Knowledge Base

Visualize Vital Signs

Aim

To display the heart rate, heart rate variability and breathing rate during or after the analysis.

Prerequisites

• Your FaceReader license includes the Vital Signs Module.
• Vital signs analysis is switched on in the Settings.

  See Analyze vital signs.

• You are running an analysis, or viewing the analysis afterwards.

Vital Signs

The Vital Signs window shows the current heart rate of the participant estimated by means of remote photoplethysmography. Heart rate is expressed in beats per minute (bpm). The Vital Signs window also shows the heart rate variability (RMSSD and SDNN) and breathing rate. The window shows confidence indicator bars indicating how confident the current measurements are.

See Introduction to the Vital Signs Module

To View The Vital Signs Window

Click the Select window button in one of the analysis windows and select Vital Signs and again Vital Signs.

If your settings deviate from the recommended settings, a warning will show up in the Vital Signs Heart Rate window, informing you that the ratio between the frame rate, bit rate and resolution is too low to estimate the vital signs heart rate with high accuracy. See Camera settings for the recommended settings.

Vital Signs Line Chart

The Vital Signs Line Chart shows the heart rate, heart rate variability estimated with Remote photoplethysmography, and the respiratory rate plotted against time.

To View The Vital Signs Line Chart

Click the Select window button in one of the visualization windows and select Vital Signs > Vital Signs Line Chart.

Vital Signs Line Chart

From the Vital Signs drop-down list, select what you want to view, Heart Rate, Heart Rate Variability (RMSSD), Heart Rate Variability (SDNN) and/or Breathing Rate. Please note that in the chart above heart rate variability was not selected. When you play back a video, a hairline shows the time in the video.

At the end of analysis, the estimated heart rate, heart rate variability, and breathing rate are post-processed to improve the accuracy, also in the initial 8.5/15 seconds and every time a new calibration was carried out. Note that the reported heart rate and breathing rate values after analysis can differ from those seen during analysis. Do not rely on the exact values you see during analysis. The heart rate, heart rate variability, and breathing rate lines in the 'Vital Signs Line Chart' have a different color before and after post-processing.

Notes

• Click Options and then select Auto Scale Y Axis to adjust the Y axis to the maximum value.

Source: FaceReader 10 Reference Manual (Help), Noldus Information Technology