August 1, 2019
AED Unit Upgrades
In order to keep AEDs in proper working condition and in keeping with regulatory requirements, AED manufacturers may provide software updates for their devices in the field.
Typically, these AED upgrades occur for one of two reasons:
1. Corrective Actions:
Corrective actions occur when device manufacturers identify a potentially problematic issue in their product, requiring a change to AEDs that have already been shipped and deployed in the field. Commonly, corrective actions do not compel customers to ship the device back to the manufacturer but, instead, require customers to install new software (or firmware) onto the device to ensure that the AED is functioning properly. The customer can complete most field corrective actions without assistance from a manufacturer representative, however, the number of steps required and the degree of difficulty varies from manufacturer to manufacturer.
In extreme cases, a product recall involves removing potentially problematic devices from the field until the faults are fixed. Usually, recalls are voluntary and initiated by the manufacturer, but the FDA also has the power to compel companies to recall faulty AEDs. An AED recall can happen for many reasons, including if the device is faulty, poses a health risk, or both.
A recall means that for a period of time, a customer could be without an AED. Sometimes there are loaner programs, but oftentimes this can be a long and trying process. There aren’t enough loaner AEDs to go around, so a company must phase in the unit updates instead of providing an immediate update.
2. Updates in AED Science:
The American Heart Association (AHA) provides periodic updates to the guidelines on Cardiopulmonary Resuscitation (CPR) and Emergency Cardiovascular Care (ECC), as established by the National Academy of Sciences of the National Research Council. The AHA has been issuing updates to the guidelines since 1966 with a frequency of between 5 and 8 years. The latest updates were released in 2015, validating:
“(1) The evidence surrounding the clinical benefit of automatic external defibrillators in the out‐of‐hospital setting by laypeople and healthcare providers. (1)
(2) The complex choreography of care needed to ensure high‐quality CPR and effective defibrillation.” (2)
In 2005, the AHA’s recommendations (3) more significantly impacted AED units of the time based on the latest science and discoveries that had the potential impact on survival. Amongst the most significant effect on AED units:
The CPR ratio of compressions-to-breaths changed from 15:2 to 30:2.
AED unit “shock” delivery was adjusted from stacked shocks (3 shocks in a row) to a “shock” followed by two minutes of CPR, then another shock, and so on.
These changes required software upgrades (and, in some cases, manufacturer hardware changes) for all AEDs that had been sold prior to the release of the new standards.
In 2010, the AHA guidelines continued the emphasis on high-quality CPR (4) and changed the basic life-support standards from A-B-C (airway, breathing, compressions) to C-A-B (compressions, airway, breathing). Like in 2005, to ensure that their products reflected the AHA’s most up-to-date science and recommended AED protocols, AED manufacturers carefully analyzed the research and, if needed, upgraded their AEDs (both new units and units already deployed in the field) to conform to the newly published standards.
Examples of field upgrades and Corrective Action
All AED units have had and will continue to require software upgrades, but the methodology and process of performing the upgrade vary by AED vendor. For instance,
In March 2011, AED manufacturer Defibtech issued a “Field Safety Notice” as a result of two faults on its DDU-100 series. The first fault, which the company estimated as happening in 1 in 400,000 devices, involved the AED canceling its charge as it prepared to deliver the shock. The second condition involved a subset of devices failing to charge in the lead-up to a shock when used in very high humidity conditions. The company provided a free software update that could be performed by customers in the field by installing a small software data card (5) into their AED(s) to rectify both of these malfunctions. (6)
In April 2009, ZOLL Medical Corporation announced field corrective action for about 180,000 of its ZOLL AED Plus® AEDs. The company had determined that some of the devices manufactured before February 12, 2009, had some issues with battery compatibility, and the AEDs’ self-test software was unable to detect defective batteries. This meant that the identified subset of AEDs carried a risk of failing to deliver a shock during the treatment of Sudden Cardiac Arrest (SCA). ZOLL provided a free software update that was downloadable from the company’s website. The new software, when installed, enabled the AED to detect battery defects and alert the user to install fresh batteries. (7)
In 2005, AED manufacturer Physio Control issued an upgrade on two of its models, the LIFEPAK CR® Plus and LIFEPAK EXPRESS, to enable the AEDs to meet the threshold set by 2005 AHA AED and ECC Guidelines. In the new guidelines, the AHA had recommended a single shock followed by CPR as the preferred sequence for helping SCA patients. In response, Physio Control’s upgrades replaced the pre-programmed series of “stacked shocks” (up to three shocks in a row before performing CPR) with a single shock, followed by two minutes of CPR. Another change involved modifying the voice prompt from “Start CPR” to “Provide chest compressions and rescue breaths.” Physio Control offered the upgrade in two forms.
1. The Basic Upgrade Package came via CD that contained upgrade software, which could be loaded using a computer, costing $30 (or $140 if a USB connection cable was included).
2. The Premium Upgrade Package provided the customer with a service representative to perform the upgrade for them alongside preventative maintenance checks. This option cost a minimum of $275. (8)
Challenges of Today’s Upgrade Processes
Although the internet, better device technology, and computing advances have made getting and installing upgrades on AEDs easier, there are several challenges with the process that remain.
Cost of the Upgrade or the Equipment Required to Upgrade the AED’s Software
A significant challenge relates to the price of upgrade equipment such as USB adapters, Bluetooth and IrDA readers, and installation CDs that may be required to upgrade units in the field. For example, ZOLL sells the USB IrDA adapter that connects the AED to the computer for $105. Physio Control’s installation CD and IrDA cable combo go for $140. These costs, which are similar to their peers across the AED market, can be prohibitive for institutions and homes with limited resources. Particularly, financial stress may be applied to the owners of multiple AEDs that are located in different geographical regions, thus requiring their own upgrade kits. Additionally, for many AED devices, the new software installation process requires the use of a compatible laptop or PC, which is another substantial investment.
