Needle Based Procedures

The problem

  • Outcome of minimally invasive needle based procedures depend on size and location of target region and the experience of the physician.
  • Manual techniques require physician to ÒguestimateÓ insertion angle.
  • Robot assisted needle insertion has attracted attention, however, 1) safety 2) cost effectiveness remain issues.

Manual needle insertion

Sequence of manual technique: (1) Use CT laser, slice number, and grid number to mark entry point, (2) "Guestimating" insertion angle, (3) and (4) inserting the needle

Setup for laser guided needle insertion

Current prototype of passive laser system. (a) iGuide system from Seibersdorf, (b) custom designed laser holder, (c) 6 DOF lockable passive arm, (d) bridge frame attached to CT table, (e) dual-axis inclinometer, (f) crosswire laser, (g) LCD screen displaying craniocaudal component of the laser direction vector, from the vertical (h), LCD screen displaying the component of laser direction in the axial plane, from the vertical.

Acubot Robot Setup

(a) Rotating Needle Driver (RND), (b) Remote Center of Motion (RCM) orientation module. (c)/(d) Force sensor, (e)/(f) Head and Barrel grippers, (g) needle hub

Solutions

  • Use a passive laser guide and have the physician insert the needle.
    • An orientation laser marks the needle trajectory.
    • Since, the needle insertion is still controlled by physician; the safety concerns are no different from manual case.
    • The device cost is less due to reduced complexity.
  • An automatic needle driver with safety release and force sensing.
    • Force/Torque sensors sense the forces that are applied to the needle during insertion.
    • A quick-release mechanism can be triggered at preset conditions.
    • The driver can incorporate mechanisms to reduce needle deflection and tissue deformation, e.g., a spinning needle driver.

Results

  • Preliminary results for passive needle suggest improvements over manual insertion in orienting accuracy.
    Angular Error (deg)
    p-value (α=0.05)
    Manual
    Laser guided
    Axial
    5.85
    (± 4.09)
    1.62
    (± 0.83)
    0.04
    Craniocaudal
    3.89
    (± 2.49)
    2.40
    (± 1.67)
    0.3
  • In preliminary studies of automatic needle driver:
    • The response of the quick release mechanism was determined to be 202ms +/- 39ms.
    • The needle spinning reduced the work done in inserting the needle.
    • A marked reduction in the variability of the work done was also observed.

Force vs. needle displacement

Force vs. needle displacement curve

Force vs. needle displacement

Average areas under the Force vs. Needle displacement curves of twelve successful insertions for three different spin rates. Thin bars represent the range of values obtained for this metric.
 

Needle insertion sequence

A sequence of images capture the insertion of the needle using the rotating needle driver, and the subsequent smooth, quick release of the needle at the end of insertion. 1-3) display of needle insertion, 4-5) beginning and end time of needle breakaway 6) end of needle release. [video]
 
The automatic needle driver is in collaboration with:
  • Kevin Cleary and his team, Department of Imaging Science and Information Systems, Georgetown University, Washington
  • Dan Stoianovici and his team, URobotics Lab, Johns Hopkins Medicine, Baltimore MD
 

Publications
  • A. Kapoor, S. Shah, P. Guion, B. J. Wood, J. Ding, D. Petrisor, D. Stoianovici, J. Karanian, W. F. Pritchard, and K. Cleary. Robotically assisted needle driver: safety release, force profiles, and needle spin in an in-vivo swine model, Conference of International Society of Computer Aided Surgery, 2008
  • S. Shah, A. Kapoor, K. Sharma, P. Guion, D. Mazilu, B. J. Wood. Semi-Automated Laser Guidance for Needle Alignment during CT guided Interventional Procedures.  Annual Meeting of Society of Interventional Radiologists, 2008