Novel Phacoemulsification System Using Feedback-Based IOP Target Control

Sunday, April 27, 2014: 9:02 AM
Room 151A (Boston Convention and Exhibition Center)
Mikhail Boukhny, PhD, Alcon, Lake Forest, CA, USA
Gary P. Sorensen, BSME, Alcon Laboratories, Lake Forest, CA, USA
Raphael Gordon, BSEE, Alcon Labs, Lake Forest, CA, USA

Narrative Responses:

Purpose
To evaluate the ability of Active Fluidics system utilizing active feedback fluidics to set and maintain target IOP in a laboratory simulated phacoemulsification model.

Methods
A transducer-based test fixture utilizing a simulated eye chamber was used to analyze simulated IOP stability with a phaco-emulsifier incorporating Active Fluidics, pressurized irrigation system with active feedback control, versus a gravity-based system without feedback control.  The Active Fluidics system utilized a low stretch flexible polymer container for irrigation that was squeezed within a computer-controlled mechanism to generate pressure.  The low compliance system allowed for very rapid changes in pressure and precise control.  Optical-based non-invasive pressure sensors in the irrigation and aspiration paths provided feedback for IOP control algorithms.

Results
With the gravity-based system, irrigation path losses caused IOP to drop as a function of aspiration flow rate.  The drop in IOP was approximately 20 mmHg at 30 cc/min and 45 mmHg at 60 cc/min.  The Active Fluidics feedback system was able to maintain IOP to within approximately 5 mmHg throughout the range of 0 to 60cc/min.

Conclusion
The Active Fluidics System, which maintained better IOP control (5 mmHg at 0 to 60 cc/min), demonstrated improved stability during laboratory testing vs. the gravity-based system.