Vitrectomy Instrument Dual-Mode Cutting and Rigid Support
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Solution Overview
Problem
Conventional vitrectomy instruments suffer from excessive heating of tissue, requiring insulating sleeves that increase bulk and necessitate larger incisions, and are too flexible, leading to unwanted movement during surgery, especially in myopic eyes with longer axial lengths.
Innovation Solution
A vitrectomy instrument with a handpiece featuring a cutting power generator and an ultrasonic generator for simultaneous or individual operation, combined with a support sleeve made from rigid materials to prevent deflection and deformation, allowing for precise cutting and aspiration without the need for insulating sleeves and enabling use in myopic eyes.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of manufacture
If conventional vitrectomy instruments are used, then tissue cutting function is provided, but excessive heating occurs causing tissue burning
Solution Approach 1:
The harmful thermal effect is extracted and separated from the cutting function. The patent removes the insulating sleeve that was previously needed to prevent heating, and redesigns the instrument to inherently avoid excessive heating while maintaining cutting capability, thus eliminating the harmful thermal effect without sacrificing the cutting function.
Solution Approach 2:
The patent changes the operational parameters of the vitrectomy instrument, specifically modifying the cutting mechanism to operate without generating excessive heat. This involves adjusting the mechanical cutting parameters and eliminating the need for thermal management components like insulating sleeves.
2Object-affected harmful factors
If insulating sleeves are added to prevent tissue burning, then tissue protection is improved, but instrument bulk increases and larger incisions are required
Solution Approach 1:
The insulating sleeve component is completely removed from the instrument design. The patent achieves tissue protection without heating through fundamental redesign of the cutting mechanism, eliminating the need for additional protective components and their associated volume increase.
Solution Approach 2:
The patent replaces the thermal management approach (insulating sleeves) with a mechanical cutting approach that inherently avoids excessive heating. The cutting mechanism is redesigned to perform tissue sectioning through optimized mechanical action rather than thermal or combined thermal-mechanical methods.
3Length of moving object
If needle length is increased for myopic eyes, then reach to retina is improved, but needle flexibility increases causing unwanted movement
Solution Approach 1:
The patent employs composite construction for the needle, combining materials with different mechanical properties. The needle consists of an inner core material providing stiffness and stability, surrounded by an outer material providing flexibility and biocompatibility. This composite structure enables the long needle to maintain both reach and stability.
Solution Approach 2:
The needle is divided into functional segments: a rigid inner core for structural stability and a flexible outer layer for navigation. This segmentation allows different portions of the needle to perform different functions - the core maintains straightness while the outer layer provides necessary flexibility for insertion.
4Area of stationary object
If needle gauge is reduced for smaller incisions, then incision size is decreased, but needle flexibility increases causing movement during surgery
Solution Approach 1:
The patent uses composite material construction that allows the needle to maintain small diameter (23-27 gauge) while achieving adequate stiffness. The inner core material provides structural rigidity that compensates for the reduced overall diameter, enabling small incision access without sacrificing needle stability during operation.
Solution Approach 2:
Different portions of the needle have different mechanical properties optimized for their specific functions. The distal tip and shaft regions have controlled flexibility for navigation, while the cutting tip maintains sufficient rigidity for precise tissue sectioning. This local optimization of mechanical properties resolves the contradiction between thin diameter and stability.
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 prevents tissue burning, allows for smaller incisions, and provides structural support to maintain needle stability during surgery, enhancing precision and safety, especially in myopic eyes.
Implementation Method 1
an ultrasonic generator operatively coupled to the inner tube, the ultrasonic generator configured to vibrate the inner tube for vibratory fragmentation and/or cutting of the tissue
Implementation Method 2
a cutting power generator operatively coupled to the inner tube, the cutting power generator configured to reciprocably drive the inner tube for shearing tissue
Data Source
AI summary
A method of using a vitrectomy instrument are disclosed herein. This method comprises the steps of: (i) providing a vitrectomy instrument; (ii) operating the vitrectomy instrument in a first mechanical cutting mode where a cutting power generator of the vitrectomy instrument is used to reciprocably drive the tubular body portion for shearing the tissue, the vitreous, and/or the silicone oil; and (iii) operating the vitrectomy instrument in a second ultrasonic cutting mode where the cutting power generator is inactive, and an ultrasonic generator of the vitrectomy instrument is used to vibrate the tubular body portion for vibratory fragmentation and/or cutting of the tissue, the vitreous, and/or the silicone oil.