CARP Movesense Sampling Package

This library contains a sampling package for the carp_mobile_sensing framework to work with the Movesense heart rate devices. This packages supports sampling of the following Measure types (note that the package defines its own namespace of dk.cachet.carp.movesense):

• dk.cachet.carp.movesense.state : State changes (like moving, tapping, etc.)
• dk.cachet.carp.movesense.hr : Heart rate
• dk.cachet.carp.movesense.ecg : Electrocardiogram (ECG)
• dk.cachet.carp.movesense.temperature : Device temperature
• dk.cachet.carp.movesense.imu : 9-axis Inertial Movement Unit (IMU)

This package uses the Flutter mdsflutter plugin, which again is based on the official Movesense Mobile API. The following heart rate devices are supported:

• Movesense Medical (MD)
• Movesense HR+
• Movesense HR2

See the CAMS documentation site for further documentation. See the CARP Mobile Sensing App for an example of how to build a mobile sensing app in Flutter.

For Flutter plugins for other CARP products, see CARP Mobile Sensing in Flutter.

If you're interested in writing your own sampling packages for CARP, see the description on how to extend CARP Mobile Sensing.

Installing

To use this package, add the following to you pubspec.yaml file. Note that this package only works together with carp_mobile_sensing.

dependencies:
  carp_core: ^latest
  carp_mobile_sensing: ^latest
  carp_movesense_package: ^latest
  ...

See the official Movesense description of using the plugin.

Android

Download mdslib-x.x.x-release.aar from the Movesense-mobile-lib repository and put it somewhere under android folder of your app. Preferably create a new folder named android/libs and put it there.

In build.gradle of your android project, add the following lines (assuming the .aar file is in android/libs folder):

allprojects {
    repositories {
        ...
        flatDir {
            dirs "$rootDir/libs"
        }
    }
}

iOS

The Movesense iOS library is installed using CocoaPods by adding this setup to your app's Podfile. You need to change the use_frameworks! flags, add use_modular_headers!, and link to the Movesense bitbucket library:

target 'Runner' do
  # undocumented flag in cocoapods to enable static linking
  # this is needed so that we can use Movesense and dynamic frameworks together
  use_frameworks! :linkage => :static
  use_modular_headers!

  flutter_install_all_ios_pods File.dirname(File.realpath(__FILE__))
  pod 'Movesense', :git => 'https://bitbucket.org/movesense/movesense-mobile-lib/'
  
  target 'RunnerTests' do
    inherit! :search_paths
  end
end

Add the permission to access bluetooth in the background by adding this to the Info.plist file located in ios/Runner:

<key>NSBluetoothAlwaysUsageDescription</key>
<string>Uses bluetooth to connect to the Movesense device</string>
<key>UIBackgroundModes</key>
<array>
  <string>bluetooth-central</string>
</array>

Using it

To use this package, import it into your app together with the carp_mobile_sensing package:

import 'package:carp_core/carp_core.dart';
import 'package:carp_mobile_sensing/carp_mobile_sensing.dart';
import 'package:carp_movesense_package/carp_movesense_package.dart';

Collection of Movesense measures can be added to a study protocol like this.

// Create a study protocol
StudyProtocol protocol = StudyProtocol(
  ownerId: 'owner@dtu.dk',
  name: 'Movesense Sensing Example',
);

// Define which devices are used for data collection - both phone and eSense
// and add them to the protocol.
var phone = Smartphone();
var movesense = MovesenseDevice();

protocol
  ..addPrimaryDevice(phone)
  ..addConnectedDevice(movesense, phone);

// Add a background task that immediately starts collecting HR and ECG data
// from the Movesense device.
protocol.addTaskControl(
  ImmediateTrigger(),
  BackgroundTask(
    measures: [
      Measure(type: MovesenseSamplingPackage.HR),
      Measure(type: MovesenseSamplingPackage.ECG),
    ],
  ),
  movesense,
);

Before executing a study with an Movesense measure, register this package in the SamplingPackageRegistry.

SamplingPackageRegistry().register(MovesenseSamplingPackage());

Use the MovesenseDeviceManager to connect to the device using the connect method. The connect method uses the bleAddress to identify the Polar device, which is typically on the form "Movesense 220330000122". You should set the BLE address before trying to connect.

Known Limitations

State Events

There is currently a hardware limitation in the Movesense device and only one movement state (movement, tap, double_tap, free_fall) can be subscribed at the same time. See issue #15. Therefore the MovesenseStateChangeProbe is only able to collect single tap events and the STATE measure hence only reports on single tap events.

Unstable Subscriptions

When subscribing to multiple high-frequency measures - like HR, ECG, IMU - these subscriptions may time out with an error code 408. This is probably because the Movesense hardware can't keep up with streaming all the data. So, if you need to stream multiple streams of data, you would often need to reconnect to the device, even multiple times. See also this thread on stackoverflow.