A device suitable for removing material from a living being is provided, featuring at least an aspiration pump, powered by a motor. The aspiration pump and any optional infusate pump preferably feature a helical pumping mechanism, and operate at a high rate of rotation, thereby ensuring adequate pumping performance and flexibility. The helical pumping mechanism may be a helical coiled wire about a central core tube. The helical coil wire, whether together with, or independent of, the core tube, may be rotated to cause a pumping action. Additionally, a narrow crossing profile is maintained, ensuring that the device may reach more tortuous regions of the vasculature. In one embodiment, the system comprises a wire-guided mono-rail catheter with a working head mounted on a flexible portion of the catheter that can laterally displace away from the guide wire to facilitate thrombus removal. The working head may be operated to separate and move away from the guide wire to come within a closer proximity of the obstructive material to more effectively remove it from the vessel.