Automated external defibrillator (AED) placement optimization

• Main Author: Muhammad Salleh Mohamed Tahir
• Other Authors: Cai Wentong
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2020
• Subjects: Engineering::Computer science and engineering::Mathematics of computing::Probability and statistics
• Online Access: https://hdl.handle.net/10356/138210
• Institution: Nanyang Technological University

Out-of-Hospital Cardiac Arrest (OHCA) is a public health issue. OHCA is extremely time sensitive as every minute this is left unattended, chances of survival will decrease by 7-10%. There are many studies determining high risk location for cardiac arrest and optimizing AED placement and accessibility for the public, however vertical AED placement has not been extensively. Singapore is a highly urbanized city and the trend of urban development are pointing towards constructions of tall (and taller) residential buildings. Based on the historical OHCA data (2010-2016) provided by Singapore General Hospital (SGH), most of the OHCA cases occurred in home residences. This poses a challenge in emergency OHCA response for patients in high-rise buildings whereby there will be delays in emergency response and at a survival disadvantage from OHCA. Thus, the need to optimize the AED placement for high-rise building in Singapore. In this report, we mathematically analyzed the average response distance for n-floor buildings with more than one elevator and a single AED which applies to most residential buildings in Singapore to determine whether elevator-based or lobby-based AED placement results in shorter vertical distance travelled. We extended the mathematical model based on the study in Toronto, Canada to experiment on a different scenario that relates to HDB buildings in Singapore. The model used independent Poisson processes for each floor of OHCA occurrences to compared two possible locations where the AED can be placed: the elevator and the elevator lobby to observed which will be a better option in terms of shortest average response time. The analysis solely depends on the height of the building, number of elevators and the relative risk of OHCA on the ground floor to an above-ground floor. Our results suggest that elevator-based AED placement had shorter average response distance if the number of floors (n) in the building with more than one elevator exceeded the OHCA risk ratio of ground-floor to above-ground floor risk (λ1/λ ≤ (3n^2-2n+1)/3n). Otherwise, a lobby-based AED had shorter average response distance.