Eccentric Dilator System for Directional Spinal Tissue Access
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Solution Overview
Problem
Current surgical dilator systems are inadequate for providing preferential directional dilation in anatomical rostral and caudal directions while minimizing dilation in the anatomical posterior direction, and existing retractors lack independent movement of blades, leading to tissue disruption and poor control during spinal surgery.
Innovation Solution
A dilator system comprising a series of dilators with eccentric channels and gaps to minimize posterior dilation, combined with a retractor system allowing independent movement of blades for enhanced control and tissue access.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If concentric symmetrically shaped dilators are used, then minimal trauma to tissue is achieved, but preferential directional dilation cannot be provided
Solution Approach 1:
The patent employs asymmetric dilator geometries including oblong-shaped dilators with varying cross-sectional dimensions and eccentric channels that are offset from the longitudinal axis. This asymmetry enables preferential dilation in specific directions (anterior, lateral, posterior) while maintaining controlled minimal trauma through the elongated shape that distributes force more evenly compared to traditional round dilators
2Adaptability or versatility
If off-center lumens are used in round-walled dilators, then some directional dilation is provided, but the system becomes unbalanced and difficult to control
Solution Approach 1:
Instead of using off-center lumens in round walls, the patent employs oblong-shaped dilators with eccentric channels where the channel is intentionally offset toward the posterior aspect. The oblong geometry provides inherent balance and stability while the eccentric channel placement achieves directional dilation without compromising rotational control or balance
Solution Approach 2:
The patent applies different geometric properties to different parts of the dilator system. The outer wall geometry is oblong for stability and control, while the inner channel is eccentric for directional dilation. This local differentiation of geometric qualities allows the system to achieve both ease of operation and directional capability
3Adaptability or versatility
If oblong-shaped dilators are used, then some relative directional dilation is achieved, but tissue disruption occurs in all directions
Solution Approach 1:
The patent uses a series of oblong dilators with progressively different cross-sectional dimensions and eccentric channel placements. Each dilator in the sequence is designed to dilate tissue preferentially in specific directions (anterior, lateral, posterior) while minimizing disruption in other directions, achieving localized controlled dilation rather than uniform disruption in all directions
4Ease of operation
If traditional retractors are used, then tissue access is provided, but blades cannot move independently leading to poor control
Solution Approach 1:
The retractor system is divided into multiple independent movable blades that can be adjusted separately. Each blade is mounted on the retractor frame in a way that allows independent movement and positioning, enabling precise control of tissue access and retraction without requiring complex coordinated movement of all blades simultaneously
Data Source
AI summary
Disclosed is an apparatus and a method for surgical dilation and retraction of tissues during a medical procedure, for example a spinal surgery. The apparatus includes a dilator assembly that includes a plurality of slidingly engaging dilators, wherein at least one dilator includes an outer wall shape different from its inner wall shape. At least one of the dilators may include an eccentrically positioned circular channel, a generally oblong outer wall shape, and a longitudinal gap in a wall. The dilator system may be used in a method that provides off center differential dilation of tissues in one or more preferred directions. A retractor system that may be used with the dilator system is also disclosed.