Development of Aspiration-Assisted End-Cut Coaxial Biopsy Needles

Abstract

Needle biopsy procedures, such as fine-needle aspiration and core needle biopsy, are used to extract tissue samples for diagnosis, and collection of larger samples allows for more accurate diagnosis of cancers. The combination of lower needle insertion force, less needle deflection, and reduced friction between the tissue and needle surface also leads to a more efficient biopsy procedure. In this research, a new end-cut-type coaxial needle with a modified aspiration mechanism has been developed to extract large tissue with minimal damage. The study shows that the clearance between the inner stylette and external needle and the insertion speed are the key factors affecting the biopsy performance including syringe friction force and amount of tissue extracted. Larger tissue samples (gelatin and chicken breast are used as samples here) can be obtained when inserting at lower speeds and using coaxial needles with smaller clearances between the external needles and inner stylettes. For solid samples (gelatin), the space inside the external needle is nearly filled with the solid sample. For samples consisting of both solid (chicken meat) and liquid components, a slower needle insertion results in extraction of more liquid than solid. To extract larger solid samples, high-speed needle insertion is required. This paper presents the design and manufacture of the system, protocol to evaluate the needle biopsy, and evaluation of the needle biopsy performance using gelatin and chicken breast as tissue samples.