Abstract
Abstract: :
Purpose: Reusable diamond blades may have advantages over single-use metal blades because of the superior cutting quality and the longer life expectancy of diamond blades. To examine the life expectancy of surgically used blades an objective, easy, and reproducible experimental method is needed. For this purpose the following method has been developed. Methods: The force-displacement of the incision of blades in a test medium is measured with a computer-controlled device. The test medium is a standardized PU-film of 80 µm thickness. Using different types of artificial diamond blades, 300 incisions are made into the cornea of a pig eye and the force-displacement in the PU-film is re-evaluated after every 50 incision into the pig cornea and then the characteristics of the force-displacement-diagram are studied for indications of possible damage of the blades. The parameter used to characterize the decay of the blade over time was the maximal force that occurred during the incision of the blade into the test medium. Results: Using this experimental set-up, we were able to measure the increase of maximal force with repeating incision. After repetitive penetration into pig cornea and the measurement with the PU-film the maximal force necessary for penetration increased in every measured blade. The mean total increase in maximal penetration force of all blades equalled to 11.4 mN, which is a decrease of only 0.038mN of the cutting performance for each incision. There was no statistically significant increase of maximal penetration force with repetitive incision into the PU-Film only Conclusions: The high sensitivity of this method allows for the first time to measure the decay of microsurgical blades. Long time use can be simulated adequately and reproducibly.
Keywords: cataract • clinical laboratory testing • wound healing