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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. [ABSTRACT FROM AUTHOR]

This paper presents a comprehensive study of the forward and inverse kinematics of a six-degrees-of-freedom (DoF) spatial manipulator with a novel architecture. Developed by Systemantics India Pvt. Ltd., Bangalore, and designated as the H6A (i.e., Hybrid 6-Axis), this manipulator consists of two arm-like branches, which are attached to a rigid waist at the proximal end and are coupled together via a wrist assembly at the other. Kinematics of the manipulator is challenging due to the presence of two multi-DoF passive joints: a spherical joint in the right arm and a universal in the left. The forward kinematic problem has eight solutions, which are derived analytically in the closed form. The inverse kinematic problem leads to $160$ solutions and involves the derivation of a $40$ -degree polynomial equation, whose coefficients are obtained as closed-form symbolic expressions of the pose parameters of the end-effector, thus ensuring the generality of the results over all possible inputs. Furthermore, the analyses performed lead naturally to the conditions for various singularities involved, including certain non-trivial architecture singularities. The results are illustrated via numerical examples which are validated extensively. [ABSTRACT FROM AUTHOR]