RELEASE NOTES

Kubios HRV Premium / Standard

Version 3.4.2 (released 15.10.2020)

  • A selection between RR distribution and HR distribution added to the time-domain results tab in the user interface. The selection applies also to the report figures.
  • HR acceleration capacity (AC) and the corresponding modified index (ACmod) added to CSV and SPSS friendly batch file exports (Note: New batch file needs to be initialized due to added columns, you can merge your old batch file manually if necessary).
  • In CSV export, “STD RR” and “STD HR” variables are renamed as “SDNN” and “SD HR”, respectively.
  • Fixed syntax errors which caused Lomb periodogram computation to fail (negative values for spectrum) and polynomic trend estimation to crash.
  • Fixed UI issues with display scaling higher than 100%.
  • Minor bug fixes.

Version 3.4.1 (released 26.6.2020)

  • Fixed a bug, which crashed Kubios HRV 3.4.0 during file open if the “Update analysis results” mode was set to “Manual” in software preferences.
  • In macOS version, “Command” key is now used instead of the “Control” key when adding analysis samples or noise markings to data (Command + left mouse button) and when zooming the data axis (Command + mouse scroll wheel).
  • User home directory is now the default destination for all file save and open actions.
  • Minor bug fixes.

Version 3.4.0 (released 11.6.2020)

Compared to previous release, the following features, changes and bug fixes have been implemented (*indicates features available only in the Premium version):

  • *ECG R-peak (and PPG pulse wave detection) editing tools updated. With the updated editing tools, adding, moving or removing R-peak (pulse wave) detection markers is much easier and faster than before. The button actions (from top to bottom, see figure below) are as follows:
    • Turn on/off the R-peak (pulse wave) detections editing mode. When editing beat detections, HRV analysis results are not updated (auto-refresh results turned off) to guarantee smooth editing. Analysis results are updated when exiting the beat editing mode.
    • Add new R-peak (pulse wave) markers to selected positions at the data axes (R-peak editing mode must be turned on).
    • Adjust R-peak snapping window width when adding a new detection (add new R-peak tool need to be selected)
    • Move any existing  R-peak (pulse wave) marker to selected positions at the data axes (R-peak editing mode must be turned on).
    • Remove R-peak (pulse wave) markers from selected positions at the data axes (R-peak editing mode must be turned on).
Beat detection correction tools
  • *Support for noise segments added to Kubios HRV Premium. Using noise segments, you can easily mark parts of your data (e.g. time periods when the measurement device has been disconnected or the data is very noisy due to movements artefacts) as noise. Data segments marked as noise are not used for HRV analysis, thus noisy data is not anymore distorting your analysis results or time-varying analysis graphs. Noise segments can be added with mouse (CTRL + left mouse button) both from the ECG/PPG data axes and the RR/IBI data axes.
Noise segments support
  • *Automatic beat correction algorithm improved regarding the first and last RR intervals. A reference for automatic beat correction algorithm now available here.
  • Custom text file import improved. Interactive visualization of the data (to be imported) was added to the import dialog, making it easier to apply the correct import settings. Support for “Beat Times” formatted text files added, i.e. text files including only beat detection times are now supported. The text file import dialog now also supports manual insertion of measurement date and time as well as subject name/ID, age, gender, height, weight, resting HR and max HR. Unrecognised text files are by default opened using this dialog.
  • *MIT file format support added to Kubios HRV Premium. MIT format is used in storing ECG data files in the Physionet database.
  • *HR deceleration capacity (DC) and acceleration capacity (AC) parameters added to Kubios HRV Premium. These parameters were originally proposed in Bauer et al. 2006 (Lancet, 367:1674-81) and refined in Nasario-Junior et al. 2014 (J Electrocardiol, 47:306-10). In Kubios HRV, DC (AC) are calculated by choosing the steepest anchor interval from each ascent (descent) phase, i.e. only one anchor interval is chosen from each cardiac deceleration (acceleration) phase. Illustration and formula of DC (AC) computations are shown below.
Heart rate deceleration capacity (DC) and acceleration capacity (AC)
  • *TRIMP and energy expenditure (EE) computations improved. TRIMP and EE are now computed in a shorter window (by default 10-sec, can be adjusted in software preferences) to provide more instantaneous estimates. TRIMP computation is now also based on individual resting HR value, making the training intensity and load estimates more accurate. TRIMP visualization also improved.
Training impulse computation
  • *Time-varying analysis window placement logic changed, the first analysis window is now placed starting from the beginning of data (previously, window center was placed at the beginning of data).
  • Added reporting of total number of beats, number of beats corrected, beats corrected percent, and effective data length in seconds and in percent for every analysis sample and for time-varying analysis. Beats corrected reveals how many beats have been corrected by the selected beat correction method within the analysis window (previously this was reported as “Artefacts”). Effective data length describes the length of analyzed data within the analysis window, which may be reduced because of data segments marked as noise or abnormally long RR intervals that have been corrected by the beat correction method. In case of time-varying analysis, results are not computed if the effective data length is lower than a specified threshold (default 50%, can be changed from software preferences).
  • Adjustment of minimum analysis sample length added to preferences. Minimum analysis sample length can now be varied between 10, 30 and 60 seconds. When using very short analysis samples, please understand that this can significantly reduce the accuracy of certain HRV parameters.
  • Welch’s periodogram computation was modified to always include all data values in spectral estimation. Depending on the specified window width and overlap, data values outside the last overlapping window were previously ignored. Now, the overlap is automatically adjusted so that all data values are always included in Welch’s periodogram computation.
  • Computation of Min and Max HR (by default at 5-sec moving window) were fixed. Previously, zero-phase (forward-backward) filtering was used, which resulted in slight over-smoothing of RR data. Computation of HR zones is also affected by this change.
  • *“SPSS friendly” batch file export bug, where column labels were not updated according to the number of analysis samples in the analysed file, is now fixed.
  • The extension of text file for HRV analysis results export changed from *.TXT to *.CSV (format of the text file now changed, but now easier to open in Excel).
  • Several minor bug fixes as well as improvements in user interface layout and software performance.
  • New default color theme introduced.

