Declaration of Conflict of Interest or Relationship

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Declaration of Conflict of Interest or
Relationship
Speaker Name Santhi Elayaperumal I have no
conflicts of interest to disclose with regard to
the subject matter of this presentation.
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MRI-compatible Haptics Strain sensing for
real-time estimation of three dimensional needle
deflection in MRI environments
Y-L. Park1, S. Elayaperumal1, S.C. Ryu1, B.
Daniel2, R. J. Black3, B. Moslehi3, and M.R.
Cutkosky1 1Mechanical Engineering, Stanford
University, Stanford, CA, United States
2Radiology, Stanford University, Stanford, CA,
United States 3Intelligent Fiber Optic Systems
Corporation, Santa Clara, CA, United States
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Introduction

• Challenges in the Manipulation of Tools in
  MRI-guided Interventions.
• Lack of Sensing Capabilities Tactile Cues in
  Medical Robotics.
• MRI-Compatible Force Deflection-Sensing
  Needle.

Dan Stoianovici and PneuStep, JHU.
MRI of needle puncturing an abscess in the pelvis.
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System Integration
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Fiber Bragg Grating (FBG) Technology
Transmission
Input
FBG
Reflection
Optical Fiber
5 mm
Input
Transmission
Reflection
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Fiber Bragg Grating (FBG) Sensors

• Wavelength Shifts Proportional to Strain.
• Immune to Electromagnetic Interference.
• Multiplexing/Demultiplexing Capabilities.
• Small and Flexible.
• High Resolution.
• Temperature Sensitive.

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Design Fabrication
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Beam Theory
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Sensor Placement
Minimum Error Regions
y1 25 mm y2 82 mm
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Calibration
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Results Animal Test
Benchtop results show lt0.1mm accuracy when
calibrated for manufacturing tolerances.
MRI of a mature male beagles prostate and needle
prototype. Deflections of 2.0mm and 2.5mm along
the x and z axes respectively (scale exaggerated
to highlight flexing.)
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Conclusions

• FBG Sensors Successful in Estimating Tip
  Deflection and Profile in 3D.
• No Image Artifact Resulted from Sensors.
• Sensor Signal Was Not Affected by the Magnetic
  Field.
• Possible Applications in
• Manual Needle Manipulation Robotic Trajectory
  Planning
• (Position Sensing)
• Tissue Deformation Validation Studies Haptic
  Feedback
• (Force Sensing)
• Cryosurgery RF Ablation (Temperature Sensing)
• etc.

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Future Work Robotic Manipulator and Integrated
System
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Acknowledgements