Phacoemulsification probe stroke length maximization system
A phacoemulsification system including a phacoemulsification probe having a probe body, a horn disposed at least partially in the probe body, a needle coupled with the horn and configured to be inserted into an eye, and a piezoelectric actuator disposed in the probe body and configured to vibrate the horn and the needle in a first direction with a stroke length with respect to the probe body; a signal generator configured to generate a drive signal to drive a vibration of the piezoelectric actuator; a stroke measurement apparatus configured to provide indications of the stroke length of the needle over time; and a controller configured to dynamically adjust a frequency of the drive signal so as to maximize the stroke length and maintain mechanical resonance of the needle responsively to the provided indications of the stroke length.
1. A phacoemulsification method comprising:
providing a phacoemulsification probe comprising a probe body, a vibrating portion, a stroke measurement device, and a piezoelectric actuator, wherein the vibrating portion comprises a needle and a horn, and wherein at least one part of the stroke measurement device is coupled with the probe body or the vibrating portion;
inserting the needle into an eye;
generating a drive signal to drive a vibration of the piezoelectric actuator which causes vibration of the needle in a direction having a stroke length with respect to the probe body of the phacoemulsification probe;
providing indications of the stroke length of the needle over time; and
dynamically adjusting a frequency of the drive signal so as to maximize the stroke length and maintain mechanical resonance of the needle responsively to the provided indications of the stroke length; wherein the stroke measurement device comprises an interferometer.
2. The method according to claim 1 , wherein the direction comprises any one or more selected from the group consisting of a longitudinal direction, a transverse direction, and a torsional direction.
3. The method according to claim 1 , wherein the interferometer comprises a first part and a second part, wherein the first part is coupled with the vibrating portion, and wherein the second part is coupled with the probe body.
4. The method according to claim 3 , wherein the first part of the interferometer includes a first reflector and the second part of the interferometer includes at least one optical fiber coupled with the probe body.
5. The method according to claim 4 , wherein the first reflector is coupled with the horn of the vibrating portion.
6. The method according to claim 4 , further comprising:
receiving an optical signal from a light source;
splitting the received optical signal into a first part directed to the first reflector and a second part directed to a second reflector; and
combining the first part reflected by the first reflector and the second part reflected by the second reflector into a combined optical signal.
7. The method according to claim 6 , wherein the at least one optical fiber includes a first optical fiber and a second optical fiber.
8. The method according to claim 6 , wherein the splitting and combining are performed by a directional optical fiber coupler.
9. The method according to claim 7 , further comprising:
conveying the first part of the optical signal from a beam-splitter-combiner to the first reflector in the first optical fiber; and
conveying the first part of the optical signal reflected by the first reflector to the beam-splitter-combiner in the second optical fiber.
10. The method according to claim 1 , wherein the stroke measurement device is configured to measure the stroke length of the needle over time.
11. The method according to claim 1 , wherein the interferometer includes a Michelson Interferometer.
12. The method according to claim 4 , wherein the interferometer further includes a third part, wherein the third part is coupled with a surgical console, and wherein the third part comprises at least one of a second reflector, a beam splitter-combiner, a light source configured to generate an optical signal, or a detector.
13. The method according to claim 4 , wherein the interferometer includes a third part, wherein the third part is coupled with a surgical console, wherein the third part comprises at least a beam splitter-combiner, and wherein the at least one optical fiber extends from the probe body to the beam splitter-combiner in the surgical console.