Hi. This is DDFA Online.

An online tool for showcasing the possibilities of Dynamical Detrended Fluctuation Analysis for studying heart rate variability, developed by the Quantum Control and Dynamics group at Tampere University. The method is particularly well-suited for highly non-stationary conditions, such as during physical exercise, or detecting transient changes in the heart rate variability.

Try it Read more

Choose data to analyze

Explore some of our example data to get started. You may also upload your own data of RR intervals or synchronize from other services to collect data from wearable devices. Please review our privacy policy regarding your data.

Examples

Settings Analyze

Upload your data

Supported files

  • .CSV with column headers
  • .FIT from Suunto devices
PolarSuunto

From other services

Register as a user to be able to synchronize your data from other services.

Explore the results of the analysis

DDFA results

Explore the dynamic RRI correlations as functions of time and scale, together with overlaid time series data. Raw data is available below for custom analysis.

Aggregated DDFA results

The dynamic RRI correlations aggregated as a function of different variables, such as the heart rate.

Map view

DDFA results visualized on the travelled route.

Dynamical detrended fluctuation analysis

The beating of the human heart is not regular, but instead follows fractal-like patterns. In fact, complex variations in the heart rate are characteristic of a healthy heart, and deviations in this heart rate variability (HRV) are induced for example by cardiac diseases or physical exercise. HRV is studied by analyzing the time between successive heart beats, also known as RR intervals. The complex behavior of the RR intervals (RRIs) may be characterized by a method called detrended fluctuation analysis (DFA), which measures statistical self-affinity by scaling exponents.

Conventionally the scaling exponents are determined for short- (4-16 beats) and long scale (16-64 beats) correlations. However, the extents of these ranges are arbitrary and in practice often the correlations are not satisfactorily described by just two exponents. The RRI correlations may also change in time, particularly as the heart rate responds to different external conditions, such as physical exercise or sleep. Therefore, we introduce dynamical DFA (DDFA), which determines the scaling exponents as the function of both scale and time.

Read more from M. Molkkari et. al., Dynamical heart beat correlations during running, Scientific Reports 10, 13627 (2020).

The team

Matti Molkkari

Matti Molkkari

Matti is a researcher in the doctoral program of engineering and natural sciences at Tampere University. He has background in physics with expertise in computational methods, mathematical modelling and data analysis. Matti is the lead developer of the DDFA methods.

Janne Solanpää

Janne Solanpää

Janne is an experienced software engineer and data analyst with a PhD in computational physics. He has developed and published several numerical methods and software. Janne performed the initial integration of our methods with Amazon Web Services.

Interested in collaboration?

Send an email to


Questions, comments, feedback?

Send an email to

Privacy policy

What data do we collect?

The service may be used as either an unregisted user or as a registered user. Upon registration and creating your user account, we collect the following data:

Required information

Optional information

Additionally, all users may upload their own heart rate data for analysis.

How do we collect your data?

You directly provide us with the data we collect. We collect data and process data when you:

How will we use your data?

We collect your data so that we can:

How do we store your data?

We securely store your data encrypted at data warehouses within EU.

The data you upload for analysis is kept on our servers for one (1) day for unregistered users. For registered users this data is retained until the user explicitly deletes the data.

The analysis results are stored for one (1) day for unregistered users. For registered users the analysis results are stored for 30 days.

What are your data protection rights?

We would like to make sure you are fully aware of all of your data protection rights. Every user is entitled to the following:

If you make a request, we have one month to respond to you. If you would like to exercise any of these rights, please contact us at our email: helpdesk@ddfa-online.accuqt.com

Cookies

Cookies are text files placed on your computer to store data between visits to a website. For further information, visit allaboutcookies.org.

How do we use cookies?

We use cookies in the following ways to improve your experience on our website:

How to manage cookies

You can set your browser not to accept cookies, and the above website tells you how to remove cookies from your browser. However, using the website as a registered user will not function as a result.

Privacy policies of other websites

Our website contains links to other websites. Our privacy policy applies only to our website, so if you click on a link to another website, you should consult their privacy policy.

Changes to our privacy policy

We keep our privacy policy under regular review and place any updates on this web page. This privacy policy was last updated on September 14th 2020.

How to contact us

If you have any questions about our privacy policy, the data we hold on you, or you would like to exercise one of your data protection rights, please do not hesitate to contact us.

Email us at: helpdesk@ddfa-online.accuqt.com.

How to contact the appropriate authority

Should you wish to report a complaint or if you feel that we have not addressed your concern in a satisfactory manner, you may contact the Information Commissioner’s Office.

Email: tietosuoja@om.fi

Phone: +358 (0)29 566 6777

Address: Lintulahdenkuja 4, 00530 Helsinki, Finland

Close