ECG delineation analyzer - additional module
This article details how to use the solution software module to perform the ECG delineation.
1. What is the ECG delineation module?
The system provides 3 biosignals: the initial cardiac parameters provided in the software by the ECG analyzer module were based on the detection of the R-peak. Today it is possible to analyze the parameters related to the other peaks P, Q, S and T (events, average pattern, intervals...) of the ECG signal thanks to the ECG delineation analyzer module, called ADVANCED ECG MODULE in the software.
For this, the software will perform an average pattern from the ECG cycles of the raw signal as a mean to filter the noise of the signal and abnormal detections : this average pattern is created by overlapping several signal complexes (60 cycles by default). It results in a smoothed, distinct pattern, on which the events P, Q, S, T peaks are placed and the intervals are calculated.
2. How to perform it in the software ?
A. Module activation
If the delineation module is present on your system, the module is displayed and available in the DETECT CONFIG pop-up window, after clicking on the DETECT button to launch algorithm detection.
By default, the module activation button will be check for Advanced ECG module :
it is also at this moment that you can configure your detection, for example, you can reduce the number of cycles used for the average pattern (Averaging : Beats = 60 cycles ) or choose to make your pattern on a duration (Averaging : Time = 10 sec).
For more details and access to the list of detection parameters for the ECG advanced module. Please, click here.
All the following parameters can be edited in the DETECT CONFIG window :
| Parameter | Default value (e.g: rats) | Description | Unit |
|---|---|---|---|
| Averaging | beat | The averaging mode (beat = number of cycles, time = fixed duration bout). | |
| Beats to average | 60 | The number of cardiac cycles used for calculating the averaged pattern. | |
| Time to average | 10 | The duration of the interval window to generate the averaged pattern. | s |
| Max time to average | 200 | The maximum distance between first and last cycle used to generate the averaged pattern. | s |
| Min beats allowed to average | 10 | The minimum number of heartbeats required to generate the averaged pattern. | |
| Maximum RRi variation | True | Enable to exclude abnormal RR intervals based on percentage variation beat-to-beat, used before coherent averaging. | |
| Percentage criteria | 0.15 | Specify the percentage threshold for identifying abnormal RR interval differences compared to the previous interval. | |
| Apply Cycles Selection | True | Enable the selection of cycles based on correlation to identify and exclude inconsistent or abnormal cycles before coherent averaging. | |
| Correlation Threshold | 0.5 | Correlation threshold. | |
| Min Percentage of Valid Cycles | 0.5 | Minimum percentage of valid cycles (after cycles selection) used for generating the averaged pattern. | |
| Maximum PR duration | 220 | Determines the start of the cycle based on the R peak position. This parameter is also used for physiological screening when ‘’Apply PR Screening’’ is activated. | ms |
| Gaussian P_on | 0.99 | Gaussian percentage to position the beginning of the P wave. | |
| Gaussian P_end | 0.99 | Gaussian percentage to position the end of the P wave. | |
| Maximum QRS duration | 120 | Used to determine the size of the cycle in conjunction with ‘’Maximum PR Duration’‘. This parameter is also utilized for physiological screening when’‘Apply QRS Screening’’ is activated. | ms |
| S/R ratio | 0.05 | Maximum ratio between the amplitude of peak S and peak R. | |
| T wave morphology | AUTOMATIC | Select the T wave morphology correction: AUTOMATIC, FORWARD, or INVERTED. Select AUTOMATIC for automatic detection. | |
| Gaussian T_on | 0.98 | Gaussian percentage to position the beginning of the T wave. | |
| Gaussian T_end | 0.98 | Gaussian percentage to position the end of the T wave. | |
| Q-Tic method | Hodge | Select the QT correction methods between formulares (Hodge, …) and Individual Holzgreffe’’s correction. | |
| Apply PR Screening | False | Enable or disable screening based on physiological PR interval ranges. Set the minimum PR interval duration here. Use the ‘’Maximum PR duration’’ parameter to define the upper limit of the PR interval. | |
| PR min | 30 | Minimum PR interval duration. | ms |
| Apply QRSi Screening | False | Enable or disable screening based on physiological QRS interval ranges. Set the minimum QRS interval duration here. Use the ‘’Maximum QRS duration’’ parameter to define the upper limit of the QRS interval. | |
| QRS min | 10 | Minimum QRS complex duration. | ms |
| Apply QT Screening | False | Enable or disable screening based on physiological QT interval ranges. | |
| QT min | 50 | Minimum QT interval duration before correction. | ms |
| QT max | 390 | Maximum QT interval duration before correction. | ms |
The parameters and default values shown above may vary according to software version (here 2.16) and species (here: rat).
