Search PubMed⌕ Search

SEARCH · Search PubMed

Results for “Surgical simulation”

Search indexed PubMed citations on genomics, clinical trials, systematic reviews and public health. Explore titles, authors and supplied subject terms, then open the PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1998

Volumetric object modeling for surgical simulation.

Surgical simulation has many applications in medical education, surgical training, surgical planning and intra-operative assistance. However, extending current surface-based computer graphics methods to model phenomena such as the deformation, cutting, tearing or repairing of soft tissues poses significant challenges for real-time interactions. This paper discusses the use of volumetric methods for modeling complex anatomy and tissue interactions. New techniques are introduced that use volumetric methods for modeling soft-tissue deformation and tissue cutting at interactive rates. An initial prototype for simulating arthroscopic knee surgery is described which uses volumetric models of the knee derived from 3-D magnetic resonance imaging, visual feedback via real-time volume and polygon rendering, and haptic feedback provided by a force-feedback device.

Arthroscopy↗
PubMed2002

Visualization and simulation techniques for surgical simulators using actual patient's data.

Because of the increasing complexity of surgical interventions research in surgical simulation became more and more important over the last years. However, the simulation of tissue deformation is still a challenging problem, mainly due to the short response times that are required for real-time interaction. The demands to hard and software are even larger if not only the modeled human anatomy is used but the anatomy of actual patients. This is required if the surgical simulator should be used as training medium for expert surgeons rather than students. In this article, suitable visualization and simulation methods for surgical simulation utilizing actual patient's datasets are described. Therefore, the advantages and disadvantages of direct and indirect volume rendering for the visualization are discussed and a neuro-fuzzy system is described, which can be used for the simulation of interactive tissue deformations. The neuro-fuzzy system makes it possible to define the deformation behavior based on a linguistic description of the tissue characteristics or to learn the dynamics by using measured data of real tissue. Furthermore, a simulator for minimally-invasive neurosurgical interventions is presented that utilizes the described visualization and simulation methods. The structure of the simulator is described in detail and the results of a system evaluation by an experienced neurosurgeon--a quantitative comparison between different methods of virtual endoscopy as well as a comparison between real brain images and virtual endoscopies--are given. The evaluation proved that the simulator provides a higher realism of the visualization and simulation then other currently available simulators.

Artificial Intelligence↗
PubMed2005

Simulating surgical incisions without polygon subdivision.

Modeling cuts, bleeding and the insertion of surgical instruments are essential in surgical simulation. Both visual and haptic cues are important. Current methods to simulate cuts change the topology of the model, invalidating pre-processing schemes or increasing the model's complexity. Bleeding is frequently modeled by particle systems or computational fluid dynamics. Both can be computationally expensive. Surgical instrument insertion, such as intubation, can require complex haptic models. In this paper, we describe methods for simulating surgical incisions that do not require such computational complexity, yet preserve the visual and tactile appearance necessary for realistic simulation.

Blood Loss, Surgical↗
PubMed1989

Evaluation of copovithane as a nonspecific immunomodulator in surgically simulated sepsis.

Copovithane (CPV), a synthetic polymer, has been shown to have antitumor activity and also to reduce mortality in experimental murine peritonitis. The purpose of this study was to compare CPV with muramyl dipeptide (MDP), an immunomodulator of proven efficacy in simulated surgical infection. Six groups of CBA/J mice were compared; they received intramuscular injections of normal saline (controls), MDP (100 micrograms), or CPV (100, 200, and 400 mg/kg) 24 h prior to bacterial challenge. The challenge consisted of a Klebsiella-impregnated thigh suture. The first experiment assessed survival after bacterial challenge. The MDP and the CPV groups both had median survival times of 3 days, significantly longer than the control group (1 day, p less than .05). In the second experiment, animals were sacrificed at 6, 24, and 48 h following bacterial challenge, and blood and infected muscle were taken for quantitative bacteriology. At 6 h, there was no difference between groups. Both the MDP and CPV groups had significantly (p less than .05) lower blood bacterial counts than the control group at 24 and 48 h. Both the MDP and CVP groups had significantly lower local bacterial recovery than controls at 48 h (p less than .05), and local bacterial recovery of the MDP group was significantly lower than the control group at 24 h (p less than .05). CPV improved survival and reduced local and systemic bacterial recovery compared with controls. Although the effect of CPV was similar to MDP in this model, it consistently was of lower magnitude and had a narrow dose range.

