Defibrillators

Coffee shops, 24-hour ATMs are the best locations for life-saving AEDs, 91�Թ� research shows

ullahnor — Mon, 20 Mar 2017 20:57:33 +0000

Coffee shops, 24-hour ATMs are the best locations for life-saving AEDs, 91�Թ� research shows

ullahnor Mon, 03/20/2017 - 16:57

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Timothy Chan (left) and Christopher Sun (right) studied data on cardiac arrest locations in Toronto to determine a list of “Top 10” businesses where placing automated external defibrillators would save lives (photo by Marit Mitchell)

Liz Do

Author legacy

Liz Do

Topic

Global Lens

Cardiac

Engineering

Cities

Defibrillators

Timothy Chan

Health

Subheadline

91�Թ� Engineering team creates list of top 10 businesses where placing automatic external defibrillators would save lives

ATMs and coffee shops such as Tim Hortons, Starbucks and Second Cup make ideal locations for placing automated external defibrillators (AEDs), says a new study led by 91�Թ� Engineering Professor Timothy Chan and PhD candidate Christopher Sun, in collaboration with St. Michael’s Hospital.

When a patient suffers cardiac arrest, every second counts — the chances of survival decrease by 10 per cent each minute. Responding quickly can be the difference between life and death, and that means having immediate access to a nearby AED.

“Previous research on AED placements had focused on broadly defined location categories, like shopping malls or office buildings,” said Sun. “But these categories generalize many individual businesses, which have different hours, activities performed, and other unique properties that meant we could be missing critical insight on which locations are really high risk. So we wanted to get more specific: which individual locations or businesses could AEDs be placed to make sure they are accessible to the largest number of people throughout the day.”

Their findings are already making headlines.

See the CBC story

See the Toronto Star story

See the CNN story

Their new study, published today in the American Heart Association journal Circulation, looked at where cardiac arrests occur, to find locations where AEDs would be most valuable.

Map of the facilities of the Top 5 ranked businesses in terms of actual coverage in all of Toronto (image courtesy of Sun & Chan)

First, the researchers identified all businesses with 20 or more locations in Toronto – facilities such as Tim Hortons coffee shops or libraries that would make good candidates to place AEDs in.

Then they looked at the number of cardiac arrests that occurred within 100 metres of each location, during the businesses’ operating hours. Using this data, Chan and Sun calculated the “spatiotemporal cardiac arrest coverage” provided by each location or business. The specific locations and businesses were then ranked to determine a “Top 10” list of prime spots to place AEDs.

“We found that coffee shops and ATMs ranked highly across several related metrics, and that those rankings were stable over the years,” said Chan, who is the director of the Centre for Healthcare Engineering at U of T and a Canada Research Chair in Novel Optimization and Analytics in Health.

“What we found really interesting is that ATMs, as opposed to the more traditional businesses, are often standalone or outdoors, and are often available 24/7. They’re also universally recognizable and already have an electronic and security infrastructure – hypothetically, if we were to have AEDs paired with ATMs, it would be very beneficial,” said Sun.

Three coffee shop chains – Tim Hortons, Starbucks and Second Cup – as well as five of the big banks with many ATM locations, including RBC and Scotiabank, made the top 10. Tim Hortons was ranked first, with more than 300 shops in Toronto. These locations alone would have provided AED coverage for more than 200 out-of-hospital cardiac arrests over an eight-year period.

The researchers hope this new study could soon lead to AEDs placed in these optimal locations.

“Health organizations, foundations and policymakers aiming to develop public access defibrillator programs could use our rankings to identify promising businesses to develop partnerships for AED deployment,” added Chan.

Chan’s lab has a number of ongoing research projects on AED placements, including using drones to deliver AEDs, and optimizing AED placements in high-rise buildings.

“Ultimately, we want to get AEDs in the right locations so they are accessible when needed most,” said Chan.

Sun says cardiac arrests are unique because in the early stages they can be treated as effectively by untrained responders as by paramedics.

“That’s why finding out the best placements for AEDs is so important,” said Sun. “We have the opportunity to save lives based on our level of preparation and organization.”

