Patent ID: 8795304

Claim:
A rotational atherectomy device for ablation of occluding material in a blood vessel having a diameter, comprising: a catheter having an outer diameter less than the diameter of the blood vessel and a lumen therethrough and further comprising a distal end and a longitudinal axis; a rotatable drive shaft having a lumen therethrough and rotatable and axially translatable within the lumen of the catheter; and an ablating element attached to the distal end of the rotatable drive shaft, comprising more than one flexible finger, each flexible finger comprising: a cutting edge, the cutting edge having an obtuse angle as defined by the angle of intersection of the cutting edge and a line tangent to a circle formed by the cutting edge's tip during rotation; an inner surface, an external surface having a grinding surface thereon, the grinding surface forms a normal angle defined by the angle of intersection of the grinding surface and a line tangent to a circle formed by the grinding surface's tip during rotation, and a thickness between the inner surface and the external surface; the ablating element having at least a deformed retracted position when constrained within the lumen of the catheter and an undeformed expanded position, wherein the deformed retracted position comprises a symmetric profile and the undeformed expanded position comprises an asymmetric profile, wherein the undeformed asymmetric expanded position is achieved by increasing the temperature differentially to select fingers of the ablating element.