Objective:To explore the application value of Holo-Hilbert spectral analysis (HHSA) in the analysis of tremor in Parkinson′s disease (PD) and essential tremor (ET).Methods:A total of 59 patients with PD with motor symptoms and 46 patients with ET were selected from the patients visiting the Department of Neurology, Qilu Hospital of Shandong University (Qingdao) between January 2022 and April 2024, and the original tremor information and myoelectric activity were recorded by accelerometer and electromyography under the condition of no weight bearing and 1 000 g weight bearing. Fourier transform (FT) and HHSA were used to convert the original data, and the effectiveness of HHSA for tremor analysis was verified by comparing the tremor characteristics under the two conversion methods.Results:The tremor data of 59 PD patients and 46 ET patients were converted by HHSA, and the amplitude modulation frequency-carrier frequency spectrum was obtained; and compared with FT, the noise-related spectrum and insignificant peaks were eliminated, and the uniqueness of tremor was maintained. And the tremor peak frequencies of PD patients under the two methods were similar, both being 4-6 Hz; the tremor peak frequencies of ET patients under the two methods were also similar, both being 6-12 Hz. The tremor peak frequencies of FT and HHSA transform in the upper limb resting state of PD patients were (4.93±0.73) Hz and (4.83±0.93) Hz, respectively, with no statistically significant difference between the two groups ( t=0.371, P=0.695). The tremor peak frequencies of FT and HHSA transform in the left upper limbs of ET patients were (8.59±2.23) Hz and (8.57±2.29) Hz, respectively ( t=0.273, P=0.968), in the right upper limbs were (8.09±1.87) Hz and (8.20±2.11) Hz, respectively ( t=0.141, P=0.890), both with no statistically significant differences. There were no significant differences in the tremor peak frequencies of the two methods in the same limb and the same state. PD patients and ET patients who showed harmonics under FT did not show harmonics after HHSA transform. Conclusions:The effectiveness and accuracy of HHSA and FT in the analysis of tremor in PD and ET patients are similar. HHSA is an effective tool for analyzing tremor and the problem of harmonics can be solved by HHSA, and the amplitude modulation frequency-carrier frequency spectrum can be used to analyze the relationship between accelerometer and electromyographic data, providing a possible way to study the mechanism of tremor.

Objective:To explore the application value of Holo-Hilbert spectral analysis (HHSA) in the analysis of tremor in Parkinson′s disease (PD) and essential tremor (ET).Methods:A total of 59 patients with PD with motor symptoms and 46 patients with ET were selected from the patients visiting the Department of Neurology, Qilu Hospital of Shandong University (Qingdao) between January 2022 and April 2024, and the original tremor information and myoelectric activity were recorded by accelerometer and electromyography under the condition of no weight bearing and 1 000 g weight bearing. Fourier transform (FT) and HHSA were used to convert the original data, and the effectiveness of HHSA for tremor analysis was verified by comparing the tremor characteristics under the two conversion methods.Results:The tremor data of 59 PD patients and 46 ET patients were converted by HHSA, and the amplitude modulation frequency-carrier frequency spectrum was obtained; and compared with FT, the noise-related spectrum and insignificant peaks were eliminated, and the uniqueness of tremor was maintained. And the tremor peak frequencies of PD patients under the two methods were similar, both being 4-6 Hz; the tremor peak frequencies of ET patients under the two methods were also similar, both being 6-12 Hz. The tremor peak frequencies of FT and HHSA transform in the upper limb resting state of PD patients were (4.93±0.73) Hz and (4.83±0.93) Hz, respectively, with no statistically significant difference between the two groups ( t=0.371, P=0.695). The tremor peak frequencies of FT and HHSA transform in the left upper limbs of ET patients were (8.59±2.23) Hz and (8.57±2.29) Hz, respectively ( t=0.273, P=0.968), in the right upper limbs were (8.09±1.87) Hz and (8.20±2.11) Hz, respectively ( t=0.141, P=0.890), both with no statistically significant differences. There were no significant differences in the tremor peak frequencies of the two methods in the same limb and the same state. PD patients and ET patients who showed harmonics under FT did not show harmonics after HHSA transform. Conclusions:The effectiveness and accuracy of HHSA and FT in the analysis of tremor in PD and ET patients are similar. HHSA is an effective tool for analyzing tremor and the problem of harmonics can be solved by HHSA, and the amplitude modulation frequency-carrier frequency spectrum can be used to analyze the relationship between accelerometer and electromyographic data, providing a possible way to study the mechanism of tremor.