Using NuraLogix™ Web Measurement Service

This guide will help you effectively use NuraLogix™ Web Measurement Service (WMS) to create useful working web applications.

The Introduction gives a basic overview of the Web Measurement Service and the basic measurement flow.

Chapter 2 provides details about the steps needed to get started with WMS.

Chapter 3 discusses the sample application that you can use to test with before you build your own application.

Chapter 4 goes into more detail about WMS data structures, call-back URL and error handling.

Chapter 5 explains regions and clusters, and how region locking can be implemented in WMS.

Styling WMS to match your own website is discussed in Chapter 6.

Chapter 7 contains a walkthrough that shows the steps that an end-user goes through while using WMS.

A troubleshooting guide is provided in Chapter 8

Chapter 9 provides recommendations about platform requirements.

Finally, there is an FAQ section containing answers to some of the questions that you may have about WMS.


Last updated on 2024-02-13 by Vineet Puri (v1.11.0)

Disclaimer

For Investigational Use Only

DeepAffex™ is not a substitute for the clinical judgment of a health care professional. DeepAffex™ is intended to improve your awareness of general wellness. DeepAffex™ does not diagnose, treat, mitigate or prevent any disease, symptom, disorder or abnormal physical state. Consult with a health care professional or emergency services if you believe you may have a medical issue.

Introduction

Before you begin, we recommend perusing the DeepAffex™ Developer Guide so that you have a basic understanding of NuraLogix™ DeepAffex™ technologies and terminologies. Please be sure to read the first two chapters - Introduction and Getting Started.

The Web Measurement Service is designed for a simple use-case, explained in the scenario described below.

Scenario overview and concepts

The user visits your website hosting a single-page application (called "app" hereafter).

In the field, the app (which you develop) will manage:

  • user authentication
  • user consent
  • collecting subject's profile information and
  • collecting answers to subject's medical history questionnaire
  • obtaining a token and a refresh token from the DeepAffex API

Then, the app will redirect the user to WMS with the profile information that is necessary to take a measurement. On WMS, the user will complete a measurement and then WMS will redirect the user back to the app with the results of the measurement.

Information will be passed from the app to WMS through a specially crafted URL (the "call-in" URL). Since this URL will contain personal information, it will be encrypted so that only a specially configured WMS will be able to read the information. Additionally, for the app to link the measurements results to the user's profile, a unique Partner ID will also be passed along with the user profile details to WMS.

The measurement results will be passed back via a preconfigured "callback" URL.

Measurement Flow

The details of the measurement flow described above are captured in the following diagram.

sequenceDiagram
    autonumber
    participant TPAPI as Third-party Cloud
    participant APP as Third-party app
    participant WMS as Web Measurement Service
    participant DFX as DeepAffex API

    APP->>+TPAPI: Request short-lived DFX_AUTH_TOKEN
    TPAPI->>+DFX: Request short-lived DFX_AUTH_TOKEN
    DFX-->>-TPAPI: Issue short-lived DFX_AUTH_TOKEN & DFX_REFRESH_TOKEN
    TPAPI-->>-APP: Return short-lived DFX_AUTH_TOKEN & DFX_REFRESH_TOKEN

    Note over APP: PROFILE_DATA { "identifier": [PartnerID], "height": 175, "weight": 75, ... }
    APP->>APP: Generate SESSION_ID
    APP->>APP: Encrypt PROFILE_DATA with public key and construct WMS URL

    Note over APP,WMS: WMS_URL: https://awe.na-east.nuralogix.ai/c/[CONFIG_ID]/[PROFILE_DATA]/[DFX_AUTH_TOKEN]/[DFX_REFRESH_TOKEN]/[SESSION_ID]
    APP->>WMS: Call WMS at WMS_URL
    WMS->>WMS: Decrypt PROFILE_DATA with private key
    WMS->>DFX: Forward DFX_AUTH_TOKEN & DFX_REFRESH_TOKEN

    loop Until measurement is successful
        WMS->>DFX: Create Measurement
        DFX-->>WMS: Return MeasurementID
        WMS->>DFX: Subscribe Results
        activate DFX
        loop Until all payloads are sent
            WMS-)DFX: Add Data
            DFX--)WMS: Send Results
        end
        deactivate DFX
    end

    WMS-->>APP: Send MeasurementID and Results back through CALLBACK_URL (SESSION_ID in Results)
    Note over WMS,APP: https://thirdparty.com/example/measurementComplete?ai.nuralogix.nura.results=<<base64encoded>>

(Click here to open a larger version of this diagram in a new window)

Getting Started

Pre-requisites

To setup the integration with the Web Measurement Service, you will need the following:

Get a public key

Since the information sent to WMS contains sensitive end-user data (e.g., age, weight etc.), it needs to be encrypted with a public key. NuraLogix will decrypt it with the corresponding private key. The encryption algorithm used is RSA.

