System diagnostics impedance

On a RDE, in the absence of a surface layer, the EHD impedance is a function of a single dimensionless frequency, pSc1/3. This means that if the viscosity of the medium directly above the surface of the electrode and the diffusion coefficient of the species of interest are independent of position away from the electrode, then the EHD impedance measured at different rotation frequencies reduces to a common curve when plotted as a function of p. In other words, there is a characteristic dimensionless diffusional relaxation time for the system, pD, strictly (pSc1/3)D, which is independent of the disc rotation frequency. However, if v or D vary with position (for example, as a consequence of the formation of a viscous boundary layer or the presence of a surface film), then, except under particular circumstances described below, reduction of the measured parameters to a common curve is not possible. Under these conditions pD is dependent upon the disc rotation frequency. The variation of the EHD impedance with as a function of p is therefore the diagnostic for... 

If one wishes to obtain an overview of the system behavior, the event counter diagnostics will frequently provide as much if not more information than a Hotter monitor, does not impede the individual s ability to pursue their normal activities, is immediately available at the time of a routine follow-up visit, and does not increase the overall expense associated with the patient s care. 

Thoracic fluid is associated with decreased impedance between a ventricular lead and the pacing system generator. Two preliminary clinical studies have reported varying results on the clinical utility of thoracic impedance monitoring for predicting hemodynamic status. The Medtronic Impedance Diagnostics in Heart Failure Trial (MlD-HeFT) evaluated 33 patients with Class III or IV heart failure due to systolic dysfunction (n = 25) or diastolic dysfunction (n =... 

Flectrochemical Impedance Spectroscopy (FIS) Applications to Sensors and Diagnostics Thermal Effects in Electrochemical Systems... 

This simulation study is the first publication of this tissue dynamics impedance simulation system and demonstrates the functioning of the simulation system. In the future the system will be used for simulating real measurement scenarios to reveal if local and small scale vascular dynamics in tissues really influence medical electric diagnostic methods. The authors hope that the knowledge of small scale impedance dynamics in the tissues can reveal innovative diagnostic opportunities. 

But caution is required because the influence of increased line impedance (aging process) has the opposite effect. This means clearly defining what faults must be covered in order to make the right choice and therefore the complete processing chain must be carefully studied and the faults that require treatment identified in light of their impact on the system and the diagnostic possibilities available. 

The number of electrochemistry-based biomedical devices for clinical applications, including various diagnostic tools, implants, and biosensors, has been steadily increasing since the 1960s. Many of these devices are fundamentally based on the application of AC frequency dielectric and impedance analysis to biological and clinical systems. 

From the separate lines of Eqs. 13-12 and 13-13 real and imaginary components of impedance at first (fundamental), second, third, and fourth harmonics can be calculated from the known voltage signal parameters and measured frequency-dependent current. The values for the Aaracteristic total capacitance C V ) and conductance G(f,j.) of the circuit can be computed. Comparison of the experimental and calculated frequency-dependent data for each harmonic serves as a diagnostic criterion that the system can indeed be represented by a simple parallel G C combination. Poor fit between the experimental and the calculated frequency-dependent impedance or current functions implies that a more complicated kinetic mechanism is responsible for the measured impedance characteristics. 

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