Methods for Madigan Endoscopic Sinus Surgery Simulator v.1.2


METHODS OF EVALUATION

METHODS OF EVALUATION

 

SUBJECTS

Three distinct groups of subjects were evaluated on the Endoscopic Sinus Surgery Simulator to determine a baseline and asymptote for the evaluation of the its efficacy as a trainer for Otolaryngologist residents.

 

Group 1: Staff and resident Otolaryngologists from Madigan Army Medical Center (MAMC), (N = 12 + Dr. Charles Edmond), were evaluated to attain the asymptote for the optimal (professional) score and average scores for each year of residency on each of the models. This group allowed us to create a range of scores to better asses the efficacy of the simulator as a training tool. Four staff Otolaryngologists were run through the simulator with an average of five years of training, six years of practice and more than 100 Endoscopic Sinus Surgery (ESS) procedures performed. The residents tested consisted of three, second year with an average of 1-5 ESS procedures performed and observed, one, third year with 6-20 ESS procedures performed and observed, two, fourth year with an average of 21-100 ESS procedures performed and 6-20 observed and two, fifth year with and average of 21-100 ESS procedures performed and observed.

 

Group 2: Non-Otolaryngologist MDs with and without endoscopic experience, (N = 4), were run for an unbiased, professional evaluation of the simulator, a shakedown of the simulator's usefulness and brainstorming its potential uses in their specialties. This group consisted of one, Radiologist and one, Anesthesiologist without previous endoscopic experience, and two Video Endoscopic Surgeons with an average of 21-100 endoscopic procedures performed.

 

Group 3: Students and faculty from the Human Interface Technology Laboratory (HITL) at the University of Washington with no previous endoscopic experience, (N = 14), gave us a shakedown on the protocol for proctoring instructions and the baseline scores for untrained/unfamiliar subjects. The majority of these subjects had extensive experience in Virtual Reality and were familiar with simulation.

 

MODELS

Model 1: The novice/abstract model, consisted of only the skin of the face and the entrance to the nasal cavity. A 3D grid pattern replaced the sinus anatomy to give a sense for depth of field during the three tasks: Navigation, Injection and Dissection. Training aids were used to guide the subjects through the task. Navigation training aids consisted of virtual hoops and Injection training aids consisted of virtual targets in space. During Navigation the subjects maneuvered the endoscope only, through four sets of virtual hoops. The paths of the hoops represented three passes (sets two and three combined are one pass) commonly taken before the surgery begins to gain familiarity with the patient's anatomy and to allow cleaning of the areas of interest. Injection consisted of maneuvering both the endoscope and instrumented forceps within the environment to inject targets in space. The instrumented forceps were used as a virtual needle for this task. The placement of the targets in space reflected the common areas of injection of a vasoconstrictor during a Maxillary Antrostomy. During Dissection the subjects were also required to use both the endoscope and instrumented forceps. The task was composed of dissecting a series of virtual spheres with pre-selected virtual tools. The instrumented forceps represented each of the tools most commonly used in the procedure. Navigation through the four sets of hoops, injection of the five targets and dissection of each of the spheres was required for a complete score. Audio Cues were given for each hoop negotiated in Navigation, for each target hit in Injection and percentages completed of each sphere in Dissection.

 

Model 2: The intermediate model, was composed of the Navigation and Injection training aids from Model 1, overlaid on a virtual anatomical model of the sinus cavity. Injection and Dissection followed the protocol for a Maxillary Antrostomy: injection of the inferior/anterior Middle Turbinate, superior root of the Middle Turbinate and the lateral nasal, followed by dissection of the Uncinate process, Bulla ethmoidalis and posterior Ethmoid cells. An additional training aid was added for all anatomical structures that the subject interacted with, including the Middle Turbinate and Maxillary Ostium. Each was labeled with their name over the corresponding virtual structure. Navigation through the four sets of hoops, injection of the five targets, medialization of the Middle Turbinate, dissection of the three anatomical structures, removal of two bone fragments placed in the Uncinate process and removal of three bone fragments placed in the Bulla ethmoidalis were required for a complete score. The widening of the Maxillary Ostium was not included in the procedure due to the inability to dissect enough of the lateral part of the Uncinate process for realistic viewing of the Ostium (see LESSONS LEARNED, Ability to see Maxillary Ostium for Antrostomy). Audio cues were given for each hoop negotiated in Navigation, for each target hit in Injection, for each bone fragment removed and percentages completed for each anatomical structure in Dissection.

