Ultrasonic Generator Resonance Control Under Sonotrode Shock Excitation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing lithotripsy devices face performance losses and instability due to mechanical and electrical disruptions caused by projectile impacts on the sonotrode, leading to reduced fragmentation efficiency and difficulty in maintaining resonant frequency.
Innovation Solution
An ultrasonic generator with a measuring apparatus featuring a resistor, capacitor, and suppressor diode in parallel configuration, along with open-loop and closed-loop control, to measure and adjust electrical power and frequency, suppressing overvoltages and ensuring resonance despite disruptions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If shock excitation by a projectile is applied to enhance fragmentation, then fragmentation power is improved, but voltage and current measurement is interfered with and resonant frequency control is disrupted
Solution Approach 1:
A voltage suppressor diode is introduced as an intermediary component in parallel with the voltage measurement circuit. This diode acts as a mediator that clamps excessive voltage peaks generated during projectile impact, preventing them from reaching and interfering with the measurement circuitry, thereby maintaining accurate voltage measurement despite shock excitation.
Solution Approach 2:
The harmful high-voltage transient signals generated during projectile impact are extracted and suppressed by the voltage suppressor diode before they can propagate to the measurement circuit. This separation protects the measurement system from contamination by impact-induced voltage spikes.
2Stability of the object's composition
If frequency correction is continuously applied to maintain resonance, then ultrasonic operation stability is improved, but system complexity increases due to constant monitoring and adjustment
Solution Approach 1:
A feedback control mechanism is implemented where the ultrasonic generator continuously monitors the actual resonant frequency of the sonotrode via voltage and current measurements, compares it with the target frequency, and automatically adjusts the drive frequency accordingly. This closed-loop feedback maintains resonance stability without requiring manual intervention.
Solution Approach 2:
The system performs self-correction of frequency deviations through automatic detection and adjustment mechanisms. The generator monitors its own operation and autonomously compensates for frequency drift caused by heating, mechanical disruptions, or loading changes, eliminating the need for external frequency tuning.
3Power
If electrical power is increased to compensate for performance losses during shock excitation, then fragmentation capability is maintained, but energy consumption increases
Solution Approach 1:
The voltage suppressor diode performs preliminary protection of the measurement circuit during impact events, preventing transient voltage spikes from causing errors or damage. This advance protection ensures that normal measurement and control functions continue uninterrupted, eliminating the need to increase power to compensate for measurement failures.
Solution Approach 2:
The voltage suppressor diode converts the potentially harmful high-voltage transient signals generated during impact into beneficial clamping action, where the diode absorbs and dissipates the excess energy as a controlled voltage drop. This transforms the harmful voltage spikes into a protective mechanism that preserves measurement accuracy and system 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 enables optimal fragmentation performance by maintaining resonance and minimizing disruptions, allowing efficient operation of the sonotrode even under mechanical and electrical disturbances.
Implementation Method 1
the measuring apparatus comprising, in parallel with the at least one measuring unit, at least one suppressor diode for suppressing overvoltages
Implementation Method 2
a resistor arranged in parallel with the at least one measuring unit
Implementation Method 3
an ultrasonic vibration excitation means for exciting a vibration of the at least one sonotrode, with the ultrasonic vibration excitation means being excitable at a vibration frequency by means of the ultrasonic generator by supplying an AC voltage
Implementation Method 4
the voltage and the current at the piezo elements of the ultrasonic transducer are usually detected
Implementation Method 5
a measuring apparatus with at least one measuring unit for measuring a time profile of a voltage and/or current
Implementation Method 6
an open-loop and/or closed-loop control apparatus for adjusting an electrical power suppliable by the ultrasonic generator to the ultrasonic vibration excitation means
Data Source
AI summary
The invention relates to an ultrasonic generator for supplying an electrical power for fragmenting calculi, the ultrasonic generator being assignable a sonotrode, an ultrasonic vibration excitation means for exciting a vibration of the at least one sonotrode, and optionally a force generation apparatus for generating a force for moving a projectile for shock excitation of the sonotrode, with the ultrasonic vibration excitation means being excitable at a vibration frequency by means of the ultrasonic generator by supplying an AC voltage, and the ultrasonic generator comprising a measuring apparatus with at least one measuring unit for measuring a time profile of a voltage and/or current, and an open-loop and/or closed-loop control apparatus for adjusting an electrical power suppliable by the ultrasonic generator to the ultrasonic vibration excitation means, with the measuring apparatus comprising at least one resistor arranged in parallel with the at least one measuring unit and optionally a capacitor arranged in parallel with the measuring unit, wherein the measuring apparatus comprises, in parallel with the at least one measuring unit, at least one suppressor diode for suppressing overvoltage. The invention also relates to a lithotripsy device and a method for operating and controlling a lithotripsy device.