118: BOGO Defibrillator (Multidisciplinary Team)

While the prevalence of shock refractory ventricular fibrillation is low, survival remains incredibly rare. Different defibrillation methods have been proposed to improve outcomes, but the double sequential external defibrillation (DSED) technique is the most promising. We aimed to produce a device, that can deliver the same functions as a manual defibrillator and employ the DSED technique without the need for an extra defibrillator. 

The DSED technique describes sending energy via electrical current through the heart forward and backward twice with each sequential shock at slightly different directions (vectors). Our design contains the same basic circuitry as a manual defibrillator but employs more semiconductors and capacitors to control shock directions (vectors) and timing (time between shocks). We developed two final prototypes.

Prototype 8 has two additional capacitors for the rapid release of energy for the subsequent vector, and prototype 9 reuses the original capacitors to shock the following vector but creates a delay for recharge. Prototype 8 will likely be most effective in the field; with supplementary components, the design holds multiple defibrillator capacities in one system. The capacitors are charged and discharged with select semiconductor switches; the design’s energy output is measured by the energy held in the capacitors, 200-J maximum, and the current through four outputs (resistors to mimic human resistance) is measured to verify capacitor discharge. The design must be scaled down to work safely in the lab, so capacitors are charged to approximately one joule while the control semiconductors remain the same. The primary verification measurement is the voltage over specific outputs at different times—the control of capacitors discharging through specific outputs at select times.