Abstract: An apparatus and a method for processing signal are provided. The signal processing apparatus comprises an input interface and a processing unit. The input interface receives smoothing parameters and a to-be-separated signal. The processing unit establishes an upper extreme envelope and a lower extreme envelope of the to-be-separated signal, and calculates a mean envelope between the upper extreme envelope and the lower extreme envelope. The processing unit performs smoothing according to the smoothing parameters and the mean envelope to generate a smoothed mean envelope, and determines a trend component or a non-trend component according to the smoothed mean envelope.

Abstract: A blood parameter measuring device and a method for measuring a blood parameter are provided. The blood parameter measuring device includes an emitted source, a receiver module, and an actuator. The emitted source is disposed at a side of a tissue to be analyzed and provides at least two different wavelengths of radiation. The receiver module is disposed at another side of the tissue to be analyzed to receive the attenuated radiation produced by the emitted source. The actuator is connected to at least one of the emitted source and the receiver module. The actuator generates a driving force to make the emitted source and the receiver module contacts the tissue to be analyzed, thereby imposing a normal stress on a surface of the tissue to be analyzed to change a wave path between the emitted source and the receiver module.

Abstract: An apparatus and a method for processing signal are provided. The signal processing apparatus comprises an input interface and a processing unit. The input interface receives smoothing parameters and a to-be-separated signal. The processing unit establishes an upper extreme envelope and a lower extreme envelope of the to-be-separated signal, and calculates a mean envelope between the upper extreme envelope and the lower extreme envelope. The processing unit performs smoothing according to the smoothing parameters and the mean envelope to generate a smoothed mean envelope, and determines a trend component or a non-trend component according to the smoothed mean envelope.

Abstract: An apparatus and a method for adaptive adaptive time-frequency analysis are suitable for nonlinear and nonstationary signal analyses. The method includes the following steps. A plurality of positions of local extrema of a signal is determined. Average frequencies between the local extrema and mean energy distribution corresponding thereto are estimated according to the positions of the local extrema of the signal. The estimated instantaneous energy distribution of the signal is determined by way of optimization according to each of the mean energy distribution between the local extrema. Finally, an instantaneous frequency of the signal is estimated according to the estimated instantaneous energy distribution of the signal.