Bi-Modal Ultrasonic Handpiece With Independent Frequency Control
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Solution Overview
Problem
Existing ultrasonic handpiece systems for ophthalmic procedures struggle to simultaneously maintain optimal resonant frequencies for both longitudinal and torsional modes of oscillation, leading to inefficiencies in operations like phacoemulsification due to the inability to independently adjust these modes in response to factors such as loading and temperature.
Innovation Solution
A bi-modal ultrasonic handpiece system that applies control signals to drive a single piezoelectric element assembly in multiple oscillation modes, using feedback to independently adjust the frequency of each mode to maintain resonance, allowing simultaneous operation of longitudinal and torsional motions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Device complexity
If a single piezoelectric element assembly is used to drive both longitudinal and torsional modes, then device complexity is reduced, but the ability to independently adjust frequencies for each mode deteriorates
Solution Approach 1:
The patent segments the control signals into two independent channels: a first control signal for longitudinal mode and a second control signal for torsional mode. Although a single piezoelectric element assembly is used, the control system divides the driving function into separate controllable components, allowing independent frequency adjustment of each mode while maintaining structural simplicity.
Solution Approach 2:
The patent implements dynamic frequency adjustment for each mode independently. The controller can vary the frequency of the first control signal and the second control signal separately, enabling the system to adapt to changing operational conditions and maintain optimal resonant frequencies for both longitudinal and torsional vibrations simultaneously.
2Productivity
If feedback control is implemented to maintain resonant frequencies, then operational efficiency improves, but device complexity increases
Solution Approach 1:
The patent incorporates feedback control mechanisms that monitor the actual resonant frequencies of the longitudinal and torsional modes and adjust the control signals accordingly. This feedback system maintains optimal operational frequencies, improves cutting efficiency, and compensates for variations in loading and temperature conditions.
Solution Approach 2:
The feedback control system enables the device to self-regulate and maintain optimal performance automatically. The controller monitors system conditions and makes real-time adjustments without external intervention, allowing the system to compensate for environmental factors and maintain peak efficiency throughout the procedure.
3Productivity
If both longitudinal and torsional modes are operated simultaneously, then tissue cutting efficiency improves, but difficulty in detecting and measuring resonant frequencies increases
Solution Approach 1:
The patent segments the measurement and detection processes into separate channels corresponding to each oscillation mode. By analyzing the electrical characteristics of the piezoelectric element assembly in response to the first and second control signals independently, the system can accurately detect and measure the resonant frequencies of both modes simultaneously without interference.
Solution Approach 2:
The patent replaces direct mechanical measurement of resonant frequencies with electrical measurement methods. By monitoring the electrical impedance and response characteristics of the piezoelectric element assembly, the system infers the resonant frequencies of both longitudinal and torsional modes through electrical signals, simplifying the measurement process while maintaining accuracy.
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 achieves a 49.13% reduction in phaco time and a 6.79 joules per milligram efficiency improvement by maintaining optimal resonant frequencies for both modes, enhancing tissue cutting efficiency during procedures like phacoemulsification.
Implementation Method 1
a piezoelectric element assembly that is driven to oscillate in a longitudinal mode and a torsional mode simultaneously
Implementation Method 2
generates feedback of a resulting oscillation of the piezoelectric element assembly in the first mode and the second mode
Implementation Method 3
The working tip is ultrasonically vibrated along its longitudinal axis within the irrigating sleeve by the crystal-driven ultrasonic horn, thereby emulsifying upon contact the selected tissue in situ
Implementation Method 4
based on the feedback, the system independently adjusts the frequency of each of the first mode and second mode, as needed, so that the resulting oscillation of each of the first mode and the second mode is each approximately at its respective resonant frequency
Data Source
AI summary
An ultrasonic handpiece includes a piezoelectric element assembly. Control signals drive the piezoelectric element assembly simultaneously in a first mode of oscillation and a second mode of oscillation. Feedback of a resulting oscillation of the piezoelectric element assembly in the first mode and the second mode is generated. Based on the feedback, the frequency of each of the first mode and second mode is independently adjusted, as needed, so that the resulting oscillation of each of the first mode and the second mode is each approximately at its respective resonant frequency.