This article presents an overview of electrochemical sensors that employ nanomaterials and utilize electrochemical impedance spectroscopy for analyte detection. The most widely utilized nanomaterials in impedance sensors are gold (Au) nanoparticles and carbon nanotubes (CNTs). Au nanoparticles have been employed in impedance sensors to form electrodes from nanoparticle ensembles and to amplify ...

In this note, we show that the impedance control strategy proposed in the paper is not feasible from practical implementation point of view. Next, a robust impedance controller is proposed for electrically driven robots using Fourier series (FS). The fact that robots' actuators have limited voltage is also considered in controller design procedure. In comparison with other impedance controllers...

Electrochemical impedance spectroscopy (EIS) is a suitable and powerful diagnostic testing method for fuel cells (FCs) since it is non-destructive and provides useful information about FC performance and its components. In this study, for the first time, a 500W cascade type 4 cells stack with integrated humidifier, water separator and internal manifolds was designed, fabricated and tested. The ...

Mitral valvular regurgitation consistently modified the wave form of the first derivative of the transthoracic impedance cardiogram. The transthoracic impedance cardiogram was recorded in 23 control subjects (group 1), and 23 patients with isolated mitral regurgitation (group 2). Simultaneous transthoracic impedance cardiogram, electrocardiogram, and mitral valve echocardiograms in group 1 show...

The aim of this study was to determine whether spontaneous respiration influences pulmonary artery input impedance, a question that has received little attention in the literature. Impedance values were assessed during three different phases of the respiratory cycle, namely inspiration, expiration and postexpiration (i.e. the null respiratory flow period between expiration and the next inspirat...

this paper is concerned with investigation of vertical impedance function of a surface rigid circular foundation resting on a semi-infinite transversely isotropic alluvium. to this end, the equations of motion in cylindrical coordinate system, which because of axissymmetry are two coupled equations, are converted into one partial differential equation using a method of potential function. the g...

Twenty-two patients undergoing CT-guided stereotaxic biopsies had intraoperative monopolar and bipolar impedance monitoring along the trajectory of the biopsy. Patterns of tissue impedance were retrospectively correlated with CT scans demonstrating decreased impedance generally corresponding to low density regions and increased impedance to the enhancing lesions.

To determine whether data quality is meaningfully reduced by high electrode impedance, EEG was recorded simultaneously from low- and high-impedance electrode sites during an oddball task. Low-frequency noise was found to be increased at high-impedance sites relative to low-impedance sites, especially when the recording environment was warm and humid. The increased noise at the high-impedance si...

INTRODUCTION This application note describes the circuit architecture and details required to measure the impedance profile of a grounded sensor using the AD5933 impedance-to-digital converter. The AD5933 is a high precision impedance converter system (see Figure 1) that combines an on-board frequency generator with a 12-bit, 1 MSPS, analog-to-digital converter (ADC). The frequency generator al...

To evaluate the clinical usefulness of measuring transthoracic electrical impedance in patients with pulmonary edema, we studied 27 normal subjects and 33 patients. In normal subjects, impedance increased when body position changed from supine to standing (p less than 0.01) and when lung volume increased from residual volume to total lung capacity (p less than 0.01). Impedance values vari7 omeg...