Optical-Marker Screw Extenders for Augmented Spinal Rod Placement
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Solution Overview
Problem
Existing orthopedic surgery methods for spinal fusion face challenges in accurately determining the placement and shape of spinal rods due to the inability to visually see the exact position of pedicle screw heads, leading to increased surgical time, risk of screw loosening, and implant failure, and requiring costly and complex imaging technologies.
Innovation Solution
A data processing device using augmented reality to detect and track screw extenders with optical markers, providing real-time graphical overlays to assist surgeons in selecting and placing spinal rods based on the position and orientation of screw heads, utilizing image processing algorithms and graphical primitives for precise rod placement.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If costly and complex imaging technologies are used to determine pedicle screw head positions, then measurement precision is improved, but device complexity and cost increase
Solution Approach 1:
The patent introduces screw extenders as intermediary devices that attach to pedicle screw heads and incorporate optical markers. These markers serve as mediators between the screw heads (which are buried in tissue) and the imaging system (camera), enabling optical detection and tracking of screw head positions without requiring complex medical imaging equipment like CT or X-ray systems.
Solution Approach 2:
The patent replaces complex mechanical/imaging systems (CT scanners, X-ray equipment) with an optical system consisting of a camera and image processing algorithms. The optical markers on screw extenders are detected and tracked using computer vision techniques, substituting expensive medical imaging technology with a simpler optical measurement system.
2Device complexity
If traditional methods without visual guidance are used, then device complexity is reduced, but manufacturing precision and reliability deteriorate
Solution Approach 1:
The patent implements a feedback system where the camera continuously captures images of the surgical site, the system processes these images to determine screw extender positions, and then displays this information via augmented reality overlays. This real-time feedback loop provides continuous visual guidance to the surgeon, enabling precise spinal rod placement while keeping the surgical system relatively simple.
Solution Approach 2:
The patent uses optical markers with specific visual characteristics (colors, patterns, shapes) that can be easily distinguished by the camera system. These markers undergo no physical color change but their visual properties are optimized for detection, allowing the system to differentiate between various surgical instruments and track their positions accurately.
3Measurement precision
If complex imaging technologies are used, then measurement precision is improved, but loss of time increases due to setup and operation complexity
Solution Approach 1:
The screw extenders with optical markers are attached to the pedicle screw heads before the spinal rod insertion procedure begins. This preliminary setup allows the imaging system to immediately start tracking screw head positions without requiring time-consuming calibration or setup of complex imaging equipment during surgery.
Solution Approach 2:
The patent replaces time-consuming complex imaging procedures (CT scanning, X-ray imaging) with rapid optical capture and processing. The camera can capture and process images in real-time or near real-time, significantly reducing the time required for measurement and guidance compared to traditional medical imaging systems.
4Ease of operation
If visual guidance systems are implemented, then ease of operation is improved, but device complexity increases
Solution Approach 1:
The augmented reality display serves as an intermediary between the complex image processing system and the surgeon. It translates complex positional data into intuitive visual overlays that show exactly where to place the spinal rod, making the system easy to use while allowing the backend processing to remain relatively simple.
Data Source
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AI summary
A method for assisting an orthopedic surgery, the method including the steps of: capturing a sequence of images such that a field of view captures images of a plurality of screw extenders, each screw extender holding a pedicle screw, the plurality of screw extenders arranged at a surgical incision of an orthopedic surgery, displaying images of the captured images to provide for a live video feed, detecting the plurality of screw extenders based on the captured sequence of images, first calculating an orientation and position of the detected plurality of screw extenders, second calculating a 3D position of a screw head of each pedicle screw based on the orientation and the position, and projecting and displaying each calculated 3D position of the plurality of screw heads with a graphical element on the display device at a location that corresponds to the location of the screw head projected to a currently displayed image of the live video feed.