Personal Alarm for Old and/or Disabled People
My neighbor from across the street is close to 90 years old and he is partly disabled. He still lives alone, but every day someone drops by to look in on him. Last Sunday evening he fell down and was unable to get up again. For some twelve hours he had to lie on his back on the floor until the Monday morning visitor could help him.
My neighbor from across the street is close to 90 years old and he is partly disabled. He still lives alone, but every day someone drops by to look in on him. Last Sunday evening he fell down and was unable to get up again. For some twelve hours he had to lie on his back on the floor until the Monday morning visitor could help him.
This was not the first time that this happened. He has a personal alarm pendant but he finds it annoying and he doesn’t always wear it. This time he wore it, but he had shifted it to his back and when he fell, he could not reach it. Not very smart, you might think, but that is the way it is.
So here is my request to you: can you help me to come up with a smart alarm system for old and disabled people that can detect all by itself when something is wrong instead of relying on the person to press a button? It should function in such a way that the person under surveillance should not have to think about it. It must be very reliable and as simple as possible.
Any input would be greatly appreciated.
Discussie (6 opmerking(en))
dsm 11 jaar geleden
Clemens,
The generic type of product you are describing is often called a PERS (Personal Emergency Response System) button. Philips Lifeline has a product like this with more than 600K clients being monitored. Numerous other companies are also in this product space.
The hardest part of this type of product is often the back-end call center.
Who responds when an emergency happens? What do they do?
Another hard problem is that POTS/PSTN lines are being replaced by VoIP, broadband, and cellular connections. What sort of communication mechanism does the sensor use to connect with the back-end call center?
Another hard problem is making sure that the sensor and radio link are reliable.
Consider the liability involved if your product doesn't work in an emergency.
Typically a signal or message is sent to a call center in response to a
To keep the size and weight of the sensor down, typically a coin cell is used which tends to limit the radio choices possible (ideosyncratic > Bluetooth 4.0 LE > 802.15.4 variants). Typically a short range radio communicates to some sort of local wireless hub (often built into a speakerphone so the call center can then call the patient). Fall detection implies that the sensor wakes up fairly frequently (~2 mS).
Another approach would be to build a device which is based on rechargable cellular telephone technology and skip the local hub entirely. How about a wristwatch-like device that can talk via Bluetooth LE 4.0 to the patient's smartphone? That seems to be the approach that Samsung, Apple, and any number of wearable sensor folks are pursuing. GPS capability built into many cellular radio chip sets could be used to help locate patients with dementia that wander off.
Cheers,
dsm
ClemensValens 11 jaar geleden
J.-M. Lindemann 11 jaar geleden
the problem you describe has often attempted to solve (eg. acceleration sensor, position sensor, image recognition ). But life is so diverse,
that a real secure solution to my knowledge does not yet exist.
Therefore, so far we can only offer solutions with a relative safety for the elderly and disabled.
The solution of NECV20 (.. instead of pushing a button to set the alarm, the pre - alarm has ... ) is offered as a standard in alarm systems. In my opinion this is actually the best solution. The problem is that people feel disturbed by the periodic signals and switch the system off.
In conjunction with an emergency telephone a request is triggered by the person once the periodic confirmation fails. This solution is problematic
because the person must check out, for example, if she wants to sleep .
I still have no idea how to solve the problems with an intelligent alarm. Perhaps it is only possible to increase the degree of relative safety.
Even that would be an important step for our clients!
I look forward to the discussion!
Jörg
ClemensValens 11 jaar geleden
NECV20 11 jaar geleden
Hello Clemens,
Most of us, when we think of RFID, we suppose that the maximum distance between sender and receiver is a couple of centimeters. But these high-freq. tags can be detected at ranges of up to 8 meters.
You don't have to communicate much between them, just with a few receivers in the house you can detect a difference in the strength of the signal.
And the tags can be intervowen in clothes, or just carried along as a credit card in a wallet. So maybe Elektor has to pick up the RFID item again, look for a cheap of the shelf tag and design a cheap wallmounted detector.
Then there is no need to power something on the body.
guyv 11 jaar geleden
NECV20 11 jaar geleden
Bobbylebob 11 jaar geleden
NECV20 11 jaar geleden
Hello Clemens,
My first idea when a read this post is to adapt the current alarm system to make it fail safe.
Instead of pushing a button to set the alarm, the pre-alarm has to be switched off by the button every now and then. The period(s) between resets can be software designed (no need to wake an old person at night).
And the length of the period also sets the maximum time of non-attendence.
Looks like a nice job for a Raspberry Pi to me.
Then, because my old mother also has such a system at her home, I know how annoying it can be. Apart from just forgetting to put the alarmbutton around her neck.
Why can these modern 'smart' watches not have this function incorperated? Most old people still do wear wristwatches (or bracelets). Or maybe it is time to bring a new oldfashioned pocketwatch back on the market with a alarm function in it. It will be a standard piece of equipment everybody has with a extra!
ClemensValens 11 jaar geleden
NECV20 11 jaar geleden
Bobbylebob 11 jaar geleden
Hi Clemens,
I worked on such a project some years ago. A small box was tied to the monitored person's belt. It embedded 4 tilt sensors (like mercury bulbs) placed in a kind of 2D inverted 'Y' (or like an umbrella, you see what I mean ?). Now, those could be replaced by a 2-axis accelerometer but take care of current drain. There was also an activity sensor. This is a smal metal cylindrical package with an iron ball inside rolling at each little movment and closing a contact. Look at those made by Assemtech : http://www.assemtech.co.uk/productpages/movement_vibration_switches_uk.asp
Those motion sensors are more suited than tilt switches for this goal because they aren't position sensitive.
A tilt detection followed by a non-activity period triggered the alarm. The algorithm has to be smart to avoid false triggering, but reliable enough...
II suggest to add a pre-alarm buzzer which could alert the patient before sending alarm. Useful if he looses it unintentionally.
You'll also need a wear switch to disable the system during the night or shower... We simply used a long arm lever switch plased behind the belt hook.
We added heart pulses monitor but I think it's a big constraint, the patient had to wear an optical peg on his finger all the day long... In my opinion this is way too binding for people...
Sorry my dear Jennifer, I know you're a great BT fan, but we chosed to use Zigbee here for its very useful mesh configuration. There was one master, located near the ADSL box and connected through ethernet with it. In each room, we developped small wall plugs with one Zigbee repeater inside. With this topology, it's very easy to increase communication range without requiring big RF power on people's side, thus increasing battery autonomy.
Finally, you'll have to manage power with an embedded lithium battery and find a way to indicate its state of charge. A charger will of course be added to allow a simple wall supply to provide charge power
Aubinais 11 jaar geleden
Aubinais 11 jaar geleden
Hello Clemens,
I'll tell you about the B...tooth. For those who do not know me, I love the Bluetooth :-) Why not put in a small box a accelerometer detects an abnormality such as a fall. How to interface with the accelerometer Bluetooth module? Reduced power ? ...
Happy reading
Jennifer