Abstract: Systems and methods for sensing tissue in a phacoemulsification procedure are provided herein. A method may include generating a sensing signal through a frequency range centered at a local resonant frequency of an ultrasonic handpiece and measuring impedance characteristics of the signal at a distal end of a needle of an ultrasonic handpiece. A method may further include comparing the measured impedance characteristics of the generated sensing signal with one or more stored impedance profiles. A method may further include classifying, based on the comparison between the measured impedance characteristics and the stored one or more impedance profiles, a medium contacting the distal end of the needle. A method may further include controlling an output of the ultrasonic handpiece based on the classification of the medium contacting the tip of the needle.

Abstract: A computer-based automated phacoemulsification method is disclosed. The method includes determining a vacuum measurement based on a reading from a sensor coupled with an aspiration line; comparing the vacuum measurement to the at least one vacuum threshold; and providing an ultrasound power based on the comparison of the vacuum measurement to the at least one vacuum threshold.

Abstract: The present invention comprises a fluid source connected to an irrigation feed line, an aspiration line providing at least a partial vacuum at a surgical site, at least one pressure sensor in communication with the aspiration line, and at least one valve in communication with the irrigation feed line, wherein the at least one valve restricts fluid flow in the irrigation feed line in accordance with at least one measurement of aspiration pressure differential and at least one predetermined system attribute, and wherein the aspiration pressure differential may equal a first measurement of aspiration pressure minus a second measurement of aspiration pressure over a predetermined time.