@article{oai:niigata-u.repo.nii.ac.jp:00002741, author = {木竜, 徹 and 飯島, 泰蔵 and 斉藤, 義明 and 石岡, 靖}, issue = {3}, journal = {医用電子と生体工学, 医用電子と生体工学}, month = {Sep}, note = {It is of interest to characterize a dynamic function of muscle during movement, which is a non-stationary case, from surface EMG signals. This paper presents a new approach. This is based on a block algorithm in which a signal is divided in time into blocks and time-varying parameters are estimated in each block. A locally quasi-stationary processing, which is proposed here, is the method to estimate the parameters of an AR (autoregressive) model more precisely. It is assumed that an AR model represents a surface EMG generation system. There have been many methods for the non-stationary analysis, for example, the synchronous averaging in stochastic approaches and the estimation methods of short-time power spectrum and system function by a locally stationary processing. However, the synchronous averaging method is restricted to the evoked responses of EEG or EMG and the locally stationary processing is not sufficient for essentially non-stationary signals. In this paper, AR parameters were estimated from the surface EMG of masseter muscle by the locally quasi-stationary processing and the results were compared with the parameters by the conventional locally stationary processing. There are non-stationary intervals around evoked response or onset of masticatory EMG. AR parameters are linear prediction coefficients, reflection coefficients and poles. As the results, the estimated characteristics of the time-varying parameters were reasonable in relation to the locus of lower jaw movement and the significant differences were showed in the non-stationary intervals.}, pages = {185--191}, title = {局所準定常処理による運動時咀嚼筋筋電図の特徴づけ}, volume = {25}, year = {1987} }