The following files will be generated by NuraLogix:

  • wms_private_key.der: a private key stored at NuraLogix.
  • wms_public_key.pem: shared by NuraLogix with you. Update the variable in src/Pages/Profile/publikcKey.ts [sic] with the contents of this file.

Get a config ID (CONFIG_ID) from NuraLogix

To get going, you need a WMS CONFIG ID - a unique identifier that is linked to your app's specific configuration. Before NuraLogix can provide one, you need to provide NuraLogix with two items:

  1. Callback URL

    After the measurement is finished, WMS will redirect the end-user to this URL in the app. The results will be encoded in the query string so that they can be saved or displayed by the app.

  2. Logo file URL

    WMS will display your logo image on the measurement page to brand it. Please host the logo image at a publicly accessible URL. The recommended format is a 150 x 55-pixel PNG with a transparent background.

After you provide the above to NuraLogix, you will receive the config ID. Please update the CONFIG_ID key in .env file with it.

Setup a CNAME

Mask the Web Measurement Service URL with your custom URL by creating a CNAME record on your DNS server's management page.

For example, if your app's domain is domain.com you can setup a CNAME called measurement to awe.na-east.nuralogix.ai. Then measurement.domain.com will mask the WMS URL.

The actual instructions for setting up a CNAME can be obtained from the documentation of your domain name provider. Follow those instructions to create the following entry:

  • Name: measurement (This can be any name that you choose).
  • Type: CNAME
  • Alias: Yes
  • Value: awe.na-east.nuralogix.ai

After you are done, please send the chosen CNAME to NuraLogix for additional setup on our end.

Once the chosen CNAME is configured, update the service URL in the file src/Pages/Profile/Profile.tsx by replacing https://awe.na-east.nuralogix.ai with your setup CNAME (example: https://measurement.domain.com)

Get a Visage SDK License from NuraLogix

Web Measurement Service relies on the Visage Face Tracker and you will need a Visage Face Tracker license bound to your domain name. NuraLogix will obtain one for you as part of the WMS package. Do please let us know if you would prefer to obtain one directly from Visage. It will need to be hosted by NuraLogix since it's used by WMS.

Sample App

Please contact NuraLogix to get access to the WMS sample application which demonstrates the call-in / callback functionality of Web Measurement Service (WMS)

The sample app consists of a backend component that obtains an authorization token and a refresh token from DeepAffex API and a frontend component which uses a simple UI to collect user information, calls in to WMS and displays the returned results using a simple UI.

Build and testing the sample app

Running for Testing & Development

Note: Please use yarn to install dependencies as npm causes some dependency issues.

Please edit the .env file to reflect the correct configuration values before running the sample app.

PropertyDescription
PUBLIC_URLPopulate only if the app will be run from a sub-path, example: /subpath otherwise leave blank
LICENSE_KEYDeepAffex API license (obtain from https://dashboard.deepaffex.ai/)
API_URLURL of the DeepAffex API (usually https://api.deepaffex.ai/)
APP_NAMEApplication name used for reporting purposes only (e.g., if more than one app will be calling Web Measurement Service)
APP_IDENTIFIERApplication ID used for reporting purposes only (e.g., if more than one app will be calling Web Measurement Service)
CONFIG_IDAs discussed above, an identifier for the your specific app configuration

Steps

# install dependencies
yarn

# build the client
yarn build:client

# build the server
yarn build:server

# run the app
yarn serve:dev

Sample app details

The sample app consists of a server component and a client component. The server component acts as a back-end for providing REST endpoints for saving the config ID and for generating DeepAffex tokens. It is also responsible for serving pre-built static assets. The client component acts as a front end for hosting the user profile form, making REST API calls to the back-end component and for hosting the results page.

Endpoints used by the client component to communicate with the server component in the sample app

/health

Used to check the health of the backend, required for deployment checks

/api/configId

Returns the application specific configuration ID, this is a fixed value provided by Nuralogix.

/api/token

Returns a DeepAffex authorization token and a refresh token, those tokens are then passed to WMS for DeepAffex licensing.

/api/status

Can be used in the deployment to check if the application is up and running.

Endpoints used by the server component in the sample app to communicate with the DeepAffex API

/organizations/licenses

Used to get a device token and a refresh token from the DeepAffex API. Those tokens are then passed to the front-end which passes it to WMS for DeepAffex licensing.

/organizations 

Retrieves information related to the current organization.

Service Details

Some additional technical details about Web Measurement Service follow.

