Flexible harmonic waveguides/blades for surgical instruments

1. An articulating ultrasonic surgical instrument, comprising:

an articulable harmonic waveguide, comprising:

a first drive section comprising a proximal end and a distal end, the proximal end configured to connect to an ultrasonic transducer;

a first flexible waveguide coupled to the distal end of the first drive section;

an end effector extending distally from the first flexible waveguide;

an articulation actuator to flex the first flexible waveguide; and

a total curvature limiter configured to prevent the first flexible waveguide from exceeding a predetermined condition;

wherein the predetermined condition comprises a local radius of curvature limiter to prevent a transmission of ultrasonic energy to the articulable harmonic waveguide when the first flexible waveguide exceeds the predetermined condition.

2. The articulating ultrasonic surgical instrument of claim 1 , wherein:

the distal end of the first drive section and a proximal end of the first flexible waveguide are located at an anti-node; and

wherein a distal end of the first flexible waveguide and a proximal end of the end effector are located at an anti-node.

3. The articulating ultrasonic surgical instrument of claim 1 , wherein:

the distal end of the first drive section and a proximal end of the first flexible waveguide are located at a node; and

wherein a distal end of the first flexible waveguide and a proximal end of the end effector are located at a node.

4. The articulating ultrasonic surgical instrument of claim 1 , wherein a center of the first flexible waveguide is located at an anti-node.

5. The articulating ultrasonic surgical instrument of claim 1 , wherein the first flexible waveguide comprises a circular rod.

6. The articulating ultrasonic surgical instrument of claim 1 , wherein the first flexible waveguide comprises a metal ribbon.

7. The articulating ultrasonic surgical instrument of claim 6 , comprising at least one slot formed in the metal ribbon.

8. The articulating ultrasonic surgical instrument of claim 1 , comprising:

a second drive section couple to a distal end of the first flexible waveguide along a longitudinal axis of the articulable harmonic waveguide; and

a second flexible waveguide coupled to a distal end of the second drive section and a proximal end of the end effector.

9. The articulating ultrasonic surgical instrument of claim 8 , comprising:

a pad tine comprising a proximal end and a distal end; and

a surgical pad located at the distal end of the pad tine;

wherein, the pad tine comprises a first tine curvature and a second tine curvature, wherein the first tine curvature is equal to a curvature of the first flexible waveguide, and wherein the second tine curvature is equal to a curvature of the second flexible waveguide.

10. The articulating ultrasonic surgical instrument of claim 1 , the articulation actuator comprising:

a first flange located at a distal end of the first flexible waveguide;

a second flange located at a proximal end of the first flexible waveguide; and

at least one control member coupling the first flange and the second flange.

11. The articulating ultrasonic surgical instrument of claim 10 , wherein:

the at least one control member comprises at least one cable extending proximally from the first flange, the at least one cable connected to the first flange and the second flange, wherein tensioning the at least one cable in a proximal direction causes the first flexible waveguide to flex.

12. The articulating ultrasonic surgical instrument of claim 1 , wherein the local radius of curvature limiter is limited such that:

r

R

<

0.1

where r is a radius of the articulating ultrasonic surgical instrument and R is a local radius of curvature.

13. The articulating ultrasonic surgical instrument of claim 1 , wherein the local radius of curvature limiter is limited such that:

R

=

c

2

⁢

π

·

f

where R is a local radius of curvature, c is a bar speed of sound of a material comprising the first flexible waveguide, and f is a drive frequency delivered to the articulable harmonic waveguide.

14. The articulating ultrasonic surgical instrument of claim 1 , the total curvature limiter comprising an electrical stroke limiter to prevent the transmission of ultrasonic energy to the articulable harmonic waveguide when the first flexible waveguide exceeds the predetermined condition.

15. The articulating ultrasonic surgical instrument of claim 1 , the total curvature limiter comprising a viewing window comprising one or more graduations, wherein the viewing window provides a visual indication of a current local radius of curvature with respect to the predetermined condition.

16. The articulating ultrasonic surgical instrument of claim 1 , the total curvature limiter comprising a resonant frequency shift-tracker configured to generate a control signal when the first flexible waveguide exceeds the predetermined condition, wherein the control signal prevents the transmission of ultrasonic energy to the articulable harmonic waveguide.

17. The articulating ultrasonic surgical instrument of claim 1 , comprising:

a flexible sheath disposed over the articulable harmonic waveguide;

a clamp arm pivotably coupled to the articulable harmonic waveguide;

wherein the articulation actuator comprises:

a first flexible strip;

a second flexible strip;

articulation member comprising a first side and a second side, wherein the first and second flexible strips are coupled to the respective first and second sides of the articulation member, wherein the first and second flexible strips are translatable in a proximal direction and a distal direction to pivot the clamp arm, and wherein the articulation member is rotatable about a center point to articulate the flexible sheath.

18. The articulating ultrasonic surgical instrument of claim 17 , comprising one or more flex features configured to provide a flex bias.

19. A surgical instrument comprising:

a handle;

an ultrasonic transducer located in the handle;

an articulable harmonic waveguide coupled to the ultrasonic transducer, the articulable harmonic waveguide comprising:

a first drive section comprising a proximal end and a distal end, the proximal end configured to connect to the ultrasonic transducer;

a first flexible waveguide coupled to the distal end of the first drive section; and

an end effector extending distally from the first flexible waveguide;

an articulation actuator to flex the first flexible waveguide; and

a total curvature limiter configured to prevent the first flexible waveguide from exceeding a predetermined condition;

wherein the predetermined condition comprises a local radius of curvature limiter to prevent a transmission of ultrasonic energy to the articulable harmonic waveguide when the first flexible waveguide exceeds the predetermined condition.

20. The articulating ultrasonic surgical instrument of claim 19 , wherein:

the distal end of the first drive section and a proximal end of the first flexible waveguide are located at an anti-node; and

wherein a distal end of the first flexible waveguide and a proximal end of the end effector are located at an anti-node.

21. The articulating ultrasonic surgical instrument of claim 19 , wherein a center of the first flexible waveguide is located at an anti-node.

22. A robotic surgical instrument, comprising:

an instrument mounting portion configured to mount to a robotic surgical system, the instrument mounting portion comprising an interface to mechanically and electrically interface to the robotic surgical instrument adapted for use with the robotic surgical system;

an ultrasonic transducer located in the instrument mounting portion;

an articulable harmonic waveguide coupled to the ultrasonic transducer, the articulable harmonic waveguide comprising:

a first drive section comprising a proximal end and a distal end, the proximal end configured to connect to the ultrasonic transducer;

a first flexible waveguide coupled to the distal end of the first drive section; and

an end effector extending distally from the first flexible waveguide; and

an articulation actuator to flex the first flexible waveguide; and

a total curvature limiter configured to prevent the first flexible waveguide from exceeding a predetermined condition;

wherein the predetermined condition comprises a local radius of curvature limiter to prevent a transmission of ultrasonic energy to the articulable harmonic waveguide when the first flexible waveguide exceeds the predetermined condition.