Tutorial: Medical Alert Systems
An Emergency Response System (medical alert system) includes some type of button you press, or automatic sensor that detects you have a problem. When you press the button or the problem is identified, the system somehow sends a message to a "responder" and then that responder takes some action.
There are quite a few different approaches to how these systems are implemented. In the most common approach the "responder" is a call center operated by or on behalf of the company that makes the medical alert system. So when there is an emergency, the system "calls" the call center where there is a person whose job it is to take action. This approach is called a "monitored" system.
There are also systems that are "unmonitored". In that case, you set them up so that in emergency the system calls a number you tell it in advance, or sends an email to people you designate in advance. The typical scenario is that you program it to call a friend or family. Or perhaps 911. Or perhaps an escalating call tree, starting with friends and then going to 911 if no-one answers.
What happens in emergency
When an emergency is detected (most typically when you press the button on the alert system), the system calls the responder. Some responders will just send emergency services right away (ie dial 911). But the more sophisticated responder services will call the older adult who is having an emergency and try and find out what is going on before taking further action.
Ideally, the older adult gets a call from a responder who says "Are you OK Mrs Smith? How can we help you?". Some services will provide a range of response services. For example they might call the towing company if you have broken down, or call an ambulance in a real emergency, or just stay on the phone while you walk through a bad neighbourhood if you are feeling unsafe.
The sensor / button / wearable
A medical alert system is only useful if it can actually summon help in an emergency. Typically, these systems have some type of pendant or wrist-worn device that has a button on it. The older adult is supposed to press the button in case of emergency.
Some pendants are designed to include a fall autodetection capability, and can automatically contact the responder when they detect a fall. One needs to consider what happens in case of a false alarm for one of these automatic systems.
A modern approach to designing a medical alert system is to make the whole system an "App" on a smart phone. In this case, instead of a pendant you just need to press the button on your smartphone.
The ergonomics and cosmetic appeal of the sensor/button/wearable is critical, and what works for one person may not be right for another. After all, if the sensor is not within reach in emergency you cannot press the button. Ideally the sensor/button would work everywhere, and be in some form factor that means you have it on at all times. Most systems fall short of this ideal and so one needs to make tradeoffs.
The different "types" of medical alert system
We think of these systems as falling into several distinct types ("flavors"). Picking which type works for you is an important first step in selecting one.
Works at home only
The original medical alert systems, designed decades ago, were designed to have a base station that attaches to a person's home phone line, and talks with the pendant/button via some type of wireless signal. There are many of this type of system still being sold, and some have been updated to include more modern and robust technology, but still with this basic "at home" concept.
Of course, this type of system will not work at all once you go far enough away from the base station so that the pendant can no longer communicate to the base station. While some systems will allow you to go into the yard, once you head off to the shopping center the system will no longer be protecting you.
Within this category, there are two sub-types of system. One sub-type has a base station that connects to the responders via a landline. The alternate approach has a base station that connects via a cellular connection.
An alternate concept has the pendant (or perhaps some additional "portable base station" communicating to the responder via cell connection. This approach has a big advantage in that it "works everywhere". The tradeoff is that these systems typically are larger and more bulky.
Furthermore "everywhere" is a term that needs definition. These systems will work "everywhere" that the system can get a cell signal from the carrier that the system uses. So if it is hard to get a cell signal in your bathroom, the system might not work there. And if you live in the country where cell coverage is poor, it will not work there either.
In theory, these systems could work in multiple countries. In North America, most of them only claim to work in the USA — or perhaps in the USA and Canada.
Form factor of the "wearable"
The traditional approach to the medical alert system is to have some type of "wearable" that is attached to the body of the older adult using the system. For example, this could be in the form of a pendant or of a wrist watch type wearable.
The alternate approach is to have the "wearable" be a smartphone, with the idea that some people have their smartphone with them at all times.
Who is the first responder?
As explained above, the system may be monitored, in which case the responder is a person in a call center. Or the system could be unmonitored, in which case the system contacts either a friend or emergency services (by dialling 911 directly).
Questions about you to answer before deciding
There are a series of questions to ask yourself, relating to which of these various types of system will work best for your circumstance. We are building a selection tool to help turn the answers to these questions into a short list of "products that should work for your circumstance". You can see that tool by pressing the green button below labelled "Use our Medical Alert Selection Tool".
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Return to the Guide: Medical Alert Systems
Or return to the main page summarizing our research results on emergency response systems (medical alerts).
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We hope you found this work useful. If you like what we do, and would like to see it continue, please consider contributing time, ideas, or some funding to help support our work.
We are currently raising contributions from those who find our work valuable to complete some new research initiatives, all targeted at helping older adults live better for longer. And we are always looking for contributions of ideas about what to work on, or help executing some of our projects.
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The team is led by Dr. Richard Caro, PhD physicist and co-author of a recent guide to home sensor systems for older adults.
Our advisory panel contains clinicians and aging services professionals with extensive experience in working with the older adult population that uses these medical alert systems. Professional competencies in the team include social work, physio-therapy, and nursing, and experience operating independent living communities.