Ultrasonic transducers and ultrasonic surgical instruments including the same

1. An ultrasonic transducer for an ultrasonic surgical instrument, the ultrasonic transducer comprising:

a proximal hub including an internal cartridge, the internal cartridge defining a plurality of indentations arranged in a radial pattern;

a piezoelectric rod array including a plurality of piezoelectric rods, an end portion of each piezoelectric rod of the plurality of piezoelectric rods configured to be inserted into one of the indentations of the plurality of indentations defined within the internal cartridge such that the plurality of piezoelectric rods are disposed about a longitudinal axis of a waveguide,

wherein each indentation of the plurality of indentations defined within the internal cartridge extends distally from the proximal hub along an axis parallel to the longitudinal axis of the waveguide, such that each piezoelectric rod of the plurality of piezoelectric rods is oriented along an axis parallel to the longitudinal axis; and

a distal horn including a distal connector configured to engage the waveguide, the distal horn defining a longitudinal axis aligned with the longitudinal axis of the waveguide when engaged therewith, the proximal hub and the distal horn configured to engage one another to retain the piezoelectric rod array therebetween under compression,

wherein the internal cartridge is disposed between the proximal hub and the distal horn and configured to retain the plurality of piezoelectric rods therein.

2. The ultrasonic transducer according to claim 1 , wherein the proximal hub and the distal horn are configured to directly engage one another to retain the piezoelectric rod array therebetween.

3. The ultrasonic transducer according to claim 1 , wherein the proximal hub and the distal horn are configured to indirectly engage one another to retain the piezoelectric rod array therebetween.

4. The ultrasonic transducer according to claim 3 , further comprising a bolt engaged between the proximal hub and the piezoelectric rod array, the bolt indirectly engaging the proximal hub and the distal horn with one another to retain the piezoelectric rod array therebetween.

5. The ultrasonic transducer according to claim 4 , wherein the bolt is disposed in parallel orientation relative to the plurality of piezoelectric rods with the plurality of piezoelectric rods radially-symmetrically disposed about the bolt.

6. The ultrasonic transducer according to claim 1 , wherein the proximal hub and the distal horn cooperate to define an enclosure enclosing the piezoelectric rod array therein.

7. The ultrasonic transducer according to claim 1 , wherein the distal horn is configured to communicate electrical energy at a first potential to the piezoelectric rod array.

8. The ultrasonic transducer according to claim 7 , wherein the proximal hub is configured to communicate electrical energy at a second, different potential to the piezoelectric rod array.

9. The ultrasonic transducer according to claim 7 , further comprising an electrode disposed between the proximal hub and the piezoelectric rod array, the electrode configured to communicate electrical energy at a second, different potential to the piezoelectric rod array.

10. An ultrasonic surgical instrument, comprising:

a housing;

a waveguide extending distally from the housing;

an ultrasonic blade disposed at a distal end of the waveguide; and

an ultrasonic transducer supported by the housing and coupled to the waveguide such that ultrasonic energy produced by the ultrasonic transducer is transmitted along the waveguide to the ultrasonic blade for treating tissue therewith, the ultrasonic transducer including:

a proximal hub including an internal cartridge, the internal cartridge defining a plurality of indentations arranged in a radial pattern;

a piezoelectric rod array including a plurality of piezoelectric rods, an end portion of each piezoelectric rod of the plurality of piezoelectric rods configured to be inserted into one of the indentations of the plurality of indentations defined within the internal cartridge such that the plurality of piezoelectric rods are disposed about a longitudinal axis of a waveguide,

wherein each indentation of the plurality of indentations defined within the internal cartridge extends distally from the proximal hub along an axis parallel to the longitudinal axis of the waveguide, such that each piezoelectric rod of the plurality of piezoelectric rods is oriented along an axis parallel to the longitudinal axis; and

a distal horn including a distal connector configured to engage the waveguide, the distal horn defining a longitudinal axis aligned with the longitudinal axis of the waveguide when engaged therewith, the proximal hub and the distal horn configured to engage one another to retain the piezoelectric rod array therebetween under compression,

wherein the internal cartridge is disposed between the proximal hub and the distal horn and configured to retain the plurality of piezoelectric rods therein.

11. The ultrasonic surgical instrument according to claim 10 , wherein the proximal hub and the distal horn are configured to directly engage one another to retain the piezoelectric rod array therebetween.

12. The ultrasonic surgical instrument according to claim 10 , wherein the proximal hub and the distal horn are configured to indirectly engage one another to retain the piezoelectric rod array therebetween.

13. The ultrasonic surgical instrument according to claim 12 , further comprising a bolt engaged between the proximal hub and the piezoelectric rod array, the bolt indirectly engaging the proximal hub and the distal horn with one another to retain the piezoelectric rod array therebetween.

14. The ultrasonic surgical instrument according to claim 10 , wherein the proximal hub and the distal horn cooperate to define an enclosure enclosing the piezoelectric rod array therein.

15. The ultrasonic surgical instrument according to claim 10 , wherein the distal horn is configured to communicate electrical energy at a first potential to the piezoelectric rod array.

16. The ultrasonic surgical instrument according to claim 15 , wherein the proximal hub is configured to communicate electrical energy at a second, different potential to the piezoelectric rod array.

17. The ultrasonic surgical instrument according to claim 15 , further comprising an electrode disposed between the proximal hub and the piezoelectric rod array, the electrode configured to communicate electrical energy at a second, different potential to the piezoelectric rod array.

18. The ultrasonic surgical instrument according to claim 10 , further comprising a clamp arm movable relative to the ultrasonic blade from an open position to a clamping position for clamping tissue therebetween.

19. The ultrasonic surgical instrument according to claim 18 , further comprising a movable handle associated with the housing and operably coupled to the clamp arm such that actuation of the movable handle moves the clamp arm from the open position to the clamping position.