Call-in URL Structure

The user is redirected to WMS via the following URL structure:

https://awe.na-east.nuralogix.ai/c/[CONFIG_ID]/[PROFILE_DATA]/[DFX_AUTH_TOKEN]/[DFX_REFRESH_TOKEN]/[SESSION_ID]
URL ParameterDescription
CONFIG_IDThe assigned configuration ID
PROFILE_DATABase64 encoded value of the encrypted profile information
DFX_AUTH_TOKENThe authorization token (Token) obtained by calling the registerLicense endpoint with the assigned license key
DFX_REFRESH_TOKENThe refresh token (RefreshToken) obtained by calling the registerLicense endpoint with the assigned license key
SESSION_IDID assigned by you to this measurement session

Note

Please note that PROFILE_DATA, DFX_AUTH_TOKEN and DFX_REFRESH_TOKEN need to be encoded using encodeURIComponent() while constructing the call-in URL.

PROFILE_DATA object structure

Example PROFILE_DATA JSON object:

{
  "identifier": "B748FD3B-DF16-4963-A654-48A9574C1059", // [Partner ID (a 2 to 148 characters long string) used by you to tag this measurement]
  "age": 44,
  "height": 175,
  "weight": 89,
  "gender": "male",
  "smoking": "0",
  "bloodpressuremedication": "0",
  "diabetes": "type2"
}

Note

Both keys and values used in the PROFILE_DATA JSON object must be lowercase. Also, please make sure that the keys are exactly the same as shown in the example above.

For more information about the questions that are included as part of the measurement questionnaire and their impact on the measurement, please refer to the Measurement Questionnaire section.

For more details about identifier/Partner ID, please refer to this page in the DeepAffex Developer Guide.

The PROFILE_DATA object will be encrypted using a public key to protect the privacy of the user. The corresponding private key will be used by WMS to decrypt it.

Config ID

The CONFIG_ID provided by NuraLogix to you will contain app specific information such as:

Config elementDescription
DeepAffex Study IDID for the DeepAffex Study to be used during the measurement. You can get it from the DeepAffex Dashboard. Under the Studies, select Details. Study Index is the Study ID.
Organization logo URLPublicly hosted URL for the logo to be displayed on WMS.
CALLBACK URLURL where WMS will send the results after the measurement is complete. The callback URL is hosted by you.
CSS file URLPublicly hosted URL for the stylesheet to customize the styling of the measurement screen.
Default languageDefault language from the supported languages list to be used for WMS. If not set, then the browser's active language is used if it is one of the supported languages.
Camera Auto startIf enabled, camera will start automatically. User won't see the start camera button.
Measurement auto startIf enabled, measurement will start automatically. User won't see the start measurement button.
Default camera on mobileAllows rear camera to be selected as default camera on mobile devices.
Expire token after measurementIf enabled, the token will expire after the measurement is completed. By default, it is disabled.
Region for data processingAllows to process the data in a specific region. Please refer to the regions chapter for more details.
Webhook URLURL where the WMS will send the Webhook events

Callback

WMS will use the pre-configured CALLBACK_URL to pass back results to your app. The results are passed as a Base64 encoded JSON object query string, along with the SESSION_ID that your app passed to WMS at call-in.

Example callback URL:

https://thirdparty.com/example/measurementComplete?ai.nuralogix.nura.results=<<base64encoded>>

Note

If you are using CNAME, then the callback URL should not be a subpath of the CNAME. For example, if measurement.domain.com is the CNAME, then the callback URL must not be of the form measurement.domain.com/results. This is required because the callback URL is hosted at your backend, whereas CNAME points towards the WMS.

Results

The results are also encoded using JSON. A snippet is shown below.

{
    "identifier": "B748FD3B-DF16-4963-A654-48A9574C1059", // [Partner ID sent in PROFILE_DATA object],
    "MEASUREMENT_ID": "[DeepAffex Measurement ID that uniquely identifies this measurement]",
    "SESSION_ID": "[Session ID passed in via call-in URL]",
    "HR_BPM": 76,
    "SNR": 5.6,
    "BR_BPM": 20,
    "BP_DIASTOLIC": 120,
    "BP_SYSTOLIC": 80,
    ...  // Other signals in the study
}

It will always contain the identifier, MEASUREMENT_ID and SESSION_ID keys which correspond to the PartnerID, MeasurementID and SessionID respectively. The results themselves will be returned with keys corresponding to the Signal IDs present in your DeepAffex Study. To check the results:

  1. Get a list of Signal IDs for your app using the Studies.Retrieve endpoint
    • If you are always going to use the same study, you can embed this list in your app
    • If you intend to change studies at runtime, you can call that endpoint in your app (usually right after switching studies)
  2. Use these Signal IDs as keys to look for results. If a key is not present in the results, then that result could not be computed by the DeepAffex Cloud. This can happen if:
    • The signal quality is too low. In this case, the SNR key, will be present and it will be negative.
    • Some demographic information wasn't sent to the Cloud or
    • Some other issue was encountered during computation - you can investigate using the DeepAffex Dashboard etc.

