The concept of mechanical impedance represents the interactive relationship between deformation kinematics and the resulting dynamics in human joints or limbs. A major component of impedance, stiffness, is defined as the ratio between the force change to the displacement change and is strongly related to muscle activation. The set of impedance components, including effective mass, inertia, damp...

Grid impedance estimation is used in many power system applications such as grid connected renewable energy systems and power quality analysis of smart grids. The grid impedance estimation techniques based on signal injection uses Ohm’s law for the estimation. In these methods, one or several signal(s) is (are) injected to Point of Common Coupling (PCC). Then the current through and voltage of ...

In recent years, impedance measurement method by piezoelectric (PZT) wafer activesensor (PWAS) has been widely adopted for non-destructive evaluation (NDE). In this method, theelectrical impedance of a bonded PWAS is used to detect a structural defect. The electro-mechanicalcoupling of PZT materials constructs the original principle of this method. Accordingly, the electricalimpedance of PWAS c...

The stressful characteristics of commuting constraints are conceptualized in terms of both physical and perceptual conditions of travel impedance. This study develops and operationalizes the concept of subjective impedance, as a complement to our previously developed concept of impedance as a physically defined condition of commuting stress. The stress impacts of high-impedance commuting were e...

Objective. Impedance measurement of cardiac output has struggled to become established partly because there have been only a few attempts to establish a sound theoretical basis for this measurement. Our objective is to demonstrate that there is valuable aortic flow information available from an intrathoracic impedance signal which may eventually be useful in the measurement of cardiac output by...

Thoracic impedance is modulated by events within the respiratory cycle, which represents a source of "noise" in impedance cardiography. Respiration itself, however, is a physiological rhythm of interest to psychophysiologists. We report here methods and validation for deriving impedance pneumographic measures of respiration from impedance cardiography signals, based on standard tetrapolar band ...

Objective(s)Bioelectrical impedance is the measure of impedance of the body. Impedance consists of electric resistance and reactance. Phase angle (PA) is the tan value of the ratio of reactance versus electric resistance. PA depends on cell membrane integrity and on body cell mass. There exists a correlation between PA values and body cell mass.The objective of this study was to compare the PA ...

Let’s define the vertical impedance of an 8-mm gap chamber due to geometric variation as one unit of impedance with the symbol zu. Since the resistive wall impedance of an 8mm gap chamber is 0.3 zu [2], the total impedance of an 8-mm gap chamber is 1.3 zu. The geometric impedance of a 5-mm gap chamber is 3.09 zu, which we obtained using the known scaling in Eq. (1) derived in [1]. Including 1.2...

The purpose of this paper is to provide a new approach for detection using bio-impedance. This impedance is measured by the four-electrode method. As the impedance changes resulting from ankle, knee, and hip movements depend on electrode placement, we determined the optimal electrode configurations for these movements by searching for high correlation coefficients, large impedance changes, and ...

Four-terminal impedance meters based on pseudo-bridges yield unexpected uncertainties when using high-contact-impedance electrodes. Adding a front-end amplifier to the impedance meter and rearranging the connection of the meter terminals overcome the contact impedance problem. However, because the compensation provisions in the instrument are meant to compensate only impedance residuals of test...