Acetylmuramyl-Alanyl-Isoglutamine↗
PubMed2005

Assessment of simulated surgical skills in parabolic microgravity.

BACKGROUND: During spaceflight crew health is paramount in the success of flight missions. The delivery of healthcare during flight requires crew readiness for medical and surgical response. METHODS: There were 20 participants who were evaluated for accurate performance of 4 basic laparoscopic surgical skills (clip applying, cutting, grasping, and suturing) during parabolic weightlessness using an inanimate workstation aboard the NASA KC-135 aircraft. RESULTS: Data indicate that motor skill performance decreased within the parabolic microgravity flight environment. Performance in parabolic microgravity flight included futile effort with an increase in number of tasks attempted and a decrease in tasks completed successfully. CONCLUSIONS: There is a decreased frequency of accurate task completion in parabolic microgravity flight, but it is not an obstacle to implementation of effective training for providing in-flight medical care. The data reveal that individuals perform basic laparoscopic surgical simulation with greater effort in microgravity following simulation training.

Aerospace Medicine↗
PubMed2006

Evaluation methods of a middleware for networked surgical simulations.

Distributed surgical virtual environments are desirable since they substantially extend the accessibility of computational resources by network communication. However, network conditions critically affects the quality of a networked surgical simulation in terms of bandwidth limit, delays, and packet losses, etc. A solution to this problem is to introduce a middleware between the simulation application and the network so that it can take actions to enhance the user-perceived simulation performance. To comprehensively assess the effectiveness of such a middleware, we propose several evaluation methods in this paper, i.e., semi-automatic evaluation, middleware overhead measurement, and usability test.

Computer Simulation↗
PubMed1995

Biomechanics for preoperative planning and surgical simulations in orthopaedics.

Surgical simulations are particularly appropriate for the large volume and expense of joint replacement procedures in orthopaedics. A first generation surgical simulator has been developed to model the implantation procedure for cementless acetabular and femoral components in total hip replacement surgery. The simulator is based upon finite element analysis and predicts the early postoperative mechanical environment that results from a proposed surgery. Since the short- and long-term clinical success of cementless hip replacement components is very dependent upon the initial mechanics of the bone-implant system, such simulations can help orthopaedic surgeons to develop better preoperative plans.

Biomechanical Phenomena↗
PubMed1998

A PC-based surgical simulator for laparoscopic surgery.

Surgical simulators for minimally invasive surgery have been developing in the 1990s. Most of them use high-end UNIX workstations for real-time simulation of complex human organ models. Only few of them have input devices with force feedback. Recently, personal computer technologies have made real-time display of relatively complex models feasible. We are developing an Intel-based laparoscopic surgical simulator that provides near real-time intuitive interaction between the trainee and simulated models of human organs. The surgical simulator has a prototypical scenario of cholecystectomic surgery. It can interactively simulate the deformation and cutting of cystic duct and vein. In addition, a set of input devices with force feedback has been designed and tested to imitate the manipulation of surgical instruments. The input device has five degrees of freedom and three of them are driven by DC motors to produce force feedback.

Cholecystectomy↗
PubMed1999

Dynamic volume texture mapping and model deformation for visually realistic surgical simulation.

