Device of the Week 1 – Health

Automated External Defibrillator

Screenshot taken from

According to this article, an AED is:

a lightweight, portable device that delivers an electric shock through the chest to the heart. The shock can potentially stop an irregular heart beat (arrhythmia) and allow a normal rhythm to resume following sudden cardiac arrest (SCA). SCA occurs when the heart malfunctions and stops beating unexpectedly. If not treated within minutes, it quickly leads to death.

How an AED work is… (here’s a video but I will also explain through text)

First, responders have to open the case to retrieve the AED, and in doing so, alerts a nearby medical response team to the location of the AED. The responder have to bring the AED to the victim and open the AED up and switch it on. The AED will guide the responder to what to do and the responder just have to follow the instructions step-by-step. There are adhesive electrodes in the AED, which, when pasted on the victim, detects the victim’s heart rate which will help the responder assess when defibrillation is needed. If a shock is required, the AED will charge up and notify the responder to press the button to deliver a shock. The shock will momentarily stun the heart, which causes it to stop for a brief moment. This helps to ‘restart‘ the heart so it will begin to beat effectively again. Afterwhich, CPR should be performed to prolong the heartbeat until medics arrive.

The AED is a really frightening yet fascinating device. It is meant to save a life, and yet, it is for public use for when emergency arise. The amount of responsibility this device give to its users is very, very great, despite how easy one is able to access and use it.

Device Breakdown

At the most basic level, the AED must be able to perform its main objective which is to defibrillate, and as such requires hardware that delivers the required electricity and a pulse detector for feedback. In order to perform its function as a public life-saving device, it needs to be portable, as user-friendly and intuitive as possible so that even the most unskilled person can attempt to use in an emergency. It must also be able to deploy quickly and teach its user as quickly as possible. For, according to this source, 7-10% chance of a person surviving cardiac arrest is lost in every minute of delay.

We can analyse how these points fare in the AEDs with reference to the image below:

Image taken from
  1. The AED has 2 obvious buttons that stands out first, the green being the switch and the red being to deliver a shock. These buttons are easy to spot for most people that operates a modern device and as such, allows people to recognise and operate efficiently. The buttons are also very spherical which allow for a quick and easy press.
  2. The image on the AED clearly tells the user on where to place the shock pads. The pads themselves also have images on them to show how to use which allows the responders to use it quickly.
  3. There seems to be a “PULL” label tells one to pull the case open, although the directional arrows are not very strategically placed. If not for the cut in the glass case, I would have tried pulling the part surrounding the label itself. That is not good interface design. This compartment probably holds the shock pads which are taken out to display in this image.
  4. The overall form of the AED is very compact and hand-held friendly.
  5. Although not seen, the AED probably have vocal instructions that people can follow, which I think helps a lot as we want to be told what to do during a stressful situation.
  6. However, it could be better as there are no text instructions as some responders may not be able to hear clearly or are deaf. Text can be simplified to easily communicate during high stress situations, but it may affect the compact form of the AED.

Overall, the device has a good form and easy to understand interface that allows the AED to perform all of its function as effectively as possible. Even though the process puts the responders at high stress and is fairly complicated to use, its interface allows people to use it quickly and correctly, saving many lives. So I would say that it has successfully concisely packaged the entire defibrillator into a portable public tool, transferring the medic’s responsibility to the public where a member of public can help save a life just as easily as he/she operates a toilet bowl. The article below is an example of how an AED can change the lives of many.

Civilians Help Man With Heart Attack In HDB Flat; Prove AEDs Can Help Save Lives

If anything were to be improved on, it would be to add text instructions for the hearing impaired. Perhaps another point of improvement is the inclusion of a female image alongside the male one, or to have an androgynous person so people will be able to respond to female victims confidently as well. See this link to why we should not always use a male body as reference to design.

My Suggestion

I do not wish to disrespect the invention of the defibrillator but I like the idea of using a defibrillator to do the opposite of what it is designed to do. As the device is designed to prevent death, what if it causes death instead? But of course, not to humans, but to mosquitoes / flies / annoying bugs.

Imagine a portable bug killing device where you go around zapping them! Would anyone be afraid of a cockroach now? Could it be turned into a game? It will definitely not be ethical as it can be misused GREATLY so it’s probably not a good idea. Still, it will be cool to own a smaller non-lethal voltage ‘stunner’ that can stun or kill insects.

I really can’t think of anything else that a defibrillator can be modified into…

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