Biomedical subjects

E Matt Ritter

Publications and source records attributed to E Matt Ritter.

9 recordsLinked to original sources

PubMed2006

Perceptual, visuospatial, and psychomotor abilities correlate with duration of training required on a virtual-reality flexible endoscopy simulator.

BACKGROUND: Trainees acquire endoscopic skills at different rates. Fundamental abilities testing could predict the amount of training required to reach a performance goal on a virtual-reality simulator. METHODS: Eleven medical students were tested for fundamental abilities. Baseline endoscopic proficiency was evaluated with the GI Mentor II VR simulator (Simbionix, USA, Cleveland, OH). Subjects trained on the simulator with a defined performance goal. Subjects who achieved the goal were then reassessed. RESULTS: All subjects completed at least 10 trials or reached the performance goal. The <10 trial group (n=6) tested better for all fundamental abilities and baseline endoscopic performance than the >10 trial group (n=5). The number of trials required to reach the performance goal correlated significantly with both perceptual (r=.92, P=0.001) and visuospatial ability (r=.76, P=.03). Multiple regression showed strong correlation of all three abilities with duration of training (r=.95, P=.015). CONCLUSIONS: Most of the variability in acquisition of endoscopic skills can be accounted for by differences in fundamental abilities of trainees. Testing of fundamental abilities could help identify trainees who will require additional training to achieve desired performance objectives.

Adult↗

PubMed2006

Visuospatial abilities correlate with performance of senior endoscopy specialist in simulated colonoscopy.

Visuospatial abilities have been demonstrated to predict the performance of medical students in simulated endoscopy. However, little has been reported whether differences in visuospatial abilities influence the performance of senior endoscopists or whether their vast endoscopy experience reduces the importance of these abilities. Eleven senior endoscopists were included in our study. Before the simulated endoscopies in GI Mentor II (gastroscopy: case 3, module 1 and colonoscopy: case 3, module 1), the endoscopists performed three visuospatial tests: (1) pictorial surface orientation (PicSOr), (2) card rotation, and (3) cube comparison tests that monitor the ability of the tested person to re-create a three-dimensional image from a two-dimensional presentation as well as mentally manipulate that re-created image. The results of the visuospatial tests were correlated to the performance parameters of the virtual-reality endoscopy simulator. The percent of time spent with clear view in the simulated colonoscopy correlated well with the performance in the visuospatial PicSOr (r = -0.75, P = 0.01), card rotation (r = 0.75, P = 0.01), and cube comparison (r = 0.79, P = 0.004) tests. The endoscopists who performed better in the visuospatial tests also were better at maintaining visualization of the colon lumen. Those who performed better in the PicSOr test formed fewer loops during colonoscopy (r = 0.60, P = 0.05). In the technically less demanding simulated gastroscopy, there were no such correlations. The visuospatial tests performed better in endoscopists not playing computer games. Good visuospatial ability correlates significantly with the performance of experienced endoscopists in a technically demanding simulated colonoscopy, but not in the less demanding simulated gastroscopy.

Adult↗

PubMed2006

The pretrained novice: using simulation-based training to improve learning in the operating room.

Enabling trainees to acquire advanced technical skills before they begin the operating room experience benefits both trainee and patient. Whether medical students who had received exclusively simulation-based training could perform laparoscopic suturing and knot-tying as well as senior surgery residents was determined. Simulators were used to train 11 fourth-year medical students with no previous suturing experience to perform intracorporeal suturing and to successfully tie a free-hand intracorporeal knot. Students' skills were assessed by the performance of the fundal suturing portion of a Nissen fundoplication in a porcine model. Their operative performance was evaluated for time, needle manipulations, and total errors. Results were compared to those of 11 senior-level surgery residents performing the same task. The study concluded that trainees could learn advanced technical skills such as laparoscopic suturing and knot tying by using simulation exclusively. The trainees and senior level surgery residents had a similar number of needle manipulations.

Clinical Competence↗

PubMed2005

Relationship between tissue ingrowth and mesh contraction.

