A diode structure that facilitates tuning the breakdown voltage of the diode structure, and a method for forming and operating the diode structure. The clamp member is a U-shaped member or an E-shaped member with end portions that project from the ends of a cross bar. A method for manufacturing the softgel capsule having one or more areas of reduced shell thickness is also described. An apparatus for simultaneous testing of multiple dies on a wafer has thermal expansion characteristics matching those of the semiconductor die or wafer and provides clean signals. The method further includes accessing an empirical correlation of the optically-measured parameter and the one or more temperature-indicative parameters to concentrations of the substance in blood. The systems, devices and methods may employ catheter based techniques and devices to plicate tissue and perform an annuloplasty.