Difficult Process of Reaching the Initial AED Owner
The typical sales and supply chain process of AED units sold in the United States can lead to challenges locating units after the initial transaction. Commonly, AED units are sold to large distribution companies that then resell the devices to a group of smaller, local distributors who, in turn, sell the AED unit to its eventual owner. While each party requires tracking of AED sales, every time the AED is sold and changes hands from one party to the next, the AED, its location, and its most up-to-date responsible party become more challenging to track. Thus, the AED manufacturers often face challenges when trying to spread information on recalls to all their customers. Furthermore, it is also the case that an AED has gone unused for so long, the owner isn’t attentive to their AED’s functionality status.
Difficult Process of Reaching Responsible Parties in the Future
After buying an AED:
Customers may resell their devices as their business contracts and expands through normal operations.
The business might move, changing addresses.
Responsible parties might change over time as company employees retire or are terminated.
Customers who are “found” but not expecting or prepared to perform a new task are unresponsive to communication, making it hard for AED manufacturers and their distributors to track them down when updates or recalls are required.
Sometimes an AED has gone unused for so long that the owner isn’t cognizant of the AED’s functionality status
The Process can be Cumbersome and Inconvenient
After a customer is notified of a possible need to upgrade their AED, their first step is to verify whether an upgrade is required or not; this can often be complex for laypeople.
While all AED manufacturers do their best to smooth the process for their customers by providing instructions to determine if their device requires an upgrade or not, this process often remains challenging. Customers are expected to follow multiple steps to ascertain their device’s upgrade status and whether or not it is affected by the field action.
For example, most instructions require the customer to find the serial number on their AED which may be complicated and burdensome for some lay-users, particularly if they own multiple units. Even when the user can verify a required upgrade, the process is time-consuming. In cases where more than one device needs to be upgraded, the process becomes even more drawn out since the units have to be updated one-by-one. While checking for upgrades, the devices are commonly taken out of service; this is not only inconvenient to the customer but may be dangerous in case there is no backup device to use in the meantime. Either a customer is without a unit, or has a unit that is potentially defective while waiting for a repair. Most instructions request that a customer keep the original unit in service.
Difficulty Performing the Upgrade on Affected Units
Once a unit has been identified as requiring an upgrade, the customer may need to purchase equipment, find a computer with which to download the latest AED software, and then manually install the software on the AED unit. Even technically savvy owners can struggle with the steps, order of operations, and time-consuming processes. With each layer of friction imposed on obtaining the new software, fewer AED owners make the necessary changes. Performing these steps on one AED can be frustrating; performing them on hundreds – or thousands – of AEDs requires full-time support.
Difficulty Tracking and Verifying When all Updates Have Been Made
Assuming an AED manufacturer can determine an AED’s responsible party at the time of an AED unit upgrade to pass on requisite information, they must maintain communication with the customer to ensure all steps were properly executed and all devices were upgraded. Some manufacturers have to apply these standards to hundreds of thousands of devices in the field, and some customers have to update thousands of their own AEDs manually.
To create a collaborative environment between the manufacturer and the customer, the AHA recommends that customers maintain regular contact with the manufacturer to stay up-to-date with information on software updates. (9)
Upgrade Process for Different AED Brands
Each AED manufacturer provides a unique “in-field” upgrade protocol, and individual AED owners should consult their manufacturer for more information including whether an AED requires an upgrade and, if so, what the upgrade process entails.
Cardiac Science: https://www.cardiacscience.com/support/
Physio Control: https://www.physio-control.com
Regular software upgrades are crucial, often mandatory procedures for AEDs to ensure that they’re operating properly. Like any high-tech piece of equipment, AEDs can be subject to malfunctions that require new software. But, unlike other technology, failures in upgrading AED units may jeopardize SCA patients’ lives. While AED unit manufacturers make concerted efforts to monitor and correct the functionality of AEDs in the field, once faults are detected or if the AHA revises their AED-related guidelines, customers must manually make software upgrades to those devices that are affected. These upgrades can be delivered to the customers through internet downloads or physical media such as CDs, and can be installed by manufacturer experts or the customer themselves. Despite the convenience of modern software upgrade delivery systems, manufacturers and customers face multiple challenges related to communication, prohibitive cost, and complexity of the process.
The prudence of US AED manufacturers in maintaining their devices in perfect working order in the post-sale phase is an important aspect of fighting SCA. Perfecting the reliability of the device is a continual process, and companies rely on learnings that they gain from their customer base. Obstacles relating to disseminating information on upgrades to customers are priority areas that manufacturers and bodies such as the FDA and AHA are urgently working on addressing.
(1) "2015 Guidelines Summary Heartsine Samaritan® PAD Automated External Defibrillators", Heartsine.Com, 2015, ®-PAD-Automated-External-Defibrillators.pdf.
(6) Defibtech.Com, 2011.
(7) "ZOLL Conducting 'Corrective Action' On 180,000 Aeds -- Occupational Health & Safety", Occupational Health & Safety, 2009,
(8) "LIFEPAK CR® Plus AED and LIFEPAK EXPRESS® AED Upgrade Information", Physio-Control.Com, 2005,
(9) "Automated External Defibrillator: Implementing an AED Program", Heart.Org, 2019,