Abstract: An ambulatory assistance device includes a base having a set of wheels the base configured to at least partially surround a patient's body to provide a maximum level of support along all possible force vectors. The base includes ballast to lower the center of gravity of the ambulatory assistance device. Furthermore, the ambulatory assistance device includes a frame assembly having a handle extending from the base. The handle is disposed at a distance between about two inches and three inches proximal to the center of gravity of the unit. This positioning of the handle, in combination with the positioning of the wheels of the base provides the ambulatory assistance device with a substantially stable design.

Abstract: Systems and methods for implementing hybrid, closed-loop control that generates control values for processes defined by a limited number of function evaluations and large amounts of process and measurement noise. The described control system is applied to a stencil printing process for applying solder paste to an electronic medium such as a printed circuit board or semiconductor wafer. The control system is defined by a hybrid approach. A first, coarse algorithm is used to rapidly produce the value of a stencil printer control value resulting in a solder paste deposit having a volume within predetermined acceptable limits. After the coarse algorithm no longer produces solder paste deposits closer to a desired volume, a second, more refined estimator is used to fine tune the process. An additional transitional algorithm may be added between the coarse algorithm and refined estimator.