Related Experiment Video
Updated: Jan 28, 2026
08:33
Detection of Extravascular Trypanosoma Parasites by Fine Needle Aspiration
Published on: August 7, 2019
9.6K
High vacuum and aspiration on phacoemulsification efficiency and chatter for Centurion
Larry Ha1, Alex Wright1, Dannen D Wright1
1Department of Ophthalmology and Visual Sciences, John A. Moran Eye Center, University of Utah, Salt Lake City, Utah.
Summary
Higher aspiration rates do not improve phacoemulsification efficiency. Increasing vacuum to 700 mm Hg decreases efficiency, while chatter remains unaffected by aspiration or vacuum settings.
Area of Science:
- Ophthalmology
- Surgical Technology
Background:
- Phacoemulsification is a key cataract surgery technique.
- Optimizing machine parameters like aspiration and vacuum is crucial for surgical efficiency and safety.
Purpose of the Study:
- To evaluate the impact of varying high aspiration and vacuum settings on phacoemulsification efficiency and chatter.
- To determine optimal settings for cataract surgery.
Main Methods:
- An in vitro study using porcine lens nuclei.
- Phacoemulsification performed with Balanced tips at different aspiration (50-60 mL/min) and vacuum (500-700 mm Hg) settings.
- Constant torsional power, longitudinal power, and intraocular pressure were maintained.
Main Results:
- Increasing aspiration rate beyond 50 mL/min did not enhance efficiency.
- Vacuum settings up to 600 mm Hg showed no significant change in efficiency.
- Aspiration and vacuum adjustments did not significantly alter chatter levels.
Conclusions:
- Elevated aspiration rates do not improve phacoemulsification efficiency.
- Vacuum settings of 700 mm Hg were found to decrease efficiency.
- Chatter is not significantly affected by increasing aspiration or vacuum settings.
Related Concept Videos
01:01Production Efficiency
18.3K
Net production efficiency (NPE) is the efficiency at which organisms assimilate energy into biomass for the next trophic level. Due to low metabolic rates and less energy spent on thermoregulatory processes, the NPE of ectotherms (cold-blooded animals) is 10 times higher than endotherms (warm-blooded animals).
18.3K
00:46Trophic Efficiency
25.1K
Trophic level transfer efficiency (TLTE) is a measure of the total energy transfer from one trophic level to the next. Due to extensive energy loss as metabolic heat, an average of only 10% of the original energy obtained is passed on to the next level. This pattern of energy loss severely limits the possible number of trophic levels in a food chain.
25.1K
01:16Efficiency of The Carnot Cycle
3.7K
The hypothetical Carnot cycle consists of an ideal gas subjected to two isothermal and two adiabatic processes. Since the internal energy of an ideal gas depends only on its temperature, which is the same before and after the completion of the Carnot cycle, there is no change in its internal energy. Hence, using the first law of thermodynamics, the total heat exchanged by the ideal gas equals the total work done. Thus, we can quantify the efficiency of the Carnot cycle via the heat exchanged...
3.7K
01:19Turnover Number and Catalytic Efficiency
21.5K
The turnover number of an enzyme is the maximum number of substrate molecules it can transform per unit time. Turnover numbers for most enzymes range from 1 to 1000 molecules per second. Catalase has the known highest turnover number, capable of converting up to 2.8×106 molecules of hydrogen peroxide into water and oxygen per second. Lysozyme has the lowest known turnover number of half a molecule per second.
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
Chymotrypsin is a pancreatic enzyme that breaks down proteins during digestion....
21.5K
01:10Column Efficiency: Plate Theory
2.0K
Band broadening in a chromatography column is measured by its efficiency. This is determined by the number of theoretical plates (N). Theoretical plate theory states that a separation column consists of a continuous series of imaginary plates where solute equilibration occurs between stationary and mobile phases.
A higher number of theoretical plates signifies better column efficiency and improved separation capabilities. Plate height affects bandwidth and separation quality; it is inversely...
A higher number of theoretical plates signifies better column efficiency and improved separation capabilities. Plate height affects bandwidth and separation quality; it is inversely...
2.0K
01:12Column Efficiency: Rate Theory
989
The rate theory of chromatography provides quantitative insight into the shapes and widths of elution bands. These bands are based on the random-walk mechanism governing molecular migration within a column. The Gaussian profile of chromatographic bands arises from the cumulative effect of random molecular motions as they progress through the column.
During elution, a solute molecule experiences numerous transitions between stationary and mobile phases, exhibiting irregular residence times in...
During elution, a solute molecule experiences numerous transitions between stationary and mobile phases, exhibiting irregular residence times in...
989