US Patent 9352131 Twisted ribbon wire guidewire coil

A medical guidewire having distal tip coil that includes a twisted ribbon wire construction. The distal tip coil is mounted to the distal end of the distal core section of the guidewire. The coil is made from a flat ribbon wire with a polygonal, preferably rectangular, cross-section that is twisted along the length of the wire. The twisted, flat ribbon wire creates a tip coil that has a roughened, undulating surface at the outer circumference that, whether coated or bare, is perceptible to the physician or cardiologist when pushing or torquing the guidewire in an interventional procedure.