Kinetostatic Design of Ankle Rehabilitation Mechanism Capable of Adapting to Changes in Joint Axis
Daisuke Matsuura, Tatsuya Koga, Shota Ishida,
and Yukio Takeda
Department of Mechanical Sciences and Engineering, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, Tokyo 152-8552, Japan
This paper proposes a simple spatial rehabilitation mechanism that aims to exert the desired flexion motion with adjustable load and also to provide an objective measure of recovery status, in terms of mobilization, force, and torque, on the affected part. This is to verify the condition of therapeutic exercise to support physiotherapists, as well as to establish selfrehabilitation by patients themselves. In this work, the composition of the mechanism is first determined by extending Oldham’s coupling mechanism. Next, a kinetostatic analysis of the mechanism is performed for two purposes. One is to determine a reasonable link dimension that achieves a suitable range of motion for the practical rehabilitation treatment of human ankle joints. The other is to calculate the magnitude of the shearing load on the ankle joint, caused by gravity and the friction of the cylindrical joints. A validation experiment demonstrates the effectiveness of the proposed mechanism and of the kinetostatic analysis. Shearing load is also compensated for through the introduction of springs to certain joints. The optimum location, spring constant, and initial offset of each spring are determined through the proposed kinetostatic analysis scheme.
-  M.Malosio et al., “Analysis of elbow-joints misalignment in upperlimb exoskeleton,” IEEE Int. Conf. on Rehabilitation Robotics, 2011.
-  R. Gregorio et al., “Mathematical models of passive motion at the human ankle joint by equivalent spatial parallel mechanisms,” Medical and Biological Engineering and Computing, Vol.45, No.3, pp. 305-313, 2007.
-  M. Esmaeili et al., “Ergonomic considerations for anthropomorphic wrist exoskeletons: A simulation study on the effects of joint misalignment,” Proc. of IEEE Int. Conf. on Intelligent Robots and Systems, pp. 4905-4910, 2011.
-  D. Jin et al., “Kinematic and dynamic performance of prosthetic knee joint using six-bar mechanism,” J. of Rehabilitation Research and Development, Vol.40, No.1, pp. 39-48, 2003.
-  H. Terada et al., “Developments of a Knee Motion Assist Mechanism for Wearable Robot with a Non-circular Gear and Grooved Cams,” Mechanisms and Machine Science, Vol.3, No.2, pp. 69-76, 2012.
-  A. H. A Stienen et al., “Self-aligning exoskeleton axes through decoupling of joint rotations and translations,” IEEE Trans. on Robotics, Vol.25, No.3, pp. 628-633, 2009.
-  D. Cai et al., “Design of self-adjusting orthoses for rehabilitation,” Proc. of the IASTED Int. Conf. on Robotics and Applications, pp. 215-223, 2009.
-  C. G.Mattacola and M. K. Dwyer, “Rehabilitation of the ankle after acute sprain or chronic instability,” J. of Athletic Training, Vol.37, No.4, pp. 413-429, 2002.
-  F. Gao, Y. Ren, E. J. Roth, R. Harvey, and L. Zhang, “Effects of repeated ankle stretching on calf muscle-tendon and ankle biomechanical properties in stroke survivors,” Clinical Biomechanics, Vol.26, No.5, pp. 516-522, 2011.
-  Y. Sekiguchi, T. Muraki, Y. Kuramatsu, Y. Furusawa, and S. Izumi, “The contribution of quasi-joint stiffness of the ankle joint to gait in patients with hemiparesis,” Clinical Biomechanics, Vol.27, No.5, pp. 495-499, 2012.
-  H. Lee, P. Ho, M. A. Rastgaar, H. I. Krebs, and N. Hogan, “Multivariable static ankle mechanical impedance with relaxed muscles,” J. of Biomechanics, Vol.44, pp. 1901-1908, 2011.
This article is published under a Creative Commons Attribution-NoDerivatives 4.0 Internationa License.
Copyright© 2013 by Fuji Technology Press Ltd. and Japan Society of Mechanical Engineers. All right reserved.