System for operating and controlling a pneumatically driven vitrectomy probe

1. A pneumatically driven vitrectomy probe system, comprising:

a cylinder having an open end in which a movable member is disposed so as to define an enclosed pressure chamber, the enclosed pressure chamber having an inlet and an outlet therein;

a pressure transducer in communication with the enclosed pressure chamber, for sensing the pressure level within the enclosed pressure chamber;

a valve having an outlet that is in communication with the inlet of the enclosed pressure chamber, wherein the valve communicates pressurized air from a pressurized air source to the inlet of enclosed pressure chamber based on the sensed pressure level;

a displacement device coupled to the movable member so as to extend and retract the movable member within the enclosed pressure chamber, to respectively increase and decrease the pressure level of the chamber and the pressurized air being communicated via the outlet of the enclosed pressure chamber; and

a pneumatically activated vitrectomy probe having an enclosed volume that is in communication with the outlet of the enclosed pressure chamber, the pneumatically activated vitrectomy probe further including a hollow outer member having a port near its distal end, and a hollow inner cutting member within the hollow outer member, which is biased by a spring away from said port, whereupon extension of the displacement member, the resulting increase in pressure within the enclosed volume acts against the biasing spring to move the hollow inner cutting member towards the port, to thereby cut vitreous material extending through the port in the hollow outer member.

2. The pneumatically driven vitrectomy probe system of claim 1 wherein the valve communicates pressurized air from a pressurized air source to the inlet of enclosed pressure chamber to maintain a pressure level that upon extension of the displacement device will cause the hollow inner cutting member to move against the biasing spring to a position in which the hollow inner cutting member closes off the port.

3. The pneumatically driven vitrectomy probe system of claim 1 wherein the operation of the displacement device causes the hollow inner cutting member to move back and forth relative to the port in a reciprocating manner.

4. The pneumatically driven vitrectomy probe system of claim 1 wherein the hollow outer member comprises a hollow sleeve having an opening port in the side of the hollow sleeve at its distal end portion, and the hollow inner cutting member is slidably disposed within the hollow sleeve and has a distal end defining a cutting edge, the hollow inner cutting member being movable towards the distal end of the hollow sleeve such that the cutting edge cuts any vitreous tissue disposed between the cutting edge and the opening port.

5. The pneumatically driven vitrectomy probe system of claim 4 , wherein the displacement device causes the hollow inner cutting member to be slidably displaced within the hollow sleeve in a reciprocating manner, such that the cutting member oscillates between a cutting position where the hollow inner cutting member closes off the opening port, and a position where the hollow inner cutting member is spaced apart from the opening port, to thereby provide for repetitive cutting action.

6. The pneumatically driven vitrectomy probe system of claim 1 wherein the movable member comprises a piston slidably disposed within the cylinder, and the displacement device comprises a crank shaft that is connected to the piston in a manner such that for every rotation of a drive motor the piston is extended and retracted within the enclosed pressure chamber, to thereby respectively increase and decrease the pressure within the enclosed pressure chamber and the enclosed volume in the pneumatically operated vitrectomy probe.

7. The pneumatically driven vitrectomy probe system of claim 1 , wherein the movable member comprises a movable diaphragm disposed within the cylinder, and the displacement device comprises a crank shaft that is connected to the movable diaphragm in a manner such that for every rotation of a drive motor the movable diaphragm is extendably displaced into the enclosed pressure chamber in the cylinder and then retracted, to thereby respectively increase and decrease the pressure within the enclosed pressure chamber and the enclosed volume in the pneumatically operated vitrectomy probe.

8. The pneumatically driven vitrectomy probe system of claim 1 wherein the movable member comprises a piston slidably disposed within the cylinder, and the displacement device comprises a drive solenoid coupled to the piston, which extends the piston within the enclosed pressure chamber when the solenoid is electrically activated and retracts the piston when the solenoid is deactivated, to thereby respectively increase and decrease the pressure within the enclosed pressure chamber and the enclosed volume in the pneumatically operated vitrectomy probe.

9. A pneumatically driven vitrectomy probe system, comprising:

a cylinder having an open end in which a piston is disposed so as to define an enclosed pressure chamber, the enclosed pressure chamber having an inlet for receiving pressurized air, and an outlet for communicating pressurized air to a pneumatically actuated vitrectomy probe;

a pressure transducer in communication with the enclosed pressure chamber, for sensing a pressure level within the enclosed pressure chamber;

a valve having an outlet that is in communication with the inlet to the enclosed pressure chamber, wherein the valve communicates pressurized air from a pressurized air source to the inlet of enclosed pressure chamber based on the pressure level;

a drive motor coupled to a crank shaft that is connected to the piston in a manner such that for every rotation of the motor the piston is extended and retracted within the enclosed pressure chamber, to thereby respectively increase and decrease the pressure level of the chamber and the pressurized air communicated via the outlet of the enclosed pressure chamber; and

a pneumatically activated vitrectomy probe having an enclosed volume that is in communication with the outlet of the enclosed pressure chamber, the pneumatically activated vitrectomy probe further including a hollow outer member having a port near its distal end, and a hollow inner cutting member within the hollow outer member, which is biased by a spring away from the port, whereupon extension of the piston, the resulting increase in pressure level within the enclosed volume acts against the biasing spring to move the hollow inner cutting member towards the port, to thereby cut vitreous material extending through the port in the hollow outer member.