For computer assisted surgical simulation to be effective, objects in the simulated environment should respond to the user's actions dynamically with correct visual information. This includes dragging and cutting that cause changes in geometry, topology and appearance. Geometric object representation can be manipulated intuitively in real-time but does not preserve interior information. Volumetric data representation, on the other hand, preserves volume content but direct manipulation is compute-intensive. 3-D texture mapping provides an alternative in representing volumetric information. We present a surgical simulation system based on geometric models that allows interactive deformation and incision of objects while displaying correct volumetric information corresponding to these changes. This is accomplished by dynamic 3-D texture mapping. This method can be applied to anatomical data and patient CT and MR images to facilitate data/patient specific surgical simulations.

Algorithms↗
PubMed2006

A software framework for surgical simulation virtual environments.

Surgical simulators are an integration of many models, capabilities, and functions. Development of a working simulator requires the flexibility to integrate various software models, to support interoperability, and facilitate performance optimizations. An object oriented framework is devised to support multithreaded integration of simulation, deformation, and interaction. A demonstration application has been implemented in Java, leveraging the features that are built into the language including multithreading, synchronization, and serialization. Future work includes expanding the capabilities of the framework with a broader range of model and interactive capabilities.

Computer Simulation↗
PubMed2006

Early exposure to haptic feedback enhances performance in surgical simulator training: a prospective randomized crossover study in surgical residents.

BACKGROUND: In the literature of skill acquisition and transfer of skills, it often is assumed that the rate of skill acquisition depends on what has been learned in a similar context (i.e., surgical simulators providing haptic feedback). This study aimed to analyze whether the addition of haptic feedback early in the training phase for image-guided surgical simulation improves performance. METHODS: A randomized crossover study design was used, in which 38 surgical residents were randomized to begin a 2-h simulator training session with either haptic or nonhaptic training followed by crossover after 1 h. The graphic context was a virtual upper abdomen. The residents performed two diathermy tasks. Two validated tests were used to control for differences in visual-spatial ability: the BasIQ general cognitive ability test and Mental Rotation Test A (MRT-A). RESULTS: After 2 h of training, the group that had started with haptic feedback performed the two diathermy tasks significantly better (p < 0.05, unpaired t-test). Only the group that had started with haptic training significantly improved during the last 1-h session (p < 0.01, paired t-test). CONCLUSION: The findings indicate that haptic feedback could be important in the early training phase of skill acquisition in image-guided surgical simulator training.

Abdomen↗
PubMed2005

Fuzzy classification: towards evaluating performance on a surgical simulator.

Computer-based surgical simulators such as the MIST-VR are able to provide scoring metrics such as time taken to complete a task, number of errors made, and economy of movement. Using MIST-VR's basic metrics, we explored the possibility of classifying skill levels using fuzzy logic. Our objective was to create a fuzzy classifier capable of classifying the performance of a subject training on a surgical simulator into 1 of 3 categories: Novice, Intermediate, and Expert. To accomplish this, we needed to establish a baseline skill level for each category. We had four laparoscopic surgeons, four surgical assistants/residents and four non-surgical staff/students with no laparoscopic experience perform two basic tasks on the simulator involving the placement of a ball into a box. We have found, through this preliminary study, that the results were inconclusive. We suspected a number of issues such as the size of our sample space used to train our classifier, and the difficulty of the chosen tasks adversely affected our results.

Canada↗
PubMed2000

Input and output for surgical simulation: devices to measure tissue properties in vivo and a haptic interface for laparoscopy simulators.

