A surgical system including a tubular shaft having a wall defining an outer surface and an inner surface disposed about an inner space, the tubular shaft having a proximal end and a distal end. The system also includes a light emitter and a light sensor disposed at the distal end of the tubular shaft, and one or more conductors electrically coupled to the light emitter or the light sensor. The one or more conductors extend from the distal end of the tubular shaft to the proximal end of the shaft, and are disposed radially outward of the inner surface of the tubular shaft.