Note

Detailed measurement results can also be retrieved later by using our API if your legal agreement with Nuralogix™ allows saving results. Please refer to the results section here for more details. Please note that the authorization token gets expired in a certain amount of time (10 mins is the default value in the sample app). If your token has expired then you must call Auths.Renew endpoint to get a fresh pair of tokens before trying to retrieve the results from the API. If you lose the authorization token, then the only way to retrieve the measurement results through API is by calling the Organizations.RetrieveMeasurement endpoint. In addition to this, you may also directly see the results from the dashboard.

⚠️ Deprecated keys ⚠️

The following keys are currently returned in the results object but are deprecated. Please do not rely on them as they will be removed in future versions of WMS.

Deprecated KeySignal ID to use instead
absiABSI
ageAGE
bmiBMI_CALC
breathingBR_BPM
cardiacWorkloadBP_RPP
cvdRiskBP_CVD
DiabetesRiskDBT_RISK_PROB
diastolicBP_DIASTOLIC
healthScoreHEALTH_SCORE
heartAttackRiskBP_HEART_ATTACK
heartRateVariabilityHRV_SDNN
HypercholesterolemiaRiskHDLTC_RISK_PROB
HypertensionRiskHPT_RISK_PROB
HypertriglyceridemiaRiskTG_RISK_PROB
irregularHeartBeatsIHB_COUNT
msiMSI
ppmHR_BPM
snrSNR
strokeRiskBP_STROKE
systolicBP_SYSTOLIC
waistToHeightWAIST_TO_HEIGHT

Handling Errors

In case the Web Measurement Service faces an issue, or if there are any validation errors in the profile data, the measurement will fail and the user will be redirected to the CALLBACK_URL with an error parameter in the query string that contains the error code.

Error CodeDescription / Cause
MISSING_MEASUREMENT_IDENTIFIERThe identifier field is missing in the PROFILE_DATA object
INVALID_AGEThe age value is invalid.
INVALID_WEIGHTThe weight value is invalid.
INVALID_HEIGHTThe height value is invalid.
INVALID_BMIThe given values for weight and height represent an invalid BMI value.
MEASUREMENT_CANCELEDThe measurement is cancelled by the user.
TOKEN_EXPIREDThe authorization token has expired.
WORKER_ERRORAn error occurred in the DeepAffex™ Cloud while processing a payload.
MEASUREMENT_TIMED_OUTIf, after sending a chunk or while waiting for the final results, no response is received from the API for 60 seconds due to network issues, this error is returned.
CAMERA_PERMISSION_NOT_GRANTEDCamera permission is denied by the user.

For acceptable value ranges for age, height, weight, and BMI please refer to the Measurement Questionnaire section.

Note

Please note that more keys may be added to results JSON and additional error codes may also be introduced in the future as we keep improving our service. It is important to handle the response in the CALLBACK_URL with these potential changes in mind to ensure your integration remains robust and reliable. We recommend regularly reviewing the documentation and testing your integration to stay up-to-date with any changes.

Supported Languages

Following languages are currently supported by WMS:

  • English
  • Simplified Chinese
  • Italian
  • French
  • Spanish
  • Portuguese
  • Brazilian Portuguese
  • Japanese

It is possible to fix a language to be used for WMS through the CONFIG_ID. Please reach out to us if you want to exercise this option. WMS follows the following order to decide the language to be used for the service :

  1. Language selected through CONFIG_ID
  2. Browser's active language if it is one of the supported languages given above
  3. English

Regions and clusters

The DeepAffex Cloud API is implemented as a connected mesh of distributed AWS clusters, each of which is hosted within a specific geographic region of the globe. To know more about different regions, please refer to the Regions and Clusters page in our Developer Guide.

Note

While we will always strive to keep the information below in sync with our Developer Guide, in case there are any conflicts, the Developer Guide should be considered the source of truth.

Static Assets

Web Measurement Service static assets (HTML, JavaScript and CSS) are always served from the na-east region, regardless of the user's location.

Results Storage

A history of measurements results may be available on the DeepAffex™ Cloud if your legal agreement with NuraLogix™ allows saving results. Results, if saved in the DeepAffex™ Cloud, will be stored in the cluster-name encode in the authorization Token. This is the Token that your backend server obtains by calling the Organization.RegisterLicense endpoint. This implies:

  • Default (no region locking): If your backend server obtains the authorization Token using the default DeepAffeX Cloud API URL (https://api.deepaffex.ai), then the results will be stored in the cluster that was selected by the geo-routing rules defined in our Developer Guide.