10. The pneumatically driven vitrectomy probe system of claim 9 wherein the valve communicates pressurized air from a pressurized air source to the inlet of enclosed pressure chamber to maintain a pressure level that upon extension of the piston will cause the hollow inner cutting member to move against the biasing spring to a position in which the hollow inner cutting member closes off the port.

11. The pneumatically driven vitrectomy probe system of claim 9 wherein the continuous displacement and retraction of the piston causes the hollow inner cutting member to move back and forth relative to the port in a reciprocating manner.

12. The pneumatically driven vitrectomy probe system of claim 9 wherein the hollow outer member comprises a hollow sleeve having an opening port in the side of the hollow sleeve at its distal end portion, and the hollow inner cutting member is slidably disposed within the hollow sleeve and has a distal end defining a cutting edge, the hollow inner cutting member being movable towards the distal end of the hollow sleeve such that the cutting edge cuts any vitreous tissue disposed between the cutting edge and the opening port.

13. The pneumatically driven vitrectomy probe system of claim 12 , wherein the extension and retraction of the piston causes the hollow inner cutting member to be slidably displaced within the hollow sleeve in a reciprocating manner, such that the cutting member oscillates between a cutting position where the hollow inner cutting member closes off the opening port, and a position where the hollow inner cutting member is spaced apart from the opening port, to thereby provide for repetitive cutting action.

14. A pneumatically driven vitrectomy probe system, comprising:

a cylinder having an open end in which a movable diaphragm is disposed so as to define an enclosed pressure chamber, the enclosed pressure chamber having an inlet for receiving pressurized air, and an outlet for communicating pressurized air to a pneumatically actuated vitrectomy probe;

a pressure transducer in communication with the enclosed pressure chamber, for sensing a pressure level within the enclosed pressure chamber;

a valve having an outlet that is in communication with the inlet to the enclosed pressure chamber, wherein the Valve communicates pressurized air from a pressurized air source to the inlet of the enclosed pressure chamber based on the pressure level;

a drive motor coupled to a crank shaft that is connected to the movable diaphragm in a manner such that for every rotation of the motor the movable diaphragm is extendably displaced into the enclosed pressure chamber in the cylinder and then retracted, to thereby respectively increase and decrease the pressure within the enclosed pressure chamber and the enclosed volume in the pneumatically operated vitrectomy probe; and

a pneumatically activated vitrectomy probe having an enclosed volume that is in communication with the outlet of the enclosed pressure chamber, the pneumatically activated vitrectomy probe further including a hollow outer member having a port near its distal end, and a hollow inner cutting member within the hollow outer member, which is biased by a spring away from the port, whereupon extension of the movable diaphragm, the resulting increase in pressure level within the enclosed volume acts against the biasing spring to move the hollow inner cutting member towards the port, to thereby cut vitreous material extending through the port in the hollow outer member.

15. The pneumatically driven vitrectomy probe system of claim 14 wherein the valve communicates pressurized air from a pressurized air source to the inlet of enclosed pressure chamber to maintain a pressure level that upon extension of the diaphragm will cause the hollow inner cutting member to move against the biasing spring to a position in which the hollow inner cutting member closes off the port.

16. The pneumatically driven vitrectomy probe system of claim 14 wherein the continuous displacement and retraction of the diaphragm causes the hollow inner cutting member to move back and forth relative to the port in a reciprocating manner.

17. The pneumatically driven vitrectomy probe system of claim 14 wherein the hollow outer member comprises a hollow sleeve having an opening port in the side of the hollow sleeve at its distal end portion, and the hollow inner cutting member is slidably disposed within the hollow sleeve and has a distal end defining a cutting edge, the hollow inner cutting member being movable towards the distal end of the hollow sleeve such that the cutting edge cuts any vitreous tissue disposed between the cutting edge and the opening port.

18. The pneumatically driven vitrectomy probe system of claim 14 , wherein the extension and retraction of the movable diaphragm causes the hollow inner cutting member to be slidably displaced the within the hollow sleeve in a reciprocating manner, such that the cutting member oscillates between a cutting position where the hollow inner cutting member closes off the opening port, and a position where the hollow inner cutting member is spaced apart from the opening port, to thereby provide for repetitive cutting action.