9 Analyzing Pain and Stress from PPG Perfusion Signal Patterns
159
Of course, most patients are awake or going to be awake in the recovery room.
Therefore, the HRV is influenced by stress due to the new environment or the fear of
an unknown diagnosis. The poor correlation in the recovery room between VAS and
ANI can be explained by comparing the spectral analysis of the HRV in the recovery
room and operating room.
The marked area is the RSA with respect to the breathing frequency, which is
very irregular (Fig. 9.7), compared to the one measured during surgical interventions
(Fig. 9.8), which is constant.
It is obvious that ANI computation in postoperative care is much more difficult.
One reason is the irregular breathing, which influences RSA analysis.
Fig. 9.7 Short-time Fourier
analysis of the RSA in the
recovery room
Fig. 9.8 Short-time Fourier
analysis of the RSA during
surgical interventions
159
Of course, most patients are awake or going to be awake in the recovery room.
Therefore, the HRV is influenced by stress due to the new environment or the fear of
an unknown diagnosis. The poor correlation in the recovery room between VAS and
ANI can be explained by comparing the spectral analysis of the HRV in the recovery
room and operating room.
The marked area is the RSA with respect to the breathing frequency, which is
very irregular (Fig. 9.7), compared to the one measured during surgical interventions
(Fig. 9.8), which is constant.
It is obvious that ANI computation in postoperative care is much more difficult.
One reason is the irregular breathing, which influences RSA analysis.
Fig. 9.7 Short-time Fourier
analysis of the RSA in the
recovery room
Fig. 9.8 Short-time Fourier
analysis of the RSA during
surgical interventions