Top 10 locations for AEDs based on coverage

Tim Hortons
RBC ATMs
Subway restaurants
Scotiabank ATMs
CIBC ATMs
TD ATMs
Green P public parking lots
Starbucks
BMO ATMs
Second Cup

Life-saving defibrillators often behind locked doors during off-hours, says 91�Թ� study

lavende4 — Mon, 15 Aug 2016 18:01:50 +0000

Life-saving defibrillators often behind locked doors during off-hours, says 91�Թ� study

lavende4 Mon, 08/15/2016 - 14:01

Liz Do

Author legacy

Liz Do

Topic

Breaking Research

Mechanical & Industrial Engineering

Defibrillators

Timothy Chan

When a person suffers cardiac arrest, there is a one in five chance a potentially life-saving Automated External Defibrillator (AED) is nearby. But up to 30 per cent of the time, the device is locked inside a closed building, according to a study led by 91�Թ� Engineering researchers, published August 15 in the Journal of the American College of Cardiology.

The work was conducted by Professor Timothy Chan of the Department of Mechanical & Industrial Engineering at the 91�Թ�, in collaboration with Rescu, led by Dr. Laurie Morrison at Li Ka Shing Institute of St Michael's Hospital in Toronto.

Currently, AED placement in Canada does not necessarily consider accessibility of the device during an emergency. Many AEDs are located within office buildings, schools and recreation facilities, which tend to be open for a limited set of hours during the daytime.

Toronto had 2,440 cases of out-of-hospital cardiac arrests in a public place during the study period, and 767 AED locations. Of these AED locations, 73.5 per cent were not open 24-hours a day, and 28.6 per cent were closed on weekends. Of the total number of out-of-hospital cardiac arrests, 451 were located near an AED but only 354 were located near an AED when the AED was accessible, resulting in a coverage loss of 21.5 per cent.

When researchers looked at cardiac arrests during evenings, nights and weekends, which is when the majority of all out-of-hospital cardiac arrests occur, coverage diminished to 31.6 percent.

The researchers concluded that a significant proportion of out-of-hospital cardiac arrests occur close to a public AED that is inaccessible at the time of the arrest, and a model that accounts for both location and availability when determining AED placement has the potential to significantly increase the likelihood of accessing an AED when needed.

“Our research has shown AED availability for cardiac arrests is overestimated when time factors, such as building access and time of day, are not considered,” said Chan (right). “The model considers time of day, building access and location information to optimize AED availability. Using the model, we found an average 25 per cent improvement in AED accessibility for cardiac arrests at all times of day.”

Government legislation mandating all AEDs be registered with emergency medical services dispatch centers and accessible to the public 24/7 would also improve access to AEDs.

But coverage is only one issue, according to the study’s authors: AED coverage does not necessarily equal survival, because the existence of an AED still doesn’t necessarily mean the AEDs are being used.

“Accessibility is only one piece of the larger puzzle in optimizing public defibrillator use and bystander response in an emergency,” said Chan, who is also director of the Centre for Healthcare Engineering at 91�Թ�.

In an accompanying editorial comment, Robert J. Myerburg, a professor of medicine at the University of Miami Miller School of Medicine, said the study is important and should be included in planning strategies for AED locations, but society would benefit more by both achieving better outcomes after out-of-hospital cardiac arrest and reducing the number that occur in the first place.

“Now we need a parallel effort to develop a roadmap for improving prediction and prevention of out-of-hospital cardiac arrest,” he said.

Defibrillators: making sure they're accessible when and where heart attacks are most likely to happen

sgupta — Tue, 10 Nov 2015 15:28:38 +0000

Defibrillators: making sure they're accessible when and where heart attacks are most likely to happen sgupta Tue, 11/10/2015 - 10:28

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(photo by Liz Do)

Liz Do

Author legacy

Liz Do

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Subheadline

Research finds life-saving devices are often located in buildings and facilities with limited opening hours

Walking through an office building on St. George Street, Engineering's Christopher Sun quickly spots a portable automated external defibrillator (AED) conveniently tucked near the side of the entrance.

From 8 a.m. to 9 p.m., its accessibility could be vital in saving a life. But after the building closes at 9 p.m., it is almost as if the AED isn’t there.

That problem is what the PhD student's research is examining, with Associate Professor Timothy Chan of Mechanical & Industrial Engineering and in collaboration with St. Michael’s Hospital and its Rescu program, led by Dr. Laurie Morrison.