Current efforts in surgical simulation very often focus on creating realistic graphical feedback, but neglect some or all tactile and force (haptic) feedback that a surgeon would normally receive. Simulations that do include haptic feedback do not typically use real tissue compliance properties, favoring estimates and user feedback to determine realism. When tissue compliance data are used, there are virtually no in vivo property measurements to draw upon. Together with the Center for Innovative Minimally Invasive Therapy at the Massachusetts General Hospital, the Haptics Group is developing tools to introduce more comprehensive haptic feedback in laparoscopy simulators and to provide biological tissue material property data for our software simulation. The platform for providing haptic feedback is a PHANToM Haptic Interface, produced by SensAble Technologies, Inc. Our devices supplement the PHANToM to provide for grasping and optionally, for the roll axis of the tool. Together with feedback from the PHANToM, which provides the pitch, yaw and thrust axes of a typical laparoscopy tool, we can recreate all of the haptic sensations experienced during laparoscopy. The devices integrate real laparoscopy toolhandles and a compliant torso model to complete the set of visual and tactile sensations. Biological tissues are known to exhibit non-linear mechanical properties, and change their properties dramatically when removed from a living organism. To measure the properties in vivo, two devices are being developed. The first is a small displacement, 1-D indenter. It will measure the linear tissue compliance (stiffness and damping) over a wide range of frequencies. These data will be used as inputs to a finite element or other model. The second device will be able to deflect tissues in 3-D over a larger range, so that the non-linearities due to changes in the tissue geometry will be measured. This will allow us to validate the performance of the model on large tissue deformations. Both devices are designed to pass through standard 12 mm laparoscopy trocars, and will be suitable for use during open or minimally invasive procedures. We plan to acquire data from pigs used by surgeons for training purposes, but conceivably, the tools could be refined for use on humans undergoing surgery. Our work will provide the necessary data input for surgical simulations to accurately model the force interactions that a surgeon would have with tissue, and will provide the force output to create a truly realistic simulation of minimally invasive surgery.

Computer Simulation↗
PubMed1999

Measuring and developing suturing technique with a virtual reality surgical simulator.

BACKGROUND: We have developed an interactive virtual reality (VR) surgical simulator for the training and assessment of suturing technique. The surgical simulator is comprised of surgical tools with force feedback, a 3-dimensional graphics visual display of the simulated surgical field, physics-based computer simulations of the tissues and tools, and software to measure and evaluate the trainee's performance. STUDY DESIGN: This study uses the simulator to measure and compare the skills of 8 experienced vascular surgeons versus 12 medical students when performing a virtual reality suturing task. Eight parameters of the suturing task were measured: total tissue damage, accuracy of needle puncture, peak tissue tearing force, time to complete the task, damage to the surface of the tissue, angular error in needle technique, total distance traveled by the tool tip, and a measure of overall error. Three test conditions (dominant hand, nondominant hand, and 3-dimensional needle guide) were tested. Statistical significance was defined as a univariate two-sided p value < or = 0.05. RESULTS: The surgeons' average performance was significantly better than the students' average performance for three of the measured parameters (total tissue damage, time to complete the task, and total distance traveled by the tool tip) for each of the test conditions. For the test condition most similar to surgery (using the dominant hand to suture) one additional parameter was also significantly different (the measure of overall error). The medical students showed improvements for 6 of the 7 parameters for which the users received feedback during the training process. The surgeons also had significant improvement for 4 of the 7 parameters. The students had a larger improvement than the surgeons for 6 of the parameters, but these differences were not statistically significant. CONCLUSIONS: Data indicate differences between surgeon and nonsurgeon performance and in improvement in performance with training. One possible explanation for the superior performance of the surgeons is that their suturing skills applied well to the simulated suturing task. Additional research is required to confirm or deny the similarity between actual and simulated surgical tasks and the relevance of virtual reality surgical simulation to surgical skill assessment and training.

Computer Simulation↗
PubMed2006

Challenges to the development of complex virtual reality surgical simulations.

