Photoplethysmographic Measurements of Finger/Toe Arterial Pulse Waveforms and Their Compound Time Domain Analysis

摘要

Optical methods, especially, photoplethysmogra phy (PPG) is an interesting and valuable method in studying human circulatory physiology. This novel model makes it possible to estimate very accurately mechanical properties of arteries. This estimation is based on the analysis of the arterial pulse waveforms and their compound decomposition analysis derived from photoplethysmographic measurements. Measured PPG signal can contain information on autonom ic neural system, gastric mobility, and stress states of the hu man under study. However, quantification of the mental stress level is not easy to confirm stressed state and also the validity of the index. It would be important to compare the stress in dexes between the stress and resting stages. We see that the PPG signal information is not yet fully un derstood. After analyzing the PPG signals in time domain it would be possible to uncover the characteristic features. These features will describe arterial properties, autonomic waving, human stress state, and also gastric mobility which will be shown in this paper. For example, high arterial stiffness is a symptom and increases the risk of cardiovascular diseases. Arteries stiffen normally as a consequence of age, but also because of arteriosclerosis. Age related stiffness occurs when the elastic fibers within the arterial walls begin to weaken due to age, but diseases as arteriosclerosis accelerate this process.