Choi Ho Seon, Lee Chang Hee, Baek Yoon Su
IEEE Int Conf Rehabil Robot. 2019 Jun;2019:276-281. doi: 10.1109/ICORR.2019.8779486.
As aging progresses, risk of falls in elderly people increases due to the decreasing the range of motion (RoM) of eversion and the weakening of the plantar flexor. Balance training is performed to reduce the risk of falls and powered ankle-foot orthosis (PAFO) can be utilized in this process. The elderly can conduct training on the narrow roads or on the rugged ground with assistance on rotation of eversion and propulsion by PAFO. However, existing PAFOs were developed just by considering the talocrural joint which make the rotation of sagittal plane of ankle which is called by plantar flexion and dorsiflexion. So, we developed the 2 Degree of Freedom (DoF) PAFO which has the Talocrural and Subtalar joints for frontal plane rotation which is called inversion and eversion. We established the coordinate system and calculated the spatial formulas for talocrural and subtalar joint based on anatomical data. Developed PAFO has the pneumatic artificial muscle (PAM) as an actuator which is controlled by solenoid valve with PWM methods, light-weight 3D printed body and knee orthosis for interfacing with wearer in three area which are thigh, shank and foot. The total weight of developed PAFO is 2. 14kg and it can be 1. 44kg without the weight of knee orthosis (0.7kg). Measurement sensors for PAFO were the absolute encoders to measure the angle of talocrural and subtalar joint, tensile loadcell to measure the magnitude of force from PAM, pressure sensor to measure the pressure of PAM and FSR sensor to judge the phase of the gait cycle. The results of the paper show the validation of design, kinematics and functional capacity for human subject experiments with proportional myoelectric control (PMc) of developed PAFO.
随着年龄的增长，老年人跌倒的风险会增加，这是由于外翻活动范围（RoM）减小以及足底屈肌减弱所致。进行平衡训练以降低跌倒风险，在此过程中可使用动力踝足矫形器（PAFO）。老年人可以在PAFO辅助下进行外翻旋转和推进训练，在狭窄道路或崎岖地面上行走。然而，现有的PAFO只是通过考虑距小腿关节来开发的，这使得踝关节矢状面的旋转（即跖屈和背屈）得以实现。因此，我们开发了具有2个自由度（DoF）的PAFO，它具有距小腿关节和距下关节，用于在额状面进行内翻和外翻旋转。我们建立了坐标系，并根据解剖学数据计算了距小腿关节和距下关节的空间公式。所开发的PAFO以气动人工肌肉（PAM）作为执行器，通过电磁阀采用脉宽调制（PWM）方法进行控制，采用轻质3D打印主体以及用于在大腿、小腿和足部三个区域与佩戴者连接的膝关节矫形器。所开发的PAFO总重量为2.14千克，不包括膝关节矫形器（0.7千克）时可为1.44千克。PAFO的测量传感器包括用于测量距小腿关节和距下关节角度的绝对编码器、用于测量来自PAM的力大小的拉力传感器、用于测量PAM压力的压力传感器以及用于判断步态周期阶段的FSR传感器。本文的结果展示了所开发的PAFO在人体实验中的设计、运动学和功能能力的验证，采用了比例肌电控制（PMc）。
