Communication headset with a stress management function

1. A system for determining heart rate data of a user, the system comprising a headset for voice communication, the headset being configured to be worn at least partly at or in the ear of a user,

the headset comprising:

a voice communication unit for enabling a voice communication call mode for establishing a call between the headset and a far-end device;

a speaker for reproduction of audio signals;

a microphone for reception of audio signals;

a photoplethysmograph (PPG) sensor for optically measuring through the skin of the user in or at the ear of the user;

wherein the headset comprises a processing unit connected to the PPG sensor, where the processing unit is configured for determining heart rate data of the user based on the PPG sensor measurements;

wherein the processing unit is configured for detecting whether the user is on-call with a far-end device or off-call; and

wherein the headset comprises a data communication unit for providing the determined heart rate data of the user, when the user is wearing the headset, for indication of the heart rate data of the user;

wherein the processing unit is configured for determining the heart rate (HR) and determining beat-to-beat (RRi) intervals based on the PPG sensor measurements, and

wherein the processing unit is configured for determining a heart rate varia bility (HRV) during a time interval based on the beat-to-beat (RRi) intervals;

wherein the processing unit is configured for determining low frequency (LF) components and high frequency (HF) components based on the heart rate variability (HRV), where the low frequency (LF) components and the high frequency (HF) components are components in a beat-to beat (RRi) periodogram, where the beat-to beat (RRi) periodogra nn is based on the determined beat-to beat (RRi) intervals;

wherein the processing unit is configured for determining a baseline measurement of the low frequency (LF) components and the high frequency (HF) components during a first time interval Ti, when the user is off-call, and wherein the processing unit is configured for measuring a first ratio (LF/H F-off call) between the low frequency (LF) components and the high frequency (HF) components during the first time interval Ti;

wherein the processing unit is configured for measuring a second ratio (LF/H F-on call) between the low frequency (LF) components and the high frequency (HF) components during a second time interval T 2 , when the user is on-call; and wherein the processing unit is configured to detect stress by evaluating the second ratio (LF/H F on-call) relative to the first ratio (LF/H F-off call).

2. The system according to claim 1 , wherein the headset comprises a notification unit for providing a notification, if the processing unit detects a heart rate increase of the user.

3. The system according to claim 2 , further comprising a motion sensor configured for detecting head movements of the user for filtering out motion-induced artefacts in the PPG sensor measurements.

4. The system according to claim 3 , further configured such that the PPG sensor is arranged at the preauricular skin pit area of the user for obtaining the PPG signal from the superficial temporary artery, when the user is wearing the headset.

5. The system according to claim 4 , further configured such that the PPG sensor is arranged at less than 5 mm over the skin surface, such as less than 4 mm, or such as less than 3 mm, or such as less than 2 mm, or such as less than 1 mm over the skin surface, when the user is wearing the headset.

6. The system according to claim 5 , further comprising an earphone housing, and wherein an ear cushion is mounted on the earphone housing, and wherein the PPG sensor is mounted in the earphone housing or in the ear cushion.

7. The system according to claim 6 , wherein the earphone housing comprises a protrusion where the PPG sensor is configured to be arranged, such that the protrusion is configured to rest/be situated at the preauricular skin pit area of the user, when the user is wearing the headset.

8. The system according to claim 6 , further comprising a fixation part for fixing the position of the earphone housing, when the user is wearing the headset, such that the PPG sensor is arranged at the preauricular skin pit area of the user.