Create a health research app using Samsung Health Stack

Objective

Create a health research app that collects and processes participant's health data, survey responses, and task results using Samsung Health Stack.

Overview

Samsung Health Stack is an open-source technology stack offering end-to-end solutions for collecting and analyzing data from wearable devices in Android and Wear OS environments. With applications ranging from medical research to clinician services and beyond, this tech stack provides the tools and infrastructure necessary to expedite the development and deployment of health-based studies.

The framework includes:

Samsung Health Stack App SDK - a Software Development Kit (SDK) for building Android and Wear OS apps capable of collecting data from wearable devices.
Web Portal - a customizable interface for creating surveys, managing team members, tracking participants, and analyzing data.
Backend Services - API endpoints to access and interact with a robust data engine.

See Samsung Health Stack descriptions for detailed information.

Set up your environment

You will need the following:

Installed and running Samsung Health Stack Backend System
Installed Samsung Health Stack Web Portal
Firebase private key used during the backend system installation
Android Studio (latest version recommended)
Android Jetpack Compose (latest version recommended)
Samsung Galaxy mobile device with Health Connect app and Samsung Health app installed
Samsung Galaxy Watch synced to the mobile device
Google Account

Sample Code

Here is a sample code for you to start coding in this Code Lab. Download it and start your learning experience!

Research App Sample Code

(4.09 MB)

Create a Firebase project

Follow the instructions at firebase.google.com/docs/android/setup to add a Firebase project to the Firebase account you created during the backend system installation.

Set applicationId as healthstack.sample and download the resulting google-services.json file from Firebase.

To learn more, see Installing the App SDK - Create a Firebase Project.

Create a new study

On the Study Collection page, click the Create new study button.

NoteOnly the account who has Team Admin role can create a new study. See the Role-Based Access Control for more details about the differing levels of access permission granted to different roles.

Set your study name and logo. Then click the Continue button to create your study.

Select the Principal Investigator role and click the Confirm button.

The Overview page appears like below:

To connect your app to the backend system of your Web portal, you need to know the ID of your study. You can get the study ID by opening Chrome's developer tools.
Right-click on the web portal page and select Inspect. Then, open the Network panel.
Click Study Settings from the left navigation bar.
You can see activities recorded on the Network tab.
The value after projectId= is the ID of the study, which you need to set up in the research app.

Connect the research app to the backend system

In Android Studio, click Open to open the project files of the research app.

Locate the downloaded Android Project (codelab-before) from the directory and click OK.

Copy and paste the downloaded google-services.json from Firebase to samples > researchsample module.

Go to samples > researchsample > res > values, and in the strings.xml file, set the following values to connect the app to the backend system:
- research_platform_endpoint - backend system’s endpoint, including the port number
- research_project_id - ID of the study created

<!-- backend integration -->
<string name="research_platform_endpoint">http://you.must.set.backend.url</string>
<string name="research_project_id">study_id</string>

Customize the introduction page and eligibility survey

The sample research app already includes introduction page and eligibility survey, which you can customize to align with the objective of your study.

To modify the introduction page and eligibility survey questions, go to samples > researchsample > java > healthstack.sample and open the OnboardingModule.kt file.

Introduction page

Go to the IntroModel constructor within the intro function, and create two IntroSections as below:

Overview - "A study on walking over an hour daily versus non-walkers."
Description - "We want to conduct a study to compare the daily life patterns of people who walk more than an hour each day and those who don't."

sections = listOf(
    IntroSection(
        "Overview",
        "A study on walking over an hour daily versus non-walkers.",
    ),
    IntroSection(
        "Description",
        "We want to conduct a study to compare the daily life patterns of people " +
            "who walk more than an hour each day and those who don’t."
    )
)

The introduction page would look like as below:

Eligibility survey

Part of the onboarding process is asking the participants questions through an eligibility survey to determine their suitability for your study.

