AR Registration Guidance for Surgical Image-to-Tracking Alignment

Solution Overview

Problem

Existing surgical navigation systems lack effective user guidance for acquiring registration points between patient image data and surgical tracking systems, particularly in scenarios where the tracking system is not activated or available, leading to potential inaccuracies in transformations between coordinate systems.

Innovation Solution

A method utilizing augmented reality (AR) devices to provide user guidance by overlaying registration instructions on patient images, determining transformations through matching generic face models to patient image data, and displaying instructions to acquire registration points on predefined body surface subsections with specific properties, enabling accurate registration point acquisition.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Measurement precision

If a surgeon manually acquires registration points without guidance, then the process is simple and quick, but the accuracy of registration between coordinate systems deteriorates

Engineering Contradiction:

Improveregistration accuracyVSAvoidoperational complexity

Core Design Contradiction:

Measurement precisionVSEase of operation

Solution Approach 1:

The system performs preliminary analysis of patient image data (CT, MRI, or ultrasound) before the surgical procedure to pre-identify optimal registration point locations on the patient's body surface. This preliminary action provides guidance information that helps the surgeon acquire registration points accurately without requiring complex real-time analysis during the procedure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary guidance system that acts as a mediator between the surgeon and the registration process. This intermediary provides visual or auditory cues indicating the optimal locations for acquiring registration points, thereby improving registration accuracy while keeping the surgical workflow simple and intuitive.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Loss of time

If the surgical tracking system is activated before patient positioning, then the transformation can be obtained quickly, but the guidance for accurate registration point acquisition is lost

Engineering Contradiction:

Improvetime for registrationVSAvoidregistration accuracy

Core Design Contradiction:

Loss of timeVSMeasurement precision

Solution Approach 1:

The system performs preliminary analysis of patient image data (CT, MRI, or ultrasound) before the surgical procedure to pre-identify optimal registration point locations on the patient's body surface. This preliminary action provides guidance information that helps the surgeon acquire registration points accurately without requiring complex real-time analysis during the procedure.

Inventive Principle:

Principle #10Preliminary action

Solution Approach 2:

The patent introduces an intermediary guidance system that acts as a mediator between the surgeon and the registration process. This intermediary provides visual or auditory cues indicating the optimal locations for acquiring registration points, thereby improving registration accuracy while keeping the surgical workflow simple and intuitive.

Inventive Principle:

Principle #24Intermediary (Mediator)

3Adaptability or versatility

If generic face models are used for transformation, then the guidance can be provided before tracking system activation, but the complexity of determining accurate transformations increases

Engineering Contradiction:

Improveguidance availability timingVSAvoidtransformation determination complexity

Core Design Contradiction:

Adaptability or versatilityVSDevice complexity

Solution Approach 1:

The system uses a generic face model as a simplified copy or template to represent the patient's face geometry. By comparing the generic face model with the actual patient image data, the system can determine transformations and provide guidance before the surgical tracking system is activated, without requiring complex patient-specific 3D modeling.

Inventive Principle:

Principle #26Copying

Solution Approach 2:

The patent employs parameter changes by adjusting the generic face model to match the specific patient's facial features and anatomical characteristics. This allows the system to adapt the generic model to individual patients while maintaining computational efficiency and avoiding the need for complex custom modeling procedures.

Inventive Principle:

Principle #35Parameter changes

Data Source

PatentEP4091567B1Technique of providing user guidance for obtaining a registration between patient image data and a surgical tracking system

Publication Date: 2026.04.22 STRYKER EUROPEAN OPERATIONS LIMITED

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AI summary

A method is provided, comprising: obtaining first patient image data of a patient's body; determining a registration instruction indicative of where to acquire a registration point relative to a surface of the body; obtaining second patient image data of the body, having been acquired by an augmented reality, AR, device; determining a transformation between coordinate systems of the first and the second patient image data; and based on the transformation, triggering display of the registration instruction on a display of the AR device such that a user of the AR device is presented an augmented view with the registration instruction being overlaid onto the patient's body, the augmented view guiding the user where to acquire the registration point. Also disclosed are a computing system, a surgical navigation system, and a computer program product.