Version 3.3.1 (released 23.8.2019)

The following changes and bug fixes have been implemented (*indicates features available only in the Premium version):

  • Minor updates to FIT file support, including corrected conversion of FIT Laps to Kubios HRV event markers (Kubios HRV markers are now triggered by lap end times, instead of lap start times).
  • Fixed a bug in EDF file support, which caused Kubios HRV not to be able to open EDF files that include empty channel label(s). Channels with an empty label (if any) are now named as “No_label_xx”.*
  • Corrected scaling of cumulative EE and TRIMP values for different analysis window lengths.*
  • Fixed a bug, which caused repetition of last analysis sample’s MSE values on text file export.*
  • Corrected a bug, which caused Kubios HRV to crash when using custom threshold in artifact correction.

Version 3.3.0 (released 7.6.2019)

Compared to previous release, the following features, changes and bug fixes have been implemented (*indicates features available only in the Premium version):

  • Instantaneous energy expenditure (EE, kcal/min) estimate based on beat-to-beat HR is now included in Kubios HRV Premium. This activity related EE is computed using Keytel’s equation, and both instantaneous and cumulative EE are included in time-varying HRV results. Diet induced thermogenesis (DIT) is not anymore separated from activity related EE, because this cannot be reliable reflected to instantaneous EE without details of dietary schedule.*
  • Banister’s Training Impulse (TRIMP) computation was added to Kubios HRV Premium. TRIMP is computed according to the exponential model proposed by Morton et al. 1995 (see details). TRIMP accumulation rate increases exponentially as a function of exercise intensity, modelling lactate accumulation during exercise. In Kubios HRV, we compute the TRIMP using beat-to-beat HR values, and thus, instantaneous value of TRIMP (TRIMP/min) can be reliably derived and used to assess training intensity. A single number describing the training load is obtained by summing the TRIMP/min over the entire training session duration. The TRIMP/min and cumulative TRIMP values computed in Kubios HRV are linked to training intensity and training load as shown below.
Training impulse (TRIMP) for heart rate (HR) data
  • Visualisation of instantaneous (time-varying) HRV parameters was modified on the time-varying analysis tab on user interface and also on the time-varying report sheet. Instantaneous activity level information (based on HR zones) was added to time-varying report page.*
  • Polar Flow authorisation and FIT file export updated. Fixed a bug that prevented exporting training data from Polar Flow if the user had manually deleted an exercise from Polar Flow.*
  • Support for Bittium Faros (a lightweight ECG device) event markers was added. The event marker data available in the EDF-files recorded with a Bittium Faros ECG sensor is now correctly imported into Kubios HRV Premium, enabling the user to use the marker data while performing HRV analyses.*
  • Added missing EDF+C file format to supported file type in Kubios HRV Premium.*
  • Added support for string event markers. Laps in FIT format files are now converted to event markers and are visualised in user interface. The Lap markers in FIT files are grouped to manual laps and time, distance, etc. based laps.
  • Event marker visualisation in user interface was modified. Event markers are now shown as down pointing triangles on top of ECG and RR axes, and marker positions are show in RR and ECG axes as dotted lines (which can be toggled on/off). A mouse-over feature for markers was added for displaying the marker annotation.
  • Added snapping to event markers when moving or resizing analysis samples. This feature will enable easy positioning of analysis samples according to event markers (e.g. start/end the analysis sample at certain event marker times).
  • Added “All Supported Files” in the file filter (this is also used as the default value for the file filter). This reduces the need to change the file filter in file open dialog and makes opening of data files more straightforward.
  • Added a “Launcher” window providing easy access to HRV data, Tools (Polar Flow Export*), and Kubios HRV support material.
  • Improved support for multiple monitors.
  • Several minor improvements in user interface layout and software performance.

