Checking AEDs: why and what do we measure?
When an Automated External Defibrillator (AED) is used, the device must always be in good condition. Wherever the AED is placed. It is assumed that as soon as the device is used, it does what it is intended to do. That is why the device is checked periodically.
For example, the battery and associated electrodes are often checked monthly by, for example, the manager of the sports complex where the device is located. A visual inspection is also always performed. In addition to these standard checks, there are more aspects that are good to check, for example, on an annual basis.
We describe several aspects to properly assess the condition of the AED. Mainly it concerns the energy output, the charging time for the energy to be delivered and the synchronization.
Energy
When the AED detects ventricular fibrillation, the device prepares for energy delivery. The device adjusts the energy output based on the resistance it measures between the electrodes. A defibrillator tester often has an internal resistance of 50 Ohm. In practice, an AED delivers approximately 150 Joules at 50 Ohm during a shock. The manufacturer provides a guideline and the permitted deviation for this. When you connect the AED to a defibrillator tester, you can measure the energy delivered.
Charging time
During resuscitation, it is often necessary to defibrillate several times. In order to be able to deliver the desired amount of energy again with the next shock, the AED needs a certain charging time. The manufacturer indicates within what time the AED must be ready to defibrillate again. You can also measure this with the defibrillator tester. If it takes too long, this may indicate a reduced condition of the battery or the generator in the defibrillator.
Synchronization
Synchronization is another important function. This takes place with tachycardia. As soon as the AED electrodes are connected to a patient, the device analyzes the heart rhythm. It is important that the AED defibrillates at the right time. The defibrillator tester measures the time between the peak of the ECG and the moment the shock is administered.
In addition to the above aspects, an electrical safety test is also performed according to IEC62353 or IEC60601.
Would you like to know more about defibrillator testing with, for example, the Impulse 6000 or 7000? Please let us know.
