Legacy AdvanTec and Sovereign WhiteStar

Abstract

There was less increase in wound temperature over time with the S-WS than with the L-ADV system in sleeved and unsleeved simulated surgery in human eye-bank eyes. Because the ultrasound handpieces respond differently under different load scenarios, meaningful comparisons of pulsing features are difficult to create.

Comparison of thermal features associated with 2 phacoemulsification machines

“…The Legacy Advantec has been documented to be hotter than the Sovereign, even adjusting for duty cycle differences when the instruments were twisted in the wound. 7 This would occur at 430 g of weight. Clearly, more clinical work must be done to correlate in vitro weights with the clinical situation; however, these examples indicate the frictional forces associated with torqueing or pressing the phaco tip against the wound may be substantial.…”

“…Miller, ''Temperature of Phaco Tip Is a Function of Ultrasound Power Management and Fluid Flow,'' EyeWorld February 2004, pages [4][5]. 7 This means in a minimal workload environment (such as water), the Sovereign has a dynamic range about 2.3 times greater than the Legacy Advantec. If this inherent bias is appropriately controlled, the results will be the same for both machines.…”

“…He does state the 2 machines respond differently to loading, and although his results do not confirm this, he agrees with our power algorithm conclusions in this article and our previous one. 7 We added weights to model incision friction, especially if the instrument is torqued in the wound, 3 as well as the workload of removing a nuclear fragment because the artificial chamber came in contact with the tip (Figure 2). The hardest cataracts would produce the heaviest workload, the risk of which is additive to any incisional friction-related temperature increase.…”

“…1,2 A series of wound-temperature studies has implicated position of the needle, 3 low-flow conditions, [4][5][6][7][8][9] and use of fullpower, nonpulse settings. 8,9 Until now, it has been unclear to what degree machine settings and operating conditions contribute to the elevation of temperature at the phaco tip.…”

Thermal effect of microburst and hyperpulse settings during sleeveless bimanual phacoemulsification with advanced power modulations

“…Laboratory studies have shown that despite a bare phaco needle, rapid on-off cycling of ultrasonic power can prevent the temperature during bimanual microincisional surgery from rising above 45 C, the level that is considered the threshold for corneal damage. [1][2][3][4][5] A study in human cadaver eyes demonstrated that the Millennium Microsurgical System (Bausch & Lomb), with conventional power settings, can be used safely to perform bimanual sleeveless phacoemulsification. 4 The current study was undertaken to assess whether software allowing precise, customizable microburst and hyperpulse power modulationsdwith bursts of phaco power as short as 4 msdfurther reduces wound temperatures during sleeveless bimanual phacoemulsification in general, but specifically with the Millennium.…”