Version 3.2.0 (released 21.1.2019)

Compared to previous release, the following features, changes and bug fixes have been implemented (*indicates features available only in the Premium version):

  • Export training data from your Polar Flow account directly from Kubios HRV Premium in FIT format. Note that the files include beat-to-beat data (RR or IBI data) required for HRV analysis only when a Polar Flow compatible device with H6, H7 or H10 heart rate sensor is used for the measurement.*
Export RR data from Polar Flow
  • Automatic sample generation based on sample specifications given at predefined CSV file (“Kubios_Samples.csv”). This file must be found from the same folder as the data files to be analysed. In the CSV file, 1) sample label and color, 2) sample start time, and 3) sample end time can be defined for as many samples as needed. The sample definitions can be made file-by-file or to apply all files found in the specific folder.
  • Analysis samples can now be also manually named (Sample Label field) and color-coded (Sample Color field). Sample labels and colors are visible in the user interface and on the reports.
  • PNS and SNS index computations modified and graphs improved in the software GUI and Report page. In the computation of these indexes, LF and HF powers in normalised units were replaced with normalised standard deviations of the Poincare plot, i.e. with SD2 (%) and SD1 (%), because these nonlinear parameters provide a more robust estimate of sympathovagal balance especially in cases of slow breathing. For details see www.kubios.com/about-hrv.
  • Energy expenditure computation was corrected and modified, now including also an estimate of the Diet Induced Thermogenesis (DIT), which is the energy expenditure related to digestion of food and is estimated to be 10% of total energy expenditure within 24 hours. In addition, in ver. 3.1 the BMR was erroneously added to the total energy expenditure, which caused the energy expenditure estimates to be unrealistically high. This has been now corrected and the total energy expenditure is now divided into three components: 1) Basal metabolic rate – BMR (Mifflin St Jeor equation), 2) Diet Induced Thermogenesis – DIT (10% of energy expenditure), and 3) Activity related energy expenditure (Keytel equation).
  • Artefact correction user interface implementation improved. The applied correction method (default: “Automatic correction” in Premium and “none” in Standard ) and acceptance threshold for artefact percent (default: 5%) can be now defined in preferences. In user interface, artefact percent is displayed for the whole measurement as well as for the analysis samples separately. Analysis samples with low data quality (Artefact percent > defined threshold) are indicated in user interface and in reports.
  • New mouse shortcuts added to RR and ECG data views for improved usability. The new mouse shortcuts are
    • Pan (scroll, SHIFT + scroll) and zoom (CTRL + scroll) data using mouse scroll wheel.
    • Add a new analysis sample (right mouse button + drag) and delete sample (CTRL + right mouse button).
    • Center ECG data view to current cursor position in RR data view (CTRL + left mouse click).
    • Pan both RR and ECG data views by dragging with middle mouse button.
  • Personal details (Name, Gender, Age, Max HR, Height, Weight and BMI) are now included on report figures and report figure layout overall modified. For example time ticks readability was improved and ranges of HR, Stress and RMSSD zones were added.
  • Several minor improvements in user interface layout and software performance.