R Brydges | PubMed Health

PubMed2006

Quantification of process measures in laparoscopic suturing.

BACKGROUND: Process measures describing the generation of movement are useful for evaluation and performance feedback purposes. This study aimed to identify process measures that differ between novice and advanced laparoscopists while completing a suturing skill. METHODS: A group of junior and a group of senior residents and fellows in surgery (n = 6) placed 10 laparoscopic sutures in a synthetic model. Process measures were quantified using an opto-electric motion/force sensor assembly that recorded: instrument rotation, applied forces, time, and time delays between force application and instrument rotation. RESULTS: Advanced trainees showed increased instrument rotation, higher peak applied force, and faster performance compared to novices (alll p < .01). However, over trials, only novices showed adaptations for instrument rotation and total time (interactions at p < .01) with no adaptation for the force application. The difference between the moments of force application and instrument rotation was not sensitive to participant training. CONCLUSIONS: Movement process measures can enhance our understanding of early adaptation processes and how such factors might be used as feedback to facilitate skill acquisition.

Clinical Competence↗

PubMed2005

Surface exploration using laparoscopic surgical instruments: the perception of surface roughness.

During laparoscopic surgery video images are used to guide the movements of the hand and instruments, and objects in the operating field often obscure these images. Thus, surgeons often rely heavily on tactile information (sense of touch) to help guide their movements. It is important to understand how tactile perception is affected when using laparoscopic instruments, since many surgical judgements are based on how a tissue 'feels' to the surgeon, particularly in situations where visual inputs are degraded. Twelve naïve participants used either their index finger or a laparoscopic instrument to explore sandpaper surfaces of various grits (60, 100, 150 and 220). These movements were generated with either vision or no vision. Participants were asked to estimate the roughness of the surfaces they explored. The normal and tangential forces of either the finger or instrument on the sandpaper surfaces were measured. Results showed that participants were able to judge the roughness of the sandpaper surfaces when using both the finger and the instrument. However, post hoc comparisons showed that perceptual judgements of surface texture were altered in the no vision condition compared to the vision condition. This was also the case when using the instrument, compared to the judgements provided when exploring with the finger. This highlights the importance of the completeness of the video images during laparoscopic surgery. More normal and tangential force was used when exploring the surfaces with the finger as opposed to the instrument. This was probably an attempt to increase the contact area of the fingertip to maximize tactile input. With the instrument, texture was probably sensed through vibrations of the instrument in the hand. Applications of the findings lie in the field of laparoscopic surgery simulation techniques and tactile perception.

Adult↗