  • Region Locking: If you want to store the results in a specific region, your server must obtain the authorization Token using the DeepAffex™ cluster-specific API URL of that region. Please refer to the direct regional URLs table below to know the different region-specific URLs.

Data Processing

Unless a region-specific API URL is setup during onboarding, blood-flow data will be processed in the region that will be selected by our geo-routing rules based on the location of the browser that loads WMS. (Not the region where your licensing backend server is located.) Specifically:

  • Default (no region locking): Region for data processing will be determined by the routing rules described in the routing table in our Developer Guide. Routing rules will be applied to the end-user's location.

  • Region Locking: If you want to process the data in a specific region, you must specify the desired region during the WMS onboarding process. The issued Config ID will determine where the data processing takes place, regardless of user's location.

DeepAffex API direct regional URLs

RegionURL
North America (N. Virginia, USA)
Short code: na-east
https://api.na-east.deepaffex.ai
Europe (Frankfurt, Germany)
Short code: eu-central
https://api.eu-central.deepaffex.ai
South America (Sao Paulo, Brazil)
Short code: sa-east
https://api.sa-east.deepaffex.ai
Asia (Tokyo, Japan)
Short code: as-east
https://api.as-east.deepaffex.ai
Asia Pacific (Hong Kong, HK)
Short code: as-hk
https://api.as-hk.deepaffex.ai

Styling

In order to customize the style of the measurement screen to match your brand identity, a stylesheet can be provided to control the colors and background images.

The Stylesheet

The provided sample stylesheet (docs/wms-styles.css) can be used as a template to style the measurement page, the following classes can be customized (please refer to the image below):

#CSS Class NameDescription
1header-logoCustomize the icon, note that customization provided here will override the value set by the config link.
2main-headerCustomize the header of the page, a background color / image can be provided. display property can be set to none to hide the header completely.
3header-iconCustomize the color of the header icon, display property can be set to none to hide icon.
4main-bodyCustomize the background color / image of the main body of the measurement screen.
5start-camera-buttonControls the Start Camera button. This can be used to control the background / text color, the width of the button and the text style. In order to control the different states of the button, classes for :hover and :active can also be specified.
6measurement-canvasControls the background of the measurement canvas before the camera is started, a background color or image can be specified.
7start-measurement-buttonControls the Start Measurement button. This can be used to control the background / text color, as well as the width of the button and the text style. In order to control the different states of the button, classes for :hover and :active can also be specified.
8mobile-top-barControls the background color of the toolbar at the top of the screen on mobile devices.
9mobile-top-bar-iconControls the color of the buttons in the toolbar at the top of the measurement screen on mobile devices.
10cameraSelectRootControls the styling of the camera dropdown menu when unexpanded.
11MuiMenu-listControls the styling of the camera dropdown menu when expanded. The background color of the list can be specified here.
12MuiMenuItem-root:hoverControls the styling of the individual menu items of the camera dropdown menu during mouse hover.
13cameraMenuItem:focusControls the styling of the individual menu items of the camera dropdown menu when in focus.

Styles Measurement button styles Mobile top bar styles

Note

The customized stylesheet should be hosted publicly and the URL is to be shared with Nuralogix team in order to update its setting in your config ID.

Webhooks

To provide more visibility and information about the events happening after the user is redirected to WMS, we offer an optional Webhook facility.

In order to opt-in to receive the events via a webhook, you need to provide a URL for the webhook which will be added to the Config ID along with an assigned MAC secret for validation.

If a Config ID has a webhook associated with it, events will be sent to the webhook as they happen. The events will be sent in the body of a POST call to the webhook.

