No abstract available.
Electric Impedance* ; Plethysmography, Impedance*

The hemodynamic characteristics of the cuff end-to-side anastomosis model are investigated using by the finite volume predictions. The flow rates and the impedance indices through of the cuff anastomosis model are compared with those of the anastomosis model without the cuff. Blood flow increased through the cuff anastomosis model than the standard anastomosis model. The impedance index decreased with the increase of flow rate. The impedance index at a given flow rate is reduced by the increase of anastomosis angle and further reduced by the addition of the cuff. The results suggest that the cuff anastomosis model should be applied for the low Reynolds number flow and/or the small artery anastomosis model.
Arteries ; Electric Impedance ; Hemodynamics*

No abstract available.
Electric Impedance ; Manometry

In the bioelectric measurement, the electrode impedance detection is an important index to the signal quality evaluation and sensor electrode contact condition. In this paper, a method of accurately measuring the electrode impedance based on EEG measurement system was put forward, the method is based on the constant current source excitation signals which are added to the human body, by monitoring the human voltage to measure the electrode impedance. And different reference resistor calibration calculation in different sections was used to reduce the effect of constant current source on the precision of measurement results to improve the measurement accuracy.
Calibration ; Electric Impedance ; Electroencephalography

No abstract available.
Electric Impedance ; Manometry ; Pathology

No abstract available.
Colorectal Neoplasms ; Electric Impedance

No abstract available.
Adult ; Electric Impedance ; Humans

This study aims to analyze and improve Howland current source circuit and to study the constant current source of alternating current with high output impedance and high stability. A simulation study was carried out on the constant-current characteristics of Howland current source from two aspects of resistance match value and the selection of Op amp parameters, and then the output impedance was analyzed. The simulation experiment showed that when it was with the best matched resistance, the constant-current characteristics of Howland current source was better. Op amp parameters could affect the constant-current characteristics of Howland current source. In Howland current source circuit, the current source after parameter optimization had better output impedance and load capacity. The results showed that there was the best matched resistance in the selection by Howland current source. The Op amp with large broadband, high slew rate and open loop gain, and wide range of power supply voltage is more suitable for the bioelectrical impedance detection circuit.
Electric Impedance ; Electric Power Supplies ; Electricity

This paper describes 5 national standards related to the term on the residual voltage with different indicators. Compare the advantages and disadvantages of various test methods. Finally, give suggestions on improving the testing method.
Electric Capacitance ; Electric Impedance ; Electricity ; Reference Standards

No abstract available.
Aortic Valve* ; Compliance* ; Electric Impedance*