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 ofthis 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 States3Intelligent 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. 3MRI of needle puncturing an abscess in the pelvis.

System Integration

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Fiber Bragg Grating (FBG) Technology

Input Transmission Reflection

FBGOptical Fiber

Input Transmission

Reflection5 mm

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Fiber Bragg Grating (FBG) Sensors

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Design & Fabrication

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Beam Theory

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Sensor Placement

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Minimum Error Regionsy1 = 25 mm

y2 = 82 mm

Calibration

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Results & Animal Test

Benchtop results show <0.1mm accuracy when calibrated for manufacturing tolerances.

MRI of a mature male beagle’s 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

Acknowledgements

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