Events

EventSeverityPayloadDescription
WMS_LOADEDINFO-WMS has been loaded
CONFIGURATION_LOADEDINFO-Config fetched using the provided Config ID
CAMERA_PERMISSION_GRANTEDINFO-User has granted the camera permission
CAMERA_PERMISSION_DENIEDERROR-User has denied the camera permission
CAMERA_STARTEDINFO-Camera started. This can be either by user or automatically.
MEASUREMENT_STARTEDINFO-Measurement Started. This can be either by user or automatically.
MEASUREMENT_CREATEDINFOMeasurement IDMeasurement created and got the measurement ID
INTERMEDIATE_RESULTSINFOSNR, Sequence, Measurement IDIntermediate result received
SCAN_COMPLETEDINFOMeasurement IDScan has completed and waiting for the final results
RESULTS_RECEIVEDINFOMeasurement IDFinal results have been received
REDIRECTING_TO_CALLBACKINFOMeasurement ID (if created)Starting the redirect to the callback URL
MEASUREMENT_CANCELEDWARNMeasurement IDMeasurement has been cnceled
CONSTRAINT_VIOLATIONERRORConstraint Violated, Measurement ID (If created)A constraint has been violated (resulting in measurement cancel)
PAGE_UNLOADEDINFOMeasurement ID (If created)Either the user has closed the browser (tab) or typed a new URL and navigating away from WMS
WEBSOCKET_DISCONNECTEDWARNMeasurement IDWebsocket has been disconnected
WEBSOCKET_RECONNECTEDINFOMeasurement IDWebsocket has been reconnected
WEBSOCKET_RECONNECTION_FAILEDERRORMeasurement IDWebsocket failed to reconnect
API_ERRORERRORAPI Error Code, Measurement ID (If created)API threw an error
PAGE_VISIBILITY_CHANGEINFOVisible / Hidden, Measurement ID (If created)User minimized / maximized the browser or switched to anothe tab / application

Event body

{
  "timestamp": 1689684577,
  "sessionId": "ryueiwoqfh910fu3rpqruvfiu",
  "sequence": 0,
  "event": "MEASUREMENT_CREATED",
  "severity": "INFO"
  "payload": {
    "measurementId": "f0c8ca8d-111d-4dcf-a69d-46ed39a2db06"
  },
}
FieldDescription
timestampThe time of the event
sessionIdThe session ID provided when constructing the call-in URL
sequenceThe sequence of the event, starts at 0 and incremented with each event
eventEvent code as shown on the list of events
payloadIf the event has a payload, it will be provided in the payload section. Example: Measurement ID, SNR etc.

Webhook Validation

A hash of the body contents using the hook's MAC secret (macSecret) is given in the X-WMS-Content-MAC header. The recipient can verify this value to make sure that the webhook call was initiated by WMS by doing the following computation (in JavaScript, for example):

// Note: Use the provided MAC secret here
const hmac = require('crypto').createHmac('sha256', macSecret);
hmac.update(requestBody.toString(), 'ascii');
const expectedContentHmac = 'hmac-sha256=' + hmac.digest('hex');

Note

The Webhook URL needs to be set up at your end and shared with the Nuralogix team in order to update it in your Config ID.

End-User Walkthrough of NuraLogix™ Web Measurement Service (WMS)

A user goes through the following steps to obtain measurements using the WMS.

1. User profile information at third party website

The user visits the third-party website with a single-page application. Let’s assume it is www.thirdparty.com.

WMS needs user profile information to carry out measurements. Third party website can provide this data as per their preference. They may ask the user to enter the information through a profile entry form, or they may already be having this data stored with them, or they may adopt any other method of obtaining this information.

An example of first option when user is asked to enter the profile information is shown in the image below.

profile-page

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2. User is redirected and asked for permission to access the camera

On submitting the profile information, the user is redirected to WMS hosted at nuralogix.ai via a third-party subdomain (using CNAME). The URL in the browser remains the same for the user as that of third-party website i.e. "thirdparty.com" in this example.

On next screen, the browser asks the user to allow access to use camera.

camera-permission-page

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3. User selects and starts the camera

The user is presented with a list available cameras on his device and can select any one of them.

The user then starts the selected camera.

camera-selection-page

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4. Measurement is ready to start

The user is presented with a view from his selected camera. To guide the user for a proper measurement, a white circle appears on the screen. The user is required to keep his face within that circle.

Face tracking begins and a certain number of points on the face are highlighted with histograms.

Stars at the bottom of the screen represent the quality of the current optical conditions. The higher the star rating, the more likely the measurement will complete successfully.

start-measurement-page

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5. Measurement progress

The measurement starts and the user is shown progress through a 30 second timer on the screen.

The histograms turn red when the quality of data captured is above a certain threshold.

A red heart with a number appears at the bottom of the screen. This number represents an intermediate heart rate.

measurement-progress-page

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6. Waiting for measurement results

The user is presented with a circular progress bar while waiting for the measurement to be processed.

The user is redirected back to the original third-party domain after DeepAffex has processed data and sent results

waiting-results-page

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7. Results for the user measurement are available

User is then redirected back to the third-party website once DeepAffex™ has completed processing the measurement results.

Partner web application is responsible for all admin/display/storage of end-user measurement results. They may use the results as per their choice of implementation.

An example of implementation when measurement results are presented to the user at third-party website is shown in the image below.

results-page

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Troubleshooting

WMS-specific issues

Please try the following troubleshooting steps if you are facing issues with WMS:

  • Check and fix camera permissions: If you see an empty list of cameras, it means that WMS was not granted the browser camera permission. Unfortunately, if camera permission is denied at the first prompt, then WMS cannot prompt again. To fix permission issues, you will have to click on the lock icon in the browser's URL bar and then grant the permissions from there. The procedure is browser-specific, so the steps might be slightly different for each browser.

