MR-compatible biopsy needle with enhanced tip force sensing.
We describe an instrumented biopsy needle that provides physicians the capability to sense interaction forces directly at the tip of the needle's inner stylet. The sensors consist of optical fiber Bragg gratings (FBGs), and are unaffected by electromagnetic fields; hence the needle is suitable for MR-guided procedures. In comparison to previous instrumented needles that measure bending strains, the new design has additional sensors and a series of micro-machined holes at the tip. The holes increase strain sensitivity, especially to axial forces, without significantly reducing the stiffness or strength. A comparison of the dynamic forces measured with the new needle and those obtained using a force/torque sensor at the needle base shows that the enhanced tip sensitivity is particularly noticeable when there is significant friction along the needle sleeve.
Mechanical Engineering Dept., Stanford University.
Santhi
S
Elayaperumal
Radiology Dept., Stanford University.
Jung Hwa
JH
Bae
Intelligent Fiber Optic Systems Corporation (IFOS), Santa Clara, CA.
David
D
Christensen
Mark R
MR
Cutkosky
Bruce L
BL
Daniel
Joannes M
JM
Costa
Richard J
RJ
Black
Fereydoun
F
Faridian
Behzad
B
Moslehi