Abstract: A control circuit that provides a driving signal to a transducer coupled to a mechanical cutting element. The transducer is capable of operating in a resonant mode. The driving signal contains a plurality of pulses provided in a time interval that does not cause the transducer to operate in the resonant mode.

Abstract: An irrigation tube that has a relatively high fluidic resistance. The high resistance can be created by providing a relatively long tube. The aspiration tube and an irrigation tube may be coupled to an anterior chamber of a cornea during a phaco procedure. The high resistance of the tube will minimize the instantaneous change of flowrate out of the cornea in the event an occlusion is cleared from the aspiration tube. Minimizing the change in flowrate will tend to insure a higher flowrate from the irrigation line and a positive pressure within the cornea. The aspiration tube may have a plurality of pre-formed coils to minimize the effective length of the tube.

Abstract: An aspiration system that may include a control valve to allow a flow of fluid into an aspiration line and vary a vacuum pressure within the line. The system may include a pressure transducer that is coupled to the aspiration line by a sensor line and a check valve. The check valve prevents a back flow of fluid from the aspiration line to the pressure line. The system may further have a control circuit that is coupled to the pressure transducer and the control valve. The control circuit may control the control valve and regulate the vacuum pressure within the aspiration line. The control circuit may receive an input signal that also controls a medical handpiece. The input signal can be generated by a foot pedal that also controls the handpiece. The system may thus have one foot pedal that can control the handpiece and the vacuum pressure of the aspiration line.

Abstract: A sleeve for a medical handpiece. The sleeve has a flexible outer sleeve and a rigid inner sleeve that are both coupled to a case of the handpiece. Coupling the rigid inner sleeve to the case increases the effective stiffness of the inner sleeve. Increasing the effective stiffness of the rigid inner sleeve reduces the likelihood of contact between the inner sleeve and a tip of the handpiece even when non-symmetric forces are applied to the sleeve.

Abstract: An ultrasonic surgical instrument that has a disposable piezoelectric driver. The surgical instrument includes an ultrasonic horn that is attached to an outer handle. A surgical tip or blade is attached to the proximal end of the horn. The piezoelectric driver is attached to the distal end of the horn. The driver contains at least one piezoelectric transducer which creates a vibratory movement of the horn and the surgical tip. The piezoelectric driver and ultrasonic horn are attached by corresponding threaded members or other means for mechanically coupling the devices so that the driver can be detached from the horn. The piezoelectric driver is disconnected from the horn after use in a surgical procedure. The horn and handle are then sterilized. A new piezoelectric driver is then attached to the horn for use in another procedure.

Abstract: An adapter assembly for a pressure sensor. The adapter includes a sensor housing that has a first port and a second port that are both in fluid communication with an inner chamber of the housing. The assembly further includes a membrane housing that is pressed into the first port of the sensor housing and connected to a fluid line. Extending from the membrane housing is a membrane which separates the sensor housing inner chamber into a first subchamber and a second subchamber. The first subchamber is in fluid communication with the fluid line. The second subchamber is in fluid communication with a pressure transducer which is pressed into the second port of the sensor housing. Any variation of pressure within the fluid line will cause a change in the volume of the first subchamber. The change in the first subchamber volume will deflect the membrane and vary the volume of the second subchamber.