Wagner Christopher R, Emmanouil Evangelos
Medical Technology, Cambridge Consultants, Cambridge, United Kingdom.
Front Robot AI. 2018 Jun 18;5:50. doi: 10.3389/frobt.2018.00050. eCollection 2018.
A popular design choice in current surgical robotics is to use mechanical cables to transmit mechanical energy from actuators located outside of the body, through a minimally invasive port, to instruments on the inside of the body. These cables enable high performance surgical manipulations including high bandwidth control, precision position control, and high force ability. However, cable drives become less efficient for longer distances, for paths that involve continuous curves, and for transmissions involving multiple degrees of freedom. In this paper, we consider the design tradeoffs for two methods of transmitting power through an access port with limited cross sectional area and curved paths - tendon/sheath mechanical transmissions and electrical wire transmissions. We develop a series of analytic models examining fundamental limits of efficiency, force and power as constrained by access geometry, material properties, and safety limits of heat and electrical hazards for these two transmission types. These models are used to investigate the potential of achieving the required mechanical power requirements needed for surgery with smaller access ports and more difficult access pathways. We show that an electrical transmission is a viable way of delivering more than sufficient power needed for surgery, highlighting the opportunity for next-generation actuators to enable more minimally invasive surgical devices.
当前手术机器人领域一种流行的设计选择是使用机械线缆，将位于体外的致动器产生的机械能通过微创端口传输到体内的器械上。这些线缆能够实现高性能的手术操作，包括高带宽控制、精确位置控制和高力输出能力。然而，对于较长距离、涉及连续曲线的路径以及涉及多个自由度的传动而言，线缆驱动的效率会降低。在本文中，我们考虑了两种通过横截面积有限且路径弯曲的接入端口传输动力的方法（腱/鞘机械传动和电线传动）的设计权衡。我们开发了一系列分析模型，研究这两种传动类型在接入几何形状、材料特性以及热和电气危险的安全限制约束下的效率、力和功率的基本极限。这些模型用于研究通过更小的接入端口和更具挑战性的接入路径来满足手术所需机械功率要求的潜力。我们表明，电力传输是一种可行的方式，能够提供远超手术所需的足够功率，这凸显了下一代致动器使手术器械更微创的机会。
