Sigma-Delta Analog-to-Digital Converter

Sigma-delta Analog-to-Digital Converter (ADC) is used in many application including telecommunications for analog to digital conversion. A Sigma-delta ADC has a modulator and a digital filter (also called as decimation filter) as shown in Fig. 1. A modulator converts the input analog signal into digital bit streams (1s and 0s). The Sigma-delta ADC method is based … Read more

Electroencephalography or EEG

Electroencephalography or EEG is the technique of capturing brain’s electrical activity. It was first discovered by Hans Berger in 1929. EEG signal recording can be done using scalp electrodes or intracranial procedure of capturing EEG. International 10-20 system of electrode placement is widely used across the globe for recording scalp EEG. Neurologist classified the brain … Read more

Voltage Telemetry System – Advantages & Applications

A voltage telemetry system transmits the measured variable as a function of AC or DC voltage. A slide wire potentiometer is connected in series with the battery. The signal transmitting medium is essentially a copper wireline. A voltage telemetry system is shown in Fig. 1.   The sliding contact is positioned by a pressure sensitive, … Read more

Types of ECG

In previous, article we discussed ECG (Electrocardiogram). In this article, we will see about different types of ECG. The type of ECG monitoring depends on the frequency and severity of symptoms. There are three types of ECG monitoring i.e. resting ECG, stress ECG, and ambulatory ECG. Ambulatory ECG is divided into 3 groups i.e. Holter monitors, … Read more

What is Holter Monitoring?

Holter Monitor It is a small, wearable device that records your heart rhythm. It is very similar to a mobile phone. A patient usually wears a Holter monitor for one to three days. The device will record all of your heart rhythms during that time. So, a Holter monitor test is usually performed after an ECG (electrocardiogram) … Read more

Magnetostriction & Villari Effect

Magnetostriction When a material (magnetic material) is magnetised, changes in dimension are generally observed.  This property of a magnetic material is called magnetostriction. There are three types of Magnetostriction Longitudinal Transverse Volume 1. Longitudinal Magnetostriction When a change in the dimension is in the direction of applied field. 2. Transverse Magnetostriction When a change in the dimension is perpendicular … Read more

SoftComputing and HardComputing

SoftComputing It is a collection of methodologies, which aim to exploit tolerance for imprecision, uncertainty and partial truth to achieve tractability, robustness, and low solution cost. SoftComputing Main Components 1. Approximate Reasoning example: Probabilistic Reasoning, Fuzzy logic. 2. Search and Optimization example: Neural Network, Evolutionary algorithms. Problem Solving Technologies HardComputing SoftComputing Comparison between HardComputing and … Read more

Electrocardiography (ECG or EKG)

Electrocardiography is the process of recording the electrical activity of the heart over a period of time using electrodes placed on the skin. It is abbreviated as (ECG or EKG). A normal ECG is shown below. Fig. 1 Electrocardiograph An electrocardiograph is a machine that is used to perform electrocardiography. Electrocardiogram It is the heart’s … Read more