Analysis of Center of Pressure Signals by Using Decision Tree and Empirical Mode Decomposition to Predict Falls among Older Adults

Table 2

Feature parameters and their code numbers.

Level	Symbol	Explanation
1	x, y	x = copx; y = copy
2	0, 1, 2, 3, 4, 5, 6	Raw signal = 0; IMF1 signal = 1; IMF2 signal = 2, …, IMF6 signal = 6
3	1, 2, 3, 4, 5	RMSD = 1; median frequency = 2; total frequency power = 3; approximate entropy = 4; sample entropy = 5