 

Model 3: The advanced model, was composed of an anatomical model only, no training aids. The subjects were expected to perform the three tasks without the training aids and follow the protocol for a Maxillary Antrostomy. Three polyps were added superior/anterior to the Bulla ethmoidalis. During Navigation the subject was required to perform the three passes in the same order as models 1 and 2: inferior pass along the floor of the nose to the Nasopharynx, followed by a more superior pass medial to the Middle Turbinate towards the upper aspect of the Nasopharynx and Sphenoid Ostium then rolling under the Middle Turbinate to inspect the Ostial Meatal Complex, finally the superior pass medial to the root of the Middle Turbinate towards the Sphenoethmoidal Recess. During Injection, the subject was only cued by the amount of blanching (whitening) of the virtual tissue as to whether more vasoconstrictor was needed. Dissection followed the protocol for a Maxillary Antrostomy. Navigation through the three passes, injection of the areas of interest, medialization of the Middle Turbinate, dissection of the three anatomical structures, dissection of the three polyps, removal of two bone fragments placed in the Uncinate process and removal of three bone fragments placed in the Bulla ethmoidalis were required for a complete score. The widening of the Maxillary Ostium was not included in the procedure due to the inability to dissect enough of the lateral part of the Uncinate process for realistic viewing of the Ostium. Audio cues were given only at the end of each of the Navigation passes for removal of bone fragments and percentages completed were given for Injection and Dissection.

 

For each model, there was both a right and left nostril. The anatomy was built for the right nostril and was reflected 180 degrees to simulate the left nostril.

 

 

PROCTORING (Concentrate on Ďmethodsí)

Proctoring for each of the groups varied according to their familiarity with the task. The nostril (left or right) which the subject started on was based on their handedness. During each trial, a proctor with knowledge of the procedure was present. The tasks which were necessary for the proctor to complete during a trial were manageable by a single proctor. To assure that all records of the trial and all subject comments were noted, usually, a second proctor was present. One proctor would be designated as an instructional proctor who would introduce the subject to the simulator and answer any questions during the trial. The second proctor would manage the forms, records and loading of the trials for the subject.

 

Group1, Staff and Resident Otolaryngologists:

Each subject was initially introduced to the simulator and informed that we were evaluating the simulator as a possible trainer for residents in Otolaryngology. They were introduced to the virtual endoscope, informed of their ability to rotate the image axially, by axially rotating the shaft of the endoscope, and of the availability of a 30 and 70 degree scope which could be swapped for the zero degree scope they would initially be given. They were then introduced to the instrumented forceps and informed that the instrumented forceps would simulate the virtual needle for Injection and all Dissection tools. The mechanics of the instrumented forceps (open and closed) were described as simulating the plunger for the syringe during Injection and opening and closing the jaws of the dissection tools. They were then informed of how the instrumented forceps would be positioned in the nostril opposite the one used in the trial until the beginning of Injection. At that time the proctor would pull the instrumented forceps across the Columella Nasi into the nostril being used and place a plug in the original nostril to inhibit re-crossing of the Columella Nasi by the instrumented forceps during the remainder of the trial.

 

The subjects were then given a brief verbal description of the three tasks of Model 1-right (Navigation, Injection and Dissection) and what would be required of them during the trial. A video of Dr. Chuck Edmond performing the trial was then started. The proctor continued to describe, in more detail, Navigation, Injection and Dissection, (as each were shown on the video) and what was required for completion of the trial (see MODELS, Model 1). During this time the subject was allowed to step up to the mannequin and become familiar with the instrumentation. The "blood effects scope" (scope becoming opaque within a set time interval) was shown in the video and reasons for it was described by the proctor as well as how to relieve the problem by wiping the scope on the foam pad located on the mannequin's forehead. The subject was then encouraged to ask any questions and "speak-aloud" during the procedure. This process was repeated before each new model: Model 2-right and Model 3-right with the appropriate, model-specific changes. On subsequent trials of Model 1-right, Model 2-right, Model 3-right, Model 3-left and Model 3-left, they were given verbal proctoring instructions only, and allowed to perform the task.