  • Reduce processor load: System performance can also cause measurements to fail, so try to close any other tabs/apps/programs that might be consuming a lot of processing power.

  • Check conflicting camera usage: If you are having issues with starting the camera then please make sure that no other program or app is using the camera.

  • Disable screen recording: Make sure there is no screen recording or screen sharing in progress. We have observed that sometimes WMS does not work properly when you are sharing your screen.

  • Check the browser type: Officially supported browsers are listed in the introduction. Please make sure that you are using one of the officially supported browsers.

  • Clear browser cache: Sometimes, clearing browser cache may also solve the issues for you.

  • Check camera FPS: We recommend a camera that supports a stable 30 fps. If fps is too low (less than 10) then it will cause measurement cancellation.

Low SNR (Signal to Noise Ratio) can lead to measurement cancellations. WMS follows the rules given in this guide to cancel a measurement early based on SNR.

For more information about SNR related issues and how to solve them, please refer to this troubleshooting guide.

Platform requirements

Supported Browsers

Officially supported browsers are:

Operating SystemBrowserMinimum Version
WindowsGoogle ChromeLast 3 versions
WindowsMicrosoft EdgeLast 3 versions
macOSGoogle ChromeLast 3 versions
macOSApple Safari>=16
AndroidGoogle ChromeLast 3 versions
iOSApple Safari>=16
iOSGoogle ChromeLast 3 versions

Other browsers (except Firefox) that are not listed in the table may also work but are not officially supported by us.

Bug

There is a known issue with Google Chrome intermittently crashing on some Android devices. Our team is currently investigating the issue. A workaround is to use other browsers like Microsoft Edge for Android, Samsung Browser for Android or Vivaldi for Android.

Platform performance guidelines:

Various low-end Android devices struggle to work properly with WMS due to its processing requirements. As a reference point, you can check your device's CPU performance scores obtained through Geekbench 6. From your Android device, use this link to install Geekbench 6. We recommend devices with a Single Thread score of 550 or more and Multi Thread score of 1700 or more.

Image Resolution (on face):

  • Minimum pixel density of ~30 pixels/inch (~12 pixels/cm) applied to the face
  • In a mobile phone "selfie portrait" scenario, this converts to an image resolution of 480p (i.e. 640 x 480, 4:3 aspect)

Frame rate:

  • 25 fps minimum (stable 30 fps recommended)
  • Accurate frame timestamps (ms) are required

Internet connectivity requirements

The payload data chunks are not very heavy (mostly less than 500 KB). Any stable internet connection which can handle such payloads is expected to work fine.

WMS Frequently Asked Questions

What is a CNAME?

A Canonical Name (CNAME) record is a type of resource record in the Domain Name System (DNS) that maps one domain name (an alias) to another (the canonical name). By using CNAME, WMS can be seamlessly integrated into your web app. The user will stay on your web app's domain in the browser during the measurement.

Do you redirect the customers to your own website for measurements?

After submitting their profile information, the user is redirected to WMS hosted at https://awe.na-east.nuralogix.ai via a third-party subdomain (using CNAME) but the domain in the browser stays the same as your web app.

Which browsers does WMS support?

For a list of officially supported browsers, please refer to the Platform Requirements section page in the WMS docs.

Is WMS localized? Which languages does it support?

For a list of officially supported languages, please refer to the Supported Languages section.

Is it necessary to collect user profile information through a form if we already have that information stored with us?

No. The information just needs to be passed to WMS.

How does WMS handle multiple cameras on a device?

On desktop devices, the user is shown a list of available cameras to choose from. On mobile devices, the user can switch between front and rear cameras on the measurement screen.

Do you offer a sample application to help us get started?

Yes. Please contact us for access.

You can learn more in the sample application section.

Is the user profile information encrypted while being transferred to you?

Yes. WMS uses the RSA public-key cryptosystem and profile information is encrypted and passed from your web app to WMS using a specially crafted URL (the "call-in" URL). It can only be decrypted by a specially-configured "instance" WMS which uses a securely stored private key.

Can you support regional data storage requirements?

Please refer to the regions and clusters page.

What is a Config ID?

A WMS Config ID is a unique identifier that is linked to your app's specific configuration.

Please refer to the Config ID section of WMS documentation for more details.

Can I use WebView inside my app to integrate the Web Measurement Service?

It is possible to do so, but WebView is not a recommended way to use WMS and you are encouraged to check out other better ways offered by us to integrate our service into your Android and iOS apps.

How can I integrate WMS into my website or app?

