Table 16.

Multi-class classification of CF from all datasets for CO (Class 0), PD Stage 2 (Class 2), PD Stage 2.5 (Class 2.5), and PD Stage 3 (Class 3) using several CNN classifiers (AlexNet, ResNet-50, ResNet-101, and GoogLeNet) with 10-fold cross-validation.

Time Window	Frequency Range	Disease Severity (Class)	AlexNet				ResNet-50				ResNet-101				GoogLeNet
			Sen (%)	Spec (%)	Acc (%)	AUC	Sen (%)	Spec (%)	Acc (%)	AUC	Sen (%)	Spec (%)	Acc (%)	AUC	Sen (%)	Spec (%)	Acc (%)	AUC
10 s	0.83–1.95 Hz	Class 0	88.43	95.81	93.54	0.9212	91.65 *	96.21 *	94.81 *	0.9393 *	89.34	97.41	94.93	0.9337	88.73	95.27	93.26	0.9200
		Class 2	78.81	90.46	86.21	0.8464	87.37 *	91.19 *	89.80 *	0.8928 *	88.81	89.29	89.12	0.8905	78.39	89.59	85.50	0.8399
		Class 2.5	85.97	91.19	89.92	0.8858	85.20 *	95.55 *	93.04 *	0.9038 *	83.67	94.53	91.90	0.8910	81.38	91.15	88.78	0.8626
		Class 3	78.34	99.02	97.25	0.8868	83.75	99.39	98.05	0.9157	78.34	99.53	97.71	0.8893	75.45	98.51	96.54	0.8698
	1.95–50 Hz	Class 0	87.83	95.31	93.01	0.9157	88.73	96.56	94.16	0.9265	90.44	96.39	94.56	0.9341	90.44	95.72	94.10	0.9308
		Class 2	83.98	85.26	84.79	0.8462	82.29	87.35	85.50	0.8482	80.34	88.47	85.50	0.8440	73.73	88.61	83.18	0.8117
		Class 2.5	71.56	95.68	89.83	0.8362	78.06	93.15	89.49	0.8560	79.08	91.84	88.75	0.8546	76.28	90.09	86.74	0.8318
		Class 3	92.06 *	98.61 *	98.05 *	0.9534 *	87	99.19	98.15	0.9310	82.31	99.26	97.81	0.9078	89.53	98.41	97.65	0.9397
15 s	0.83–1.95 Hz	Class 0	88.15	95.34	93.13	0.9174	91.03	95.61	94.20	0.9332	86.17	97.16	93.78	0.9167	86.32	94.46	91.96	0.9039
		Class 2	82.59	87.92	85.97	0.8525	82.71	91.68	88.41	0.8720	85.92	88.51	87.56	0.8732	78.87	86.60	83.78	0.8274
		Class 2.5	81.59	93.35	90.51	0.8747	85.66	93.96	91.96	0.8981	83.14	93.96	91.35	0.8855	76.16	92.24	88.36	0.8420
		Class 3	77.72	99.54	97.66	0.8863	84.78	98.98	97.76	0.9188	83.70	98.87	97.57	0.9129	76.63	98.41	96.54	0.8752
	1.95–50 Hz	Class 0	89.36	93.79	92.43	0.9157	85.11	95.75	92.47	0.9043	86.47	96.49	93.41	0.9148	86.93	94.06	91.87	0.9049
		Class 2	78.75	83.43	81.72	0.8109	78.75	86.60	83.73	0.8267	78.75	86.38	83.59	0.8256	70.04	87.04	80.83	0.7854
		Class 2.5	64.15	94.15	86.91	0.7915	78.68	92.05	88.83	0.8537	78.88	90.20	87.47	0.8454	77.52	88.91	86.16	0.8321
		Class 3	89.13	98.52	97.71	0.9382	85.87	98.67	97.57	0.9227	76.63	99.44	97.48	0.8803	81.52	98.67	97.19	0.9010
30 s	0.83–1.95 Hz	Class 0	82.24	94.39	90.62	0.8832	87.54	96.91	94	0.9223	81.93	97.34	92.55	0.8963	85.36	91.87	89.85	0.8861
		Class 2	75.46	82.75	80.08	0.7910	84.70	88.09	86.85	0.8639	81.79	86.87	85.01	0.8433	74.41	82.75	79.69	0.7858
		Class 2.5	67.90	91.28	85.78	0.7959	79.42	92.41	89.36	0.8592	82.72	90.90	88.97	0.8681	63.79	93.68	86.65	0.7873
		Class 3	82.42	97.67	96.32	0.9004	73.63	98.73	96.52	0.8618	75.82	98.52	96.52	0.8717	85.71	97.45	96.42	0.9158
	1.95–50 Hz	Class 0	83.18	92.01	89.26	0.8759	83.19	93.97	90.62	0.8857	84.42	92.29	89.85	0.8835	80.05	91.30	87.81	0.8568
		Class 2	67.81	79.54	75.24	0.7368	71.24	82.60	78.43	0.7692	59.10	87.02	76.79	0.7306	57.52	81.22	72.53	0.6937
		Class 2.5	56.79	89.63	81.91	0.7321	67.90	89.38	84.33	0.7864	78.60	83.69	82.50	0.8115	68.31	84.07	80.37	0.7619
		Class 3	82.42	97.45	96.13	0.8994	79.12	97.99	96.32	0.8855	70.33	98.41	95.94	0.8437	72.53	98.30	96.03	0.8542

Note: * selected by Youden’s index criteria as the best classification result.