Ultrasonic Handpiece

• US 20100004585A1
• Filed: 09/11/2009
• Published: 01/07/2010
• Est. Priority Date: 08/12/2004
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: Novartis Ag
• Inventors: Boukhny, Mikhail, Chon, James
• Granted Patent: US 8,771,301 B2
• Time in Patent Office: Days
• US Class Current: 604/22
• CPC Class Codes: A61B 2017/32007 with suction or vacuum means
• CPC Class Codes: A61B 2017/320089 node location
• CPC Class Codes: A61F 9/00745 using mechanical vibrations, e.g. ultrasonic
• CPC Class Codes: A61F 9/00763 with rotating or reciprocating cutting elements, e.g. concentric cutting needles atherectomy cutting instruments A61B17/3207; endoscopic cutting instruments A61B17/320016

Abstract

A handpiece having a single set of piezoelectric elements polarized to produce longitudinal motion when excited at the relevant resonant frequency. The piezoelectric crystals are connected to an ultrasonic horn to which a cutting tip is attached. The horn and/or the cutting tip contains a plurality of diagonal slits or grooves. The slits or grooves produce optimized torsional movement in the cutting tip when the piezoelectric crystals are excited at a second resonant frequency. Preferably, the two drive frequencies are not coincident, but provided in non-overlapping pulses.

Claims

1. An ultrasonic handpiece, comprising:

a handpiece shell;

an ultrasonic horn held within the shell, the horn containing a plurality of circumferential, diagonal slits sized and spaced so as to produce torsional movement in the horn in response to a drive signal having a first frequency and longitudinal movement in the horn in response to a drive signal having a second frequency; and

a plurality of piezoelectric elements;

wherein the piezoelectric elements and the horn are held within the shell so that a torsional nodal point and a proximal longitudinal nodal point are coincident; and

further wherein the shell is less than 100 centimeters in length.

2. The apparatus of claim 1 wherein the first drive signal and the second drive signal are alternated and do not overlap.

3. An ultrasonic handpiece comprising:

a handpiece shell;

an ultrasonic horn at least partially located in the shell, the horn having a plurality of slits sized and spaced so as to produce torsional movement in the horn in response to a drive signal having a first frequency and longitudinal movement in the horn in response to a drive signal having a second frequency;

a piezoelectric element connected to the horn; and

a plug for sealing the outer shell;

wherein a torsional nodal point and a longitudinal nodal point are coincident at the plug; and

further wherein the shell is less than 100 centimeters in length.

4. The handpiece of claim 3 wherein the plurality of slits are spiral.

5. The handpiece of claim 3 wherein the plurality of slits are helical.

6. The handpiece of claim 3 further comprising:

an aspiration shaft extending through the horn.

7. The handpiece of claim 6 further comprising:

a tip attached to the horn, the tip coupled to the aspiration shaft.

8. The handpiece of claim 3 wherein the horn has an outside diameter, and the width of the plurality of slits is between about 2% and 65% of the outside diameter of the horn.

9. The handpiece of claim 8 wherein the depth of the plurality of slits is between about 4% and 45% of the outside diameter of the horn.

10. The handpiece of claim 3 wherein the horn has a larger diameter, and the plurality of slits are between about 8% and 75% of the length of the larger diameter of the horn.

11. The handpiece of claim 10 wherein the pitch of the plurality of slits is between about 125% and 500% of the larger diameter of the horn.

12. The handpiece of claim 3 further comprising:

a drive circuit for driving the handpiece.

13. The handpiece of claim 3 wherein the first frequency is about 32 kHz.

14. The handpiece of claim 3 wherein the second frequency is about 44 kHz.

15. An ultrasonic handpiece comprising:

a handpiece shell with a plug location;

an ultrasonic horn at least partially located in the shell and coupled to the shell at the plug location, the horn having a plurality of slits sized and spaced so as to produce torsional movement in the horn in response to a drive signal having a first frequency and longitudinal movement in the horn in response to a drive signal having a second frequency; and

a piezoelectric element connected to the horn;

wherein a torsional nodal point and a longitudinal nodal point are coincident at the plug location; and

further wherein the shell is less than 100 centimeters in length.

16. The handpiece of claim 15 wherein the horn is sealed to the shell at the plug location.

17. The handpiece of claim 16 further comprising:

a plug at the plug location, the plug for sealing the horn to the shell.

18. A phacoemulsification handpiece comprising:

a handpiece shell;

a horn at least partially located in the shell and sealed to the shell at a location, the horn having a plurality of slits sized and spaced so as to produce torsional movement in the horn in response to a drive signal having a first frequency and longitudinal movement in the horn in response to a drive signal having a second frequency;

a tip coupled to the horn, the tip suitable for insertion into an eye, the tip configured to remove a lens from the eye when the tip is vibrated; and

a piezoelectric element coupled to the horn;

wherein a torsional nodal point and a longitudinal nodal point are coincident at the location; and

further wherein the shell is less than 100 centimeters in length.

19. The handpiece of claim 18 further comprising:

a plug at the location, the plug for sealing the horn to the shell.

20. The handpiece of claim 18 further comprising:

an aspiration shaft extending through the horn.

21. The handpiece of claim 18 further comprising:

a drive circuit for driving the piezoelectric element.

22. A phacoemulsification handpiece comprising:

a handpiece shell configured to be held in the hand;

a horn at least partially located in the shell, the horn having a plurality of slits sized and spaced so as to produce torsional movement in the horn in response to a drive signal having a first frequency and longitudinal movement in the horn in response to a drive signal having a second frequency;

a hollow tip coupled to the horn, the hollow tip suitable for insertion into an eye, the hollow tip configured to remove a lens from the eye when the hollow tip is vibrated;

an aspiration shaft extending through the horn;

a piezoelectric element coupled to the horn;

a drive circuit for driving the piezoelectric element; and

a plug for sealing the outer shell;

wherein a torsional nodal point and a longitudinal nodal point are coincident at the plug; and

further wherein the shell is less than 100 centimeters in length.