Steerable Needle for Core Biopsy Team Members Evan

Steerable Needle for Core Biopsy Team Members Evan Rogers – Leader Tyler Allee – BWIG Kristen Sipsma – BSAC Betsy Appel – Communicator Client Fredrick Kelcz, Ph. D, M. D Department of Radiology UW Medical School Advisor Willis Tompkins, Ph. D. Department of Biomedical Engineering

Presentation Overview ► Problem Statement ► Client Requirements ► Background § Core Biopsy § Current Devices ► Design Alternatives ► Future Work

Problem Statement Radiologists perform image guided biopsies and sometimes the target mass is missed, requiring the biopsy needle to be withdrawn and redirected. This process is time consuming and painful for the patient. Therefore, radiologists need a biopsy needle that contains a tip which can be steered inside the body.

Client Requirements ► Needle size <14 gauge ► Must extract a core sample of tissue ► Compatible for use with CT and Ultrasound ► Steering must not damage adjacent tissue ► Distal 1 -2 cm of needle should be steerable ► Must have intuitive external control mechanism ► Single use device

Background – Biopsy Method ► Local anesthetic is injected ► Ultrasound is placed on surface of body to guide needle placement ► Needle is inserted along line created by ultrasound to obtain sample http: //www. med-ars. it/gastroenterology/liver_biopsy(1). JPG

Background: Core Biopsy ► Core biopsy removes 1 -3 cm sample of tissue using a hollow needle ► Reasons for core biopsy § Much larger sample taken than with fine needle aspiration (FNA) § Higher diagnostic accuracy rate (93% vs. 88% for FNA in diagnosing lymphomas) ► Tissues Biopsied: Liver, Abdomen, Breast

Current Devices ► Rigid needle ► Spring-loaded tissue capture § Rapid firing of outer sheath cuts quickly to minimize tissue damage ► Single http: //www. vin. com/Image. DBPub/IM 25000/IMC 24242. jpg Use Cook’s Quick Core Biopsy Needle http: //www. cookgroup. com/cook_urological/products/cystoscopy/1_04_02. html www. justeves. com/tumor/family_history. shtml

Current Device: Pneum. Rx ► Designed for FNA of lung ► Co-axial design § § § Semi-rigid outer piece Removable rigid inner piece Steerable inner piece ► Joystick allows steering in 2 planes

Coaxial Biopsy Needle Design Semi-rigid outer needle with rigid inner needle is inserted into body ► Rigid inner needle can be replaced with semi-rigid steerable needle ► Passive steering due to beveled needle tip ► Tissue is cut by movement of outer sheath ►

Coaxial Biopsy Needle Design

Joint Biopsy Needle Design ► Joint § Floating elastic joint ► Steerable by external push buttons ► Semi rigid core bends with joint ► Cutting action is provided by needle tip

Future Work ► Incorporate coaxial needle with steerable joint ► Identify rigid and semi-rigid materials ► Model needle mechanisms on larger scale to demonstrate properties and show it works

References ► Yang, Yi Jun and Damron, Timothy A. , “Comparison of Needle Core Biopsy and Fine-Needle Aspiration for Diagnostic Accuracy in Musculoskeletal Lesions” ARCHIVES OF PATHOLOGY & LABORATORY MEDICINE, Jul 2004

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