Mobile Device Overlay for Radiolucent PEEK Implant Positioning

Resolve Bottlenecks,
Find Innovative Solutions
Generate Solutions

Solution Overview

Problem

Radiolucent PEEK implants used in medical procedures are difficult to accurately position and orient due to their lack of visibility in C-arm x-ray images, and even with radio-opaque markers, determining the exact distance between markers and implant edges remains challenging.

Innovation Solution

A method using a mobile computing device to capture images of the implant and internal markers, estimate the implant's pose by relating 2D and 3D positions of the markers, and overlay a 3D model image onto the captured image, optionally refining the pose with additional surgical information.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If PEEK implants are made radiolucent to improve biomechanics and post-operative assessment, then bony fusion assessment is improved, but intraoperative positioning accuracy deteriorates

Engineering Contradiction:
Improvebony fusion assessmentVSAvoidimplant positioning accuracy
Core Design Contradiction:
ReliabilityVSMeasurement precision

Solution Approach 1:

The patent introduces radio-opaque markers as intermediary elements embedded within the radiolucent PEEK implant. These markers serve as mediators that enable visualization and positioning assessment without compromising the radiolucent properties of the implant material itself. The markers provide reference points for intraoperative imaging while the implant body remains radiolucent for post-operative bony fusion assessment.

Inventive Principle:
Principle #24Intermediary (Mediator)

Solution Approach 2:

The patent creates a virtual 3D copy of the implant that is superimposed onto 2D fluoroscopic images. This virtual model is generated based on the positions of radio-opaque markers and contains information about the implant's true 3D geometry and orientation. The virtual copy enables accurate positioning assessment without requiring the physical implant to be visible in the images.

Inventive Principle:
Principle #26Copying

2Measurement precision

If radio-opaque markers are added to PEEK implants to improve positioning visibility, then implant position estimation is improved, but the ability to assess bony fusion deteriorates

Engineering Contradiction:
Improveimplant position estimationVSAvoidbony fusion assessment
Core Design Contradiction:
Measurement precisionVSReliability

Solution Approach 1:

The patent applies radio-opaque markers only at specific locations within the implant (at the extremes of the implant body), rather than making the entire implant radio-opaque. This localized application of radio-opacity provides sufficient reference points for positioning while leaving the majority of the implant body radiolucent, allowing bony fusion to be assessed through the implant material.

Inventive Principle:
Principle #3Local quality

3Difficulty of detecting and measuring

If semi-radiolucent PEEK material is used to make implant edges visible, then implant visibility is improved, but bony fusion assessment capability deteriorates

Engineering Contradiction:
Improveimplant edge visibilityVSAvoidbony fusion assessment
Core Design Contradiction:
Difficulty of detecting and measuringVSReliability

Solution Approach 1:

The patent uses radio-opaque markers as intermediary reference points rather than relying on the implant material itself to provide visibility. The markers are positioned at the extremes of the implant and serve as proxies for locating implant edges, eliminating the need to compromise the implant material's radiolucency.

Inventive Principle:
Principle #24Intermediary (Mediator)

4Measurement precision

If 2D image data with markers is used to determine implant orientation, then spatial positioning is improved, but exact distance measurement between markers and implant edges deteriorates

Engineering Contradiction:
Improvespatial positioningVSAvoiddistance information between markers and implant edges
Core Design Contradiction:
Measurement precisionVSLoss of information

Solution Approach 1:

The patent transitions from 2D image analysis to 3D virtual modeling. By creating a virtual 3D model of the implant and using 2D-to-3D registration techniques, the system recovers three-dimensional position and orientation information including distances between markers and implant edges that are not directly measurable from 2D images alone. The virtual model contains complete geometric information that enables accurate distance measurements.

Inventive Principle:
Principle #17Another dimension (Dimensionality change)

Applied Scientific Principles

This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.

Function Achieved in This Case

Enhances the accuracy of implant positioning and orientation by providing a clear visual representation of the implant's position and orientation, overcoming the limitations of radiolucency and marker visibility in medical imaging.

Implementation Method 1

capturing an image of the implant with the camera of the mobile computing device

Methodology Applied
Scientific EffectPhotoelectric Effect: Photoelectric Effect

Implementation Method 2

C-arm x-ray system

Methodology Applied
Scientific EffectX-Ray: X-Ray

Implementation Method 3

radio-opaque internal markers within the PEEK implants that define the edges of the PEEK implants. The markers appear as fiducial markers in the image captured by the C-arm x-ray system

Methodology Applied
Scientific EffectAbsorption (EM radiation): Absorption (EM radiation)

Data Source

PatentEP2854646B1Methods and apparatus for estimating the position and orientation of an implant using a mobile device
Publication Date: 2019.03.06 DEPUY SYNTHES PROD INC
  • EP2854646B1 patent drawingFigure 1
  • EP2854646B1 patent drawingFigure 2
  • EP2854646B1 patent drawingFigure 3

AI summary

Methods and apparatus for providing an overlay image of an implant during a surgical procedure using a mobile computing device are provided herein. The implant may include radio-opaque internal markers adjacent to and defining edges of the implant. The method may include: capturing an image of a imaging display device screen; estimating a pose of the implant based on the relationship between the 2-D positions of the radio-opaque internal markers and the 3-D positions of the radio-opaque internal markers; retrieving or generating a 3-D model image of the implant at the determined pose using the 3-D implant data; and overlaying the 3-D model image onto the image of the implant. The captured image may include the implant and at least two of the radio-opaque internal markers being visible as fiducial markers within the image. The fiducial markers may be 2-D positions of the radio-opaque internal markers in a 2-D plane.