Catheter devices for treating occlusions in body lumen are described herein. The
catheter devices may include a tubular body having a distal end, an
distal portion elastically connected to the distal end of the tubular body, an impactor connected to the
distal portion and separated by a space from the distal end of the tubular body, a distal
shock wave emitter located adjacent to the space and connected to a power source, and an
enclosure at least partially surrounding each of the distal end of the tubular body, the elastic
distal portion, the impactor, and the distal
shock wave emitter. The impactor may be configured to move in response to shock
waves generated from the distal
shock wave emitter, such that a length of the space in the proximal-distal direction increases by between 0.05 mm and 0.6 mm.