone had no effect. The MCRT and MCRDHA of castrated adult male rhesus monkeys are the same as those of normal males; the MCRDHA is 4-fold greater. Testosterone treatment suppressed the MCRDHA of the castrated groups but estradiol treatment did not. The sex-steroid binding protein (SBP) levels were lower in males than females, and these values were reduced by testosterone. Estrogen suppressed the higher SBP values of females. The sex-steroid milieu of adult rhesus monkeys regulates SBP binding capacity and the enzyme activities of skin measured in vitro. Prenatal testosterone does not exert a crucial role in presetting the peripheral metabolic network in rhesus monkeys.
View details for Web of Science ID A1979HX07700017
View details for PubMedID 159625