Medical instruments for performing minimally-invasive procedures

1. Apparatus for performing a minimally-invasive procedure, the apparatus comprising:

a shaft having a distal end and a proximal end;

a monopolar knife assembly attached to the distal end of the shaft, the monopolar knife assembly comprising a knife;

a handle attached to the proximal end of the shaft;

wherein the shaft comprises a flexible portion and a first articulating portion, wherein the flexible portion extends distally from the handle and the first articulating portion extends distally from the flexible portion;

wherein the shaft comprises a second articulating portion, wherein the second articulating portion is disposed between the flexible portion and the first articulating portion;

wherein at least one first articulation cable extends from the handle to the first articulating portion, such that when tension is applied to the at least one first articulation cable, the first articulating portion deflects;

wherein at least one second articulation cable extends from the handle to the second articulating portion, such that when tension is applied to the at least one second articulation cable, the second articulating portion deflects;

wherein an actuation element extends through the shaft from the handle to the knife, such that when the actuation element is moved, the knife is moved; and

wherein the actuation element transmits electrical power from the handle to the knife.

2. Apparatus according to claim 1 wherein the knife comprises a distal end and a proximal end, and further wherein the distal end of knife comprises a rounded front portion and a flattened back portion.

3. Apparatus according to claim 1 wherein the knife comprises a distal end and a proximal end, and further wherein the proximal end of the knife comprises a mount.

4. Apparatus according to claim 3 wherein the mount comprises a distal end, a proximal end and a cylindrical wall extending between the distal end and the proximal end, and further wherein the cylindrical wall is recessed to provide a plurality of concave portions and a plurality of convex portions.

5. Apparatus according to claim 1 wherein the knife is received in a knife housing, and further wherein the actuation element extends and retracts the knife relative to the knife housing.

6. Apparatus according to claim 5 wherein the knife housing comprises a stepped bore having a first portion and a second portion, wherein the first portion is distal to the second portion, and further wherein the first portion has a smaller diameter than the second portion.

7. Apparatus according to claim 6 wherein the second portion limits extension of the knife relative to the knife housing.

8. Apparatus according to claim 1 further comprising a tube extending from the handle to the distal end of the shaft.

9. Apparatus according to claim 8 wherein the actuation element extends through the tube.

10. Apparatus according to claim 8 wherein the tube is configured so that fluid can be passed through the tube from the handle to the distal end of the shaft.

11. Apparatus according to claim 10 wherein the handle comprises a fluid inlet port for receiving fluid.

12. Apparatus according to claim 1 wherein the articulating portion and the second articulating portion articulate independently of one another.