This paper presents a semi-automatic method for tracking the mitral valve leaflet in transesophageal echocardiography. The algorithm requires a manual initialization and then segments an image sequence. The use of two constrained active contours and curve fitting techniques results in a fast segmentation algorithm. The active contours successfully track the inner cardiac muscle and the mitral v...

Water soluble pullulan films were formatted into paper-based microfluidic devices, serving as a controlled time shutoff valve. The utility of the valve was demonstrated by a one-step, fully automatic implementation of a complex pesticide assay requiring timed, sequential exposure of an immobilized enzyme layer to separate liquid streams. Pullulan film dissolution and the capillary wicking of aq...

A numerical optimization methodology is applied to improve the design of a microchannel structure used in a valveless micropump. The flow simulation algorithm employs the control volume method for Cartesian grids, while advanced numerical techniques are implemented for automatic generation of unstructured, adaptively refined grids and for the representation of irregular boundaries. Several geom...

Reed valves in many small compressors arc usually activated automatically by pressure differences across the valve. These valves arc sometime called automatic valves. They have a very simple geometry and construction but they comprise one of the most complicated performance characteristics. The unsteady vibration of the valve reed during the operation requires a proper design. Generally too sti...

Recently, power assisted nursing care systems have received much attention and active research. In such control system, an actuator and a control valve are mounted on the human body. In such designs, the size and weight of the valve become serious concerns. At the same time, the valve should be operated with lower energy consumption using limited electrical power. The purpose of our study is to...