Defibrillators, CPR Feedback and Readiness
An automated external defibrillator analyses a collapsed person's heart rhythm and, where the rhythm is one a shock can correct, delivers that shock. This collection carries the ZOLL range: AED Plus, AED 3, AED Pro and Powerheart G5 in semi-automatic and fully automatic versions, the R Series for professional BLS use, a trainer unit and battery systems.
The case for placing an AED rests on a single fact about sudden cardiac arrest: survival falls with every minute that passes before defibrillation. Emergency services take time to arrive that is measured in minutes, and a device on the wall closes the gap between collapse and the first shock.
That is why AEDs are placed in public spaces, schools, gyms, offices and transport hubs rather than only in clinical settings, and why placement is measured in how long it takes someone to fetch one and return.
→ Part of First Aid & Emergency. Also see Patient Monitors, Oxygen Therapy and All Patient Care.
Semi-Automatic or Fully Automatic?
Both types analyse the rhythm and decide whether a shock is indicated. The difference is who presses the button.
| Semi-automatic | Fully automatic | |
|---|---|---|
| Rhythm analysis | Device decides | Device decides |
| Delivering the shock | Rescuer presses a button when prompted | Device delivers after a warning countdown |
| Suits | Rescuers who want explicit control | Untrained or infrequent rescuers |
The argument for fully automatic in a public or workplace setting is hesitation. A bystander who has never used an AED can freeze at the moment of pressing a button to shock another person, and that hesitation costs the seconds the device exists to save. A fully automatic unit removes that decision point: it warns, counts down, and delivers.
The argument for semi-automatic is control. A rescuer can confirm nobody is touching the patient before the shock is delivered, which matters in a crowded scene or where a professional responder wants to coordinate the moment.
Fully automatic options: the ZOLL AED Plus 91687 fully automatic, the fully automatic AED Plus and the Powerheart G5 fully automatic. The AED Plus and the AED 3 cover the core range.
CPR Feedback: What the Device Adds Beyond the Shock
Defibrillation is one part of resuscitation. The compressions between and around shocks are what keep blood moving, and their quality varies enormously between rescuers.
The problem is that a rescuer performing compressions has no reliable way to judge their own depth or rate. Untrained rescuers commonly compress too shallowly; trained rescuers fatigue within minutes and their depth falls off without them noticing. Neither group gets feedback from the task itself.
Real-time CPR feedback addresses that by measuring compression depth and rate and telling the rescuer to push harder or faster as they work. It converts compressions from something done blind into something with a signal attached, and it is the reason a feedback-capable AED costs more than one that only shocks.
For a workplace where the likely rescuer is a colleague with basic or lapsed training, that feedback is arguably worth more than any other feature on the device, because compressions are the part they are most likely to do poorly.
Professional and Advanced Units
The ZOLL AED Pro sits between public-access AEDs and hospital defibrillators, adding capability for trained responders such as EMS and workplace medical teams while retaining AED operation.
The ZOLL R Series BLS defibrillators are professional units for clinical and EMS environments, where the operator is trained, the device is part of a wider resuscitation protocol, and manual control and monitoring matter alongside automated analysis.
Choosing between tiers follows who will use it. A device with capability beyond the operator's training adds cost and complexity without adding outcome, and in an emergency a more complex interface is a slower one.
Readiness: The Part That Fails Quietly
An AED spends years doing nothing and then has to work on the first attempt. Everything about owning one is about making sure that first attempt succeeds.
Self-test and status indicator
AEDs run periodic self-tests and display a status indicator showing whether the device is ready. Checking that indicator is the single most important ongoing task, and it takes seconds. A device that has failed a self-test looks identical from across the room to one that has passed, which is exactly why the indicator exists and why someone has to be assigned to look at it on a schedule.
Batteries and pads expire
Both have finite shelf lives and both are consumables rather than permanent parts. Pads carry a conductive gel that dries out, and an expired pad may not adhere or conduct properly. Batteries lose capacity whether or not the device has been used.
The practical failure mode is an AED in place for years, never used, with pads that expired eighteen months ago and nobody tracking it. Expiry dates should be logged somewhere that generates a reminder rather than being noted on the device and forgotten.
Battery options: ZOLL type 123 lithium batteries, 10 pack for the AED Plus and SurePower defibrillator battery systems.
