Method and apparatus for removal of tissue
A surgical instrument includes a deflectable cutting element extending from the distal end of the instrument. The deflection of the cutting element is controllable based on a user operating a moveable member of the instrument. The deflectable cutting element is normally disposed within a circumferential region defined by the distal end of the instrument. The moveable member can be moved in relation to the instrument to deflect the deflectable cutting element, such that the cutting element is at least partially outside of the circumferential region. The extent that the cutting element is outside of the circumferential region is a function of the position to which the moveable member is moved in relation to the instrument. The instrument further includes direct imaging of the distal end, such that the deflection of the cutting element for selective removal of bone tissue at the distal end of the instrument can be controlled in real-time.
1. A surgical instrument comprising:
a tubular member having an axis, a first end coupled to a drive housing and a second end coupled to a cutting apparatus including a rotatable and deflectable cutting element, wherein the second end of the tubular member defines a circumferential region;
a drive shaft having a first end coupled to a rotatable drive member in the housing and a second end coupled to the cutting element, wherein the drive shaft translates rotational motion at the drive member to the cutting element to cause rotation of the cutting element;
a thrust member having a first end within the housing and a second end coupled to a resilient member in the cutting apparatus, wherein the resilient member is coupled to the cutting element and bending of the resilient member causes movement of the cutting element away from the axis of the tubular member;
a first fluid flow path extending from within the housing, through a bore defined in the tubular member, and terminating at the cutting apparatus;
wherein the bore of the tubular member includes a second fluid flow path extending between the drive housing and the cutting apparatus and being distinct from the first flow path;
wherein, in an at rest condition of the instrument, the cutting element is disposed within the circumferential region defined by the second end of the tubular member;
wherein the first flow path or the second flow path is for receiving an optical waveguide having a lens tip positionable proximate the cutting apparatus; and
a moveable member coupled to the first end of the thrust member and operable to set the instrument to a deflected condition, wherein when the instrument is in the deflected condition the moveable member applies a force at the first end of the thrust member causing the second end of the thrust member to bend the resilient member, such that the cutting element is moved away from the axis of the tubular member and is disposed at least partially outside the circumferential region defined by the second end of the tubular member, wherein, in the deflected condition of the instrument, an extent the cutting element is disposed outside the circumferential region is in accordance with an extent the thrust member is caused to move toward the cutting element by movement of the moveable member.
2. The surgical instrument of claim 1 , wherein the moveable member includes a lever rotatably coupled to the housing, wherein when the lever rotates towards the housing the cutting element moves away from the tubular axis, and wherein when the lever rotates away from the housing the cutting element moves toward the tubular axis.
3. The surgical instrument of claim 2 , wherein the resilient member biases the cutting element toward the axis of the tubular member such that the extent that the cutting element is moved away from the tubular axis depends on an amount of force applied to the lever to cause rotation of the lever toward the housing.
4. The surgical instrument of claim 1 , wherein the resilient member includes first and second leaf springs coupled to each other and to the cutting element, wherein the second leaf spring is fixed to the tubular member, wherein the first and second leaf springs are flat and parallel when the instrument is in the at rest condition and wherein, when a force is applied to the first end of the thrust member, the first leaf spring moves in relation to the second spring to cause bending of the first and second leaf springs away from the tubular axis such that the cutting element is moved away from the axis of the tubular member.
5. The surgical instrument of claim 4 , wherein the first and second leaf springs have a torsional stiffness sufficient to provide for cutting of tissue based on contact between the cutting element and the tissue when the instrument is in the deflected condition and the cutting element is rotating.
6. The surgical instrument of claim 1 , wherein the thrust member defines a bore through which the drive shaft extends.
7. The surgical instrument of claim 1 , wherein the drive member includes a shaft fitting for transmitting torque applied to the drive member to the first end of the drive shaft.