Open AccessDesign and evaluation of prosthetic shoulder controller
Author(s) -
Joseph E. Barton,
John D. Sorkin
Publication year - 2014
Publication title -
journal of rehabilitation research and development
Language(s) - English
Resource type - Journals
eISSN - 1938-1352
pISSN - 0748-7711
DOI - 10.1682/jrrd.2013.05.0120
Subject(s) - position (finance) , amputation , prosthesis , protocol (science) , controller (irrigation) , simulation , computer science , kinematics , physical medicine and rehabilitation , robot end effector , work (physics) , humerus , control theory (sociology) , engineering , control (management) , medicine , robot , surgery , artificial intelligence , mechanical engineering , physics , alternative medicine , finance , pathology , classical mechanics , agronomy , economics , biology
We developed a 2-degree-of-freedom (DOF) shoulder position transducer (sensing shoulder protraction-retraction and elevation-depression) that can be used to control two of a powered prosthetic humerus' DOFs. We also developed an evaluation protocol based on Fitts' law to assess the performance of our device. The primary motivation for this work was to support development of powered prosthetic shoulder joints of a new generation of prosthetic arms for people with shoulder disarticulation and very high-level transhumeral amputation. We found that transducers that provided resistance to shoulder movement performed better than those providing no resistance. We also found that a position control scheme, where effector position is proportional to shoulder position, performed better than a velocity control scheme, where effector velocity is proportional to shoulder position. More generally, our transducer can be used to control motion along any two DOFs under a proportional control scheme. It can also be used in a more general 4-DOF control scheme by sequentially controlling two DOFs at a time. The evaluation protocol has general applicability for researchers and practitioners. Researchers can employ it to compare different prosthesis designs and control schemes, while practitioners may find the evaluation protocol useful in evaluating and training people with amputation in the use of prostheses.