Rotary shaver arrangement for a surgical instrument

Abstract A rotary shaver arrangement for a surgical instrument, the rotary shaver arrangement comprising an outer tubular member with a first cutting window at the distal end thereof; an inner tubular member rotatably mounted in a central passageway of the outer tubular 5 member, the inner tubular member providing a central suction lumen, the inner tubular member having a second cutting window at the distal end of the inner tubular member. Wherein, the first and second cutting windows are arranged such that: (i) when the inner tubular member is rotated to a first range of angular positions, the first and second cutting windows overlap to form an opening of the central suction lumen; and (ii) when the inner to tubular member is rotated to a second range of angular positions, the first and second cutting windows do not overlap and thus do not form the opening of the central suction lumen. Wherein, the first and/or second cutting window comprises a first shaped region, the first shaped region being a spline-shaped region to permit the second range of angular positions to be greater than if the first shaped region was notch-shaped having angular t5 discontinuities. This rotary shaver arrangement optimises suction flow by closing off the opening to the central suction lumen via the cutting windows of the rotary shaver at a greater range of angles than if the cutting window did not have a spline-shaped region and instead had a notch-shaped region. This means less precision is required to close the cutting windows and thus close the opening of the central suction lumen. 14 2 g 7a g 5 7b 6 3a34 3b 3c 5a 5b