Dual-Mode Lithotripter Resonance for Efficient Stone Fragmentation
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Solution Overview
Problem
Current lithotripsy devices are often expensive, complicated, and/or less effective at fragmenting stones, and may require percutaneous access due to large shaft sizes or inadequate waveform delivery methods.
Innovation Solution
A lithotripter with dual drivers for producing ultrasonic and sonic waveforms, adjustable to resonate at the natural frequency of the stone, and a wave guide shaft to transmit these waveforms for efficient fragmentation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Volume of moving object
If a single shaft is used to deliver waveform to the stone, then the device size is reduced and percutaneous access is avoided, but the waveform delivery effectiveness is insufficient for efficient stone fragmentation
Solution Approach 1:
The patent combines ultrasonic and sonic drivers into a single integrated shaft system. The ultrasonic driver (piezoelectric crystal) and sonic driver (electromagnetic motor) are mounted coaxially on the same shaft, allowing both waveform types to be delivered through one catheter rather than requiring separate concentric shafts. This merging reduces device size while maintaining effective stone fragmentation through combined waveform action.
2Productivity
If multiple drivers are used to provide different waveforms to the stone, then stone fragmentation effectiveness is improved, but the device complexity and shaft size increase requiring percutaneous access
Solution Approach 1:
The single shaft is designed to perform multiple functions: it serves as the mechanical support structure, the transmission medium for ultrasonic waves, and the transmission medium for sonic waves. The shaft integrates functions that would traditionally require separate components, reducing overall device complexity while maintaining the ability to deliver both ultrasonic and sonic waveforms for effective stone fragmentation.
3Reliability
If traditional lithotripsy devices are used, then stone fragmentation can be achieved, but the cost is high and the devices are complicated
Solution Approach 1:
The patent extracts the essential waveform-generating components (ultrasonic piezoelectric crystal and sonic electromagnetic motor) and mounts them directly on the shaft, eliminating the need for complex housing and support structures required by traditional lithotripsy devices. This extraction and direct mounting approach simplifies the overall device design, reduces manufacturing complexity, and lowers cost while maintaining reliable stone fragmentation capability.
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 dual-driver lithotripter effectively fragments stones with adjustable frequencies, reducing the need for percutaneous access and improving fragmentation efficiency.
Implementation Method 1
an ultrasonic driver configured to produce an ultrasonic waveform having an ultrasonic frequency
Implementation Method 2
a sonic driver configured to produce a sonic waveform having a sonic frequency
Implementation Method 3
The sonic driver is mechanically coupled to the ultrasonic driver. The wave guide shaft is driven by at least one of the ultrasonic driver and the sonic driver
Implementation Method 4
The sonic waveform is provided at a frequency that is about equal to a natural frequency of the urinary tract stone
Data Source
AI summary
A lithotripter is provided for fragmenting a stone inside a patient's body. In one form, the lithotripter includes a motor having at least two modes of operation and is configured to produce first and second waveforms. A wave guide shaft is configured to transmit the first and second waveforms to the stone. In one form, at least one of the first and second waveforms is provided to the stone at a frequency that is about equal to a natural frequency of the stone. In a variation, the lithotripter may include an ultrasonic driver configured to produce an ultrasonic frequency waveform and a sonic driver configured to produce a sonic frequency waveform. The sonic driver is mechanically coupled to the ultrasonic driver. The ultrasonic driver and the sonic driver may be disposed within a driver housing. In another variation, the lithotripter may include a brushless DC motor.