System and Method For Actuation of A Vitreous Cutter

• US 20090082715A1
• Filed: 09/21/2007
• Published: 03/26/2009
• Est. Priority Date: 09/21/2007
• Status: Active Grant

• Current Assignee: Alcon Incorporated
• Original Assignee: Novartis Ag
• Inventors: Charles, Steven T.
• Granted Patent: US 8,080,029 B2
• Time in Patent Office: Days
• US Class Current: 604/22
• CPC Class Codes: A61B 2017/00544 pneumatically
• 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

Embodiments of systems and methods disclosed herein regard simplifying and improving the performance and reliability of pneumatic actuators operable to actuate surgical cutters or shears. Various embodiments include systems and methods for vitreous cutting apparatuses utilizing self-valving vitreous cutters that actuate at a frequency based on the properties of the vitreous cutter.

Claims

1. A vitreous cutting apparatus, comprising:

an actuator body defining an input port and an exhaust port;

an actuating member movable in the actuator body from a first position to a second position;

a diaphragm coupled to the actuator body and the actuating member to form a chamber accessed by the input port and the exhaust port;

a tube coupled to the actuating member; and

a passive valve located upstream of the input port having a threshold opening pressure;

wherein the actuating member is movable from the first position in which the input port is open to the chamber and the exhaust port is blocked and the second position in which the exhaust port is open to the chamber and the input port blocked.

2. The vitreous cutting apparatus of claim 1, wherein the passive valve is a pop-off valve.

3. The vitreous cutting apparatus of claim 1, wherein the passive valve is a reed valve.

4. The vitreous cutting apparatus of claim 1, wherein tube is an inner tube of a vitreous cutter.

5. The vitreous cutting apparatus of claim 1, wherein the exhaust port exhausts to atmosphere.

6. The vitreous cutting apparatus of claim 1, further comprising a pneumatic pressure source to provide pressurized air to the passive valve at a first pressure and a second pressure, wherein the first pressure is below the opening threshold pressure of the passive valve and the second pressure is above the opening threshold pressure of the passive valve.

7. The vitreous cutting apparatus of claim 1, wherein the second pressure and mechanical characteristics of the diaphragm are selected to cause the actuating member to actuate with a selected frequency.

8. A vitreous cutting apparatus, comprising:

an actuator body defining an first input port, a second input port, a first exhaust port and a second exhaust port;

an actuating member movable in the actuator body from a first position to a second position;

a diaphragm coupled to the actuator body and the actuating member to form a first chamber accessed by the first input port and the first exhaust port and a second chamber on the obverse side of the diaphragm accessed by the second input port and the second exhaust port; and

a tube coupled to the actuating member;

wherein the actuating member is movable from the first position in which the first input port is open to the first chamber, the first exhaust port is blocked, the second exhaust port is open to the second chamber and the second input port is blocked to the second position in which the first exhaust port is open to the first chamber and the first input port blocked, the second input port is open to the second chamber and the second exhaust port is blocked.

9. The vitreous cutting apparatus of claim 8, wherein actuating member moves back and forth from the first position to the second position at a frequency based on the pneumatic power applied to the first input port and the pneumatic power applied to the second input port.

11. The vitreous cutting apparatus of claim 8, wherein the first exhaust port and the second exhaust port exhaust to atmosphere.

10. The vitreous cutting apparatus of claim 10, wherein the tube is an inner tube of a vitreous cutter.

12. A method of vitreous surgery, comprising:

inserting a distal end of a probe of a resonating self-valving vitreous cutter into an eye, the probe comprising an outer and an inner tube;

applying a substantially steady pneumatic pressure to the vitreous cutter during cutting to cause the inner tube of the probe to actuate at a resonance frequency; and

cutting vitreous of the eye with the probe.