 

The subject's familiarity with the procedure determined the need for further instruction by the proctor. On average, the staff Otolaryngologists needed no further instruction on the procedure for the remainder of the session, except for the need to be shown the active areas for dissection of the Uncinate process, Bulla ethmoidalis and Posterior Ethmoid cells within the virtual model. The staff were run through Model 1-right, Model 2-right and Model 3-right. On average, the residents needed no further instruction for Model 1-right. In Model 2-right more detailed instruction was needed during Dissection, on what anatomy to dissect and where the active dissection areas were located within the anatomy. In Model 3-right more detailed instruction was needed during Navigation on the order of passes to perform (see MODELS, Model 3) and where the active dissection areas were located within the anatomy. All residents were run through Model 1-right, Model 2-right, Model 3-right, Model 3-left and Model 2-left.

 

Group2, Non-Otolaryngologist MDs:

Each subject was initially introduced to the simulator and informed that we were evaluating the simulator as a possible trainer for residents in Otolaryngology. They were encouraged to think of ways in which this type of simulator could be used in their own fields. They were then introduced to the virtual endoscope, informed of their ability to rotate the image axially, by axially rotating the shaft of the endoscope, and of the availability of a 30 and 70 degree scope which could be swapped for the zero degree scope they would initially be given. The optics of the 30 and 70 degree scopes were explained where necessary. They were then introduced to the instrumented forceps and informed that the instrumented forceps would simulate the virtual needle for Injection and all Dissection tools. The mechanics of the instrumented forceps (open and closed) were described as simulating the plunger for the syringe during Injection and opening and closing the jaws of the dissection tools. They were then informed of how the instrumented forceps would be positioned in the nostril opposite the one used in the trial, until the beginning of Injection. At that time the proctor would pull the instrumented forceps across the Columella Nasi into the nostril being used and place a plug in the original nostril to inhibit re-crossing of the Columella Nasi by the instrumented forceps during the remainder of the trial.

 

The subjects were then given a brief verbal description of the three tasks of Model 1-right (Navigation, Injection and Dissection) and what would be required of them during the trial. A video of Dr. Chuck Edmond performing the trial was then started. The proctor continued to describe, in more detail, Navigation, Injection and Dissection, (as each were shown on the video) and what was required for completion of the trial (see MODELS, Model 1). During this time the subject was allowed to step up to the and mannequin become familiar with the instrumentation. The "blood effects scope" was shown in the video and reasons for it was described by the proctor as well as how to relieve the problem by wiping the scope on the foam pad located on the mannequin's forehead. The subject was then encouraged to ask any questions and "speak-aloud" during the procedure. This process was repeated before their first introduction to Model 2-right with the appropriate, model-specific changes. On subsequent trials of Model 1-right and Model 2-right, they were given verbal proctoring instructions only, and allowed to perform the task.

 

The subject's familiarity with the procedure determined the need for further instruction by the proctor. On average this group had no familiarity with procedure, but all had had previous introduction to anatomy (during medical school) and had an understanding of the reasons for the procedure. Progression to Model 2-right for this group was based on performance on Model 1-right. An average score of 69% was achieved by the subjects on Model 1-right before progressing to Model 2-right. Proctoring in Model 2-right required instructions on locations and anatomy to dissect during the procedure. Training aids and video of procedure provided adequate familiarity of task for Model 1-rightís entirety and Model 2-right's Navigation and Injection. No subjects from this group were run through Model 3, because of the limited availability of the subjects.

