A-Bridge Biphasic PFA Generator With Finite Energy Transfer
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Solution Overview
Problem
Conventional PFA systems are bulky, complex, and costly, with high energy storage risks, requiring large capacitors and centralized switching, leading to inefficiencies and safety concerns, and lack flexibility in energy delivery.
Innovation Solution
A biphasic waveform generator using spark gap switches in an A-bridge topology, with localized energy delivery and inherent patient and operator isolation, utilizing spark gap switches for high-speed switching and reduced impedance, enabling precise and flexible energy transfer.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Use of energy by moving object
If conventional H-bridge topology with large bulk capacitors is used for PFA biphasic waveform delivery, then the system can deliver the required energy, but the physical size of the console dramatically increases
Solution Approach 1:
The patent divides the single large bulk capacitor into multiple smaller series capacitors (C1, C2, C3, C4) arranged in an H-bridge topology. This segmentation allows the system to deliver the required energy while reducing the physical size of individual capacitor components and enabling more compact console design.
Solution Approach 2:
The patent transitions from a single-dimension energy storage approach (one large capacitor) to a multi-dimensional approach using multiple capacitors arranged in series and parallel combinations within the H-bridge configuration. This dimensional change in circuit topology enables efficient energy delivery with reduced overall console volume.
2Quantity of substance
If series bulk capacitors are used in H-bridge generator, then the energy storage capacity increases, but the equivalent series resistance and equivalent series inductance characteristics increase by a factor of n
Solution Approach 1:
The patent applies local quality optimization by selecting capacitors with specific low ESR and ESL characteristics for each position in the H-bridge circuit. By carefully choosing capacitor components with optimized local properties (low series resistance and inductance), the system achieves high energy storage capacity while minimizing the cumulative ESR and ESL effects.
3Use of energy by moving object
If large amount of energy is stored in high voltage capacitors, then the energy delivery capability is sufficient, but the energy cannot be discharged immediately upon powering off, posing a safety risk
Solution Approach 1:
The patent extracts the residual energy safety hazard from the main system by incorporating a dedicated discharge circuit with discharge resistors connected across the capacitor bank. This separate extraction mechanism safely dissipates residual energy after therapy delivery, eliminating the safety risk associated with trapped energy in the capacitors.
Solution Approach 2:
The patent introduces a discharge resistor as an intermediary component that mediates the safe release of energy from the capacitors. This intermediary element provides a controlled path for energy dissipation, acting as a buffer between the stored energy and the system output, thereby ensuring safety without compromising the energy delivery capability during therapy.
4Measurement precision
If conventional H-bridge generator is dedicated to each electrode, then the energy delivery precision is improved, but the cost and complexity of high voltage high current switching devices increases
Solution Approach 1:
The patent implements a centralized H-bridge generator that serves multiple electrode pairs through time-multiplexed operation. The same H-bridge circuit and switching devices are reused for different electrode combinations by controlling the timing and configuration of capacitor connections. This universal approach maintains precise energy delivery to each electrode pair while avoiding the need for separate dedicated H-bridge generators for each electrode, thereby reducing overall system complexity and cost.
5Device complexity
If centralized configuration of switching electrodes is used, then the system complexity is reduced, but the therapy cannot be applied within the same cardiac rhythm time period
Solution Approach 1:
The patent employs dynamic switching configurations within the centralized H-bridge generator, allowing the circuit topology to change in real-time based on the selected electrode pair. The switching devices dynamically reconfigure the capacitor connections and current paths to accommodate different electrode combinations, enabling flexible therapy timing that can adapt to cardiac rhythm requirements while maintaining a single centralized generator structure.
6Reliability
If feedback control is used to reduce voltage and energy applied in fault modes, then the safety is improved, but the system requires precision and synchronous current and voltage sensing adding to complexity
Solution Approach 1:
The patent implements preliminary safety measures through hardware-based current limiting circuits and pre-programmed protection logic that automatically activate in fault conditions. These preliminary protective actions are built into the circuit design itself, providing immediate safety responses without requiring complex real-time feedback control loops, thereby enhancing safety while minimizing the added complexity of sensing and control systems.
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 provides a fail-proof, cost-effective, and safer PFA with reduced size and complexity, delivering a finite amount of charged energy efficiently and flexibly, while minimizing energy storage risks and enhancing patient safety.
Implementation Method 1
spark gap switches for high-speed switching and reduced impedance
Implementation Method 2
large bulk capacitors that dramatically increase the physical size of the console
Data Source
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AI summary
A pulse phase ablation biphasic PFA generator with finite energy source and delivery mechanism is disclosed, comprising: a signal source configured to output electrode input signals; a trigger circuit configured to trigger signals; at least one electrode channel circuit including a charge transfer source circuit including a source capacitor and coupled to the signal source to receive the electrode input signals, the charge transfer source circuit being configured to charge the source capacitor to a source voltage, a switching circuit coupled to charge transfer source circuit to receive the source voltage and to the trigger circuit to receive the trigger signals, and a charge transfer load circuit including a load capacitor coupled to the switching circuit; wherein the switching circuit further includes a plurality of spark gap switches activated by the trigger signals to cause the electrode channel to apply a biphasic waveform to electrodes configured to contact tissue.