Low-Voltage Impedance Pulse Checks for nsPEF Generator Control
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current nanosecond pulsed electric field (nsPEF) generators lack effective control over pulse generator charge state, making safe and effective cancer treatments challenging due to limitations in impedance matching and pulse duration variability, especially when dealing with unknown load resistances.
Innovation Solution
A tunable, high-voltage nsPEF generator system utilizing a Marx-switch stack hybrid circuit with power MOSFETs and multiple stages in parallel, allowing for flexible impedance matching and extended pulse duration, controlled by a controller that adjusts switch stack operations to achieve desired voltage and current levels.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If a charged pulse generator is used to generate high voltage nsPEF pulses for therapeutic treatment, then the treatment effectiveness is improved, but the control over pulse generator charge state becomes difficult and unsafe
Solution Approach 1:
The patent implements a feedback control system that continuously monitors the charge state of the pulse generator and adjusts the charging process accordingly. The controller receives feedback signals about the voltage level and automatically regulates the charging current to maintain precise control over the charge state, eliminating the safety issues associated with uncontrolled high voltage charging while preserving treatment effectiveness.
Solution Approach 2:
The system performs preliminary impedance measurement and load assessment before initiating therapeutic pulse delivery. By measuring load impedance in advance and determining appropriate charging parameters based on expected impedance values, the system prepares the optimal charging state beforehand, ensuring both safety and effectiveness without requiring manual intervention during the actual treatment.
2Reliability
If high voltage pulses are delivered to treat cancerous tumors, then the therapeutic effect is improved, but the risk of affecting normal cells and system safety decreases
Solution Approach 1:
The patent employs dynamic pulse parameter adjustment where voltage, current, and pulse duration are continuously optimized based on real-time feedback from load impedance measurements. The system adapts pulse characteristics to match the specific electrical properties of the target tissue, delivering high voltage pulses only when and where needed for therapeutic effect while automatically reducing or suspending pulses when normal tissue is detected, thereby minimizing harm to healthy cells.
Solution Approach 2:
The system dynamically changes multiple pulse parameters including voltage amplitude, pulse width, frequency, and duty cycle based on load conditions and treatment progress. By adjusting these parameters in response to feedback signals, the system maintains therapeutic effectiveness on cancerous tissue while preventing excessive energy delivery to normal cells, thus reducing harmful side effects.
3Object-affected harmful factors
If low voltage pulses are used for system testing and impedance measurement, then the safety is improved, but the ability to assess actual treatment conditions is reduced
Solution Approach 1:
The patent implements periodic impedance measurements at multiple stages: initial low-voltage measurement for safety assessment, intermediate measurements during treatment progression, and continuous monitoring throughout therapy. This periodic sampling at different voltage levels and time points provides comprehensive information about load conditions, enabling accurate assessment of both safety and actual treatment effectiveness without requiring continuous high-voltage exposure.
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 high efficiency, low impedance, and variability in pulse duration, enabling effective treatment of cancerous tumors with precise control over nsPEF parameters, improving treatment outcomes and system safety.
Implementation Method 1
a charged pulse generator including an energy storage device and a switch
Implementation Method 2
discharged through a load by a relatively low voltage transistor
Data Source
Figure 1
Figure 2
Figure 3
AI summary
Methods and systems for testing a pulse generator circuit are disclosed. The methods include calculating one or more impedances of a load from applied pulses and comparing the one or more impedances with an expected impedance. The results of the comparison are used to determine whether the pulse generator system is working properly, whether the therapeutic treatment may be initiated or continued, or whether parameters of the pulses should be changed. The pulses may be therapeutic or test pulses, and they may have various parameters of voltage, duration, frequency, or any other electrical parameter. The methods of the disclosure may be performed by a treatment system comprising a controller.