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[Cutting speeds and success of biopsy with different punch biopsy instruments]
1Institut für Mikrotechnik und Medizintechnik, Fachgebiet Biomedizinische Technik, Technische Universität Berlin, Dovestrasse 6, 10587 Berlin-Charlottenburg. owendt@bmt1.kf.TU-Berlin.de
Purpose:
The goal of our investigations was the verification of the relationship between the reachable cutting speed and the biopsy success for different large-core needle biopsy devices in dependence of the cutting depth as well as different kinds of tissue.
Methods:
We measured the dynamic cutting properties of five large-core needle devices with moveable outer needles in air and different tissues. An incremental stripe had been attached on to the outer needle and was moved through a photooptical sensor during the cutting phase. For the valuation of the biopsy success we compared the absolute weight respectively the volume of the tissue probes as well as the relative weight in relation to the size of the sample chambers within the inner trocars.
Results:
A clear correlation between the cutting speed, the tissue properties and the biopsy success had been registered, especially for more solid tissues.
Conclusions:
For a successful large-core needle biopsy a cutting speed of 8 to 12 metres per second is essential. To compensate slower needle movements high quality requirements for the surface, geometry and edge have to be fulfilled.