US Patent 7086266 Method of producing tapered or pointed cannula

A method of producing a tubular device is provided. The method comprises providing a tubular stock having an axial passage, heating the tubular stock at a first heating location to form a softened section, the softened section separating a workpiece portion of the tubular stock from a remaining portion of the tubular stock, and drawing the workpiece portion away from the remaining portion to elongate the softened section and separate the workpiece portion from the remaining portion to form the tubular device. The drawing is performed at a rate such that the tubular device has an axial passage having a substantially uniform inside diameter, and an end of the tubular device formed from the elongated softened section is tapered.