Reciprocating rotary surgical cutting device and system for tissue resecting, and method for its use

A tissue resecting system comprising:

• a cutting device having an elongated outer member and an elongated inner member received at least partially within the elongated outer member;
• an endoscope having a distal region configured to be inserted into an organ, the endoscope forming an internal working channel configured to receive at least a portion of the cutting device therein such that a distal tip of the cutting device protrudes out of a distal end of the endoscope;
• and
• a driving assembly coupled to the cutting device such that the driving assembly is configured to cause the elongated inner member to rotate and move linearly relative to the elongated outer member of the cutting device, the driving assembly including:
• (i) a helical member comprising a platen and at least one helical channel, the helical member being configured to be rotated by a rotary driver at a first rotational speed, and
• (ii) a planetary gear assembly including a ring gear, a plurality of planetary gears, and a sun gear, the sun gear being coupled to the elongated inner member of the cutting device such that the sun gear and the elongated inner member rotate at the same rotational speed and move linearly at the same linear speed, each of the plurality of planetary gears engaging the ring gear and being rotationally coupled to a respective stub shaft protruding from the platen of the helical member, the sun gear being positioned between the plurality of planetary gears such that the plurality of planetary gears engage the sun gear and cause the sun gear to rotate at a second rotational speed that is different than the first rotational speed.

A method of removing tissue from an organ, the method comprising:

• inserting a distal portion of an endoscope into the organ, the endoscope having an internal working channel;
• inserting a cutting device into the working channel of the endoscope such that a distal tip of the cutting device protrudes out of a distal end of the endoscope and into the organ for cutting and detaching tissue, the cutting device having an elongated outer member and an elongated inner member received at least partially within the elongated outer member;
• energizing an electric motor to rotate an inner hub that transfers motion to a driven member about a central axis of a helical member at a first rotational speed, the helical member having a platen with a plurality of stub shafts extending therefrom;
• rotating a plurality of planetary gears about the central axis of the helical member at the first rotational speed, each of the plurality of planetary gears being rotationally coupled with a respective one of the plurality of stub shafts;
• engaging the plurality of planetary gears with a ring gear thereby causing each of the planetary gears to rotate about its respective one of the plurality of stub shafts at a second rotational speed that is different than the first rotational speed;
• and
• engaging a sun gear with the plurality of planetary gears such that the plurality of planetary gears causes the sun gear to rotate about the central axis of the helical member at a third rotational speed that is different from the first and second rotational speeds, the sun gear being attached to the elongated inner member of the cutting device such that the elongated inner member rotates at the third rotational speed.