Design Innovations Led to a Compact Medical Defibrillator
You’veVolumetric Efficiency seen those live-saving defibrillators in offices, shopping malls and even homes, standing at the ready for immediate use in case of a medical emergency.
When the Philips Medical Systems division of Royal Philips Electronics introduced its HeartStart defibrillator in 2002, it was among the first low-cost, mass-market units designed for ordinary, untrained users. It received attention and plaudits due to its small size (a little bigger than a large hardcover book), light weight (2.1 kg/4.6 pounds) and ease of use, with prompts delivered by a soothing human voice. (Watch this video to see the defibrillator unit in action.)
This type of unit–formally known as an automated external defibrillator (AED) to distinguish it from the implanted pacemaker–was soon either mandated or voluntarily installed in tens of thousands of public locations and private homes.
The initial AED design began with a team at Heartstream Inc. (US Patent 5,735,879, April 7, 1998), prior to the company’s acquisition by Hewlett-Packard/Agilent (1998), which subsequently sold it to Philips (2001). The product had to meet a maze of constraints with respect to size, weight, performance, regulatory mandates and cost (around $2,000 retail).
It required innovative circuitry based largely on standard components and a custom application-specific integrated circuit (ASIC) processor to arrive at its user-friendly appearance and operation. Despite the inherent complexity of restarting a heart via defibrillation, the designers did not want a graphical user interface, multi-line text display or touchscreen to direct and guide a user, just a voice.