Bone-Mounted Reference for Surgical Tool Tracking

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In minimally invasive orthopedic surgery, tracking tools is challenging due to limited space for trackers on the tools, especially during procedures like bone sculpting where traditional tracking methods are impractical.

Innovation Solution

A system and method for tracking bone-altering tools in computer-assisted surgery, involving a trackable reference secured to a bone, sensors to track the reference for position and orientation, and a calculator to determine the tool's position and orientation based on the reference and interface with the bone, allowing for precise tracking and alteration parameter calculation.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Volume of moving object

If traditional trackers are positioned directly on the tool, then tracking precision is maintained, but the tool cannot be fitted within small incisions for minimally invasive surgery

Engineering Contradiction:

Improvetool sizeVSAvoidtracking precision

Core Design Contradiction:

Volume of moving objectVSMeasurement precision

Solution Approach 1:

The tracking system is segmented into two independent parts: the tool itself (which remains small for minimally invasive surgery) and the tracker (which is positioned on the bone). This separation allows the tool to maintain its compact size while the tracker provides the necessary tracking functionality on a larger surface area.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

An intermediary reference frame is introduced that connects the bone to the tool through mathematical transformation. The tracker on the bone establishes a reference frame, and through calculated transformation matrices, the system determines tool position and orientation without requiring direct attachment of the tracker to the tool.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Ease of operation

If the tool is made small to fit within small incisions, then minimally invasive surgery is enabled, but space for trackers on the tools is eliminated

Engineering Contradiction:

Improveminimally invasive capabilityVSAvoidtracking system complexity

Core Design Contradiction:

Ease of operationVSDevice complexity

Solution Approach 1:

The patent introduces an intermediary reference frame established on the bone that mediates between the tracker and the tool. This reference frame serves as a bridge, allowing the system to calculate tool position and orientation through mathematical transformation rather than direct tracker attachment, thus enabling minimally invasive surgery while maintaining tracking capability.

Inventive Principle:

Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent replaces the mechanical attachment of trackers to tools with a mathematical calculation system. Instead of physically mounting trackers on the tool (mechanical approach), the system uses sensors to track a bone-mounted reference frame and calculates tool parameters through coordinate transformation and interface relation analysis (mathematical approach).

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

3Volume of moving object

If trackers are removed from the tool for minimally invasive procedures, then space constraints are satisfied, but direct tracking of the tool becomes problematic

Engineering Contradiction:

Improvetool volumeVSAvoidtool position detection

Core Design Contradiction:

Volume of moving objectVSDifficulty of detecting and measuring

Solution Approach 1:

The system creates a virtual model (copy) of the tool with defined geometric parameters and interface relations. This digital replica allows the calculation system to determine tool position and orientation by combining the bone reference frame data with the stored tool model, eliminating the need for physical trackers on the actual tool.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent replaces direct mechanical tracking (trackers on the tool) with an indirect calculation system that uses sensor data from a bone-mounted reference frame combined with mathematical models of the tool's interface relations and geometry to determine tool position and orientation.

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

Data Source

PatentUS11583224B2Method and system for tracking tools in computer-assisted surgery

Publication Date: 2023.02.21 ORTHOSOFT ULC

AI summary

A system for tracking a bone-altering tool in computer-assisted surgery, comprising a first trackable reference secured to a first bone, with a first frame of reference being associated with the first trackable reference. A bone-altering tool is securable to the first bone in a secured configuration. Sensors track the trackable reference for position and orientation. A position/orientation calculator is connected to the sensor device to calculate a position and orientation of the first frame of reference. An alteration parameter calculator is associated with the position/orientation calculator to determine a position and orientation of the bone-altering tool in the secured configuration as a function of the position and orientation of the first frame of reference and of the secured configuration. A method for tracking tools using the tracking of a bone is provided.