Sun recently presented their findings at the American Heart Association (AHA) conference in Orlando. Chan had previously presented at the AHA conference in 2010, sharing his findings on the placement of registered AEDs in Toronto and Peel Region. What he discovered back then was that spatial distribution of AEDs was not optimal.

“Our original finding was that less than one in four cardiac arrests occurred near an AED,” Chan said.

Sun’s research takes that research a step further.

“Previous work has focused almost entirely on spatial factors,” said Sun. “Time factors, such as when cardiac arrests occur and the time of day, have been largely overlooked.

“We found that if we do take into account time, there is a significant decrease in perceived coverage of cardiac arrests.”

Based on the hours of the buildings where AEDs are placed, the research revealed that AED coverage was diminished more than eight per cent during the day, 28 per cent in the evening and 48 per cent at night.

His research also found that only some buildings in Toronto are accessible 24 hours a day and seven days a week. Many AEDs are located within office buildings, schools and recreation facilities, which tend to be open for a limited set of hours during the daytime.

“There’s definitely a gap there,” said Sun. That gap can be the difference between life and death.

Over a period of roughly eight years, 2,440 out-of-hospital cardiac arrests occurred in Toronto. Of those that occurred near an AED, approximately one in five occurred when an AED was inaccessible.

“Emergency medical services and investigators are united and willing to reposition AEDs to locations that are accessible,” said Dr. Morrison, an emergency medicine specialist at St. Michael’s and collaborator in the research.

According to Sun and Chan, the true coverage of cardiac arrests is overestimated when temporal factors are not considered. To address this issue, they have developed an optimization approach that can regain that lost coverage by optimizing AED deployment in more time-available buildings. This research was also recently presented at the AHA conference.

“We’ve developed the first mathematical optimization approach for AED deployment that considers both spatial and temporal availability to improve cardiac arrest coverage,” said Chan, who is the Canada Research Chair in Novel Optimization and Analytics in Health, and leads the Centre for Healthcare Engineering (CHE) as well as the Applied Optimization Lab (AOL) at 91�Թ� Engineering.

“We found that our model provided the largest improvement in coverage during the night, which was precisely when the largest loss in coverage due to limited temporal accessibility was experienced, as well as when survival was lowest.”

Chan said he hopes this research demonstrates how critical temporal accessibility is to both the measurement of true cardiac arrest coverage as well as the decision on where to locate AEDs.

“Our optimization model can be beneficial towards developing policies and guidelines for AED placements across the world, and ultimately to help save more lives,” said Chan.

Alongside Sun’s findings, Chan’s AOL researchers will continue to focus their attention on the city’s distribution of AEDs. The lab is analyzing the optimization of defibrillators in high-rise buildings, as well as in Toronto’s heavily frequented PATH underground walkway.

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Engineering a better healthcare system: placing defibrillators where they're needed most; redesigning clinic schedules to reduce wait times

sgupta — Mon, 01 Dec 2014 11:51:17 +0000

Engineering a better healthcare system: placing defibrillators where they're needed most; redesigning clinic schedules to reduce wait times sgupta Mon, 12/01/2014 - 06:51

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Professor Timothy Chan is the new director for 91�Թ� Engineering's Centre for Healthcare Engineering (photo by Mark Balson)

RJ Taylor

Author legacy

RJ Taylor

Topic

Subheadline

Timothy Chan on how the Centre for Healthcare Engineering is making health care better, faster and less costly

Mending broken bones or prescribing medication may seem like simple tasks but they're part of a hugely complex healthcare system of hospitals, clinics, ambulances, research centres, suppliers and governments.

And according to Professor Timothy Chan of mechanical and industrial engineering, that system needs re-engineering.

Chan is the new director of 91�Թ� Engineering’s Centre for Healthcare Engineering (CHE) (formerly the Centre for Research in Healthcare Engineering). The collaborative hub brings a highly interdisciplinary, systems engineering approach to drastically improve how health care works.

“Health-care systems are a lot like giant factories – they involve a large number of people and processes all working together in different stages to meet one goal,” said Chan. “At the CHE, we pioneer research that optimizes many of those stages, making health-care delivery more efficient, less costly and quicker.”

