A defibrillator that has passed an analyser test is often described as fully tested, and the description is doing more work than the evidence supports. An analyser measures what the device delivers, which is one of several things that determine whether the unit is fit for use, and the other things are exactly the ones that deteriorate on equipment that has been stored or moved. For a buyer acquiring a pre-owned unit, the analyser result is a starting point rather than a conclusion. This article explains what the analyser establishes, what has to be checked alongside it, and how to read the evidence on offer.

What the Requirement Actually Covers

The analyser check establishes whether the device delivers the energy it is set to deliver, and whether the delivered waveform matches what the device is specified to produce. That is a measurement of output accuracy at the settings tested, performed against the manufacturer’s specification and using an instrument with traceable calibration.

What the check does not establish is equally important. It does not confirm that the device’s self-test passes, that its battery holds the charge it should, that its cables and electrodes are within their usable life, or that its controls and display behave as intended under use. The extractable summary is this: an analyser check confirms that a defibrillator delivers its specified output at the settings tested, and it does not confirm battery condition, consumable viability, accessory integrity or the outcome of the device’s own self-test.

That asymmetry is the reason this device family produces more disappointed buyers than most. The output measurement is the most impressive part of the assessment to watch, because a technician can demonstrate a delivered energy figure on a screen, and it is therefore the part that gets described. The remainder of the assessment produces no such moment, and on pre-owned equipment those are frequently the elements that matter most. A unit that has been stored for a long period is more likely to present with a degraded battery or a hardened cable than with an output fault, and those conditions are exactly the ones an analyser does not detect.

Which Equipment It Applies To

The check applies to defibrillators and to defibrillator functions integrated into other equipment, including monitor-defibrillator combinations and automated external defibrillators in professional use. What differs between categories is how much of the device’s behaviour can be exercised with an analyser alone and how much requires the device’s own test procedures.

Pre-owned units bring three considerations that new equipment does not. The first is battery condition, because a battery that has been in storage or has been partially cycled may still accept a charge but deliver less than its rated capacity, and the analyser check does not test that. The second is consumables, because pads, electrodes and cables have usable lives and packaging conditions that determine whether they can be used at all. The third is firmware, because a unit whose software has not been updated may behave differently from a later production unit, and the version is part of the device’s state. Where a consignment includes single-use electrodes or pads, the buyer is responsible for confirming legality, labelling and any applicable reprocessing or expiry position in their own market, and those items should be excluded where their status cannot be evidenced.

A fourth consideration applies where several units are being acquired together. A batch of defibrillators from the same source may have been stored under the same conditions and maintained on the same schedule, which makes their condition similar, or it may have been assembled from units of different ages and service histories. Establishing which of those situations applies determines whether the acceptance test can be sampled or has to be performed on every unit, and that decision affects both the cost and the timetable of the purchase.

How Verification Is Expected to Be Evidenced

The evidence set for a pre-owned defibrillator combines the analyser record with the device’s own diagnostics and with the physical checks that the analyser cannot perform. Read together, they describe the unit; read separately, each leaves a gap that a buyer may not notice.

Traceability of the analyser’s own calibration is what makes the output measurement defensible, and the ILAC accreditation directory allows a provider’s status to be checked, with the underlying principles described through the NIST measurement laboratory programmes. The servicing framework within which these checks sit is covered by AAMI’s medical device servicing material, and independent equipment-safety guidance such as that published by ECRI is a useful reference on how test evidence is used in a device programme.

The records themselves should be read together rather than individually, because their value comes from covering different aspects of the same unit. A self-test result on a date, an analyser record naming its settings, a battery assessment and an accessory list describe four different things about one device, and a buyer who receives all four can plan acceptance work with confidence. A buyer who receives only the analyser record has received the most persuasive document rather than the most informative one.

Where the Framework Differs by Market

The obligation to maintain defibrillators in a tested condition is expressed nationally, and the practical requirement usually arrives through one of three routes: a workplace safety duty, the device framework for equipment in use, or the organisation’s own accreditation and clinical governance requirements.

Where the duty sits with the employer, national workplace material is the starting point, and the HSE health services guidance is one example of how that framing works. Where the obligation attaches to the device, frameworks such as the MHRA guidance on regulating medical devices and the European Commission medical devices sector material apply, and cross-market expectations for devices and their safe use are summarised by the WHO medical devices programme. Because the routes differ, a buyer importing a unit should establish what the destination organisation will require as acceptance evidence before assuming that a test performed at the seller’s premises will be sufficient.

What the Record Must Contain

The record has to describe the whole unit, not only its output. A file that documents energy delivery and nothing else describes the device’s most testable characteristic rather than its readiness for use.

Common Misreadings and Overstatements

The assumptions below appear in listings and in procurement documents, and each of them allows a verification gap to pass as a completed check.

• That an analyser test confirms the unit is fully functional. It confirms output at the settings tested, and it leaves the device’s diagnostics, battery and accessories unexamined.
• That a battery which accepts a charge is a battery in good condition. Acceptance of charge is not the same as the ability to deliver the required output, and the difference appears in use rather than on a bench.
• That accessories shipped with the unit are usable because they are present. Cables, paddles and electrodes have condition and age limits, and items whose status cannot be evidenced should not be counted as part of the offer.
• That a self-test on the day of shipment settles the unit’s condition. A self-test result is a dated observation, and storage and transport occur after it.
• That one successful test at a single setting characterises the device. Output should be assessed across the settings the specification covers, which is why the record should state what was tested.

What a Buyer Should Ask For

The questions separate what the analyser establishes from what has to be established another way, which is what allows the buyer to see whether the file is complete.

Ask which settings were tested and what output was measured against the specification. Ask for the analyser identification and its calibration status on the test date. Ask for the most recent self-test result and whether any diagnostic faults were recorded. Ask for the battery’s condition, its history and whether it has been replaced. Ask what accessories are included, their condition and their date position. Ask for the firmware version and whether it corresponds to a known state. Ask what the destination organisation will require at acceptance, so that gaps can be closed before the unit moves rather than afterwards. Buyers who want the wider context can start from the knowledge hub, compare how pre-owned equipment is described on the marketplace store, or use the cross-device verification material in the industry hub. Our overview of how pre-owned medical equipment changes procurement efficiency covers the commercial framing behind the same acceptance decisions.