The objective of this project is to improve the fundamental understanding of needle design and manufacturing in order to enable more efficient needle core biopsy. The tissue biopsy length will be increased by optimizing the high-inclination-angle needle cutting edges and smoothing the needle surfaces to reduce friction at the tissue-needle interface and thereby reduce the required cutting forces. This project involves three tasks. Task 1 is to realize simultaneous internal and external polishing of 18-gauge stainless steel needle tubes using magnetic abrasive finishing. Task 2 is to design and machine (i.e., grind and polish) the high-inclination-angle needle cutting edges. Task 3 is to measure the friction force between tissue and the needle interior, develop the mathematical model of the biopsy length as a function of the needle cutting edge and internal friction force, and optimize the needle design and manufacture to give the maximum biopsy length possible.
If successful, the outcomes of this research will reveal the micro-machining (deformation and cutting) mechanisms of soft tissue using the engineered biopsy needles. Modifications to the existing metal-cutting models and observations of new phenomena in cutting tissue can broaden the application of the traditional field of machining to biomedical and healthcare components. Biopsy is a widely used medical procedure in which a tissue sample is cut and removed for examination to identify and diagnose diseases. The improvement in the tissue-cutting efficiency will reduce pain and improve accuracy in pathology diagnosis, and the innovative needle design and manufacturing will be translatable to any field of medicine that uses needles. The research activities will be integrated into graduate and undergraduate courses creating a learning environment that engages the students in the university engineering experience and enhances their long-term retention in engineering careers.