Virtual reality simulation in surgical training has become more widely used and intensely investigated in an effort to develop safer, more efficient, measurable training processes. The development of virtual reality simulation of surgical procedures has begun, but well-described technical obstacles must be overcome to permit varied training in a clinically realistic computer-generated environment. These challenges include development of realistic surgical interfaces and physical objects within the computer-generated environment, modeling of realistic interactions between objects, rendering of the surgical field, and development of signal processing for complex events associated with surgery. Of these, the realistic modeling of tissue objects that are fully responsive to surgical manipulations is the most challenging. Threats to early success include relatively limited resources for development and procurement, as well as smaller potential for return on investment than in other simulation industries that face similar problems. Despite these difficulties, steady progress continues to be made in these areas. If executed properly, virtual reality offers inherent advantages over other training systems in creating a realistic surgical environment and facilitating measurement of surgeon performance. Once developed, complex new virtual reality training devices must be validated for their usefulness in formative training and assessment of skill to be established.

Computer Simulation↗
PubMed2006

Project hydra--a new paradigm of internet-based surgical simulation.

Computer-based surgical simulation systems have produced tremendous benefits and demonstrated validity as a better method for many areas of surgical skills acquisition. However, despite these benefits, broad proliferation of these systems has continued to be elusive. While in large part this lag in adoption of this technology is due to social factors (organizational momentum, curriculum integration difficulties, etc), the cost of computer-based simulation systems has certainly remained a major deterrent toward broad deployment. Instead, what if it were possible to eliminate the cost of the large computer completely from the system, yet provide a much more extensive and detailed simulation than currently available? Finally, what if a simulation with even greater detail over a wider anatomical area were possible?This is the genesis of Project Hydra- a shared simulation supercomputer were made available for free and all that is required to access it is a low-end Internet-connected computer and, optionally, interaction/haptics devices as needed for the particular task. This would enable supercomputer-class simulation at every desktop with much greater fidelity than any user could individually afford and provide an online community for simulation research and application. Further, Internet-based simulation provides for many other benefits as well. By the user merely plugging optional, additional hardware into their existing, low-end PC and using the Internet as a means of simulation dissemination, distribution, and delivery means that the user can have immediate access to simulation updates/upgrades and download/access new content (didactic curriculum and cases). Further, this ease of access and use could lead to accelerated adoption and use of simulation within the medical curriculum and this access is provided anywhere in the world 24 x 7. In addition, once connected, a server-based simulation system would be a natural point for performing easy, automated clinical studies of surgical performance and skills.

Computer Simulation↗
PubMed2006

Surgical simulation: a systematic review.

OBJECTIVE: To evaluate the effectiveness of surgical simulation compared with other methods of surgical training. SUMMARY BACKGROUND DATA: Surgical simulation (with or without computers) is attractive because it avoids the use of patients for skills practice and provides relevant technical training for trainees before they operate on humans. METHODS: Studies were identified through searches of MEDLINE, EMBASE, the Cochrane Library, and other databases until April 2005. Included studies must have been randomized controlled trials (RCTs) assessing any training technique using at least some elements of surgical simulation, which reported measures of surgical task performance. RESULTS: Thirty RCTs with 760 participants were able to be included, although the quality of the RCTs was often poor. Computer simulation generally showed better results than no training at all (and than physical trainer/model training in one RCT), but was not convincingly superior to standard training (such as surgical drills) or video simulation (particularly when assessed by operative performance). Video simulation did not show consistently better results than groups with no training at all, and there were not enough data to determine if video simulation was better than standard training or the use of models. Model simulation may have been better than standard training, and cadaver training may have been better than model training. CONCLUSIONS: While there may be compelling reasons to reduce reliance on patients, cadavers, and animals for surgical training, none of the methods of simulated training has yet been shown to be better than other forms of surgical training.

Computer Simulation↗
PubMed2000

Laparoscopic surgical simulator and port placement study.

We have developed a virtual laparoscopic surgical simulator and gathered data during student trial runs. The students performed simulated surgical dissections from 3 pairs of port positions with angles between the cutting and grasping instruments set to 60, 90, and 120 degrees. Preliminary data indicates improved performance at the 90 degree angle. Study updates can be found at http:¿www.hitl.washington.edu/research/lss

Cholecystectomy, Laparoscopic↗