The eligibility survey consists of three steps:

EligibilityIntroStep - displays an introduction about the survey
EligibilityCheckerStep - displays the eligibility questions
EligibilityResultStep - displays the result of the survey based on the answers

The EligibilityCheckerStep receives the eligibilityQuestions. The questions can be a ChoiceQuestionModel, DataTimeQuestionModel, or MultiChoiceQuestionModel, depending on the type of survey question model you set.

Modify the eligibility question pages as below:

Eligibility Question 1
Type	ChoiceQuestionModel
id	average_walking_time
query	How many minutes on average do you spend walking each day?
explanation	Unit: minute
candidates	listOf(0, 30, 60, 90, 120)
viewType	Slider

Eligibility Question 2
Type	ChoiceQuestionModel
id	tracking_device
query	Are you willing to wear a tracking device to monitor your daily walking activity?
candidates	listOf("Yes, I'm willing to use a tracking device", "No, I'm not comfortable using any tracking device")
answer	Yes, I’m willing to use a tracking device

Eligibility Question 3
Type	ChoiceQuestionModel
id	participate
query	Are you available and willing to commit to participating in the study for a specified duration?
candidates	listOf("Yes, I'm available and willing to commit", "No, I'm not available or willing to commit")
answer	Yes, I’m available and willing to commit.

private val eligibilityQuestions: List<QuestionModel<Any>> = listOf(
    ChoiceQuestionModel(
        id = "average_walking_time",
        query = "How many minutes on average do you spend walking each day?",
        explanation = "Unit: minute",
        candidates = listOf(0, 30, 60, 90, 120),
        viewType = Slider
    ),
    ChoiceQuestionModel(
        id = "tracking_device",
        query = "Are you willing to wear a tracking device to monitor your daily walking activity?",
        candidates = listOf(
            "Yes, I’m willing to use a tracking device",
            "No, I’m not comfortable using any tracking device"
        ),
        answer = "Yes, I’m willing to use a tracking device"
    ),
    ChoiceQuestionModel(
        id = "participate",
        query = "Are you available and willing to commit to participating in the study for a specified duration?",
        candidates = listOf("Yes, I’m available and willing to commit", "No, I’m not available or willing to commit"),
        answer = "Yes, I’m available and willing to commit"
    )
)

You can make a pass condition for each question by setting the answer field.

A failed result means the participant is not eligible for the study.

After defining eligibility questions, the eligibility survey pages would look like as below:

Set health data permissions

You can request permission to collect health data from your study participants.

However, before requesting permissions, your app must first declare them in the manifest.

Go to researchsample module > res > values.

In health_permissions.xml, you can declare permissions to read or write data on Health Connect for Steps, SleepSession, SleepStage, OxygenSaturation, and BloodPressure data types.

NotePermission to read and write HeartRate data is already declared in the project.

<item>androidx.health.permission.Steps.READ</item>
<item>androidx.health.permission.Steps.WRITE</item>
<item>androidx.health.permission.SleepSession.READ</item>
<item>androidx.health.permission.SleepSession.WRITE</item>
<item>androidx.health.permission.SleepStage.READ</item>
<item>androidx.health.permission.SleepStage.WRITE</item>
<item>androidx.health.permission.OxygenSaturation.READ</item>
<item>androidx.health.permission.OxygenSaturation.WRITE</item>
<item>androidx.health.permission.BloodPressure.READ</item>
<item>androidx.health.permission.BloodPressure.WRITE</item>

TipFor more information, see the list of data types and permissions.

Then, go back to healthstack.sample folder.

In ResearchApplication.kt, request permissions from the participants to collect required health data.

val healthDataRequired = listOf("HeartRate", "SleepSession", "SleepStage", "BloodPressure", "Steps", "OxygenSaturation")

TipSee the list of health data types you can collect on Health Connect.

Set sync interval and choose health data to display

You can set the sync interval per health data type.

However, it is recommended to set a minimum interval of 15 minutes because the app is using Android's WorkManager.

TipTo learn more about the WorkManager, see PeriodicWorkRequest.

