Resonant Electrotherapy Waveform Control With Low Switching Loss

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Solution Overview

Problem

Existing electrotherapy systems for treating cardiac arrhythmias, such as defibrillation, face challenges in efficiently delivering precise electrotherapeutic waveforms while minimizing switching losses and electromagnetic interference, which can affect the synchronization and effectiveness of cardiac pumping.

Innovation Solution

A system comprising an energy storage capacitor, a therapeutic current control network with resonant electrical circuits and current control switches, and a controller that adjusts the delivery of electrotherapeutic waveforms to match a specified waveform, using sensors to monitor and control current and voltage parameters to reduce switching losses and interference.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Loss of energy

If conventional switching techniques are used to generate electrotherapeutic waveforms, then waveform generation is achieved, but switching losses and electromagnetic interference increase

Engineering Contradiction:
Improveswitching lossesVSAvoidwaveform delivery precision
Core Design Contradiction:
Loss of energyVSReliability

Solution Approach 1:

The patent applies resonant oscillation principles to the electrical circuit, using the natural resonant frequency of the LC circuit to generate the therapeutic waveform. This resonant approach eliminates the need for high-frequency switching, thereby reducing switching losses and electromagnetic interference while maintaining waveform precision through the circuit's inherent resonance characteristics.

Inventive Principle:
Principle #18Mechanical vibration

Solution Approach 2:

The patent replaces conventional mechanical/electronic switching mechanisms with a resonant electrical oscillation system. By using the natural resonant properties of the LC circuit instead of active switching components, the system achieves waveform generation with minimal energy loss and reduced electromagnetic interference.

Inventive Principle:
Principle #28Mechanics substitution (Replace mechanical system)

2Power

If high current or high voltage stress is applied to switching elements, then waveform generation capability is improved, but device stress and potential failure increase

Engineering Contradiction:
Improvewaveform generation capabilityVSAvoidswitching element durability
Core Design Contradiction:
PowerVSStrength

Solution Approach 1:

The patent utilizes resonant oscillation at the circuit's natural frequency to generate therapeutic waveforms, eliminating the need for high-stress switching operations. This resonant approach allows powerful waveform delivery without subjecting switching elements to excessive current or voltage stress, thereby improving component durability.

Inventive Principle:
Principle #18Mechanical vibration

3Manufacturing precision

If precise waveform control is implemented, then therapeutic effectiveness is improved, but system complexity increases

Engineering Contradiction:
Improvewaveform precisionVSAvoidcontrol system complexity
Core Design Contradiction:
Manufacturing precisionVSDevice complexity

Solution Approach 1:

The patent employs the natural resonant characteristics of the LC circuit to automatically generate precise therapeutic waveforms without requiring complex external control systems. The circuit self-regulates its oscillation frequency and amplitude based on its inherent electrical properties, achieving waveform precision while minimizing control system complexity.

Inventive Principle:
Principle #25Self-service

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 energy efficiency, precise waveform delivery, and reduced electromagnetic interference, ensuring effective cardiac synchronization and pumping by minimizing energy differences to less than 15% from the specified waveform.

Implementation Method 1

a resonant therapeutic current control network including a resonant tank, for use in controlling an electrotherapeutic waveform being delivered to a patient

Methodology Applied
Scientific EffectResonance: Resonance

Implementation Method 2

an energy storage capacitor for providing electrotherapeutic current for delivery to a patient

Methodology Applied
Scientific EffectCapacitance: Capacitance

Data Source

PatentEP4157439B1Electrotherapeutic waveform and pulse generation and delivery system
Publication Date: 2025.11.19 ZOLL MEDICAL CORPORATION
  • EP4157439B1 patent drawingFigure 1A
  • EP4157439B1 patent drawingFigure 1B
  • EP4157439B1 patent drawingFigure 2A

AI summary

Electrotherapy waveform and pulse generation and delivery systems, methods and devices are described, such as for generation and delivery of defibrillation or pacing electrotherapeutic waveforms to patients, using open or closed loop current control. An example system includes a power supply, a therapeutic current control network and a controller. A therapeutic current control network may include at least one current control switch and a resonant tank. During delivery of an electrotherapeutic waveform to a patient with optional closed loop current control, the controller may compare a signal associated with a determined or estimated current provided to the patient with a signal associated with a reference waveform. Based at least in part on the comparison, the controller may adjust operation of the at least one current control switch of the therapeutic current control network in adjusting delivery of the electrotherapeutic waveform to the patient to correspond with the reference waveform. The system may utilize one or more of soft switching, wide bandgap materials and a bidirectional power supply.