A system measures propagation delays in any number of test circuits, each having two asynchronous inputs and an output, without using their clock inputs to re-initialize the test circuits during measurement operations. The optical-mode-converter structure includes a tapered optical core on a planar substrate, an optical cladding layer covering the tapered optical core and a mode-expanding layer. This system includes a cooler housing, a reinforced lid, a radiation reflective material application, and a system to remove air from the containment area, thus creating a vacuum within the cooler itself and sealing the lid to the cooler housing. The DDD is written in a platform independent markup language. The cavity includes a coupling portion near the distal end of the connector, and the proximal end of the connector is connected to the distal end of the flush tube portion or the distal end of the catheter tube such that the cavity of the connector is in fluid communication with the single lumen of the flush tube portion or the plurality of lumens in the catheter tube.