Programm & Abstracts                 "Innovationen in der Augenheilkunde"

Aktuelle Tagungsinformationen
   News and Updates

Anmeldung zur Tagung
   Hotel Registration
   Welcome address
Beteiligte Gesellschaften
   Societies involved
Eröffnung des Kongresses
   Opening Ceremony
Wissenschaftliches Programm
   Scientific program
   Poster Presentation
Begleitende Veranstaltungen
   Collateral Events
   Social program
   Jubilee Party
DOG Information
   DOG Information
Allgemeine Informationen
   General Information
   Index of Authors
   Registration fees

DOG Homepage

Study on the Life Expectancy of Micro-surgically used Diamond Blades with the Help of a New Measurement System

1Weingärtner W. E., 1Spraul C. W., 2Schirmer E., 2Ertl S., 3Pelzmann A., 3Junghardt A., 1Lang G. K.,
1Universität Ulm, Augenklinik und Poliklinik (Ulm)
2GFD-Gesellschaft für Diamantprodukte (Ulm)
3GFDmbh (Ulm)

Purpose: Diamond blades are usually preferred in ophthalmic surgery over common metal blades. Reusable diamond blades have advantages over single-use metal blades. First there is the better wound-healing process and the more precise cutting geometries and the longer lasting life expectancy compared to common metal 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.
Method: Over a defined area the force-displacement-diagram of the incision of the blades in a test medium are measured with a computer controlled device. The test medium is a PU-film of 80 µm thickness. The force-displacement-information of the blade incision is measured over a large number of repetitions and then the characteristics of the force-displacement-diagram are evaluated for indications of possible damage of the blades. The main focus was on measuring the maximal force that occurred during the incision of the blade into the test medium.
Results: The test medium shows the characteristics of a given blade-geometry in a force-displacement-diagram meaning that the maximal penetration force, the initial penetration of the blade and the complete penetration of the whole blade can be resolved. The force-displacement-diagrams obtained with the PU-film show similar curves as compared to the curves produced with pig eyes. After repetitive penetration in pig eyes and the measurement with the PU-film the maximal force necessary for penetration increased (0.038mN for each incision), that means that after 300 incisions into pig eyes a minor decrease of the cutting performance of the blades occur (Total increase of the force equalled to 11.4mN).
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.