Methods and apparatus for enabling local content sharing are described. The current collector plate 50 has a plurality of protrusions 52 extending radially thereof and joined to an edge of the electrode unit. The sensor may have an emitter and a detector configured to pass a multi-wavelength PDW input signal into a patient and receive a resulting multi-wavelength PDW output signal. The data can be filtered to a reduced number of events with a network monitoring engine. The op amp output supplies the resistor and diode network and brings the op amp inputs within desired regulation voltages.