Abstract: There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a pneumatic system for driving pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor.

Abstract: There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a vacuum generation system using venturis and linear valves and a pneumatic system for driving vitrectomy probes and pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor.

Abstract: A linear suction control system 10 includes a linear solenoid valve 11 which exhibits a flow through rate having a known proportional relationship with the current through the solenoid 30. Regulated fluid pressure 12 is fed through the linear solenoid valve 11 to a venturi-type pressure vacuum converter 17. The resulting vacuum is proportional to the flow rate through the valve 11 and thus to the current through the solenoid 30. A transducer 16 samples the vacuum output and produces a signal fed to a differential amplifier 17. The signal is compared in negative feedback fashion with a variable input voltage set by a potentiometer 18 or other variable voltage source, so that the transducer signal tracks the voltage source signal. The voltage source can comprise a potentiometer 18 actuated by a foot switch 19 or the like, so that angular position of the foot switch 19 relates directly and predictably to the vacuum output of the converter 13.

Abstract: There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a vacuum generation system using venturis and linear valves and a pneumatic system for driving vitrectomy probes and pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor. The frequency of the vitrectomy probe cutting action can also be controlled and the level of vacuum can be controlled from a foot operated position sensor which can also be used to turn on or off a fragmentation device. The footswitch can also be used to turn irrigation fluid on or off, and the flow rate can be controlled from a control on the front panel. By making a certain foot motion in any certain aspiration modes, reflux of the aspiration line can be controlled.

Abstract: There is disclosed herein a system for providing control of multiple functions needed to perform eye surgery. A microprocessor based system controls a pneumatic system for driving pneumatic scissors in either a variable frequency, multicut mode or a proportional cut mode where the cutting pressure is proportional to the position of a foot operated position sensor.

Abstract: A system 10 for proportional control of a pneumatic cutting device 13 includes a linear solenoid valve 11 having a flow rate therethrough proportional to the current passing through the solenoid 32. The linear solenoid valve 11 is actuated by a selectively varied electrical signal generated by a power supply 18 and controlled by a potentiometer 14 which is itself operated by a pedal foot controller 16. Regulated fluid pressure is fed through the linear soleoid valve 11 to a pneumatic cutting device 13 such as an intraocular microscissors which closes increasingly as the applied pressure increases. The linear solenoid valve 11 includes a flow path which is variably constricted or closed by a valve member 36, and a solenoid 32 which is arranged to pull the valve member 36 to open the flow path.

Abstract: A linear suction control system 10 includes a linear solenoid valve 11 which exhibits a flow through rate having a known proportional relationship with the current through the solenoid 30. Regulated fluid pressure 12 is fed through the linear solenoid valve 11 to a venturi-type pressure vacuum converter 17. The resulting vacuum is proportional to the flow rate through the valve 11 and thus to the current through the solenoid 30. A transducer 16 samples the vacuum output and produces a signal fed to a differential amplifier 17. The signal is compared in negative feedback fashion with a variable input voltage set by a potentiometer 18 or other variable voltage source, so that the transducer signal tracks the voltage source signal. The voltage source can comprise a potentiometer 18 actuated by a foot switch 19 or the like, so that angular position of the foot switch 19 relates directly and predictably to the vacuum output of the converter 13.

Abstract: A variable pneumatic output device for use with ophthmalic micro-surgical instruments including a reversible servo motor which operates in response to instructions from an electronic control circuit. The rotatable drive shaft of the servo motor is operatively connected to the adjustable level control of a precision pressure regulator which operates between a fully open level and a fully closed level. The pressure regulator is operatively connected between a pressurized air source and the pneumatically driven micro-surgical instrument and according to the instructions of the electronic control circuitry, the servo motor, through the connecting drive to the regulator, adjusts the level of pneumatic output to the surgical instrument.