carp_movesense_package 1.4.4

The CARP Movesense sampling package. Samples sensor data from the Movesense MD and ACTIVE (HR+, HR2) devices.

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 carp_mobile_sensing wiki for further documentation, particularly on available measure types. 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 are interested in writing your own sampling packages for CARP, see the description on how to extend CARP on the wiki.

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 Integration

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"
        }
    }
}

NOTE: The first time the app starts, make sure to allow it to access the phone location. This is necessary to use BLE on Android.

iOS Integration

Install the Movesense iOS library using CocoaPods with adding this line to your app's Podfile:

pod 'Movesense', :git => 'https://bitbucket.org/movesense/movesense-mobile-lib/'

• Remove use_frameworks! from your Podfile so that libmds.a can be used correctly.
• In your project target settings enable Background Modes, add Uses Bluetooth LE accessories
• In your project target property list add the key NSBluetoothAlwaysUsageDescription

Add this permission in 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: '[e-mail]',
    name: 'Movesense Sensing Example',
  );

  // define which devices are used for data collection - both phone and eSense
  var phone = Smartphone();
  var movesense = MovesenseDevice(
    serial: '220330000122',
    address: '0C:8C:DC:3F:B2:CD',
    name: 'Movesense Medical',
    deviceType: MovesenseDeviceType.MD,
  );

  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());

NOTE that the Movesense device address must be specified before the phone can connect to the device via BLE. This entails that a Movesense device and its probes should not be connected and resumed, before the device address is know.

Also note that the package does not handle permissions for Bluetooth scanning / connectivity. This should be handled on an app level.

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.