Haptic interfaces play a critical role in medical teleoperation by enabling surgeons to interact with remote environments through realistic force and motion feedback. Achieving high fidelity in such systems requires balancing the trade-offs among workspace, dexterity, stiffness, inertia, and bandwidth, particularly in applications demanding pure rotational motion. This paper presents the design methodology and kinematic analysis of a Cable-Driven Coaxial Spherical Parallel Mechanism (CDC-SPM) developed to address these challenges. The proposed approach focuses on the mechanical design and parametric synthesis of the mechanism to meet task-specific requirements in medical applications. In particular, the design enables the relocation of the center of rotation to an external point corresponding to the tool-tissue interaction, while ensuring appropriate workspace coverage and collision avoidance. The proposed cable-driven interface design allows for reducing the mass placed at the robot arm end-effector, thereby minimizing inertial loads, enhancing stiffness, and improving dynamic responsiveness. Through parallel and coaxial actuation, the mechanism achieves decoupled rotational degrees of freedom with isotropic force and torque transmission. A prototype is developed to validate the mechanical feasibility and kinematic behavior of the proposed mechanism. These results demonstrate the suitability of the proposed mechanism design for future integration into haptic interfaces for medical applications such as ultrasound imaging.

翻译：力触觉接口在医疗遥操作中发挥关键作用，通过提供真实的力和运动反馈使外科医生能够与远程环境交互。实现此类系统的高保真度需要权衡工作空间、灵巧度、刚度、惯性和带宽等参数，特别是在需要纯旋转运动的应用场景中。本文提出了一种解决这些挑战的线缆驱动同轴球面并联机构（CDC-SPM）的设计方法与运动学分析。所提方法聚焦于该机构的机械设计和参数综合，以满足医疗应用中的特定任务需求。具体而言，该设计能够将旋转中心移至对应工具-组织相互作用点的外部位置，同时确保适宜的工作空间覆盖和避碰条件。所提出的线缆驱动接口设计可减少机器人手臂末端执行器的质量，从而降低惯性载荷、增强刚度并提升动态响应性能。通过并联同轴驱动方式，该机构实现了解耦的旋转自由度，并具备各向同性的力和力矩传递特性。开发了原型样机以验证该机构的机械可行性和运动学特性。结果表明，提出的机构设计方案适用于未来集成至超声成像等医疗应用的力触觉接口中。