13. The method of claim 12, wherein the vitreous cutter further comprises:

an actuator body defining an input port and an exhaust port;

an actuating member coupled to an inner tube movable in the actuator body from a first position to a second position;

a diaphragm coupled to the actuator body and the actuating member to form a chamber accessed by the input port and the exhaust port; and

a passive valve located upstream of the input port having a threshold opening pressure

wherein the actuating member is movable from the first position in which the input port is open to the chamber and the exhaust port is blocked and the second position in which the exhaust port is open to the chamber and the input port blocked; and

wherein the method further comprises applying an initial pneumatic pressure that is less than the threshold opening pressure of the passive valve prior to applying the substantially steady pneumatic pressure.

16. The method of claim 12, wherein the vitreous cutter further comprises:

an actuator body defining a first input port, a second input port, a first exhaust port and a second exhaust port;

an actuating member coupled to an inner tube movable in the actuator body from a first position to a second position; and

a diaphragm coupled to the actuator body and the actuating member to form a first chamber accessed by the first input port and the first exhaust port and a second chamber on the obverse side of the diaphragm accessed by the second input port and the second exhaust port;

wherein the actuating member is movable from the first position in which the first input port is open to the first chamber, the first exhaust port is blocked, the second exhaust port is open to the second chamber and the second input port is blocked to the second position in which the first exhaust port is open to the first chamber and the first input port blocked, the second input port is open to the second chamber and the second exhaust port is blocked.

17. The method of claim 16, wherein applying substantially steady pneumatic pressure to the vitreous cutter comprises applying approximately the same pressure to the first chamber and the second chamber.

18. The method of claim 16, wherein applying substantially steady pneumatic pressure to the vitreous cutter comprises applying different pressures to the first chamber and the second chamber.

14. The method of claim 14, wherein the passive valve is a pop-off valve.

15. The method of claim 14, wherein the passive valve is a reed valve.

20. The method of claim 14, wherein the passive valve is a pop-off valve.

21. The method of claim 14, wherein the passive valve is a reed valve.

19. A method for eye surgery comprising:

providing a vitreous cutter comprising;

an actuator body defining an input port and an exhaust port;

an actuating member coupled to an inner tube of a probe, the actuating member movable in the actuator body from a first position to a second position;

a diaphragm coupled to the actuator body and the actuating member to form a chamber accessed by the input port and the exhaust port; and

a passive valve located upstream of the input port having a threshold opening pressure;

wherein the actuating member is movable from the first position in which the input port is open to the chamber and the exhaust port is blocked and the second position in which the exhaust port is open to the chamber and the input port blocked;

applying an initial pressure to the vitreous cutter that is less than the threshold opening pressure of the passive valve;

inserting the probe into the eye to contact the vitreous;

applying a second substantially steady pressure that is greater than the threshold pressure of the passive valve to the vitreous cutter to actuate the actuating member at a resonate frequency; and

removing vitreous from the eye.

22. A method for eye surgery comprising:

providing a vitreous cutter comprising;

an actuator body defining a first input port, a second input port, a first exhaust port and a second exhaust port;

an actuating member coupled to an inner tube of a probe movable in the actuator body from a first position to a second position; and

a diaphragm coupled to the actuator body and the actuating member to form a first chamber accessed by the first input port and the first exhaust port and a second chamber on the obverse side of the diaphragm accessed by the second input port and the second exhaust port;

wherein the actuating member is movable from the first position in which the first input port is open to the first chamber, the first exhaust port is blocked, the second exhaust port is open to the second chamber and the second input port is blocked to the second position in which the first exhaust port is open to the first chamber and the first input port blocked, the second input port is open to the second chamber and the second exhaust port is blocked;

inserting the probe into the eye to contact the vitreous;

applying a substantially steady pressure to the vitreous cutter to actuate the actuating member at a resonate frequency; and

removing vitreous from the eye.

23. The method of claim 22, wherein applying substantially steady pneumatic pressure to the vitreous cutter comprises applying the same pressure to the first chamber and the second chamber.

24. The method of claim 22, wherein applying steady pneumatic pressure to the vitreous cutter comprises applying different pressures to the first chamber and the second chamber.