Phacoemulsification circuit
Disclosed is a surgical instrument directed to phacoemulsification for cataract eye surgery. The instrument generally includes a dual frequency voltage producing circuit comprising a low-frequency voltage pathway with a low-frequency LC Network and a high-frequency voltage pathway with a high-frequency LC network. A phacoemulsification needle extends from a handpiece able to be driven by a piezoelectric transducer. The piezoelectric transducer is electrically connected to the dual frequency voltage producing circuit. The high-frequency voltage pathway is electrically tuned with the physical high natural frequency of the handpiece and the low-frequency voltage pathway is electrically tuned with the physical low natural frequency of the handpiece for efficient transfer of energy.
1. A phacoemulsification arrangement for a phacoemulsification procedure, comprising:
a needle extending from a handpiece that includes a piezoelectric transducer; and
a dual frequency producing circuit comprising a low-frequency oscillator and a high-frequency oscillator,
the dual frequency producing circuit is electrically connected to the piezoelectric transducer,
the low-frequency oscillator is configured to drive the piezoelectric transducer that periodically vibrates the needle at a low frequency of less than 60 kHz, and
the high-frequency oscillator is configured to drive the piezoelectric transducer that periodically vibrates the needle at a high frequency of greater than or equal to 60 kHz while producing a single node of minimum amplitude along the needle.
2. The phacoemulsification arrangement of claim 1 , wherein the dual frequency producing circuit is external to the needle and the handpiece.
3. The phacoemulsification arrangement of claim 1 , wherein the low-frequency oscillator is operable with the high-frequency oscillator to collectively periodically vibrate the needle with a hybrid standing wave that is defined by the low frequency standing wave superimposed over the high frequency standing wave.
4. The phacoemulsification arrangement of claim 3 , further comprising an actuator configured to change a percent contribution of the low-frequency standing wave inversely proportional to the high-frequency standing wave when generating the hybrid standing wave.
5. The phacoemulsification arrangement of claim 3 , wherein the hybrid standing wave causes a single node of reduced amplitude along the needle, wherein the single node of reduced amplitude is a higher amplitude than the single node of minimum amplitude.
6. The phacoemulsification arrangement of claim 1 , wherein the dual frequency producing circuit comprises:
a low-frequency pathway and a high-frequency pathway,
the low-frequency pathway comprises a low-frequency LC network tied to the low-frequency oscillator, and the high-frequency pathway comprises a high-frequency LC network tied to the high-frequency oscillator; and
a tapped output transformer inductively coupled to the low-frequency LC network and the high-frequency LC network,
the tapped output transformer is electrically connected to the piezoelectric transducer, and
the tapped output transformer is configured to drive the piezoelectric transducer with a low-frequency voltage from the low-frequency LC network, a high-frequency voltage from the high-frequency LC network, or combination of the high frequency voltage and the low-frequency voltage.
7. The phacoemulsification arrangement of claim 6 , further comprising a low-frequency circuit resonance corresponding to the low-frequency LC network and a high-frequency circuit resonance corresponding to the high-frequency LC network,
wherein the low frequency circuit resonance matching a first natural frequency of the needle and the handpiece, and
wherein the high-frequency circuit resonance matching a second natural frequency of the and the handpiece.
8. The phacoemulsification arrangement of claim 1 , wherein the needle and the handpiece are only applicable to cataract surgery using the phacoemulsification procedure.
9. The phacoemulsification arrangement of claim 1 , wherein the dual frequency producing circuit further comprising a low-frequency LC network corresponding to and connected to the low-frequency oscillator and the high-frequency LC network corresponding to and connected to the high-frequency oscillator,
wherein the low-frequency LC network comprising electrical components that define a low natural electrical frequency response that matches a low natural physical frequency of the handpiece.
10. The phacoemulsification arrangement of claim 9 , wherein the high-frequency LC network further comprising different electrical components that define a high natural electrical frequency response that matches a high natural frequency of the handpiece.
