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Biomedical subjects

R Laycock

Publications and source records attributed to R Laycock.

7 recordsLinked to original sources
PubMed2006

A role for the 'magnocellular advantage' in visual impairments in neurodevelopmental and psychiatric disorders.

Evidence exists implicating abnormal visual information processing and visually driven attention in a number of neurodevelopmental and psychiatric disorders, suggesting that research into such disorders may benefit from a better understanding of more recent advances in visual system processing. A new integrated model of visual processing based on primate single cell and human electrophysiology may provide a framework, to understand how the visual system is involved, by implicating the magnocellular pathway's role in driving attentional mechanisms in higher-order cortical regions, what we term the 'magnocellular advantage'. Evidence is also presented demonstrating visual processing occurs considerably faster than previously assumed, and emphasising the importance of top-down feedback signals into primary visual cortex, as well as considering the possibility of lateral connections from dorsal to ventral visual areas. Such organisation is argued to be important for future research highlighting visual aspects of impairment in disorders as diverse as schizophrenia and autism.

Animals↗
PubMed2001

Comparison of video trainer and virtual reality training systems on acquisition of laparoscopic skills.

Training on a video trainer or computer-based minimally invasive surgery trainer leads to improved benchtop laparoscopic skill. Recently, improved operative performance from practice on a video trainer was reported. The purpose of this study was three fold: (a) to compare psychomotor skill improvement after training on a virtual reality (VR) system with that after training on a video-trainer, (VT) (b) to evaluate whether skills learned on the one training system are transferable to the other, and (c) to evaluate whether VR or VT training improves operative performance. For the study, 50 junior surgery residents completed baseline skill testing on both the VR and VT systems. These subjects then were randomized to either a VR or VT structured training group. After practice, the subjects were tested again on their VR and VT skills. To assess the effect of practice on operative performance, all second-year residents (n = 19) were evaluated on their operative performance during a laparoscopic cholecystectomy before and after skill training. Data are expressed as percentage of improvement in mean score/time. Analysis was performed by Student's paired t-test. The VR training group showed improvement of 54% on the VR posttest, as compared with 55% improvement by the VT group. The VR training group improved more on the VT posttest tasks (36%) than the VT training group improved on the VR posttest tasks (17%) (p <0.05). Operative performance improved only in the VR training group (p <0.05). Psychomotor skills improve after training on both VR and VT, and skills may be transferable. Furthermore, training on a minimally invasive surgery trainer, virtual reality system may improve operative performance during laparoscopic cholecystectomy.

Animals↗
PubMed2000

Laparoscopic training on bench models: better and more cost effective than operating room experience?

BACKGROUND: Developing technical skill is essential to surgical training, but using the operating room for basic skill acquisition may be inefficient and expensive, especially for laparoscopic operations. This study determines if laparoscopic skills training using simulated tasks on a video-trainer improves the operative performance of surgery residents. STUDY DESIGN: Second- and third-year residents (n= 27) were prospectively randomized to receive formal laparoscopic skills training or to a control group. At baseline, residents had a validated global assessment of their ability to perform a laparoscopic cholecystectomy based on direct observation by three evaluators who were blinded to the residents' randomization status. Residents were also tested on five standardized video-trainer tasks. The training group practiced the video-trainer tasks as a group for 30 minutes daily for 10 days. The control group received no formal training. All residents repeated the video-trainer test and underwent a second global assessment by the same three blinded evaluators at the end of the 1-month rotation. Within-person improvement was determined; improvement was adjusted for differences in baseline performance. RESULTS: Five residents were unable to participate because of scheduling problems; 9 residents in the training group and 13 residents in the control group completed the study. Baseline laparoscopic experience, video-trainer scores, and global assessments were not significantly different between the two groups. The training group on average practiced the video-trainer tasks 138 times (range 94 to 171 times); the control group did not practice any task. The trained group achieved significantly greater adjusted improvement in video-trainer scores (five of five tasks) and global assessments (four of eight criteria) over the course of the four-week curriculum, compared with controls. CONCLUSIONS: Intense training improves video-eye-hand skills and translates into improved operative performance for junior surgery residents. Surgical curricula should contain laparoscopic skills training.

Clinical Competence↗
PubMed2000

Evaluating surgical competency with the American Board of Surgery In-Training Examination, skill testing, and intraoperative assessment.