Wait a few minutes.... Software processes data :
Once the detection is done you have access to the MERGE withs different delineation module views ( 
) and the intervals expressed in ms when exporting ( 
) your data.
The additional views available with the ECG delineation module are described in the following sections.
B. ECG delineation analyzer moduel views
- PQRST Delineation of ECG pattern
This view allows to observe the average pattern from the 60 cycles and visualize the identification of key events (P wave, QRS complex and T wave) by detection algorithms. .
- RR and QT correlation
This view allows to observe correlations between the RR interval and the corrected or uncorrected QT interval.
- Calculated conduction intervals of ECG pattern
This view shows the evolution of heart rate and interval values over time.
If you want to display the average pattern and its associated interval values (i.e. a pattern-by-pattern value), you must uncheck the box "Displayed mean parameters" to avoid displaying parameters averaged over 10 seconds (default setting to simplify display of large amounts of data).
- Patterns Waterfall for 3D viewing
This view aligns the patterns (based on the R peaks), to offer a 3D rendering of the evolution of the signal.
3. What are the physiological variables obtained with this module and how are they obtained?
In the Excel export file, the physiological variables of this supplementary module can be found at the end of the column in the sheet, as illustrated below:
Details of how to obtain an excel spreadsheet of data from different acquisition sessions are given here.
For more details and access to the list of List of cardiac delineation parameters provided by the LASA software ECG advanced module. Please, click here.
| Acronym | Type | Description | Unit |
|---|---|---|---|
| P-duration | Parameter | P wave duration. Measured as the time interval between P-on and P-end. | ms |
| QRSi | Parameter | QRS complex duration. Measured as the time interval between QRS-on and QRS-end. | ms |
| T-duration | Parameter | T wave duration. Measured as the time interval between T-on and T-end. | ms |
| P-amplitude | Parameter | P wave amplitude. Measured as the amplitude difference between P-peak and P-end. | mV |
| Q-amplitude | Parameter | Q wave amplitude. Measured as the amplitude difference between Q-peak and baseline. | mV |
| R-amplitude | Parameter | R wave amplitude. Measured as the amplitude difference between R-peak and baseline. | mV |
| S-amplitude | Parameter | S wave amplitude. Measured as the amplitude difference between S-peak and baseline. | mV |
| QRS-amplitude | Parameter | QRS complex amplitude. Measured as the amplitude difference between R-peak and S-peak. | mV |
| T-amplitude | Parameter | T wave amplitude. Measured as the amplitude difference between T-peak and T-end. | mV |
| P-area | Parameter | P wave area. Measured as the integral of the P-wave between P-on and P-end. | µV.s |
| QRS-area | Parameter | QRS complex area. Measured as the integral of the QRS complex between QRS-on and QRS-end. | µV.s |
| T-area | Parameter | T wave area. Measured as the integral of the T-wave between T-on and T-end. | µV.s |
| P-Rs | Parameter | P-R segment. Measured as the mean amplitude between P-end and QRS-on. | mV |
| S-Ts | Parameter | S-T segment. Measured as the mean amplitude between QRS-end and T-on. | mV |
| P-Ri | Parameter | P-R interval. Measured as the time between the onset of the P-wave (P-on) to the onset of the QRS complex (QRS-on). | ms |
| Tp-e | Parameter | T peak-end interval. Measured as the time measured from the peak of the T wave (T-peak) to the end of the T wave (T-end). | ms |
| S-Ti | Parameter | S-T interval. Measured as the time interval between QRS-end and T-on. | ms |
| Q-Ti | Parameter | Q-T interval. Measured as the time between the onset of the QRS complex (QRS-on) to the end of the T-wave (T-end). | ms |
| Q-Tic | Parameter | Corrected Q-T interval (available with a choice of 7 correction formulas) | ms |
| J-Ti | Parameter | J-T interval. Measured as the time measured between QRS-end and T-end. | ms |
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