INTRODUCING A NOVEL INDEX FOR MEASURING DEPTH OF ANESTHESIA BASED ON VISUAL EVOKED POTENTIAL (VEP) FEATURES

Abstract– Although several studies have been conducted toward quantitative measuring depth of
anesthesia (DOA), the state of art DOA indexes sometimes fail in practice. Hence, specialists are
looking to find a new source of information, rather than modifying the former indexes, to
introduce an accurate DOA index. In this regard, here, a new horizon to this field has been
unveiled by photic stimulating the anesthetized patients’ eyelashes during surgical operations. In
this way, this paper presents a new recording protocol to produce the depth-related visual evoke
potential (VEP). Another contribution of this paper is to introduce an efficient method to elicit the
VEPs within short trials (10 seconds). The suggested VEP extraction method can explain and
detect the deterioration of VEP waveform through the successive trials. Finally, a novel DOA
measure based on features of the clean VEPs is presented. Specificity and sensitivity of the
proposed DOA is assessed by measuring its statistical similarity to the gold-standard BIS index
over six patients. The presented VEP-based DOA index can be considered as an alternative of BIS
index in the light and moderate anesthetic depth.