A filter for filtering micro-emboli from a patient’s blood during an angioplasty procedure is disclosed which comprises a plurality of curved wires connected to a rod between a first connector fixed with respect to the rod and a second connector slidingly mounted on the rod. The digital demodulation apparatus includes a pulse width counter for measuring a cycle of a modulated signal to generate digital cycle information. The side portions and a rear portion may also be partially constructed out of a mesh material to allow for air flow to the skin. An end user application is stored in the memory for controlling the processor and the memory, and operates on top of the operating system image.