 

Group 3, Faculty and Students from HITL:

Each subject was initially introduced to the simulator and informed that we were evaluating the simulator as a possible trainer for residents in Otolaryngology. A summary of the reasons for this type of surgery was given along with a brief introduction to the anatomical structures and their locations in the sinus cavity to give the subjects a feel for the dimensions of the area, in which, they will be working. They were then introduced to the instrumented endoscope, informed of their ability to rotate the image axially, by axially rotating the shaft of the endoscope. They were then introduced to the instrumented forceps and informed that the forceps would simulating the virtual needle for Injection and all Dissection tools. The mechanics of the forceps (open and closed) were described as simulating the plunger for the syringe during Injection and opening and closing the jaws of the dissection tools. They were then informed of how the instrumented forceps would be positioned in the nostril opposite the one used in the trial, until the beginning of Injection. At that time the proctor would pull the instrumented forceps across the Columella Nasi into the nostril being used and place a plug in the original nostril to inhibit re-crossing of the Columella Nasi by the instrumented forceps during the remainder of the trial.

 

The subjects were then given a brief verbal description of the three tasks of Model 1-right (Navigation, Injection and Dissection) and what would be required of them during the trial. They were informed that their introduction to Model 1-right would be broken up into three separate subtasks: Navigation, Injection and Dissection. A video of Dr. Chuck Edmond performing the trial was then started. During this time the subject was allowed to step up to the mannequin become familiar with the instrumentation, while the proctor described the task in more detail. The video playback was consequently paused and broken up into task-specific segments. Proctoring and video for Navigation was given, then the Navigation task was performed. The trial was then paused, proctoring and video for Injection was given and the Injection task was performed. The trial was then paused, proctoring and video for Dissection was given and the Dissection task was performed. The subject was then encouraged to ask any questions and "speak-aloud" during the entire procedure. Model 1-right was the only model where this process was used and it was only used on their initial introduction to the simulator. On subsequent trials of Model 1-right, they were given verbal proctoring instructions only, and allowed to perform the task. Those which were introduced to Model 2-right did not require breaking the trial into subtasks.

 

The subjects had no familiarity with the procedure or anatomy. Progression to Model 2-right for this group was based on performance on Model 1-right. An average score of 54% was achieved by the subjects on Model 1-right before progressing to Model 2-right. Proctoring on Model 2-right required extensive instructions on locations and anatomy to dissect during the procedure. No students from this group were run through Model 3 because of the limited availability of the subjects and their inability to achieve a proficiency in Model 2-right during the time they were able to volunteer.

 

 

LESSONS LEARNED AND INFORMAL EVALUATION OF VERSION 1.3

Based on subjectís comments, observations by the proctor and problems experienced during trials.

 

Haptics: Subjects had unrealistic difficulties (especially the residents and ENT staff) with the need to steady their thumb, during injection and dissection using the instrumented forceps. This stabilization while opening and closing the forceps was required to keep the tip of the virtual tool from moving away from the area of interaction. Without stabilizing the thumb the virtual tool would move forward and away from the injectable or dissectable region when opening and closing the jaw of the virtual tool. This need for stabilization has been attributed to a lack of realistic haptics. Version 1.3 of the software has significant improvements to the haptics, which give a more realistic representation of grasping, tearing and injecting the virtual tissue. Grasping of the virtual tissue is represented by a "hold" on the tip of the instrumented forceps, after closing the jaw on the tissue, as if holding onto a static object. Tearing of virtual tissue is represented by a resistive force on the tip of the instrumented forceps as it is being pulled away from the "hold" position, with a final "release" after a predetermined distance. Injecting is represented by a "pop" when initially passing the virtual needle through the tissue and a "hold", keeping the instrumented forceps static in the X,Y,Z position, but not the Heading, Pitch and Roll. In addition to these enhancements on the need for stabilization, the suction tools is "pulled" toward the virtual tissue based on its proximity, an initial "jolt" was placed on all tools when initially interacting with the virtual tissue and the feel of the sickle knife simulates cutting paper with a straight razor. These improvements have added a tremendous amount of realism, not only to the injection and dissection tasks but also, to the realism of navigating the instrumented forceps through the sinus cavity (state?). These improvements will be implemented and tested in the next phase of the simulatorís development.

