Development of a 7-DOF Position-Orientation Decoupled Microsurgical Robot with Motorized Instruments for Microvascular Anastomosis
Dunfa Long, Chen Shaoan, Shuai Ao, Zhi-Qiang ZHANG, Chengzhi Hu, Chaoyang Shi
AI summary
Problem
Existing robotic systems for microvascular anastomosis struggle with bulky footprints, limited dexterity, and unaddressed parasitic instrument motions, hindering precision in super-microsurgery.
Approach
The design combines a proximal XYZ positioning platform with a compact parallel dual-chain RCM mechanism for orientation, while motorized instruments employ a reverse self-compensation method to eliminate tip displacement.
Key results
- Sub-40 µm absolute positioning accuracy and ~12 µm repeatability
- 64% reduction in RCM envelope radius and 39% area reduction
- Parasitic tip motion compensated to under 58 µm for motorized instruments
- Validated dexterity through successful needle-threading and stamen peeling tasks
Why it matters
Provides a compact, high-precision robotic platform that overcomes current size and accuracy limitations, advancing the feasibility of automated super-microvascular surgery.
Abstract
This work introduces a novel compact 7-degree-of- freedom (7-DOF) microsurgical robot with position-orientation decoupling capacity for microvascular anastomosis. The proposed system employs a modular architecture combining a proximal displacement platform for 3D small-stroke translation and a distal compact remote center of motion (RCM) mechanism for wide- range orientation adjustment. This design meets the workspace requirements for microvascular anastomosis, requiring extensive orientation adjustments with minimal positional movement and reducing the system footprint. The parasitic motion reverse self- compensation method has been developed for motorized surgi- cal instruments, effectively reducing operational resistance to im- prove precision. Theoretical analysis has been performed on both the RCM mechanism and motorized surgical instruments, and kinematics-based parameter optimization and data-driven cali- bration have been conducted to enhance superior performance. A prototype has been constructed, and its experimental validation demonstrated that the system achieved repeatability of 11.24 ± 2.31 μm (XY) and 12.46 ± 4.48 μm (YZ), and absolute positioning accuracy of 29.80 ± 12.27 μm (XY) and 37.02 ± 19.47 μm (YZ), meeting super-microsurgical requirements. Experiments that in- clude needle-threading and stamen peeling tasks demonstrate the robot’s superior dexterity and manipulation capabilities.