Please check out the getting started section of WMS documentation.

How are the measurement results returned to our website or app?

Measurement results are sent back to you through a callback URL as a JSON. User is redirected back to the third-party website once DeepAffex™ has completed processing the measurement results.

Your web application is responsible for all admin/display/storage of end-user measurement results. You may use the results as per your choice of implementation.

How can I customize the look of the WMS according to my brand?

To customize the style of the measurement screen to match your brand identity, a stylesheet can be provided to control the colors and background images.

Please refer to the styling section of WMS documentation.

What is authentication procedure while using WMS?

Please refer to the measurement flow section of WMS documentation.

What is the camera auto-start feature?

If this feature is enabled, then a camera will start automatically during the measurement and users won't see the start camera button. You need to request a Config ID update to enable this feature.

What is the measurement auto-start feature?

If this feature is enabled, then the measurement will start automatically, and users won't see the start measurement button. You need to request a Config ID update to enable this feature.

Is it possible to change the default camera on mobile devices?

Yes, there is an option available through Config ID that allows rear camera to be selected as default camera on mobile devices. You need to request a Config ID update to enable this feature.

Do you have a troubleshooting guide for WMS?

Please refer to the Troubleshooting section of WMS documentation.

NuraLogix™ Web Measurement Service Guide Changelog

1.11.0 - 2024-02-13

  • Updated the supported browsers section on the platform requirements page

1.10.0 - 2023-11-07

  • Updated screenshots as per the new UI
  • Added a note about an intermittent crash on Google Chrome on some Android devices
  • Added new CSS classes on the styling page

1.9.0 - 2023-8-31

  • Added a Frequently Asked Questions section
  • Added a Webhook section
  • Updated the Geekbench scores as per Geekbench 6

1.8.0 - 2023-7-13

  • Added MEASUREMENT_TIMED_OUT and CAMERA_PERMISSION_NOT_GRANTED error codes in the error codes table
  • Added new CSS classes and screenshots on the styling page
  • Added token expiry config element

1.7.0 - 2023-5-29

  • Updated a link to Geekbench 5 on the platform requirements page
  • Added WORKER_ERROR in the errors table on the service details page
  • Updated Partner ID length on the service details page
  • Added a note about possible future changes on the service details page

1.6.0 - 2023-4-19

  • Added a new chapter about regions and clusters
  • Updated the Config ID section on the service details page

1.5.0 - 2023-02-14

  • Added supported languages on the service details page

1.4.0 - 2023-01-18

  • Updated troubleshooting section to include FPS and SNR criteria for cancellation
  • Added more information in the Config ID section
  • Added information that keys and values used in the measurement questionnaires are case sensitive
  • Added more information about the callback URL structure
  • Removed future measurement flow
  • Updated screenshot on the styling page.

1.3.0 - 2022-11-28

  • Update references to questionnaire page in core guide
  • Added a note about URI encoding
  • Added a disclaimer page
  • Made links relative

1.2.0 - 2022-10-31

  • Added platform requirements and moved supported browsers to this new chapter
  • Added information about token expiry and results retrieval
  • Added required length of partner ID
  • Added two new error codes- MEASUREMENT_CANCELED and TOKEN_EXPIRED
  • Updated the words user profile and demographics
  • Replaced the word 'end users'
  • Formatting improvements

1.1.0 - 2022-09-29

  • Added a troubleshooting guide
  • Added encryption algorithm in the getting started chapter
  • Updated Sample App details section to explain the endpoints used in the sample app
  • Updated URLs in some screenshots
  • Updated screenshots in walkthrough with new images

1.0.9 - 2022-08-22

  • Added a note regarding usage of keys in profile data JSON object
  • Removed user profile value ranges and added reference to the Anura guide
  • Updated some keys in the deprecated keys table
  • Updated a reference to an old deprecated URL

1.0.8 - 2022-07-29

  • Added information about deprecated keys
  • Added a changelog

1.0.7 - 2022-06-20

  • Updated guide with refresh token information
  • Updated sequence diagrams

1.0.6 - 2022-05-13

  • Updated officially supported browsers
  • Updated about page
  • Added an end user walkthrough for the WMS
  • Updated validation error codes

1.0.5 - 2022-04-25

  • Updated the NA-East urls and diagram files

1.0.4 - 2022-04-25

  • Updated public-private key related info and text of wms url link

1.0.3 - 2022-04-11

  • Updated about page

1.0.2 - 2022-04-11

  • Added downloadable sequence diagrams

1.0.1 - 2022-04-08

  • Replaced wms styling image with a better one
  • Changed scenario heading in intro doc
  • Visual improvements

1.0.0 - 2022-04-07

  • Finished about this guide chapter
  • Fixed some typos