Surgical Bone Screw with Internal Conductor for Nerve Safety
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional surgical pedicle screws often result in nerve damage due to improper placement, as existing methods lack effective means to ensure precise screw placement without causing electrical interference or shunting.
Innovation Solution
A surgical bone screw design featuring an elongate screw body with an electrical conductor and insulated terminals, allowing a stimulating current to be applied at the proximal end and directed into bone tissue at the distal end, minimizing electrical interference from surrounding tissue.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a stimulating current is applied during screw insertion to detect nerve damage, then nerve safety can be monitored, but electrical current may shunt through surrounding tissue instead of bone, reducing detection accuracy
Solution Approach 1:
The patent introduces an electrical conductor as an intermediary element that runs through the screw body. This conductor acts as a dedicated pathway for electrical current, mediating between the power source and the bone tissue. By using this intermediary, the current is guided through the bone rather than shunting through surrounding soft tissues, thereby improving both nerve damage detection accuracy and electrical stimulus localization.
Solution Approach 2:
The patent segments the electrical conduction path by separating it from the surrounding tissue environment. The conductor is divided into insulated sections and exposed terminal sections, creating distinct functional zones. This segmentation ensures that current flows through controlled pathways (the conductor) rather than dispersing through surrounding tissues, resolving the contradiction between reliable nerve monitoring and precise stimulus localization.
2Reliability
If conventional screws without internal conductors are used, then the screw design is simpler, but electrical current cannot be effectively channeled through the bone for accurate nerve monitoring
Solution Approach 1:
The patent makes the screw multi-functional by integrating an electrical conductor within its structure. The screw now serves both its traditional mechanical function (anchoring to bone) and a new electrical function (conducting stimulus current through the bone). This universal design enables reliable nerve monitoring without requiring a separate monitoring device, while the conductor is configured to minimize overall device complexity.
Solution Approach 2:
The electrical conductor is nested within the hollow interior of the screw body. This nesting arrangement allows the conductor to be housed inside the screw without significantly increasing the external dimensions or complexity of the screw construction. The conductor is positioned within the existing screw geometry, enabling nerve monitoring capability while maintaining a compact, integrated design.
3Measurement precision
If the conductor is electrically connected to the screw body, then the structure is simpler, but current will shunt through surrounding tissue instead of flowing through bone
Solution Approach 1:
The patent applies local quality by providing electrical insulation only where necessary - specifically at the terminals and at sections where the conductor contacts the screw body. The insulation is not applied uniformly throughout but is strategically placed to prevent current shunting at critical points. This localized insulation approach ensures precise current flow direction through the bone while minimizing the overall complexity of insulation requirements.
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
This design reduces the risk of nerve damage by ensuring that the electrical stimulus is channeled directly into the bone tissue, enhancing the precision of screw placement and minimizing the likelihood of nerve activation during insertion.
Implementation Method 1
An electrical conductor is disposed in the passage between the proximal and the distal ends of the screw body. The conductor has a first terminal at the proximal end and a second terminal at the distal end.
Implementation Method 2
The conductor and both of the terminals are electrically insulated from surrounding portions of the screw body.
Data Source
AI summary
A surgical bone screw includes an elongate body having a proximal end, a distal end, a threaded portion on the circumference of the body, and a passage extending between the proximal and the distal ends of the body. An electrical conductor is disposed in the passage between the proximal and the distal ends of the screw body. The conductor has a first terminal at the proximal end and a second terminal at the distal end. The conductor and both of the terminals are electrically insulated from surrounding portions of the screw body. When the screw is driven into bone tissue and a stimulating current is applied to the first terminal, the current is directed substantially through the conductor to flow into tissue adjacent to the second terminal at the distal end, without shunting by other tissue that surrounds the screw body.