When is a defibrillator like a telephone?

When is a defibrillator like a telephone?

It sounds like the beginning of a joke: when is a defibrillator like a telephone?

(Answer: both deliver a shock when you least expect it!)

Beyond the bad punchline, there are many similarities between the evolution of the telephone, and of defibrillation.


Scottish-born Alexander Bell invented the first working telephone in 1876.  Using metal wiring and other heavy hardware, the first telephone was proof of simultaneous transmission and reception of the human voice.

In addition to being an inventor and scientist, Bell was also a businessman; a year later, he established the Bell Telephone Company.

Defibrillation was proven a couple of decades later.  In Switzerland in 1899, scientists demonstrated that electric shocks could both induce and reverse ventricular fibrillation (VF).

RELATED ARTICLE: a history of defibrillation

In VF as well as in ventricular tachycardia (VT), chaotic electrical activity in the heart stops blood from being pumped to the body and brain.  That moment at the turn of the century was formative for scientists and medical professionals seeking ways to help patients recover from sudden cardiac arrest.

Early applications

It wasn’t until nearly 50 years later when in 1947, cardiac defibrillation was first used in surgery.  The equipment designed for the purpose was heavy and complicated, strictly for use only by medical professionals in a hospital setting.

Early telephone applications were similarly restricted.  At that time, while anyone could pick up a handset and make a call, telephone exchanges were complicated affairs run by trained operators.

Calling someone required asking a human operator to patch you through to the lines of other subscribers on the exchange, or connect to different exchanges.

Public access

Public telephones started to appear in the US in the 1880s, and in the UK in the early 1900s.  At that time, home phones were uncommon – so to call someone, you needed to do so from the office or a store, or from a public payphone.

This is the point defibrillation has reached today in terms of public diffusion.  Automated external defibrillators, or AEDs were first made available to the general public in 2004 – but their high cost mean that nearly two decades on, there aren’t many around relative to population sizes.

Home access

Home telephones started to become more common in the US from the 1920s, and by the 1950s approximately half of all US households had a telephone.

The immediate opportunity for people and organisations looking for solutions to the high death rate associated with out-of-hospital cardiac arrest, is to achieve a similar rate of diffusion for AEDs.

For that to happen, AEDs need to be affordable.  Currently, purchasing an AED costs several thousand on average, with annual maintenance costs in the hundreds.


Today, mobile phones are not only small, light and portable, they are millions of times more powerful than the guidance computers that took Apollo 11 to the moon.

This is the longer-term opportunity for AEDs – to be small, light and robust enough to be carried on your person wherever you go.

Today’s AEDs are too bulky and heavy, with perishable parts that degrade quickly outside controlled storage conditions.  Unlike the evolution of the telephone however, we’ve addressed the home access and portability barriers to AED adoption in one stroke.


Like a telephone, next-generation AEDs will also be connected.

There are many benefits to this, such as remote monitoring to remove the risk of device degradation, and data-sharing to speed up and enable emergency response to out-of-hospital cardiac arrest.

Ultimately, this will also include functionality enabling the device to automatically call local Emergency Medical Services (EMS) upon activation.

RELATED ARTICLE: Why AEDs need to be connected