A piezoelectrically actuated valveless micropump has been designed and developed. The principle components of this system are piezoelectrically actuated (PZT) metal diaphragms and a complete fluid flow system. The design of this pump mainly focuses on a cross junction, which is generated by a nozzle jet attached to a pump chamber and the intersection of two inlet channels and an outlet channel respectively. During each PZT diaphragm vibration cycle, the junction connecting the inlet and outlet channels with the nozzle jet permits consistencies in fluidic momentum and resistances in order to facilitate complete fluidic path throughout the system, in the absence of any physical valves. The entire micropump structure is fabricated as a plate-by-plate element of polymethyl methacrylate (PMMA) sheets and sandwiched to get required fluidic network as well as the overall device. In order to identify the flow characteristics, and to validate the test results with numerical simulation data, FEM analysis using ANSYS was carried out and an eigenfrequency analysis was performed to the PZT diaphragm using COMSOL Multiphysics. In addition, the control system of the pump was designed and developed to change the applied frequency to the piezoelectric diaphragms. The experimental data revealed that the maximum flow rate is 31.15 mL/min at a frequency of 100 Hz. Our proposed design is not only for a specific application but also useful in a wide range of biomedical applications.

Prosthesis is a device extension which is used to replace a missing body part. Amputees who lost all or part of the upper limb may use a prosthesis depending on their requirement. Externally powered prosthesis holds an importance since it is capable of imitating natural limb motions. However, the way they are controlled stand way back from the natural limb. Myoelectric control systems which uses electromyographic signals holds an important role in controlling prosthesis. This paper reviews the myoelectric control systems for upper limb prosthesis. At first control methods based only on myoelectric signals are briefly reviewed. The main focus is given to review hybrid myoelectric control systems. Hybrid myoelectric control methods are categorized and each category is compared and reviewed. Finally feasibility of using vision as an added sensor was discussed with examples from literature.