MKP Film Capacitors for Defibrillator

Defibrillators are life-saving medical devices designed to deliver an electric shock to the heart, treating arrhythmias and restoring a normal heartbeat. At the heart of this process lies a critical component: the capacitor. In this blog, we’ll explore the basic structure of a defibrillator circuit and highlight the pivotal role capacitors play in ensuring reliable and effective operation.

The Basics of a Defibrillator Circuit

A defibrillator circuit, in its simplest form, comprises several key components: a capacitor, transformer, rectifier, and inductor (Figure 1). Each component serves a specific function in delivering controlled electrical energy to a patient.

• Transformer: Elevates the voltage from hundreds to thousands of volts to produce the energy required for defibrillation.

• Rectifier: Converts the alternating current (AC) to direct current (DC), allowing the capacitor to charge effectively.

• Capacitor: Stores the electrical energy and releases it in a controlled manner during defibrillation.

• Inductor: Ensures a steady current flow for several milliseconds, crucial for effective treatment.

When the defibrillator is activated, charged paddles are applied to the patient’s chest, completing the circuit and delivering the shock.

Monophasic vs. Biphasic Waveforms in Defibrillation

Modern defibrillators leverage either monophasic or biphasic waveforms to optimize treatment while minimizing potential damage to the myocardium (Figure 2).

• Monophasic Waveforms: Deliver the shock in a single direction.

• Biphasic Waveforms: Deliver the shock in two directions by reversing the polarity mid-cycle. This approach, commonly used in contemporary systems, discharges the capacitor with a truncated exponential decay, ensuring more effective treatment.

Power Requirements and Voltage Conversion

The instantaneous power required for defibrillation surpasses the capacity of typical mains electricity. To address this:

1.Step-Up Transformer: Converts the standard mains voltage (AC) to high-voltage AC.

2.Rectifier: Converts high-voltage AC into high-voltage DC.

3.Variable Voltage Settings: Allow healthcare professionals to adjust the charge to suit individual patient needs, ensuring precise and effective treatment.

The Crucial Role of Capacitors

Capacitors are at the core of a defibrillator’s functionality. They store significant electrical charge and release it rapidly during defibrillation, dictating the pulse size, shape, and overall reliability of the system. Key considerations for capacitor selection include:

• Pulse Characteristics: The size and shape of the discharge pulse directly impact treatment effectiveness.

• System Form Factor: Compact capacitors contribute to portable defibrillator designs.

• Reliability: High-quality capacitors ensure consistent performance and long-term durability.

Why CRE High-Reliability Film Capacitors?

CRE offers a range of high-reliability film capacitors tailored for external defibrillators. These capacitors undergo rigorous process validation and quality testing, ensuring:

• Extended Product Lifespan: Designed to withstand repetitive use.

• Compact Form Factor: Ideal for portable and compact defibrillator systems.

• Complete Traceability: Comprehensive records ensure accountability and quality assurance.

Explore our product page or reach out directly for detailed specifications and assistance.

Capacitors may seem like a small part of the overall system, but their performance and reliability are critical to the life-saving capabilities of defibrillators. By understanding their role, you can appreciate the engineering and precision that goes into designing these essential medical devices.

CRE Solution

DC-link C1

DEMJ-PC