A linkage design for the 'machine-to-patient' interface of a servo-controlled motorised hand therapy machine

摘要

The authors have developed a continuous passive motion (CPM) machine for the therapeutic treatment of finger disorders. The machine operates under position feedback control using Visual Basic software operating on a laptop computer. It has proved to be extremely difficult to provide adequate fixation of the machine's actuating rod onto a patient's finger because of the latter's cylindrical shape and the small sizes of the phalanges. The authors identified an urgent need to develop a linkage assembly which could be applied to a finger and which fulfilled three functions, namely; it securely attached an actuating rod to a finger, it moved the finger in an arcuate fashion, and it provided the facility for individual goniometer attachment to all three finger joints. The authors have used DE/Mec mechanism software to design two linkages, with one and two degrees of freedom, which behave as 'kinematic chains'. The two degree of freedom linkage has been manufactured and it can be used either in a passive mode (i.e. driven by a machine) or an active mode (i.e. driven by a patient).