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Lecture

Differential Amplifier for Noise Reduction

In course

EE-511: Sensors in medical instrumentation

Fundamental principles and methods used for physiological signal conditioning. Electrode, optical, resistive, capacitive, inductive, and piezoelectric sensor techniques used to detect and convert physiological information to electrical signals. Medical dev ...

Description

This lecture covers the design and operation of a differential amplifier for noise reduction in biomedical instrumentation. Topics include noise reduction techniques, common mode voltage, differential amplifier models, and instrumentation amplifier examples.

Instructors (2)

Kamiar Aminian

Kamiar Aminian received the M.S. degree in electrical engineering in 1982, the Ph.D degree in biomedical engineering in 1989 and the Postgraduate degree on technical computing in 1993 from Ecole Polytechnique Fédérale de Lausanne (EPFL). He was assistant professor (1994-1996) with Sharif University of Technology (Tehran). He joint EPFL in 1996 where he is currently Professor of medical instrumentation and the director of the Laboratory of Movement Analysis and Measurement in the Institute of Bioengineering of EPFL. His research interests include methodologies for human movement monitoring and analysis in real world conditions mainly based on wearable technologies and inertial sensors with emphasis on gait, physical activity and sport. His research aims to perform outcome evaluation in orthopaedics, to improve motor function and intervention programs in aging and patients with movement disorders and pain, and to identify metrics of performance in sport science. Kamiar Aminian is a member of the International Society of Posture and Gait Research, the Institute of Electrical and Electronics Engineers, the European Society of Movement Analysis in Adults and Children, the Prevention of fall Network Europe, the Intentional Society of Biomechanics and the President of the 3D analysis of the human movement group. He is author or co-author of more than 450 scientific papers published in reviewed journals and presented at international conferences and holds 10 patents related to medical devices. Full CV ORCID

Anisoara Ionescu

Official source

Related concepts (28)

Operational amplifier

An operational amplifier (often op amp or opamp) is a DC-coupled high-gain electronic voltage amplifier with a differential input and, usually, a single-ended output. In this configuration, an op amp produces an output potential (relative to circuit ground) that is typically 100,000 times larger than the potential difference between its input terminals. The operational amplifier traces its origin and name to analog computers, where they were used to perform mathematical operations in linear, non-linear, and frequency-dependent circuits.

Differential amplifier

A differential amplifier is a type of electronic amplifier that amplifies the difference between two input voltages but suppresses any voltage common to the two inputs. It is an analog circuit with two inputs and and one output , in which the output is ideally proportional to the difference between the two voltages: where is the gain of the amplifier. Single amplifiers are usually implemented by either adding the appropriate feedback resistors to a standard op-amp, or with a dedicated integrated circuit containing internal feedback resistors.

Amplifier

An amplifier, electronic amplifier or (informally) amp is an electronic device that can increase the magnitude of a signal (a time-varying voltage or current). It is a two-port electronic circuit that uses electric power from a power supply to increase the amplitude (magnitude of the voltage or current) of a signal applied to its input terminals, producing a proportionally greater amplitude signal at its output. The amount of amplification provided by an amplifier is measured by its gain: the ratio of output voltage, current, or power to input.

Instrumentation amplifier

An instrumentation amplifier (sometimes shorthanded as in-amp or InAmp) is a type of differential amplifier that has been outfitted with input buffer amplifiers, which eliminate the need for input impedance matching and thus make the amplifier particularly suitable for use in measurement and test equipment. Additional characteristics include very low DC offset, low drift, low noise, very high open-loop gain, very high common-mode rejection ratio, and very high input impedances.

Valve amplifier

A valve amplifier or tube amplifier is a type of electronic amplifier that uses vacuum tubes to increase the amplitude or power of a signal. Low to medium power valve amplifiers for frequencies below the microwaves were largely replaced by solid state amplifiers in the 1960s and 1970s. Valve amplifiers can be used for applications such as guitar amplifiers, satellite transponders such as DirecTV and GPS, high quality stereo amplifiers, military applications (such as radar) and very high power radio and UHF television transmitters.

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