Contraction is a well-documented phenomenon occurring within two months of mesh implantation. Its etiology is unknown, but it is suggested to occur as a result of inadequate tissue ingrowth into the mesh and has been associated with hernia recurrence. In continuation of our previous studies, we compared tissue ingrowth characteristics of large patches of polyester (PE) and heavyweight polypropylene (PP) and their effect on mesh contraction. The materials used were eight PE and eight PP meshes measuring 10 x 10 cm2. After random assignment to the implantation sites, the meshes were fixed to the abdominal wall fascia of swine using interrupted polypropylene sutures. A necropsy was performed three months after surgery for evaluation of mesh contraction/shrinkage. Using a tensiometer, tissue ingrowth was assessed by measuring the force necessary to detach the mesh from the fascia. Histologic analysis included inflammatory and fibroblastic reactions, scored on a 0-4 point scale. One swine developed a severe wound infection that involved two PP meshes and was therefore excluded from the study. The mean area covered by the PE meshes (87 +/- 7 cm2) was significantly larger than the area covered by the PP meshes (67 +/- 14 cm2) (p = 0.006). Tissue ingrowth force of the PE meshes (194 +/- 37 N) had a trend toward being higher than that of the PP meshes (159 +/- 43 N), although it did not reach statistical significance. There was no difference in histologic inflammatory and fibroblastic reactions between mesh types. There was a significant correlation between tissue ingrowth force and mesh size (p = 0.03, 95% CI: 0.05-0.84). Our results confirm those from previous studies in that mesh materials undergo significant contraction after suture fixation to the fascia. PE resulted in less contraction than polypropylene. A strong integration of the mesh into the tissue helps prevent this phenomenon, which is evidenced by a significant correlation between tissue ingrowth force and mesh size.

Animals↗

PubMed2005

Video-assisted surgery represents more than a loss of three-dimensional vision.

BACKGROUND: Loss of depth cues is a major challenge facing surgeons performing video-assisted surgery (VAS). Whether the degradation of image quality from a video-displayed image plays a direct role in performance of VAS has not been studied. METHODS: Twenty-four volunteer novice subjects were randomized to binocular direct-vision (BDV), monocular direct-vision (MDV), or video-imaging (VI) conditions. Each subject completed ten trials of a simple cutting task in a box trainer using standard laparoscopic instruments. RESULTS: VI subjects made significantly fewer correct incisions than both of the other groups for all trials. Differences between the BDV and MDV groups did not reach statistical significance. Improvement in performance was more rapid in the BDV group than in either the MDV or VI groups. CONCLUSIONS: The degradation of image quality with VI has a detrimental influence on VAS performance above and beyond the loss of binocular vision.

Adult↗

PubMed2005

Simulation for trauma and combat casualty care.

Training medical providers to care for traumatically injured patients is a difficult undertaking and currently used training strategies are often suboptimal. The further strains placed on trauma care in the military environment only add to the challenge. Simulation applications ranging from simple physical models to complex, computer-based virtual reality systems have either been developed or are being developed to help support and improve trauma care training. Several of these applications have been shown to be as good as or better than the standard training methods they are designed to replace. Simulators are available for training in the treatment of disorders of the airway, difficulty with breathing, and problems dealing with circulation as well as various non-life-threatening but disabling injuries. Some of these simulators have already drastically changed how the standard Advanced Trauma Life Support course is taught. Advances in both technology and application of simulators will continue to affect trauma skills training for the foreseeable future.

Journal Article↗

PubMed2005

Virtual reality simulation for the operating room: proficiency-based training as a paradigm shift in surgical skills training.

