Share My Creation Cardio Respiratory Monitor

Hi B4A folks,

I just uploaded my first apps to Google Play Market a couple days ago. B4A is a great programming platform, and the forum help has been fantastic. I bought my first smartphone in May, and I bought my B4A license a week later.

I uploaded both free and Pro (paid) versions of the app. Here is the web link to the free version:

https://play.google.com/store/apps/...zY2llbmNld2l0aGFuZHJvaWQuY3Jtb25pdG9yZnJlZSJd

Best,

G^2

 

[Gsquared]

Failed to attach image in my first post. Here it is.

 

[walterf25]

Nice App

Very nice app, i didn't know you could do this without attaching any type of special sensors to the phone, would you mind elaborating a little more as to how exactly the phone measures the heart beat and the breathing parameters?

thanks,
Walter

 

[Gsquared]

Hi Walter,

I use the built-in sensor fusion technology to measure the changes in the tilt of the phone due to the breathing and heartbeat motions of the chest. First, I had to separate out the signal into the breathing and heartbeat components in the code and then use different methods to determine the periods. This is because the heartbeat period is fairly steady over about 20 seconds, but the breathing period can vary considerably. It was a real challenge to get it to work properly most of the time.

I mostly tested the app on me, but I know that heartbeat and breathing parameters can vary considerably from person to person. So, I would appreciate feedback from anyone who tries the app.

Best,

G^2

 

[walterf25]

Awesome

Thanks, so did you have to write a wrapper for the sensor fusion api?

Thanks,
Walter

 

[NJDude]

Interesting app.

If you don't mind, I have a few observations:

1- Center the add on the screen, THIS is how it looks on Tablets or large screen smartphones.

2- When selecting an item on the MENU button, pressing the BACK button exits the app, it would be better if you took the user back to the previous screen instead.

3- The "first run" screen flashes when the app is ran more than once.

ADDED: It seems there's a minimum version compatibility, installing your app on a Froyo device runs, but it gets stuck on "Status: Preparing..."

Also, you better mention that the app might not work properly if it's enclosed on a case (soft or hard shell).

 

[Gsquared]

Thanks NJDude for the helpful suggestions.

G^2

 

[walterf25]

Doesn't work

Hey, i just tried it on my Motorola Photon, i have version 2.2.3 running and i don't get any readings at all.



thanks,
Walter

 

[Gsquared]

No, I used one of the built-in sensor types.

 

[Gsquared]

The fact that it gave you 'error' on the outputs means that it was probably taking readings but the app failed to converge on accurate heartbeat or breathing periods. If your device was missing the needed built-in sensors, you should have seen a message right after you pushed the start button. It will probably take several attempts on your first use of the app to find a position on your chest that works most of the time. Or, it could be that your chest movements are too shallow for the device to detect reliably.

 

[NJDude]

I've added a couple of comments to my previous post.