Engineering’s RJ Taylor spoke with Chan to learn more about how the Centre is taking the “waiting” out of “waiting room”.

Medical breakthroughs make headlines every day but they aren’t the only way to improve health care. How does CHE contribute?
Each year, Canadians spend over $200 billion on health care – that’s almost $6,000 a person. Healthcare spending can consume over 40 per cent of the annual budget of some Canadian provinces. With numbers like these, even small efficiencies can lead to significant cost savings and decreased wait times.

At the Centre for Healthcare Engineering, we use systems engineering to find and take action on these efficiencies. Hailing from many different fields, our researchers focus on optimizing health-care delivery, decision-making and policy. We collaborate directly with industry partners, lead fundamental research and also focus on educating the next generation of health-care engineers.

Can you explain what systems engineering is?
Systems engineering is a multidisciplinary field that looks at how a process or processes operate and often how to improve them. Projects can involve leveraging vast amounts of data to create computer simulation models – models that we can use to test variables and mimic potential outcomes, leading to better decision-making.

The field is rooted in industrial engineering, which historically examined the most efficient layouts for manufacturing facilities. Today, systems engineering can involve virtually any discipline linked to the process you’re trying to build or improve. With healthcare engineering, this can include public health, medicine, business, law, political science and more.

How are you using this systems engineering approach in your research?
Have you ever had to wait well beyond your appointment time at the doctor’s office? It was probably because of inefficient scheduling. Recently, Professor Michael Carter and I worked with Women’s College Hospital in Toronto to redesign their entire clinics scheduling system from scratch. By shifting clinic schedules to better balance resources – like not booking clinics that require time-consuming blood tests all at once – we were able to keep waiting to a minimum for both patients and staff.

Another project I’m working on looks at automatic external defibrillators (AEDs), which are publicly-available devices to treat patients suffering from cardiac arrest. With data on historical cardiac arrests, building layouts and current AED locations, my team and I can determine the ideal places to put these machines. Our computer models show that by using such comprehensive data – as opposed to merely placing AEDs according to population density – we can triple the number of cardiac arrests that are supported within 100 metres of a defibrillator. (Read more about this project.)

Internationally, I’m also involved in a collaboration to improve emergency medical care in Dhaka, Bangladesh. Unlike Toronto, Dhaka’s roads are congested with motorcycles, bicycles and pedestrians that can be barriers for ambulances. We are developing models that use GPS data from cell phones to depict how traffic is moving in real time – recommending the best routes to an emergency scene. This can significantly cut down on response times and help emergency medical responders save more lives.

What about others at the CHE?
Radiation treatment for cancer can be a complex balancing act, as doctors deal with many different variables when trying to make sure that the right amount of radiation gets into a tumour without too much getting into healthy tissues. Professor Dionne Aleman and her team simplified this treatment by creating mathematical models and algorithms that can balance the many factors involved.

These models target tumours with greater than 90 per cent accuracy, a significant improvement on current plans. Working with Princess Margaret Cancer Centre, Sunnybrook Hospital and Elekta AB (a Swedish radiation equipment manufacturer), her team has already demonstrated that their models can save time and money, with better treatment.

A few years ago, Professor Carter also worked with the Ontario Ministry of Health to develop a plan that reduced wait times for cataract operations. The goal was to bring down the wait times from an average of one year down to six months – and his model figured out how many additional surgeries were required to meet the target. When implemented, his numbers accurately predicted the real-life numbers.

Where do students fit into CHE’s mandate?
Great question. With our researchers leading such groundbreaking research, we definitely want them to share it – as well as their expertise – with students. We offer a number of graduate and undergraduate courses in health-care engineering, systems and policy, as well as fundamental engineering methodologies that are applicable to health care.

At the graduate level, we offer a master of engineering certificate in health-care engineering, which includes specialized courses and an opportunity to work directly on an industry-related project. We are also looking to expand beyond engineering and engage students from across 91�Թ� campus.

What’s next?
At the Centre for Healthcare Engineering, we have ambitious plans to expand well beyond our home in the department of mechanical and industrial engineering. We are looking to actively involve researchers and students from across 91�Թ�: medicine, law, business, public health, you name it. We want to bring more diverse perspectives, add more collaborative projects, increase industry engagement and expand our student opportunities. And, of course, we want to improve health care for everybody around the world.

