Variable-Rigidity Cannula for Ophthalmic Illumination
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Solution Overview
Problem
Existing small-gauge wide-angle illuminators for ophthalmic surgery lack sufficient rigidity to effectively manipulate eye tissue, which is essential for providing an unobstructed view and access to the surgical area.
Innovation Solution
A variable-rigidity, small-gauge illuminator system comprising a light source, optical cable, handpiece, and cannula, where the cannula can extend and retract to vary its length, maintaining co-incident distal ends with the optical fiber, allowing for adjustable stiffness and biocompatible materials for enhanced tissue manipulation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Length of moving object
If the cannula diameter is reduced to 25 gauge or smaller, then the incision size and trauma to the eye are reduced, but the rigidity of the cannula becomes insufficient for effective tissue manipulation
Solution Approach 1:
The cannula is designed with variable rigidity through a telescoping mechanism that allows the distal portion to extend or retract relative to the proximal portion. When extended, the cannula provides sufficient rigidity for tissue manipulation; when retracted, it reduces to a smaller profile. This dynamic adjustment resolves the contradiction between maintaining small gauge dimensions and providing adequate rigidity when needed.
Solution Approach 2:
The cannula is divided into multiple segments (proximal and distal portions) that can move independently relative to each other. The distal portion can extend beyond the proximal portion to increase rigidity when tissue manipulation is required, then retract to maintain the small gauge profile during illumination-only phases of surgery.
2Length of stationary object
If the cannula length is increased to reach peripheral retinal areas, then access to the surgical field is improved, but the cannula becomes more flexible and less effective for tissue manipulation
Solution Approach 1:
The cannula employs a telescoping design where the distal portion can extend to achieve the necessary length for reaching peripheral retinal areas while maintaining rigidity through the extended structure. When retraction occurs, the overall length is reduced but the rigidity-to-length ratio is optimized for manipulation tasks.
3Strength
If a 20 gauge cannula is used, then adequate rigidity for tissue manipulation is achieved, but the incision size and trauma to the eye increase compared to 25 gauge devices
Solution Approach 1:
The variable rigidity mechanism allows the cannula to dynamically adjust its structural properties. During illumination phases, the cannula maintains a compact small-gauge profile minimizing incision size. During manipulation phases, the distal portion extends to provide the rigidity equivalent to larger gauge cannulas, thus resolving the contradiction between size and strength.
4Strength
If the cannula is made more rigid to improve tissue manipulation, then manipulation effectiveness increases, but the ability to navigate through small gauge incisions is reduced
Solution Approach 1:
The segmented telescoping design allows the cannula to be inserted in a compact, flexible state through small gauge incisions. Once positioned, the distal portion can be extended to provide the necessary rigidity for tissue manipulation, thus resolving the contradiction between insertability and manipulation effectiveness.
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
The system provides the necessary rigidity for tissue manipulation while maintaining effective illumination, allowing surgeons to adjust the cannula length for optimal illumination and rigidity during surgical procedures, addressing the limitations of prior art small-gauge illuminators.
Implementation Method 1
an optical fiber, operably coupled to the handpiece, wherein the optical fiber is optically coupled to the optical cable to receive and transmit the light beam to illuminate an area
Implementation Method 2
an optical element, optically coupled to a distal end of the optical fiber, for receiving the light beam and scattering the light beam to illuminate the area
Data Source
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AI summary
A variable-rigidity, small-gauge illuminator is disclosed, one embodiment being a small-gauge illumination surgical system comprising: a light source (12) for providing a light beam; an optical cable (14), optically coupled to the light source for receiving and transmitting the light beam, a handpiece (10), operably coupled to the optical cable; an optical fiber (22), operably coupled to the handpiece, wherein the optical fiber is optically coupled to the optical cable to receive and transmit the light beam to illuminate an area; and a cannula (16), operably coupled to the handpiece, for housing and directing the optical fiber, wherein the cannula is operable to extend and retract from the handpiece to vary the length of the cannula extending from the handpiece, and wherein the optical fiber is operably connected to the cannula such that the distal end of the optical fiber and the distal end of the cannula remain co-incident as the length of the cannula extending from the handpiece is varied. The optical fiber, the cannula and the handpiece can be fabricated from biocompatible materials.