Table 3.

Performance of video-based pain classifiers with different numbers of hidden layers in bidirectional long short-term memory (BiLSTM) networks.

	Hidden layers	Pain score 0 vs. 1 vs. 2	Pain score 0 vs. 1/2	Pain score 0 vs. 2
Accuracy	64	0.6144	0.8145	0.8810
Sensitivity		0.6144	0.7947	0.8755
F1-score		0.6123	0.8107	0.8803
Accuracy	128	0.5941	0.8054	0.8461
Sensitivity		0.5942	0.7858	0.7589
F1-score		0.5902	0.8015	0.8314
Accuracy	256	0.6006	0.8268	0.8367
Sensitivity		0.6006	0.8244	0.7500
F1-score		0.5948	0.8264	0.8212

BiLSTM, bidirectional long short-term memory.