Harshith.
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Run 04Computer Integrated Surgery · Johns Hopkins · Fall 2024

3D Point-Cloud Registration & Surgical Navigation

ICP · BVH · EM tracking

ICP runtime
-40%
EM error
-30%

C++ · Python · Eigen

Problem

Surgical navigation has to keep a tracked instrument registered to anatomy while the tracker itself is noisy, distorted, and slow if you naively search a 100k-point cloud every iteration.

What I built

A modular C++/Python library for 3D registration, calibration, error modeling, and distortion correction, written for the Computer Integrated Surgery course at Johns Hopkins.

  • Bounding-volume hierarchies accelerate nearest-neighbor lookup inside ICP, cutting per-iteration cost on large point clouds and dropping overall ICP runtime by 40%.
  • EM-tracker distortion is modeled as a polynomial deformation field calibrated from a known phantom, reducing positional error by 30%.
  • Each component has unit tests and verification documentation, so the registration path is checkable rather than a single opaque binary.

The work is the unglamorous half of image-guided surgery: if the transform is wrong, the model never gets a chance to be useful.