 

Retraction of Instrumented forceps: During pilot studies, when the subjects wanted to swap tools, they were required to retract the instrumented forceps from the sinus cavity (retracting to just posterior to the Columella Nasi) before receiving the new instrumented forceps. This requirement was the major contributor to two problems with the encoders on the instrumented forceps. The first problem took place during the pilot studies, the retraction of the instrumented forceps caused the endoscope shaft to collide with the encoder measuring the Roll of the instrumented forceps, which would then cause either fraying or displacement of the cable on the sector of the encoder. The second problem was interaction of the sector of the encoder and the hard pallet of the mannequin during retraction. This interaction forced rotation of the sector, introducing an offset in the initial calibration of the instrumented forceps and therefore an offset in the vector of the virtual tool. The problem was repaired by addition of Loc Tite? to the sector and eliminating the requirement of the subjects to retract the instrumented forceps during swapping. Immersion Corporation is currently upgrading/improving the design of the instrumented forceps's encoders for the next phase of the simulator's evaluation.

 

Grabbing bone fragments with jawed tools: Removal of two bone fragments from the Uncinate process and three bone fragments from the Bulla ethmoidalis, which were required for a complete score, were unrealistically difficult to grasp with a jaw of the virtual tool. The fragments could only be grasped at their center. Regardless of skill, the subject was required to "learn" how to grasp the bone fragments in the simulator and was instructed by the proctor on how to do so during their orientation to the simulator. Many of the staff and resident ENT surgeons would initially try to grasp the bone fragments on their edge, as they would in a real surgical theatre, without success. Version 1.3 has corrected this problem by allowing a jawed virtual tool to grasp the bone fragments anywhere along its circumference as well as at its center.

 

Improvement of the virtual suction tool: During testing, the suction toolís only function was to reduce the volume of the blood spheres inside the anatomy, after dissection of part of the tissue. It was brought to our attention that in a surgical theatre the ENT surgeon would not only use the real suction tool to remove blood, but also to remove small amounts of tissue an mucous in the Posterior Ethmoid cells and bone fragments throughout. Version 1.3 allows a small amount of dissection by the virtual suction tool as well as the ability to grasp and slowly remove bone fragments.

 

Need to break up model 1-right into 3 separate tasks for Group 3: During the pilot testing of Group 3 it was discovered that an initial verbal summary of the task to be performed, without giving a visual example of the task, was overwhelming to the untrained/unfamiliar subject. The need for the subject to memorize each subtask and also to gain an understanding of what was needed to complete the task proved to be too much information. The original presentation of the material consisted of a videotaped introduction to the simulator by Dr. Charles Edmond followed by verbal instructions by the proctor, describing each subtask (Navigation, Injection and Dissection) in order and in totality(see INSTRUCTIONAL VIDEO). The subject was then introduced to the endoscope and instrumented forceps and instructed on their functions for each task. The subject was then asked if there was anything which needed further explanation. We found, the proctoring instructions needed to be repeated multiple times throughout the trial to reinforce what the task required and entailed. By trial and error, it was finally decided to split each subtask into three independent tasks for their initial trial on the simulator. This division of tasks proved to be a viable solution to the problem of the untrained/unfamiliar subjectís confusion and only needed to be implemented into their initial trial (see PROCTORING, Group 3).

 

Ability to see Maxillary Ostium for Antrostomy: Although the subjects were told to perform a Maxillary Antrostomy, the antrostomy of the Maxillary Ostium was removed from the requirements during the procedure on the simulator because of the inability to realistically view the Ostium. After dissection of the Uncinate process in an actual procedure, the Maxillary Ostium would be in view with a zero or 30 degree scope and the antrostomy would easily be conducted. After dissecting the Uncinate process in the simulation ,however, to view the Ostium required a 70 degree scope, with unrealistic positioning of the scope inside the sinus cavity. To correct this problem, Version 1.3 allows dissection of the Uncinate process more superior/laterally and inferior/laterally than Version 1.2. This added realism will be tested and evaluated in the next phase of the evaluation of the simulator.

