Assessment of patterns of flow in the small bowel is difficult. Multiple intraluminal impedance has been recently used for study of flow dynamics in the esophagus. Our aims were 1) to validate multiple intraluminal impedance by correlating impedance events with intestinal flow as detected by fluoroscopy and 2) to determine intestinal flow patterns in the fasting and postprandial period and thei...

BACKGROUND Deep brain stimulation (DBS) electrode impedance is a major determinant of current delivery to target tissues, but long-term variation in impedance has received little attention. OBJECTIVES To assess the relationship between electrode impedance and time in a large DBS patient population and characterize the relationship between contact activity and impedance. METHODS We collected...

A sample holder was designed and built to facilitate measuring the magnitude and phase angle of the electrical impedance of internodal stem sections from Cornus stolonifera Michx. A nonpolarizing, electrically conducting manganese dioxidecarbon paste used between the stem sample and the electrodes of the sample holder allowed measurement of impedance at frequencies from 50 hertz to 500 kilohert...

Impedance changes of the anode, cathode and solution were examined for an air-cathode microbial fuel cell (MFC) under varying conditions. An MFC inoculated with a pre-enriched microbial culture resulted in a startup time of less than ten days. Over this period, the anode impedance decreased below the cathode impedance, suggesting a cathode-limited power output. Increasing the anode flow rate di...

Impedance control is one of the most effective control methods for interaction between a robotic manipulator and its environment. Robot impedance control regulates the response of the manipulator to contact and virtual impedance control regulates the manipulator’s response before contact. Although these impedance parameters may be regulated using neural networks, conventional methods do not con...

In the previous lecture, we leant about impedance spectroscopy. Electrochemical impedance spectroscopy is the technique where the cell or electrode impedance is platted versus frequency. Thus, the impedance is measured as a function of the frequency of the AC source. Electrochemical impedance spectroscopy is a useful method for investigating porous electrodes, which are extensively used in the ...

many real devices such as batteries are nonlinear and their impedance values depend on either current or voltage. However, impedance analysis is based on the assumption of a linear system. If certain conditions such as sufficiently small excitation amplitude to ensure quasi-linearity and measurements at several operating points are fulfilled, also the impedance of a nonlinear system can be inte...

In this paper, we propose a mechanical impedance for the whole arm of a serial-chain manipulator. The proposed impedance has a geometrically natural property owing to use of a spatial curve which describes a virtual reference of the impedance. The proposed impedance is useful for geometric task planning in whole-arm manipulation. Illustrative examples are shown for understanding of the impedance.

OBJECTIVE Mitral regurgitation (MR) is generally characterised as exhibiting a 'low impedance leak into the left atrium'. This notion is widely accepted without measured impedance data. The aim of this study was to define the impedance to retrograde and forward blood flow and to examine hydraulic (pressure-volume) and mechanical (stress-shortening) function in chronic severe MR. METHODS A mat...