SUMMARY BACKGROUND DATA: To inform surgeons about the practical issues to be considered for successful integration of virtual reality simulation into a surgical training program. The learning and practice of minimally invasive surgery (MIS) makes unique demands on surgical training programs. A decade ago Satava proposed virtual reality (VR) surgical simulation as a solution for this problem. Only recently have robust scientific studies supported that vision METHODS: A review of the surgical education, human-factor, and psychology literature to identify important factors which will impinge on the successful integration of VR training into a surgical training program. RESULTS: VR is more likely to be successful if it is systematically integrated into a well-thought-out education and training program which objectively assesses technical skills improvement proximate to the learning experience. Validated performance metrics should be relevant to the surgical task being trained but in general will require trainees to reach an objectively determined proficiency criterion, based on tightly defined metrics and perform at this level consistently. VR training is more likely to be successful if the training schedule takes place on an interval basis rather than massed into a short period of extensive practice. High-fidelity VR simulations will confer the greatest skills transfer to the in vivo surgical situation, but less expensive VR trainers will also lead to considerably improved skills generalizations. CONCLUSIONS: VR for improved performance of MIS is now a reality. However, VR is only a training tool that must be thoughtfully introduced into a surgical training curriculum for it to successfully improve surgical technical skills.

Attention↗

PubMed2005

Real-time objective assessment of knot quality with a portable tensiometer is superior to execution time for assessment of laparoscopic knot-tying performance.

OBJECTIVE: Laparoscopic intracorporeal knot tying is a difficult skill to acquire. Currently, time to complete a knot is the most commonly used metric to assess the acquisition of this skill; however, without a measure of knot quality, time is a poor indicator of skills mastery. Others have shown that knot quality can be accurately assessed with a tensiometer, but obtaining this type of assessment has typically been cumbersome. We investigated a new method of real-time assessment of knot quality that allows for more practical use of knot quality as a performance metric. METHODS: Eleven experienced endoscopic surgeons tied 100 intracorporeal knots in a standard box trainer. Each of the knots was immediately tested using the InSpec 2200 benchtop tensiometer (INSTRON, Canton MA) where a knot quality score (KQS) is generated based on the load handling properties of the knotted suture. The execution time was also recorded for each knot. RESULTS: The assessment of all knots ended with one of two end points: knots that slipped (n=48) or knots that held until the suture broke (n=52). Knots that slip are generally of poorer quality than those that held. Execution time did not correlate with knot-quality score (r=0.009, P=.9), and the mean execution time did not differ significantly between slipped and held knots (65 vs 68 seconds, P=.8). No completion time criteria were able to accurately predict slipped versus held knots. The mean KQS difference between held and slipped knots was highly significant (24 vs 12, P<.0001). A knot with a KQS exceeding 20 was nearly 10 times more likely to hold than slip. CONCLUSION: Time to complete a knot is a poor metric for the objective assessment of intracorporeal knot-tying performance in the absence of a measure of knot quality. Real-time evaluation of the knot quality can accurately distinguish well-tied knots from poorly tied knots. This mode of assessment should be incorporated into training curriculum for surgical knot tying.

Biomechanical Phenomena↗

PubMed2003

Objective psychomotor skills assessment of experienced and novice flexible endoscopists with a virtual reality simulator.

The objective of this study was to determine whether the GI Mentor II virtual reality simulator can distinguish the psychomotor skills of intermediately experienced endoscopists from those of novices, and do so with a high level of consistency and reliability. A total of five intermediate and nine novice endoscopists were evaluated using the EndoBubble abstract psychomotor task. Each subject performed three repetitions of the task. Performance and error data were recorded for each trial. The intermediate group performed better than the novice group in each trial. The differences were significant in trial 1 for balloons popped (P=.001), completion time (P=.04), and errors (P=.03). Trial 2 showed significance only for balloons popped (P=.002). Trial 3 showed significance for balloons popped (P=.004) and errors (P=.008). The novice group showed significant improvement between trials 1 and 3 (P<0.05). No improvement was noted in the intermediate group. Measures of consistency and reliability were greater than 0.8 in both groups with the exception of novice completion time where test-retest reliability was 0.74. The GI Mentor II simulator can distinguish between novice and intermediate endoscopists. The simulator assesses skills with levels of consistency and reliability required for high-stakes assessment.

Adult↗