Project Overview

My name is Ashwin West and my senior project revolves around proving whether it is possible to transform a smartphone into an Automated External defibrillator (AED). AEDs work to restore the electrical connection between both systems by applying current to the SA node equal to that of its own impulses. The current enters through the SA node and travels throughout the heart and other atrioventricular nodes, contracting or relaxing different regions. AEDs function off of an oscillating circuit, which allow the current to be active at high frequencies. If fed into a transformer, the oscillating circuit can be raised to voltages suitable enough for shock. [4] [3]

William Kouwenhoven first invented the Automated External Defibrillator in the 1930’s. [2] It was created in response to the discovery of fibrillation, the process whereby the electrical impulses generated by the sinoatrial node in the heart are interrupted. Since the nervous system’s only means of communication with the heart are via the SA node, loss of electrical connection results in uncontrolled contraction and heart “quivering.” [4]

The basic design of the AED is a multi-stage circuit containing an external power source fed into a transformer, 2 switches, a capacitor unit capable of stowing and discharging between 150 and 360 J, a diode unit or variable resistor, and an external application unit, usually paddles. Initially, charge is fed into a capacitor from the transformer. Then, the first switch closes and allows the capacitor to discharge the current into the patient. When designing AEDs, patient resistance is also accounted for and is a factor in determining power supply. [5] [1]

The circuit I will be creating for the project differs from the conventional design in that it will have to interact with the electrical components of the phone. To accomplish this, I am considering several types of designs to create. The first mirrors the abovementioned construction except that it will use an external battery source to draw current from. The second design directly interacts with the phone’s battery by using a coil mechanism to draw the correct voltage needed. Both of these small-scale circuits would use arduino microprocessors and drivers connected to sensors to analyze the patient resistance and determine/deliver the correct amount of voltage. The microprocessor will interact with the application on the phone, which will be written in Android Studio. The app will contain the user interface and algorithms for determining the voltage amount.

Some expected obstacles that I have already encountered are whether the phone battery has enough energy to provide the consecutive shocks needed for resuscitation and the size and effect of the components in terms of mobility. For the purposes of this proof-of-concept project, I will design and conduct the experiment in small-scale, and then convert and compare the data to full-scale results from actual AEDs. In theory, these components could work at the small-scale level, but their functionality could change as more current is introduced. These are the questions I hope to answer as I embark on my project to revolutionize consumer interaction with the medical field and lifesaving technologies.

Sources

[1] N/A. "Automatic External Defibrillation." Automatic External Defibrillation: Overview, History, Machine Mechanics. N.p., n.d. Web. 28 Nov. 2016.

[2] "History of AEDs & Defibrillation: AED - AEDGRANT.COM ~ FREE AED GRANT MONEY!!! ~ AED Grant for Individual, and Organizations." History of AEDs & Defibrillation: AED - AEDGRANT.COM ~ FREE AED GRANT MONEY!!! ~ AED Grant for Individual, and Organizations. N.p., n.d. Web. 28 Nov. 2016.

[3] "What Does An AED Do To The Heart? - AED.com Blog." AED.com Blog. N.p., 19 June 2013. Web. 28 Nov. 2016.

[4] “Campbell Biology.” Reece, Urry, Cain, Wasserman, Minorsky, Jackson. Pearson, 2014. Print. Nov. 28, 2016.

[5] “Defibrillators and How They Work.” N/A. Boston Scientific, 2011. Print. Nov. 28, 2016.