We investigate mechanisms which could generate transient monopole signals in measuring current source density (CSD), as it had been indicated to occur in recent small volume experiments. A simple model is defined for this purpose. It is emphasized that the active nature of the neural biological activity, with its ability to generate ionic density imbalances, might be able to induce appreciable ...

A method for fast time-domain simulation of piecewise-linear networks with switches is described in this paper. The method is based on a discrete-time switch model that consists of a constant conductance in parallel with a current source. In each simulation step, value of the current source is updated as a function of known network signals. The function takes one of two forms, depending on the ...

The current-source density analysis is a widely used method in brain electrophysiology, but this method rests on a series of assumptions, namely that current sources are exclusively made by dipoles, and that the surrounding medium is resistive and uniform. Because of these assumptions, this standard model cannot be used to estimate the contributions of monopolar sources or of non-resistive aspe...

This document discusses the use of impedance pneumography as a technique to measure respiration rate. The generation of high-frequency ac current source is described, and the issues related to delay in modulated signal and finite transition times of carriers are addressed. The report also includes descriptions of potential implementations of a respiration rate measurement system using the ADS12...

This paper presents a new structure of a bandgap circuit which can be programmed to get any desired output voltage. Unlike conventional bandgap circuits, the proposed bandgap circuit uses MOS transistors operating in subthreshold region instead of bipolar transistors to generate PTAT and IPTAT currents. Use of the current conveyor makes the circuit capable of being operated at lower supply volt...

The problem of microwave tomography consists of finding the electrical characteristics (permittivity and conductivity) of a medium using scattered fields measured under various conditions of illumination. Such inversion can be achieved with a variety of techniques based upon the minimization of an appropriate criterion. The popular current source inversion (CSI) technique is one of those. In th...

As described in my previous paper [1], the voltage-source equivalent was first derived by Hermann von Helmholtz (1821–1894) in a 1853 paper [2]. Exactly thirty years later in 1883, Léon Charles Thévenin (1857–1926) published the same result [3, 4] apparently unaware of Helmholtz’s work. The generality of the equivalent source network was not appreciated until forty-three years later. Then, in 1...

This paper presents the development of a control scheme for a multilevel diode-clamped converter connected in a series–parallel fashion to the electrical system such that it can compensate for deviations in utility voltage (sag, surge, and unbalance) and act as a harmonic and/or reactive current source for a load. New carrier-based multilevel pulsewidth modulation techniques are identified to m...

A telescopic cascode opamp typically has a higher frequency capability and consumes less power than other topologies. The disadvantage of a telescopic opamp is severely limited output swing. In a conventional telescopic opamp shown in Figure 1, all transistors are biased in the saturation region. Transistors M1-M2, M7-M8 and the tail current source M9 must have at least Vds,sat to offer a good ...

Abstract Electronic loads are a family of power converters which can be used as a variable impedance load in different applications. This paper analyzes high efficiency zero-voltage electronic loads based on the quasi Z-source converter topology .The proposed topology operate as an ideal current source which enables the operation of the zero input voltage. It can achieve a high efficiency of mo...