The research objective of this award is to investigate the cutting mechanics of biological tissue in needle biopsy procedures by viewing biopsy as a cutting process with tissue as the work-material. This will be accomplished by testing novel needle tip geometries using high speed tissue cutting test machines to characterize the mechanics of tissue cutting and by modeling the mechanics of tissue cutting. Advanced helical needle-tips and micro-grinding methods will be applied to generate novel needle-tip geometries with sharp, burr-free cutting edges. Two test machines, one for high speed orthogonal and oblique tissue cutting and another for high speed needle insertion, will be built to investigate the effects of cutting speed and needle tip geometry. Mechanistic models will be built to predict the tissue cutting force related to the needle geometry and cutting speed. Tissue fracture and tissue-needle tribological phenomena in high-speed tissue cutting will be studied to develop the fundamentals of tissue cutting mechanics.
If successful, the benefits of this research will be improved performance of the most commonly used medical device - the needle. Tissue cutting efficiency will increase thereby reducing pain and trauma in biopsy procedures. New biopsy machines with advanced needles and optimized operating parameters will increase the volume of tissue samples collected in each needle insertion and improve the accuracy of pathology diagnoses in a wide range of biopsy procedures. Results of the proposed research will also extend the traditional field of machining to biomedical and health care applications and promote the emerging research frontiers in biomedical manufacturing.