This interview has been condensed and edited.

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91�Թ� researchers identify 10 dangerous cardiac 'hot spots' in Toronto

sgupta — Fri, 03 May 2013 16:06:51 +0000

91�Թ� researchers identify 10 dangerous cardiac 'hot spots' in Toronto sgupta Fri, 05/03/2013 - 12:06

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(photo by AlamosaCountyPublicHealth via Flickr)

Terry Lavender

Author legacy

Terry Lavender

Defibrillators

Engineering

Features

Subheadline

91�Թ� researchers determine where best to place defibrillators, identify under-serviced areas

Those with a history of heart disease should stay clear of the Queen and Bay Street area.

It's one of the public places in Toronto where most heart attacks occur, yet it's out of reach from life-saving automated external defibrillators (AEDs), according to new research from 91�Թ�.

“If you have a cardiac arrest, every second counts," said Dr. Laurie Morrison, from St. Michael's hospital. "Only five per cent of people who suffer out-of-hospital cardiac arrest survive to be discharged from hospital. The probability of survival decreases up to 10 per cent with each minute of delay between collapse and treatment.”

In a paper published in Circulation, Morrison and 91�Թ� mechanical and industrial engineering professor Tim Chan note that publicly registered AEDs in Toronto are not in the best locations to help victims of cardiac arrest. In fact, less than one in four of all cardiac arrests had an AED close by (within 100 metres is the required distance). The average distance to the nearest AED was closer to 300 metres.

Morrison and Chan developed a new formula to determine where the costly AEDs are best placed to serve their life-saving purpose—and identified key areas in Toronto where AEDs are not currently within reach, hindering the prompt use that can greatly increase survival rates.

Current guidelines suggest areas associated with the highest risk of cardiac arrest should be targeted for AED deployment, after they have been placed in obvious high-traffic areas such as transportation hubs or major sports venues. But it’s not clear how to identify these "cardiac hot spots."

Chan and Morrison looked at the locations of all 1,310 public cardiac arrests in Toronto between December 2005 and July 2010 and the locations of all 1,699 AEDS registered with Toronto Emergency Medical Services.

They found that 304 cardiac arrests occurred within 100 metres of at least one AED (23 per cent).One hundred metres was chosen as the yardstick because it’s the approximate distance a bystander could transport an AED in a 1.5-minute walk—the maximum recommended by the American Heart Association.

There were almost three times as many public cardiac arrests in downtown Toronto as the rest of the city – 3.5 per square kilometer per year vs. 0.4 – said Chan. Almost half of all downtown cardiac arrests were near an existing AED compared to only 17 per cent of those outside of downtown.

Chan then looked at the 1,006 cardiac arrests that did not take place near an AED. He said that by placing AEDs in the top 30 cardiac arrest “hot spots,” they could have covered an additional 112 historical arrests, or 32 per cent. The average distance between a cardiac arrest and an AED would fall to 262 metres from 281 meters.

“Reducing the distance a bystander needs to travel by 20 metres or up to 40 meters in a roundtrip has the potential to save close to half a minute in response time,” said Morrison, an emergency medicine specialist who heads Rescu, the largest research team of its kind in Canada dedicated to improving out-of-hospital resuscitation.

Chan said his mathematical model is more accurate than a population-based model, in which AEDs are placed in areas of densest daytime population.

“Our optimization model should be viewed as a decision-support tool to help prioritize placement of AEDs, make efficient use of public, donor or private funds directed toward public access defibrillator programs, and potentially maximize survival on the basis of geographic patterns of cardiac arrest,” said Chan. “Because AEDs are expensive and cannot be placed everywhere, our model allows a decision-maker to quantify the trade-off between the number of AEDS deployed and coverage.”

While it was not part of the research paper, Chan used his mathematical model to indicate the top 10 cardiac hot spots in Toronto not currently covered by AEDs:

View Top 10 cardiac 'hot spots' in Toronto in a larger map

1.Jarvis and Gerrard
2.Queen and Bay
3.Jarvis and Dundas
4.Brimley and Progress
5.Eglinton and Warden
6.Wellington and Strachan
7.Dundas and Spadina
8.Queen and Shelbourne
9.Danforth and Pape
10.Jarvis and Adelaide

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