Behavior of tip-steerable needles in ex vivo and in vivo tissue

Ann Majewicz*, Steven P. Marra, Mark G. Van Vledder, Mingde Lin, Michael A. Choti, Danny Y. Song, Allison M. Okamura

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review

73 Citations (Scopus)


Robotic needle steering is a promising technique to improve the effectiveness of needle-based clinical procedures, such as biopsies and ablation, by computer-controlled, curved insertions of needles within solid organs. In this paper, we explore the capabilities, challenges, and clinical relevance of asymmetric-tip needle steering through experiments in ex vivo and in vivo tissue. We evaluate the repeatability of needle insertion in inhomogeneous biological tissue and compare ex vivo and in vivo needle curvature and insertion forces. Steerable needles curved more in kidney than in liver and prostate, likely due to differences in tissue properties. Pre-bent needles produced higher insertion forces in liver and more curvature in vivo than ex vivo. When compared to straight stainless steel needles, steerable needles did not cause a measurable increase in tissue damage and did not exert more force during insertion. The minimum radius of curvature achieved by prebent needles was 5.23cm in ex vivo tissue, and 10.4cm in in vivo tissue. The curvatures achieved by bevel tip needles were negligible for in vivo tissue. The minimum radius of curvature for bevel tip needles in ex vivo tissue was 16.4cm; however, about half of the bevel tip needles had negligible curvatures. We also demonstrate a potential clinical application of needle steering by targeting and ablating overlapping regions of cadaveric canine liver.

Original languageEnglish
Article number6
Pages (from-to)2705-2715
Number of pages11
JournalIEEE Transactions on Biomedical Engineering
Issue number10
Publication statusPublished - 13 Jun 2012

Bibliographical note

Funding Information:
Manuscript received December 20, 2011; revised April 10, 2012; accepted May 24, 2012. Date of publication June 13, 2012; date of current version September 14, 2012. This work was supported by the National Institutes of Health under Grant R01 EB006435 and by the National Science Foundation fellowship. Philips Healthcare and the Johns Hopkins Medical Institutions provided access to the Allura Xper FD20. This work was performed at The Johns Hopkins University. Asterisk indicates the corresponding author.


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