Biologically inspired knee prosthesis

对于膝上(AK)截肢的患者来说，需要更好的假体解决方案。尽管通过引入微控膝盖和能量恢复足取得了改善，但使用当代假体的AK截肢者仍然存在严重的步态不对称，与非截肢者相比，跌倒的风险更高，消耗的能量也更多。在过去的40年里，有一个因素没有太大变化，那就是假体的“运动学”设计，它的设计特性决定了小腿相对于大腿的运动方式。1970年S推出的多中心膝关节，采用平面连杆机构提供站姿(锁定和释放)控制，仍然是固定铰链的首选替代方案。尽管多中心膝关节比微控膝关节更实惠，但如果截肢者需要对失去行走平衡做出快速反应，多中心膝盖的固有稳定性实际上可能是一个潜在的危险。电动膝盖将很快出现在商业市场上，但目前的运动学设计解决方案不适合控制膝盖在行走过程中如何传递能量。工程师们必须重新思考假膝的设计理念。 这项Discovery Grant研究的长期目标是改善膝关节以上截肢者的假体功能。短期目标是探索一种新的设计AK假体的方法，该方法借鉴了自然关节组织的显著生物排列，提供了控制假体的最佳生物力学系统，同时保持了一种节俭和经济的设计方法。具体执行目标如下： 目标1(1-3岁)是设计和开发一种在矢状面上对膝关节进行主动(同心)和被动(偏心)控制的有效的屈伸肌机构，它利用“生物力学”膝关节模拟来控制屈伸旋转和前后平移的运动学控制。 目标2(3-5年)是设计和开发一种动力总成和执行器控制系统，能够通过基于计算机算法的假体调节能量传输来提供对生物启发的膝关节的同心和偏心控制，该计算机算法模拟中枢神经系统如何识别和自动调节关节的运动模式。 其结果将是一个经过充分台架测试的假体原型，将为下一阶段的开发(6-10年)做好准备，下一阶段将把脚踝-脚控制纳入假肢。

There is a significant need for better prostheses solutions for individuals with above-knee (AK) amputation. Despite improvements made by introducing micro-controlled knees and energy returning feet, individuals with AK amputation that use contemporary prostheses still have significant gait asymmetry, are at a higher risk of falls, and expend more energy compared to non-amputees. One factor that has not changed much in the past four decades is the “kinematic” design of prostheses the properties of its design that governs how it moves the lower-leg relative to the upper leg. The polycentric knee introduced in the 1970's that employs a planar linkage for providing stance (lock and release) control is still the favored alternative to a fixed hinge. Although more affordable than micro-controlled knees, the inherent stability of polycentric knees can actually be a potential hazard to the amputee should they need to quickly respond to a loss of walking balance. Powered knees will soon be emerging in the commercial market but the current kinematic design solutions will not be suitable for controlling how the knee transfers energy during walking. Engineers must re-think the design philosophy of the prosthetic knee. The long-term objective of this Discovery Grant research is to improve functionality of prostheses for above-knee amputees. The short-term objective is to explore a new approach to the design of AK prostheses that borrows from the salient biological arrangement of tissues of the natural joint that provide an optimal biomechanical system for controlling the prosthesis, while maintaining a parsimonious and economical design approach. The specific aims to be executed are as follows: Aim 1 (Years 1-3) is to design and develop an efficient flexor/extensor mechanism for both active (concentric) and passive (eccentric) control of the knee in the sagittal plane, that utilizes a “bio-mechanical” knee analog to govern kinematic control of the flexion/extension rotation and anterior/posterior translation. Aim 2 (Years 3-5) is to design and develop a power train and actuator control system capable of providing concentric and eccentric control of the biologically inspired knee by regulating power transfer through the prosthesis based on computer algorithms that models how the central nervous system recognizes and automatically regulates movement patterns of the joints. The outcome will be a fully bench-tested prototype of the prosthesis that will be ready for the next phase of development (Years 6-10), which is incorporating ankle-foot control into the prosthesis.