Superelastic Nitinol Ring for Uniform Capsulotomy Heating
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Solution Overview
Problem
Current nitinol rings used in capsulotomy devices are difficult and expensive to produce, leading to nonuniform heating and potential defects in the capsulotomy edge, which can result in tears in the capsular bag.
Innovation Solution
A method for manufacturing a super elastic nitinol ring by compressing a nitinol wire to produce permanently flattened edges, forming a rectangular cross section, and bending the wire into a ring shape, ensuring uniform current density and heating.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If a super elastic nitinol ring is used for capsulotomy, then the capsulotomy can be performed with a single continuous cut, but the ring is difficult and expensive to produce and difficult to manufacture with uniform dimensions
Solution Approach 1:
The nitinol ring is segmented into multiple identical sections along its circumference, with each section containing a heating element. This segmentation allows independent manufacturing of each section and simplifies the overall production process while maintaining the continuous cutting capability of the complete ring.
Solution Approach 2:
The patent changes the manufacturing parameters by specifying precise dimensional tolerances (e.g., 0.05mm to 0.15mm ring width, 0.5mm to 1.5mm spacing between heating elements) and material properties (nitinol alloy composition, superelasticity characteristics) to achieve uniform heating and consistent capsulotomy results.
2Power
If electrical current is passed through the nitinol ring to produce heat, then tissue cutting is achieved, but nonuniform current density causes hot spots and cold spots leading to defects in the capsulotomy edge
Solution Approach 1:
Heating elements are distributed locally and uniformly around the entire circumference of the nitinol ring at specified intervals (0.5mm to 1.5mm spacing). This local distribution ensures uniform current density and heating across different regions of the ring, eliminating hot spots and cold spots that would cause edge defects.
Solution Approach 2:
The nitinol ring is designed with uniform electrical conductivity and symmetric geometry to create equipotential conditions along its circumference. This ensures that electrical current flows uniformly through all sections of the ring, producing consistent heating and smooth capsulotomy edges without defects.
3Ease of manufacture
If the nitinol ring is made with variable cross-sectional area, then manufacturing is simpler, but current density becomes nonuniform causing inconsistent heating
Solution Approach 1:
The nitinol ring is manufactured with a substantially uniform cross-sectional area along its entire circumference, ensuring homogeneous electrical conductivity and current distribution. This homogeneity is achieved by controlling the wire diameter and ring geometry to maintain consistent dimensions, which produces uniform current density and consistent heating throughout the ring.
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 solution provides a cost-effective and uniformly heated nitinol ring that consistently produces smooth, defect-free capsulotomies, reducing the risk of tears in the capsular bag.
Implementation Method 1
compressing a nitinol wire on a first side of the nitinol wire and a second side of the nitinol wire to produce permanently flattened edges
Implementation Method 2
the nitinol ring, upon receiving current flow from the capsulotomy device, produces heat sufficient to cut tissue in contact with the nitinol ring
Data Source
AI summary
A method for manufacturing a super elastic nitinol ring. The method includes compressing a nitinol wire on a first side and a second side to produce permanently flattened edges and cutting off a portion of the nitinol wire on a third side and a fourth side to produce flattened edges. The method includes producing a modified nitinol wire with a rectangular cross section formed by the flattened edges on the four sides, bending the modified nitinol wire into a ring shape such that a first end of the modified nitinol wire aligns with a second end of the modified nitinol wire; and permanently coupling the first end to the second end to produce a nitinol ring. The nitinol ring is coupled to a capsulotomy device such that the nitinol ring, upon receiving current flow from the capsulotomy device, produces heat sufficient to cut tissue in contact with the nitinol ring.