Department of Bioengineering, University of Washington, Seattle, WA 98195, United States.
Department of Mechanical Engineering, University of Washington, Seattle, United States.
Med Eng Phys. 2019 Jun;68:94-100. doi: 10.1016/j.medengphy.2019.04.003. Epub 2019 Apr 23.
Sockets that allow incremental size adjustment during ambulation may help prosthesis users improve management of their changes in limb volume and the quality of their prosthetic fit. A platform system was developed that allowed people with trans-tibial limb loss to adjust the radial positions of socket panels during ambulation in small increments via a motor mounted beneath the socket. The motor altered the length of a cable running through the socket panels according to commands communicated from a mobile phone. A proportional-integral-derivative controller adjusted the voltage applied to the motor via pulse-width modulation to achieve target settings. Bench test results showed that when the system was subjected to loads comparable to those expected during clinical use, maximum absolute steady state error was 0.036 mm. Treadmill testing on 16 people with trans-tibial limb amputation demonstrated that the range of cable lengths over which participants deemed fit clinically acceptable varied between 24 mm and 114 mm depending on the user. In field testing 11 of 13 participants were comfortable making socket size adjustments while walking. The developed system achieves incremental socket size adjustments appropriate for research and development of ambulatory adjustable sockets.
在助行过程中允许进行增量尺寸调整的插座可能有助于假肢使用者更好地管理肢体体积的变化和假肢适配的质量。开发了一种平台系统，允许小腿截肢者通过安装在插座下方的电机，以小增量调整插座面板的径向位置。电机根据从移动电话发送的命令，改变穿过插座面板的电缆的长度。比例积分微分控制器通过脉宽调制调整施加到电机的电压，以实现目标设置。当系统承受与临床使用中预期的负载相当的负载时，台架测试结果表明，最大绝对稳态误差为 0.036 毫米。对 16 名小腿截肢者进行的跑步机测试表明，参与者认为在临床可接受范围内的电缆长度范围因用户而异，在 24 毫米至 114 毫米之间。在现场测试中，13 名参与者中有 11 名在行走时感到舒适，可以进行插座尺寸调整。开发的系统实现了适合于研究和开发可调节助行器插座的增量插座尺寸调整。