 

Ability to "push through" the virtual anatomy during trials: While the subjects were performing the three tasks they had the ability to push through the virtual anatomy with both the virtual endoscope and virtual tool. The staff Otolaryngologists had the greatest problem with the ability of the shaft of the virtual tool to pass through the virtual anatomical structures during Injection and Dissection. This unrealistic ability of the virtual tool's shaft, reflected learning of invalid positioning of virtual tool within the anatomy. A potential, but expensive and cumbersome, solution to this problem would be implementation of haptics with 6 degrees of freedom on the instrumented tool. The implementation of 6 degrees of freedom of haptics would prohibit the tool from passing through the virtual anatomy in all movable directions as opposed to just the X,Y,Z directions currently implemented, thus solving this problem. Current haptic technology would be too cumbersome to implement in the current design of the mannequin box, but should be considered for future designs. The unrealistic ability of the virtual endoscope to pass through the virutal anatomy, however, was welcomed my the majority of the staff Otolaryngologists. When the virtual endoscope would pass through the anatomy, the image on the monitor would disappear and the screen would be black until the position of the instrumented endoscope was maneuvered back inside the anatomical model. This reaction of the image was seen as helpful because the residents were taught to concentrate on staying within the anatomy during the duration of the procedure without potentially traumatizing real tissue in the operating room. This was seen as one of the many advantages of using the simulator to gain the hand-eye coordination necessary to maneuver the endoscope through the anatomy.

 

 

INSTRUCTIONAL VIDEO

An instructional video was made to initially introduce the subjects to the simulator in order to standardize the instructions across subjects. This video was intended to instruct them on the procedure, the anatomical structures inside the sinus cavity, all available tools at their disposal.

The video proved to be too advanced for Group 3, presenting an excessive amount of information to the untrained/unfamiliar person. The pilot subjects from this group which were shown the video were confused as to what was required of them. The video presented too much information without giving the untrained/unfamiliar subject enough time to understand the purpose of the procedure and what it entailed.

The subjects from Group 1 would have most greatly benefited from the video, although, its duration made it unusable for this group.

Future work in this area is to create a more group-specific video for each type of subject. Shorten the duration of the instructional video to make it a more viable solution, which, in turn, will automate most of the proctoring instructions, allowing one proctor to complete all necessary tasks without difficulty.

 

Original Storyboard for Video Instruction Set:

 

? Endoscope and Forceps

? Introduction was to the instrumented endoscope

? How to handle it

? The need and process for stabilization using both hands

? Hints on guiding the scope, by use of angles, through the anatomy

? How to eliminate the effect of your natural tremor

? Introduction to the transferring the tool across the Columella Nasi

? Instructions on cleaning the scope when it becomes bloody

? Hints on alignment of the scope within the plane of the mannequin to keep track of your heading and orientation

? The scope's ability to rotate the image, by axially rotating the shaft of the scope

? Explanation of the 30 and 70 degree scopes and their uses to view around corners

? Introduction to the instrumented forceps

? Limitations of the subject's ability to fully retract the forceps

? Reasons behind the need to pass the forceps across the Columella Nasi

? Their rigid connection to the mechanics of the haptics inside the mannequin

? How to swap tools in models 2 and 3

? Calling out the desired virtual instrument

? Retracting the forceps to just posterior to the Columella Nasi to receive the desired virtual instrument

 

? Body Positioning

? Keeping your body parallel with the mannequin

? Turning head to see the monitor instead of turning body

 

? Anatomy

? Introduction to major anatomical structures on physical "pull away" model

? Nasal Passage, Septum and Nasopharynx

? Introduction to sinus cavity anatomical structures on physical "pull away" model

? Superior, Middle and Inferior Turbinates, Uncinate Process and Bulla ethmoidalis

? Description of anatomical structures which will be interacted with and removed during procedure

? Definition and procedure for a Maxillary Antrostomy

? Description and demonstration of sites for injection during procedure in models 2 and 3