BACKGROUND: Evaluation of surgical competency should include assessment of knowledge, technical skill, and judgment. The purpose of this study was to determine the relationship between the American Board of Surgery In-Training Examination (ABSITE), skill testing, and intraoperative assessment. METHODS: Postgraduate year 2 (PGY-2) and postgraduate year 3 (PGY-3) surgery residents (n = 33) were tested by means of (1) the ABSITE, (2) skill testing on a laparoscopic video-trainer, and (3) intra-operative global assessments during laparoscopic cholecystectomy. The Pearson correlation was used to determine the correlation between the ABSITE, skill testing, and intraoperative assessments. For the comparison of PGY-2 and PGY-3 resident performance, Wilcoxon rank sum tests were used. RESULTS: The ABSITE scores did not correlate with skill testing or intraoperative assessments (not significant). Skill testing correlated with the intraoperative composite score and with 4 of 8 operative performance criteria (P<.05). The ABSITE scores and skill testing were not different for PGY-2 and PGY-3 residents (not significant). Intraoperative assessments were better in 5 of 8 criteria and the composite score for PGY-3 versus PGY-2 residents (P<.05), which demonstrated construct validity. CONCLUSIONS: The ABSITE measures knowledge but does not correlate with technical skill or operative performance. Residency programs should use multiple assessment instruments to evaluate competency. There may be a role for both skill testing and intraoperative assessment in the evaluation of surgical competency.

Adult↗
PubMed2000

Measuring operative performance after laparoscopic skills training: edited videotape versus direct observation.

BACKGROUND AND PURPOSE: Global assessment by direct observation has been validated for evaluating operative performance of surgery residents after formal skills training but is time-consuming. The purpose of this study was to compare global assessment performed from edited videotape with scores from direct observation. MATERIALS AND METHODS: Junior surgery residents (N = 22) were randomized to 2 weeks of formal videotrainer skills training or a control group. Laparoscopic cholecystectomy was performed at the beginning and end of the rotation, and global assessment scores were compared for the training and control groups. Laparoscopic videotapes were edited: initial (2 minutes), cystic duct/artery (6 minutes), and fossa dissection (2 minutes). Two independent raters performed both direct observation and videotape assessments, and scores were compared for each rater and for interrater reliability using a Spearman correlation. RESULTS: Correlation coefficients for videotape versus direct observation for five global assessment criteria were <0.33 for both raters (NS for all values). The correlation coefficient for interrater reliability for the overall score was 0.57 (P = 0.01) for direct observation v 0.28 (NS) for videotape. The trained group had significantly better overall performance than the control group according to the assessment by direct observation (P = 0.02) but not by videotape assessment (NS). CONCLUSIONS: Direct observation demonstrated improved overall performance of junior residents after formal skills training on a videotrainer. Global assessment from an edited 10-minute videotape did not correlate with direct observation and had poor interrater reliability. Efficient and valid methods of evaluating operative performance await development.

Cholecystectomy, Laparoscopic↗
PubMed1982

A comparison of freezing and thawing methods for the cryopreservation of human semen.

The purpose of this study was twofold. In the first part are compared cryosurvival rates for human semen following two different freezing and three different thawing techniques. In the second part a larger number of samples processed by the best of the six methods described were examined to ensure reproducibility. Eighteen human semen samples with initial motility greater than 60% and density greater than 20 X 10(6)/ml were mixed with a cryopreservative medium at 35 degree C and vacuumed into 0.5 ml straws. Six aliquots were prepared from as many specimens as possible. Three straws were frozen by a programmed method (P) and three by a rapid freezing technique (V). All six straws were stored in liquid nitrogen vapor (-196 degree C) for 1 week. The straws were thawed by 1 of 3 methods: (1) room temperature for 10 minutes and 37 degree C hot plate for 10 minutes, (2) ice water for 10 minutes and 37 degree C hot plate for 10 minutes, (3) 35 degree C water for 12 seconds and 37 degree C hot plate for 10 minutes. Postthaw motility was assessed for each aliquot. The freeze/thaw method P/1 was judged optimal. In the second part of the study a larger number of samples were processed by P/1. The mean +/- standard deviation postthaw motility o 57 semen specimens processed by this method was 61.4 +/- 12.1.

Freezing↗