This paper describes research work directed towards the development and application of a design methodology to determine the optimal configuration of a powered upper-limb orthosis. The design objective was to minimize the orthosis complexity, defined as the number of degrees of freedom, while maintaining the ability to perform specific tasks. This objective was achieved in three stages. First, potential users of a powered orthosis were interviewed to determine their priority tasks. Secondly, the natural arm motions of able-bodied individuals performing the priority tasks were profiled using a video tracking system. Finally, a kinematic simulation algorithm was developed and employed in order to evaluate whether a proposed orthosis configuration could perform the priority tasks. The research results indicate that task functionality is overly compromised for orthosis configurations with less than five degrees of freedom, plus prehension. Acceptable task performance, based on the specific priority tasks considered, was achieved in the simulations of two different orthosis configurations with five degrees of freedom. In the first design option, elevation (rotation about a horizontal axis through the shoulder) and radidulnar deviation are fixed, while in the second option wrist flexion and radiduhar deviation are hed. A prototype orthosis is currently being developed using the first design option.

No abstract

No abstract

The accuracy and reproducibility of a new non-contact sensor for monitoring skin temperature was examined. Thirty measurements taken by the device were compared with those taken by a commonly used thermocouple contact sensor. The result was a very high correlation coefficient (r = 0.9999). This accuracy was achieved with the probe held at an angle of 90 degrees 1 cm from the skin. Changes in angle and distance were found to contribute to measurement error. Little difference was found between 39 pairs of measurements taken of the left and right sides of subjects. However, intra-subject variability was noted with respect to the dermotomal segmental fields. Inter-tester reliability analysis resulted in a correlation of r = 0.937 involving two independent testers and 26 pairs of measurements. These preliminary data will be used for power calculations to study further the device which we found to be simple to operate, portable, and practical for routine clinical use. This sensor may have applications in the diagnosis of nerve and vascular disorders and in prospective monitoring of skin conditions such as bony areas at risk of pressure ulcers.

No abstract