An AED can seem like a mysterious black box in the middle of an emergency. In reality, the process happening inside the device from power-on to shock delivery is straightforward, fast, and designed entirely around user safety.
Step 1: Self-Check and Voice Guidance Begins
The moment you switch on a device like the Philips HeartStart OnSite, it runs a rapid internal check and immediately starts talking you through the process — there's no waiting for it to "boot up" in any meaningful sense.
Step 2: Pad Placement Sensing
Once the pads are attached to the patient's bare chest, the AED detects electrical contact and confirms placement is adequate before moving forward — if contact is poor, it will tell you exactly that, rather than proceeding blindly.
Step 3: Rhythm Analysis
The device analyzes the heart's electrical rhythm through the pads, a process that typically takes just a few seconds. This is the moment everyone needs to stand clear, since movement can interfere with an accurate reading.
Step 4: The Shock Decision
Here is the most important safety feature of any AED: it will only charge and prompt a shock if it detects a genuinely shockable rhythm. If the heart's rhythm doesn't require defibrillation, the device will not allow a shock to be delivered — full stop.
Step 5: Shock Delivery and Continued Guidance
If a shock is advised, the AED charges and either delivers it automatically or prompts you to press the shock button, depending on whether the unit is fully or semi-automatic. Immediately afterward, it guides you back into chest compressions and will reanalyze the rhythm at set intervals.
Why This Design Matters
Every step is built so an untrained bystander can follow along under pressure, with the device making every clinical decision. Understanding this process removes much of the hesitation people feel before ever touching one.
See a Real AED in Action
Heart First Response supplies, installs, maintains and trains organizations on AEDs across Dubai, United Arab Emirates and the wider Gulf region. Call us on +971 52 1746500 or visit heartfirstaed.com to get started.
