“…Most of these algorithms were supervised classification or regression techniques to address issues related to pain. The selected studies used mostly classical ML algorithms, such as SVM [ 9 , 12 , 15 , 21 , 22 , 25 – 27 ], and random forest (RF) [ 14 , 15 , 28 , 29 , 31 , 32 ] followed by Bayes [ 17 , 19 , 20 , 22 ] techniques to classify tasks by assigning a predefined class label to an observation.…”