Broadband Bioimpedance Spectroscopy Based on a Multifrequency Mixed Excitation and Nuttall Windowed FFT Algorithm

Table 4

Experiment results of BIS measurement under the excitation of the MFM signal 𝑓(9,𝑡).

Primary harmonic	Frequency (kHz)	Standard 𝑍; 𝑍s	Measured 𝑍; 𝑍𝑚	Relative errors |𝐸𝑧| (%)	Standard Ps	Measured Pm	Absolute errors |𝐸𝑝| (°)
𝑓0	3.90625	918.1501	918.1311	0.0021	−2.4951	−2.5098	0.0148
2𝑓0	7.8125	912.6795	912.8680	0.0207	−4.9562	−4.9745	0.0183
4𝑓0	15.625	891.9151	891.8473	0.0076	−9.6518	−9.6461	0.0057
8𝑓0	31.25	823.2610	822.8110	0.0547	−17.5164	−17.5659	0.0495
16𝑓0	62.5	668.0581	667.5680	0.0734	−26.1026	−26.1476	0.0450
32𝑓0	125	487.1455	486.5256	0.1273	−27.3403	−27.4284	0.0881
64𝑓0	250	381.8698	381.0998	0.2016	−19.6909	−19.7728	0.0819
128𝑓0	500	344.2257	343.3310	0.2599	−11.1973	−11.2497	0.0524
256𝑓0	1000	333.6487	332.7088	0.2817	−5.8059	−5.8323	0.0263