SELECTABLE STROKE CUTTER

• US 20090088784A1
• Filed: 09/29/2008
• Published: 04/02/2009
• Est. Priority Date: 09/27/2007
• Status: Active Grant

• Current Assignee: Doheny Eye Institute
• Original Assignee: Doheny Eye Institute
• Inventors: Bhadri, Prashant R., Humayun, Mark S., McCormick, Matthew, DeBoer, Charles, Kerns, Ralph, Barnes, Aaron
• Granted Patent: US 8,172,865 B2
• Time in Patent Office: Days
• US Class Current: 606/167
• CPC Class Codes: A61B 17/22031 Gripping instruments, e.g. forceps, for removing or smashing calculi A61B17/221 takes precedence
• CPC Class Codes: A61B 17/32002 with continuously rotating, oscillating or reciprocating cutting instruments
• CPC Class Codes: A61B 17/320783 through side-hole, e.g. sliding or rotating cutter inside catheter
• CPC Class Codes: A61B 2017/00544 pneumatically
• CPC Class Codes: A61B 2017/320028 with reciprocating movements
• CPC Class Codes: A61B 2017/32004 having a laterally movable cutting member at its most distal end which remains within the contours of said end
• CPC Class Codes: A61F 9/007 Methods or devices for eye surgery
• CPC Class Codes: A61F 9/00736 Instruments for removal of intra-ocular material or intra-ocular injection, e.g. cataract instruments A61F9/008 takes precedence

Abstract

Apparatus, systems, and devices are described that utilize an adjustable biological tissue cutting handpiece that is based on selectable settings. The biological tissue cutting handpiece includes a cutter tip that allows multiple duty cycles as well as multiple port configurations. For example, when working next to the retina, the port could be adjusted to be a smaller size, allowing delicate membrane dissection. When working near or in less sensitive tissue, e.g. the center of the eye, the port could be wide open. The port aperture size can be independent of cut speed, allowing a surgeon to work at high speed both next to the retina and away from the retina. High speeds have been shown to have increased tissue (e.g., vitreous) removal, e.g., in 25 and 23-gauge instruments. Duty cycle is not necessarily dependent on cut speed, allowing high cutter performance and varied flow characteristics.

Claims

1. A biological tissue cutting device configured and arranged to provide multiple selectable strokes, the device comprising:

a cutting blade tip configured and arranged to be driven in reciprocating motion; and

a cutting tip including one or more ports configured and arranged to receive the cutting blade tip, wherein the one or more ports are configured and arranged to provide a variable aperture size based on the position of the cutting blade tip within the cutting tip.

2. The device of claim 1, wherein the one or more ports comprise two types of ports that are operated at the different strokes, wherein shorter stroke length cuts at the distal port while the other port is occluded by the shaft of the cutting blade tip and the longer stroke length cuts at both ports.

3. The device of claim 1, where the one or more ports comprise a plurality of holes having at least two port configurations.

4. The device of claim 3, wherein a port closest to the distal end of the cutting tip comprises a single slit to allow the cutting blade tip to dissect membranes.

5. The device of claim 3, wherein a port closest to the distal end of the cutting tip comprises a grating structure that has a plurality of small apertures configured and arranged to allow vitreous to enter but prevent retina from entering.

6. The device of claim 3, wherein a port furthest from the distal end of the cutting tip comprises a deep groove configured and arranged for bulk biologic tissue removal.

7. The device of claim 1, wherein a cutting stroke defines port size and port size is not dependent on cutter speed.

8. The device of claim 7, comprising a single rectangular port.

9. The device of claim 7, comprising a triangular port that has a vertex aligned toward the distal end of the cutting tip.

10. The device of claim 7, comprising a port with a keyhole shape that has a narrow vertical section near the distal end of the tip and a wider end away from the tip.

11. The device of claim 1, wherein the device is configured and arranged to have multiple duty cycles or an adjustable duty cycle.

12. The device of claim 1, further comprising a proportional handpiece connected to the cutting tip and configured and arranged to allow a surgeon to adjust the opening of the one or more ports in a proportional mode.

13. The device of claim 1, wherein the distal end of the cutting tip has a gripping feature that can be used to manipulate tissue.

14. The device of claim 1, wherein a port or inner cutting element is configured and arranged to grip lens fragments, membranes, or clots.

15. The device of claim 1, further comprising a drive mechanism that is configured to drive the cutter blade tip in a dual stroke or full modulation fashion.

16. The device of claim 15, wherein the drive comprises an electromechanical drive including a motor and an adjustment that adjust the stroke length of the cutting blade tip.

17. The device of claim 15, wherein the drive mechanism comprises an electroactive element, electrorestrictive element, or magnetorestrictive element that allows continuous modulation of cutter stroke.

18. The device of claim 15, wherein the drive mechanism comprises a spring return pneumatic drive with a non-zero return pressure, wherein the backpressure determines how far the cutting blade tip retracts.

19. The device of claim 15, wherein the drive mechanism comprises a pneumatic drive with a modulated return.

20. The device of claim 1, wherein the device is configured and arranged for different cut profiles that allow the instrument to be operated at 2×

speed in one direction and 1×

speed in the other direction

21. The device of claim 15, wherein the drive mechanism comprises a voice coil used to modulate the stroke of the cutter,

22. The device of claim 1, wherein the cutter is configured and arranged to use a modular stroke to adjust the cut profile of the device.

23. The cutter of claim 22 wherein the form of the modular stroke is reciprocating, triangular, or incorporates a dwell either at the top or bottom of the stroke.

24. A method of using a cutting device configured and arranged to provide multiple selectable strokes, the method comprising:

adjusting the stroke length of a cutting blade tip, independent of the operation speed of the cutting blade tip.

25. The method of claim 24, further comprising adjusting a variable port size of the port, independent of the operation speed of the cutting blade tip.

26. The method of claim 24, further comprising adjusting a variable duty cycle of the cutting blade tip, independent of the operation speed of the cutting blade tip.

27. The method of claim 24, further comprising using different duty cycles for different operational modes.

28. The method of claim 24, wherein the duty cycle is independent of speed.