Share My Creation JP eMamie : fall detection IoT

Hi here is my latest creation : a fall detection device eConnected

real size = 75 mm height

What's inside the box ?
- a lipo
- a lipo charger
- an ESP8266
- a MPU6050

The MPU is providing 3 axis motion information (gyro + accelerometers). It runs in "quiet mode" fully autonomous an can wake up the ESP8266 when an abnormal motion is detected on any axis

The ESP when waken up launchs motion information acquisition and checks the current attitude of the people wearing the device.

• If almost vertical then it is a normal "strong motion" the ESP enters into DeepSleep,
• if not then its a "fall" ESP wakes up WIFI and sends a firebase notification and then enters again into DeepSleep.

Well and B4A ?
Here comes the App, quite simple :

• You can configure the device, register to its messages, capture the firebase message and display a nice notification.
• You can register any number of smartphone you want (whole family will get the message).
• You can as well register any number of "eMamies"

I designed this little thing just because my mother (87 years old, broke her ankle 4 months ago, she had a mobile phone... but not in her pocket... By chance she is fine now but she suffered really a lot while crawling to get the phone...)

The design is simple but efficient, power consumption is interesting : less than 6mA when just looking at motion --> most of the time.
With a little 180mAh battery it lasts more than 24 hours before charging it.
Wifi range of ESP8266 is rather large : I measured more than 50m in open air. And it covers my whole (big) house.

The case is milled into wood. All the device weights less than 30g.

 

[Cableguy]

I wonder how many false positives you have, since the device itself may be in a upright position even when the user is down.... i.e. the device inside a pocket will most certainly find its way in a normal horizontal position...

 

[freedom2000]

Yes you are right, if you put the device into your pocket, it could go horizontal and then generate false alarms.

That's the reason why I use it as a necklace pendant. The center of gravity being rather low it stays vertical.
The detection proccess is double :
- internal motion detection into the MPU6050 (look for Digital Motion Processor : http://playground.arduino.cc/Main/MPU-6050)
- confirmation of position with the ESP8266

I have tuned the MPU6050 thresholds in order to generate a detection when you jump or sit down "strongly", so I do rely on the second check to avoid "false positives".
The "vertical condition" is in fact a cone of +-45° around the vertical.


And surprisingly it works very very well with no false detection provided you keep the device almost vertically.

I have tested it in various conditions :
- walk (no detectiopn at all)
- run (no detection)
- jump (motion detection only)
- sit normally (no detection)
- sit strongly (motion detection only)
- lie gently (no motion detection)
- lie strongly (motion detection and position) --> alarm

So you can take elevators, drive a car, it will works when you stay "vertical"
you can bend a little, it won't detect an alarm
The only conditions of no detection of a real fall could be :
- you slide on a wall and your chest remains vertical (motion detection but no alarm)
- you collapse "smoothly" without rapid motion (no motion detection).

Most of commercial system rely on a strong motion detection followed by no motion at all and this is not good if you break a leg, still can move your body but are forced to stay of the ground...

I started my researchs on internet and found a very interesting thesis : Design of a Fall Detection and Prevention System for the Elderly
I have based my design on this paper.

 

[Cableguy]

Have you adding a gsm shield and make it completely stand alone? Incase of a hard fall, the phone may be damaged as well, so no alert would be given, also I would consider embeddingit on a piece of clothe, like an inside jacket pocket

[Edit] dahm t9 that can't figure out French from English and does what it pleases!

 

[freedom2000]

Have you adding a game shield and make it completely stand alone? Incase of a hard fall, the phone may be damaged as well, so no alert would be given, also I would consider embeddingit on a piece of clothe, like an inside jacket pocket

The phone is not needed for this device to work.
It is totally autonomous (excepted that it needs wifi connection)
Smartphones are on the other side of the link, they just receive alarms.
A normal configuration is :
- Granny has the pendant
- the children have their own smartphones and receive alarms anywhere in the world at no charge and with the very high reliability of Google Firebase/GCM servers

As there is no button, nothing external to the device, you can wear it safelly and even if you fall it goes on working (mine has already fallen on the floor !)

 

[Cableguy]

It is totally autonomous (excepted that it needs wifi connection)

That's what I don't understand... If it needs WiFi, it is not totally autonomous, at least it wouldn't be here in France, nor in Portugal, nor most countries... (Free open WiFi networks are still a dream in most countries)... Plus, I can imagine it not being only used by grannies, but hikers, and the likes that like to explore... Some wild places don't even have gsm, imagine WiFi!

 

[freedom2000]

Yes sure it's devoted to protect grannies when in home.
Most of the accidents for elderly people occur at home when there is nobody to help them.
When outside there is always somebody to rescue.


By the way you can put your phone into access point modem and connect the device to internet with your phone (but not very handy).
Furthermore if you have the phone in your pocket then you can easily do the same function just with its accelerometer and a few lines of B4A !

 

[Cableguy]

Now I got it, it's very target specific...
But I see a market there... SOS devices... Go for it

 

[Cableguy]

By the way you can put your phone into access point modem and connect the device to internet with your phone (but not very handy).
Furthermore if you have the phone in your pocket then you can easily do the same function just with its accelerometer and a few lines of B4A !

True, but the ever power eager smartphone won't laslaa whole day...
I imagine a matchbox size device able to "call Home" without user interference... Even a children tracker would find its way into market...

 

[freedom2000]

But I see a market there... SOS devices... Go for it

Yes I have already tested SOS devices :
SOSbodyguard : too complex to get success
iTagAlarm : a quite good success with more than 300 download per day

I do believe that in those sad times of unsecurity, there is a market for SOS devices...

 

[freedom2000]

True, but the ever power eager smartphone won't laslaa whole day...
I imagine a matchbox size device able to "call Home" without user interference... Even a children tracker would find its way into market...

I wanted to test Lora transmission, but it is still a little expensive and needs a quite big antenna...

 

[JordiCP]

I wanted to test Lora transmission, but it is still a little expensive and needs a quite big antenna...

The drawback about LoRa is that you need another device for reception, since unfortunately it isn't yet included in smartphones

I think it could be made with "reasonable" size and cost. Not as cheap as an ESP8266, but still affordable

 

[freedom2000]

The drawback about LoRa is that you need another device for reception, since unfortunately it isn't yet included in smartphones

I think it could be made with "reasonable" size and cost. Not as cheap as an ESP8266, but still affordable

And we have also to take care of energy drain.
I don't know how much curent a Lora device eats ?

 

[JordiCP]

And we have also to take care of energy drain.
I don't know how much curent a Lora device eats ?

The module I know (RFM95W: 868/915MHz) drains about 10mA in Rx mode.
Tx current is quite higher, but as it will only transmit when there is an event, it is not the determinant figure.

The price is about 10$, but I have seen (but not tested) some cheaper modules

 

[freedom2000]

Did you test point to point connection between 2 RFM95W ?
Does it have a good range (it's supposed to have !)

 

[JordiCP]

About 1.5Km (free air). A lot compared to others, but less than I expected.

A good path to antenna and filtered power supply (which I didn't have) can help, I guess.

 

[Cableguy]

About 1.5Km (free air). A lot compared to others, but less than I expected.

A good path to antenna and filtered power supply (which I didn't have) can help, I guess.

Also a well designed antenna ( if point to point use, then a high gain directional one) will improve range in a few km

 

[freedom2000]

Also a well designed antenna ( if point to point use, then a high gain directional one) will improve range in a few km

Sure but if I put it on a Granny's necklace I will not ask her to fine tune the antenna

However it could be fine to have a range of 1km... would be enough for elderly people

Now comes the problem of size and weight...