11. A phacoemulsification configuration, comprising:
a dual frequency voltage producing circuit comprising a low-frequency voltage pathway that includes a low-frequency oscillator and a low-frequency LC network and a high-frequency voltage pathway that includes a high-frequency oscillator and a high-frequency LC network;
a needle extending from a handpiece, the handpiece including a piezoelectric transducer, the piezoelectric transducer electrically connected to the dual frequency voltage producing circuit;
when the high-frequency oscillator is in a high-frequency on state and the low-frequency oscillator is in a low-frequency off state, the needle comprises a single non-displacement region that has essentially no vibration displacement, and when the low-frequency oscillator is in a low-frequency on state and the high-frequency oscillator is in an off state, the needle does not comprise a single non-displacement region.
12. The phacoemulsification configuration of claim 11 , wherein the phacoemulsification configuration is only operably used for a cataract surgery.
13. The phacoemulsification configuration of claim 11 , wherein the handpiece comprises at least a low natural frequency and a high natural frequency,
wherein the low-frequency LC network comprises a first set of electrical components that electrically match the low natural frequency within +/−10%, and
wherein the high-frequency LC network comprises a second set of electrical components that electrically match the high natural frequency within +/−10%.
14. The phacoemulsification configuration of claim 11 , further comprising a frequency mixer configured to produce a combined frequency output voltage, which is a combination of a low-frequency output voltage from the low-frequency oscillator when in the low-frequency on state and a high-frequency output voltage from the high-frequency oscillator when in the high-frequency on state, wherein when the piezoelectric transducer is subjected to the combination frequency output voltage, the needle comprises a single low displacement region, the single low displacement region has higher displacement than the single non-displacement region.
15. The phacoemulsification configuration of claim 11 , wherein the dual frequency voltage producing circuit is configured to shift in-phase a low-frequency voltage and low-frequency current produced by the low-frequency oscillator; and wherein the dual frequency voltage producing circuit is further configured to shift in-phase a high-frequency voltage and high-frequency current produced by the high-frequency oscillator.
16. The phacoemulsification configuration of claim 15 , wherein the frequency mixer is an operator controlled actuator that adjusts the high-frequency output voltage inversely proportional to the low-frequency output voltage.
17. A method for driving a phacoemulsification assembly, comprising:
providing a dual frequency producing circuit electrically connected to a phacoemulsification assembly comprising a needle extending from a handpiece, the handpiece comprising a piezoelectric transducer;
generating one of an independent high-frequency ringing in the needle, an independent low-frequency ringing in the needle or a combination high-low frequency ringing in the needle;
producing the high-frequency ringing by energizing the piezoelectric transducer with a high-frequency voltage from the dual frequency producing circuit, the high-frequency ringing causing a single node of minimum amplitude along the needle;
producing the low-frequency ringing by energizing the piezoelectric transducer with a low-frequency voltage from the dual frequency producing circuit, the low-frequency ringing causing no node of minimum amplitude along the needle.
18. The method of claim 17 , further comprising producing a combination of the low-frequency ringing and the high-frequency ringing by energizing the piezoelectric transducer with both the low-frequency voltage combined with the high-frequency voltage,
the needle comprising a single node of low amplitude along the needle at the combination of the low-frequency ringing and the high-frequency ringing,
wherein the node of low amplitude is a higher amplitude then the node of minimum amplitude.
19. The method of claim 17 , wherein the dual frequency circuit comprises a low-frequency voltage pathway that includes a low-frequency oscillator and a low-frequency LC network and a high-frequency voltage pathway including a high-frequency oscillator and a high-frequency LC network, and
wherein the low-frequency voltage pathway provides the low-frequency voltage and the high-frequency voltage pathway provides the high-frequency voltage.
20. The method of claim 19 , further comprising balancing at least a portion of the low-frequency voltage pathway with electrical components that electrically oscillate within +/−10% of a low natural frequency of at least the handpiece.