Tapered Phaco Needle Structure for Node Placement and Low Incision Heat
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing phacoemulsification procedures face challenges with cavitation-induced occlusions and heating at the corneal incision site due to conventional ultrasonic vibrations, affecting the efficiency and safety of lens fragmentation.
Innovation Solution
A surgical instrument that switches between ultrasonic and high ultrasonic frequencies to oscillate the phacoemulsification needle, utilizing a piezoelectric transducer to generate standing waves with nodes of minimum amplitude, reducing cavitation and heating by modulating the frequency in response to occlusions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional ultrasonic vibrations are used for lens fragmentation, then lens emulsification is achieved, but cavitation-induced occlusions and heating at the corneal incision site occur
Solution Approach 1:
The patent applies dynamics by making the ultrasonic frequency adjustable rather than fixed. The system dynamically switches between low ultrasonic frequency (20-40 kHz) for effective lens fragmentation and high ultrasonic frequency (60-100 kHz) to minimize cavitation and heating. This dynamic frequency adjustment resolves the contradiction by allowing the system to adapt operating conditions to avoid harmful effects while maintaining productivity.
Solution Approach 2:
The patent changes the physical parameter of ultrasonic frequency to resolve the contradiction. By varying the frequency parameter between low (20-40 kHz) and high (60-100 kHz) ranges, the system achieves effective lens emulsification while minimizing cavitation-induced occlusions and heating at the corneal incision site. This parameter change allows the same ultrasonic device to operate in different regimes to balance productivity and safety.
2Object-affected harmful factors
If high ultrasonic frequency is used to reduce cavitation, then heating is minimized, but lens fragmentation efficiency decreases
Solution Approach 1:
The patent applies periodic action by alternating between low ultrasonic frequency (for effective lens fragmentation) and high ultrasonic frequency (for minimizing heating and cavitation). The system periodically switches frequencies based on operational needs, allowing the needle to perform effective lens emulsification at low frequency while using high frequency intervals to reduce cumulative heating and cavitation effects. This periodic switching resolves the contradiction between fragmentation efficiency and heating control.
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
Enhances followability and reduces tissue heating, improving the efficiency and safety of lens fragmentation by minimizing cavitation and maintaining consistent aspiration and irrigation flow.
Implementation Method 1
a piezoelectric transducer, driven by a circuit, to periodically expand and contract at a high-ultrasound frequency that rings the hollow titanium needle with a high-ultrasound frequency standing wave
Implementation Method 2
periodically expand and contract at a high-ultrasound frequency that rings the hollow titanium needle with a high-ultrasound frequency standing wave having a node of minimum amplitude
Implementation Method 3
rings the hollow titanium needle with a high-ultrasound frequency standing wave having a node of minimum amplitude residing in the substantially cylindrical portion
Implementation Method 4
cavitation-induced occlusions and heating at the corneal incision site due to conventional ultrasonic vibrations
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Disclosed is a surgical instrument directed to phacoemulsification for cataract eye surgery. The instrument generally includes a hollow titanium needle extending from a vibration generating handpiece. Together, the hollow needle and handpiece form an aspiration pathway to suck cataractous debris from an eye. A piezoelectric transducer in the handpiece generates both high and low ultrasonic frequency vibrations that rings the needle. The low frequency produces a node-free standing wave along the needle and the high frequency produces a standing wave along the needle with a node of minimum amplitude along the needle. Both frequencies produce a high anti-node at the needle's tip. The low frequency causes higher cavitation for emulsifying the cataract and the high frequency facilitates fragmentation of the cataract with a low heat portion of the needle at the eye incision point. The placement of the node along the needle can be tailored by way of a tapered section in a step horn region of the handpiece.