Abstract: A programmable signal translating device, praticularly a transversal filter, includes a wave transport body for transporting a wave along its length, a first channel of electrical conductors having a plurality of code sections spaced along its length for generating phase-coded electrical signals from the wave propagated by the transport body, a second channel of electrical conductors connected in parallel to the first channel and of identical code sections as, but of opposite polarity to, the first channel, and programmable electrical connections between the code sections of the first channel and the code sections of the second channel and the output circuit, for connecting selected code sections of the first and second channels to the output circuit.

Abstract: A drop monitoring unit for monitoring the rate of drop formation in an infusion set includes an attaching section at its upper end for attaching the drop monitoring unit to the inlet tube of the infusion set, and a pair of spaced parallel arms depending below the attaching section to straddle the opposite sides of the drip chamber, one of the arms including a light transmitter, and the other including a light receiver.