? Medial Middle Turbinate, root of Uncinate Process and the lateral Nasal wall

? Description and "pull away" of Dissection tasks for models 2 and 3

? Medialization of Middle Turbinate and dissection of Uncinate Process, Bulla ethmoidalis and widening of the Maxillary Ostium

 

? Procedures

? Playback of video of Model 1, performed by Dr. Chuck Edmond, no voice over to allow the proctor to discuss the trial with the subject

? Examples of all virtual instruments available to the subject

? Playback of video of Model 2, performed by Dr. Chuck Edmond, no voice over to allow the proctor to discuss the trial with the subject

? Playback of video of Model 3, performed by Dr. Chuck Edmond, no voice over to allow the proctor to discuss the trial with the subject

 

 

 

USER PERFORMANCE CRITERIA

The scoring algorithm for Version 1.2 takes into consideration two major performance measures for Endoscopic Sinus Surgery: Accuracy/Completeness and Time.

 

The scoring algorithm used for the evaluation of the first phase of the Endoscopic Sinus Surgery Simulator took into account the most important skills needed to perform sinus surgery.

Model 1 introduces the student into an abstract environment allowing the student to gain the required hand-eye coordination with the endoscope and the special skills needed to maneuver the instrumented forceps, without requiring them to concentrate on anatomy.

Model 2 introduces the student to the anatomy, but still utilizes the training aids from Model 1. This model gives the student the advantage of working within an anatomical environment and performing a common procedure with the help of hoops for the initial passes through the anatomy, targets for injection areas and labels on the anatomical structures in which interaction is necessary. The educational advantages of this model can only be best utilized with a simulation of this kind.

Model 3 introduces the student to a more realistic environment. There are no longer any training aids to guide the student through the procedure. For Navigation of the scope, the student must rely on what was learned when navigating through the hoops in Model 2. For Injection the student must remember where the proper areas of injection of the vasoconstrictor is useful. For dissection, the student has no labels to indicate what anatomy to interact with, so the student must rely on what was learned in Model 2 to perform the procedure.

 

 

BIBLIOGRAPHY

[1] Rosser J, Rosser L, Savalgi. (Feb 1997) Skill Acquisition and Assessment for Laparoscopic Surgery. Archives of Surgery. Vol. 132. 200-204

 

[2] Bartlett, Worley, Simpson, Aylward, Bailey, Fish. (1995) Report out to the Modeling and Simulation Working group. Alexandria, VA. Modeling and Simulation Benefits Task Force, Defense Modeling and Simulation Office. [Online: WWW] Available: http://triton.dmso.mil/docslib/reports/msbtf/report.html

 

[3] Geis, Kim, McAfee, Kang, Brennan. (March 1996) Synergistic benefits of combined technologies in complex, minimally invasive surgical procedures. Surgical Endoscopy. Vol 10. 1025-1028

 

[4] Cohen, MacRae, Jamieson. (June 1996) Teaching Effectiveness of surgeons. The American Journal of Surgery. Vol 171. 612-614

 

[5] Caird. (1996) Persistent Issues in the Application of Virtual Environment Systems to Training. IEEE Computer Society: Human Interaction with Complex Systems. Vol 3. 124-132

 

 

 

Post Test Questionnaires?

 

Does the novice training protocol affect performance on the int. Model? Use:HITL people

What impact do the simulator components (haptics, etc) have on training effectiveness?

Discuss the types of changes that occurred throughout the evolution of the simulator...

 

With and without Maxillary and Sphenoidal sinuses in model?

Filtering on Jaw of virtual tool to make it more realTime?

Ability to adjust position of mannequin?

 

We are missing Wayne's video, I think Chuck has it in Madigan......

 

Questions:

Why evaluation is important?

Training effectiveness?

Methods for each group?

Conclusions/Recommendations?

*Lessons learned

Future Directions?

*How did we come to Version 1.3

 

They were then introduced to the virtual endoscope, which is attached to a Microscribe? and tracks the position of the tip of the scope's shaft, then feeds this data to the Onyx which then updates the image on the monitor.