Tremor Assessment in Robot-Assisted Microlaryngeal Surgery Using Computer Vision-Based Tool Tracking.

OBJECTIVE: Use microscopic video-based tracking of laryngeal surgical instruments to investigate the effect of robot assistance on instrument tremor. STUDY DESIGN: Experimental trial. SETTING: Tertiary Academic Medical Center. METHODS: In this randomized cross-over trial, 36 videos were recorded from 6 surgeons performing left and right cordectomies on cadaveric pig larynges. These recordings captured 3 distinct conditions: without robotic assistance, with robot-assisted scissors, and with robot-assisted graspers. To assess tool tremor, we employed computer vision-based algorithms for tracking surgical tools. Absolute tremor bandpower and normalized path length were utilized as quantitative measures. Wilcoxon rank sum exact tests were employed for statistical analyses and comparisons between trials. Additionally, surveys were administered to assess the perceived ease of use of the robotic system. RESULTS: Absolute tremor bandpower showed a significant decrease when using robot-assisted instruments compared to freehand instruments (P = .012). Normalized path length significantly decreased with robot-assisted compared to freehand trials (P = .001). For the scissors, robot-assisted trials resulted in a significant decrease in absolute tremor bandpower (P = .002) and normalized path length (P < .001). For the graspers, there was no significant difference in absolute tremor bandpower (P = .4), but there was a significantly lower normalized path length in the robot-assisted trials (P = .03). CONCLUSION: This study demonstrated that computer-vision-based approaches can be used to assess tool motion in simulated microlaryngeal procedures. The results suggest that robot assistance is capable of reducing instrument tremor.

Effect of dietary cholesterol on biliary lipids in patients with gallstones and normal subjects.

The purpose of this study was to determine the effect of dietary cholesterol on biliary lipids in subjects with and without gallstones. Twelve patients with asymptomatic gallstones (six men, six women) were assigned diets containing 500, 750, and 1000 mg cholesterol daily for 3-wk periods in random sequence. Seven healthy women similarly were assigned diets containing 500 and 1000 mg cholesterol daily. With increasing dietary cholesterol in patients with gallstones, biliary saturation indices and molar percents of cholesterol and phospholipids increased significantly while molar percent of biliary bile acids decreased significantly. With increasing dietary cholesterol in healthy women, the biliary saturation index and molar percent of cholesterol increased significantly; the mean saturation index exceeded unity on the diet containing 1000 mg cholesterol daily. In conclusion, augmented dietary cholesterol for brief periods increased biliary cholesterol saturation in subjects with and without gallstones.