Robot-assisted surgery has been extensively applied in various microsurgical disciplines owing to its enhanced accuracy and dexterity based on the motion-scaling function between a hand and a surgical instrument. However, the surgical robot system developed thus far incurs high manufacturing costs and restricted compatibility due to the complicated control system, including many actuators and sensors. This paper proposes a novel passive mechanism for motion scaling based on the pantograph structure to resolve these drawbacks of robotic assistance devices. As a first step, a design configuration featuring gravity compensation and the duplication of directional motion is suggested. Subsequently, the geometric dimensions required to satisfy the surgical space and structural constraints are defined. Moreover, the mass of elements required to enable gravity compensation is calculated using moment equations. After determining the principal design parameters, the motion scaling of the proposed passive model is identified using a three-dimensional computer-aided design. In addition, for an extremely precise operation in microsurgery, the dynamic reaction force is expected to be constant in any location. Therefore, to investigate dynamic dexterity, the mathematical model is formulated based on the Lagrangian dynamic equation. Then, the dynamic workspace range is analysed from the determinant of the mass matrix. In addition, the analysis results are evaluated through comparative simulations in different workspace ranges; hence, a constant reaction force can be achieved only in the dynamic workspace range.

中文翻译：

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基于受电弓的显微手术被动运动缩放机构的计算设计和工作空间分析

机器人辅助手术由于其基于手和手术器械之间的运动缩放功能增强的准确性和灵巧性而被广泛应用于各种显微外科学科。然而，由于复杂的控制系统，包括许多致动器和传感器，迄今为止开发的手术机器人系统导致高制造成本和受限的兼容性。本文提出了一种基于受电弓结构的新型被动运动缩放机制，以解决机器人辅助设备的这些缺点。作为第一步，建议采用重力补偿和重复定向运动的设计配置。随后，定义满足手术空间和结构约束所需的几何尺寸。而且，使用力矩方程计算启用重力补偿所需的元素质量。在确定主要设计参数后，所提出的被动模型的运动缩放使用三维计算机辅助设计进行识别。此外，对于显微外科极其精确的手术，预期动态反作用力在任何位置都是恒定的。因此，为了研究动态灵巧性，建立了基于拉格朗日动力学方程的数学模型。然后，从质量矩阵的行列式分析动态工作空间范围。此外，分析结果通过不同工作空间范围内的比较模拟进行评估；因此，只有在动态工作空间范围内才能实现恒定的反作用力。