In MainActivity.kt, set healthDataSyncSpecs as below:

Health Data Type	Sync Interval
HeartRate	15 minutes
Steps	20 hours
SleepSession	1 day
SleepStage	1 day
OxygenSaturation	30 minutes
BloodPressure	30 minutes

val healthDataSyncSpecs = listOf(
    SyncManager.HealthDataSyncSpec("HeartRate", 15, TimeUnit.MINUTES),
    SyncManager.HealthDataSyncSpec("Steps", 20, TimeUnit.HOURS),
    SyncManager.HealthDataSyncSpec("SleepSession", 1, TimeUnit.DAYS),
    SyncManager.HealthDataSyncSpec("SleepStage", 1, TimeUnit.DAYS),
    SyncManager.HealthDataSyncSpec("OxygenSaturation", 30, TimeUnit.MINUTES),
    SyncManager.HealthDataSyncSpec("BloodPressure", 30, TimeUnit.MINUTES),
)

You can set which data type to display in the research app.

The status card for heart rate is already set to display.

To show other status cards, such as SleepSessionStatus, add them to the list of healthDataToDisplay.

val healthDataToDisplay = listOf(HeartRateStatus, SleepSessionStatus, TaskStatus)

Run the app, join the study and sync your health data

Build and run the app on a Samsung Galaxy mobile device.

Ensure the Samsung Health app and Health Connect app is installed on the device and a Galaxy Watch is connected.

Note

Reset the app to its initial state by clearing its data.

Go to your phone's settings and then swipe to and tap Apps.
Select or search for the ResearchSample app.
Tap Storage, tap Clear data, and then click OK.

In the research app, you can join the study by signing in with your Google Account after passing the eligibility survey, providing consent, and allowing data access to Health Connect.

The research app shows your heart rate data (BPM) and the time you spent sleeping (hrs) based on the data from your Galaxy Watch and mobile device.

NoteThe data shows and updates in the app based on the sync interval you set. If you want the heart rate data to display immediately, you can measure your heart rate manually using the Galaxy Watch. Then, click the Sync Health Data button in the research app's Settings. Check Health Connect's recent logs if data is not showing or updating.

The web portal also displays and processes the data from the research.

To see the average heart rate data, go to the Overview section.

Scroll to the Participant List table, then click the participant data row.

The Participant Management shows health data collected on average, such as heart rate.

Create a survey task

A survey is a sequence of questions that collect information from the participants in your study.

In this step, create a survey task and see the result from the web portal.

Go to the Study Management section and expand the Task Management.
Open the Surveys tab and click the Create survey button on the top right corner.

Set survey title as Daily Survey. Then, write three questions as below:

After writing all the survey questions, click the Publish button.
Set the Frequency as Daily and the Publish time as early as possible.
Then, click the Publish button on the bottom right corner.

You can find your survey task on the Published list.

Go to the research app and touch the refresh button next to Upcoming Tasks or Today to see the survey you created.

Answer and complete the survey task.

Go back to the web portal. Click your survey task from the Published list.
Reload the web page or re-login to get the result.
You can see the survey report in the Responses and Analytics tab.

Create an activity task

Activities allow researchers to collect specific types of data from users.

For this study, add an activity to collect measurements related to manual dexterity.

In Study Management, go to the Activities tab and click the Create activity button.
Select Motor for the activity category and choose Tapping Speed.
Click the Create button.

Click the Publish button on the task edit page.
Set Frequency as Daily and Publish time as early as possible.
Then, click the Publish button.

You can find your activity task on the Published list.

In the research app, touch the refresh button to see the newly added activity.

Open and perform the activity task.

In the web portal, click your activity task from the Published list.
Enter the Participant Id to see the collected data.

You're done!

Congratulations! You have successfully achieved the goal of this Code Lab. Now, you can create your own research app that can collect and process users’ health data, answers to survey and activity task results for research purposes by yourself! If you face any trouble, you may download this file:

Research App Complete Code

(4.09 MB)

To learn more, see Samsung Health Stack.