Vertebra Pose Tracking via Multi-Tracker Registration

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Current surgical tracking techniques for spinal surgery face challenges in maintaining accuracy, particularly when tracking vertebrae poses, due to patient movement and anatomical changes during surgery, leading to prolonged and risky procedures.

Innovation Solution

A computer-implemented method using two trackers, each with 5 degrees of freedom, attached to vertebrae, which register a tracking coordinate system with an image coordinate system, allowing for efficient determination of vertebrae poses through intraoperative data processing and visualization, reducing the need for repeated registrations and minimizing surgical obstruction.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Device complexity

If a single tracker is attached to one vertebra for tracking, then the tracking setup is simple, but tracking accuracy decreases the further away the surgical site gets from the tracker due to patient movement and anatomical changes

Engineering Contradiction:
Improvetracker setup complexityVSAvoidtracking accuracy
Core Design Contradiction:
Device complexityVSMeasurement precision

Solution Approach 1:

The patent divides the tracking system into multiple independent trackers, each attached to a specific vertebra. Instead of relying on a single tracker that loses accuracy with distance, the system segments the tracking function across multiple vertebrae, ensuring each surgical site has a locally attached tracker providing high-accuracy tracking without distance-related degradation.

Inventive Principle:
Principle #1Segmentation

2Measurement precision

If repeated registrations are performed to compensate for movement and anatomical changes, then tracking accuracy is maintained, but surgical time increases and patient exposure to health risks increases

Engineering Contradiction:
Improvetracking accuracyVSAvoidsurgical time
Core Design Contradiction:
Measurement precisionVSLoss of time

Solution Approach 1:

The patent attaches trackers to multiple vertebrae before surgery begins, establishing a distributed tracking network in advance. This preliminary action eliminates the need for repeated registrations during surgery, as the system can continuously track all vertebrae simultaneously without requiring intermittent re-registration to maintain accuracy.

Inventive Principle:
Principle #10Preliminary action

3Measurement precision

If multiple tracking arrays are attached to multiple adjacent vertebrae to maintain accuracy, then tracking coverage is improved, but vertebral access is obstructed due to the size of the trackers

Engineering Contradiction:
Improvetracking coverageVSAvoidvertebral access
Core Design Contradiction:
Measurement precisionVSEase of operation

Solution Approach 1:

The patent employs miniaturized trackers that can be nested within or integrated into the existing surgical instrumentation and vertebral structures. The trackers are designed to fit within the confined surgical space without protruding significantly, allowing vertebral access to be maintained while still providing comprehensive tracking coverage across multiple vertebrae.

Inventive Principle:
Principle #7Nested doll (Nesting)

Data Source

PatentEP4104786A1Technique for determining poses of tracked vertebrae
Publication Date: 2022.12.21 STRYKER EUROPEAN OPERATIONS LIMITED
  • EP4104786A1 patent drawingFigure 1A~1B
  • EP4104786A1 patent drawingFigure 1C~1D
  • EP4104786A1 patent drawingFigure 2

AI summary

A tracker system for determining poses of at least two vertebrae and a computer-implemented method of using the tracker system are presented. The tracker system comprises a first tracker trackable in 5 degrees of freedom, DOF, and attachable to a first vertebra and a second tracker trackable in 5 DOF and attachable to a second vertebra. In some variants, the first and second tracker each comprises an elongated body and two imageable markers that are attached to the elongated body and spaced apart from each other along a length of the elongated body. A tracking coordinate system is registered in 6 DOF with an image coordinate system associated with first image data taken by a medical imaging system and indicative of the first and second vertebra. The method comprises receiving intraoperative tracking data and determining, from the received intraoperative tracking data, tracker poses of the first tracker and the second tracker in 5 DOF. Further still, the method comprises determining, from the tracker poses and based on the registration of the tracking coordinate system with the image coordinate system, poses of the first vertebra and the second vertebra in 5 DOF.