An IGBT includes at least one first type transistor cell, including a base region, first and second emitter regions, and a body region arranged between the first emitter region and base region. The apparatus includes red and green lights, a circuit that controls energization of the lights, and a pushbutton switch that operates a portion of a circuit. If the desired SNR is greater than the SNR of an exposure using the maximum exposure time, multiple exposures can be taken at the maximum exposure time, and can be combined to obtain a spectrum having a SNR which at least approximates the one desired. Thus, both ends of a double-ended needle cannula are lockingly enclosed following use of the needle assembly of the inventive safety shield system. The power supply is contained in a rear end of the device and the case forms a portion of the power supply circuit.