Patent ID: 7727179

Claim:
A phacoemulsification system comprising: a phacoemulsification needle; an ultrasonic handpiece arranged to vibrate at ultrasonic frequencies, the ultrasonic handpiece being coupled to the phacoemulsification needle; a sleeve surrounding the phacoemulsification needle, wherein an annulus is defined between the sleeve and the phacoemulsification needle; a source of irrigation fluid; an irrigation line coupled in fluid communication between the source of irrigation fluid and the handpiece so that irrigation fluid is delivered through the annulus between the sleeve and the phacoemulsification needle, a vacuum source; a length of aspiration tubing extending between the ultrasonic handpiece and the vacuum source and being coupled in fluid communication between the phacoemulsification needle and the vacuum source; the aspiration tubing forming a lumen having an interior surface and first and second ends; wherein the interior surface of the lumen of the aspiration tubing extends between the first and second ends thereof and the aspiration tubing includes a means for enhancing the turbulence of fluid flow within the lumen, and; wherein the means is configured to proportionally increase fluid flow resistance as vacuum levels increase.