The applicability and performance of spectral entropy as a measure of the depth of sedation was studied by comparison to the Richmond sedation and agitation scale (RASS). A biopotential signal was meas-ured from the forehead of eight ICU patients. From this biopotential four different frequency bands were defined using trend fitting to the low and high frequency limits of the pooled power spectra, two fre-quency bands representing EEG and the other two representing fEMG. The spectral entropy from the EEG bands correlated very well with the sedation levels of RASS. From levels 0 to –5 the decrease was almost linear (r=0.51 and r=0.53). A similar comparison for the spectral entropy of the fEMG bands did not produce any clear correlation (r=0.07 for both fEMG bands), however there was still some clear in-teraction at some levels. It seems that the RASS is dependent upon both EEG and fEMG effects. That is; RASS is related to both cortical and sub-cortical components of sedation.
|Title of host publication||The 26th Annual International Conference of the IEEE Engineering in Medicine and Biology Society|
|Publisher||IEEE Institute of Electrical and Electronic Engineers|
|Publication status||Published - 2004|
|MoE publication type||A4 Article in a conference publication|