Abstract
This thesis investigates the design of a standardized forearm orthosis cuff for attaching a user to an upper limb (UL) rehabilitative robot. A well-designed forearm cuff should safely and comfortably support the arm throughout the range of motions required to perform activities of daily living (ADLs), minimize tracking error, be easy to don and doff, and have reasonable manufacturability. Intimate contact with the user’s arm and good alignment between the user and robot are essential for minimizing tracking error and maximizing comfort. Knowledge of arm shape and deformation throughout the desired range of motion is needed to design a high level of contact with the user. Existing data on forearm shape was not found in literature. Therefore, a study with six subjects was conducted where a jig aligned each subject’s arm in two poses: 1) a nearly extreme supination position and 2) a nearly extreme pronation position. Poses were scanned with a white light scanner to obtain point cloud models of the arm shapes. Ellipses were fit to transverse slices of the point cloud data along the rotation axis, and ellipse parameters were curve-fit as a function of axial distance from the elbow. These generalized fits were extrapolated using data from two large scale anthropometric studies of the United States (US) population for a full 5th percentile female to 95th percentile male individual spread for use in the sizing of a standardized forearm orthosis. Design recommendations were made from the results by quantifying size accommodation requirements.