Placement
Placement is measured in retrieval time, not floor plan tidiness. Somebody has to notice a collapse, go to the device, and return, and every second of that route counts against survival. Signed, visible, unlocked locations near where people congregate beat a secure cupboard in an office that is locked at weekends.
Training Units
The ZOLL AED Plus Trainer II replicates the device's prompts and operation without delivering a shock, so staff can practise on the equipment they will actually use.
That specificity matters more than it sounds. Someone trained on a generic AED and then faced with a different device in an emergency has to interpret unfamiliar prompts and controls while under maximum stress, which is when interface familiarity counts most. Training on the same model removes that gap.
A trainer also makes refresher practice cheap enough to do regularly, which matters because the skills decay. Familiarity with the device six months after a course is not the same as familiarity the week after it, and a trainer unit sitting in the building makes the difference.
Frequently Asked Questions
What does an AED actually do?
It analyses a collapsed person's heart rhythm and, where the rhythm is one a shock can correct, delivers that shock. The device makes the decision about whether a shock is indicated, not the rescuer. That is the design principle behind public-access defibrillation: the analysis is the part requiring clinical judgement, and the device supplies it.
Why does speed matter so much?
Because survival from sudden cardiac arrest falls with every minute that passes before defibrillation. Emergency services take time to arrive measured in minutes, and a device on the wall closes the gap between collapse and the first shock. That is why placement is measured in retrieval time rather than floor plan convenience.
Semi-automatic or fully automatic?
Both analyse the rhythm and decide whether a shock is indicated; the difference is who presses the button. Fully automatic suits public and workplace settings because a bystander who has never used an AED can freeze at the moment of shocking another person, and that hesitation costs the seconds the device exists to save. Semi-automatic gives a trained rescuer explicit control over the moment.
Do you need training to use an AED?
AEDs are designed to be usable by untrained bystanders, with voice and visual prompts guiding each step, and that is the point of public-access defibrillation. Training still improves speed and confidence substantially, and most workplace programmes combine device placement with trained responders. Requirements for training, registration and maintenance vary by jurisdiction and should be checked locally.
What is CPR feedback and why does it matter?
It measures compression depth and rate in real time and tells the rescuer to push harder or faster as they work. A rescuer has no reliable way to judge their own compressions: untrained rescuers commonly compress too shallowly, and trained rescuers fatigue within minutes with depth falling off unnoticed. Feedback converts compressions from something done blind into something with a signal attached.
How often should an AED be checked?
The status indicator should be checked on a regular assigned schedule, and it takes seconds. A device that has failed a self-test looks identical from across the room to one that has passed, which is exactly why the indicator exists. Assigning the check to a named person rather than leaving it to whoever notices is what makes it actually happen.
Do AED pads and batteries expire?
Yes, both are consumables with finite shelf lives. Pads carry a conductive gel that dries out, and an expired pad may not adhere or conduct properly. Batteries lose capacity whether or not the device has been used. The common failure is an AED in place for years with pads that expired long ago and nobody tracking it, so expiry dates should be logged somewhere that generates a reminder.
Where should an AED be placed?
Where retrieval is fastest: signed, visible and unlocked, near where people congregate. Somebody has to notice a collapse, go to the device and return, and every second of that route counts. A secure cupboard in an office that locks at weekends fails the test even though the device is technically on site.
What is the difference between an AED and a professional defibrillator?
An AED automates the analysis and guides an untrained or lightly trained rescuer through the sequence. Professional units add manual control, monitoring and capability intended for trained responders operating within a wider resuscitation protocol. Choose by who will use it: capability beyond the operator's training adds cost and complexity without adding outcome, and a more complex interface is a slower one in an emergency.
Is a trainer unit worth buying?
Where staff will be trained, yes. A trainer replicates the actual device's prompts and operation without delivering a shock, so staff practise on what they will use. Someone trained on a generic AED then faced with a different device has to interpret unfamiliar prompts under maximum stress. A trainer also makes refresher practice cheap enough to do regularly, which matters because these skills decay.
MediDepot Purchasing Advantages
- Price Match Guarantee: found the same model for less elsewhere? We will match the verified price.
- Equipment Financing: available when placing devices across multiple sites or floors.
- Extended Warranty: available on qualifying devices.
- Military Discount: available for qualifying military medical facilities and personnel.
- Request a Quote: multi-unit placement, consumable replacement scheduling and trainer bundles.
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