Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [biopotential]

Instrumentation related to the measurement of bioelectric phenomena from the living system, such as ECG, EEG, EMG, and galvanic skin response.

Reading:

High Quality Recording of Bioelectric Events. II : A Low-Noise, Low-power Multichannel Amplifier Design

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Noise reduction strategies in electrophysiology

When recording electrical signals from cells (in a dish or inside a living human or animal body), one major problem is to increase the signal to noise ratio. These signals are usually in the 10uV to 100mV range and are generated by very low power…
Ali
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Can an oscilloscope be used as an EKG?

I was at my doctor's office and noticed an EKG machine that looked like a standard oscilloscope. In fact, its case was almost identical to my dual channel Tektonix 1104b. The main difference was that it had more probes, but I didn't check if they…
user148298
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RnD on an EEG, Help required, what op-amp?

this is my first post, and I need some help/advice finding the right integrated circuits. I'll start by describing the project background a bit. I've received a fellowship to develop an open source electroencephalograph, the finished hardware will…
Jim
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Why would you put your input amplifier in front of your filtering for an ECG signal?

In this article at eetimes.com they show the signal chain for measuring an ECG. The raw signal of an ECG contains noise and offsets at least a magnitude larger than the real signal. (Some few mV ECG, several tens of mV from power line noise and…
jusaca
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What does this op-amp circuit do? (part of an ECG)

I would like create an ECG circuit based on this schematic (from the AD620AN datasheet): I don't know this part of the circuit and how it works. I know this is called a right leg driven circuit which is reducing the effect of the noise. But I don't…
herp
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50hz noise removal from ECG power supply

We are currently working on a bio medical project that is an ECG machine.There is a problem that we are unable to solve on software side is the removal of 50 Hz noise. Now we are trying to remove 50 Hz noise using analog filters. Does anybody have…
Idrees
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Detect electrical signals from plants

My daughter wants to do a science fair experiment that involves reading the electrical signals in plants, but the cost of a multi voltmeter with data logging is very high. Can anyone suggest a setup for less than $100? Maybe she doesn't need as…
Catherine Gruber
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Circuit for small level voltage detection (microvolts)

I have been working on a project lately which help in the detection myogenic potentials (of the levels of micro-volts). After studying from several places, I finalized the following test circuit. The initial voltage dividers helps in generating the…
DodZi
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Patient protection resistors in the biopotential amplifiers

In biopotential amplifiers like ECG amplifier, I often see protection resistors (around 100kohm) between electrode and the input of instrumentation amplifier or ECG amplifiers like ADS1298. I understand that the resistor are supposed to limit the…
zud
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ECG: gain of right leg drive?

I am trying to build a simple ECG circuit. I designed the circuit based on multiple ideas from the internet and the parts (INA118P) available. What I do not exactly understand is how much the gain of the right leg drive should be. I marked on the…
szali
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Optical heart rate sensor vs bioimpedance sensor?

I didn't know a better place to ask this, so here it goes. For activity trackers, Fitbit has the Charge HR with an optical heart rate monitor, while Jawbone has the UP3 with a bioimpedance sensor for heart rate. Can you please explain the…
adamaero
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How does a driven right leg work?

A driven right leg (DRL) circuit is often added to a biopotential amplifier to reduce the common mode voltage (i.e. to increase the common mode rejection ratio, CMRR). A basic form of biopotential amplifier is just an instrumentation amplifier which…
David Cian
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60Hz "click" or clipping noise when differential amplifier is surrounded by salt water

I am a graduate student attempting to take electrophysiology recordings from a lobster under water. In the current set up I am using, two differential amplifier boards are attached the the lobster's back in waterproof casing, with a transmitter and…
Benjamin
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Does an electrocardiography recorder put current/voltage on its electrodes?

(I do hope my question is not off-topic) Currently learning about ECG recorders (Our 7-months old daughter has to have one during her sleep), I wonder whether this is a pure "passive" measuring device (like a multimeter) or not. I do think I…
Uwe Keim
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Does anyone have advice on homemade EKG/ECG leads?

I'm not sure this is where it should be posted, so apologies in advance, but I'm working with an Arduino and Sparkfun's heart rate monitor AD8232 (https://www.sparkfun.com/products/12650) to gather ECG data for heartrate. I want to try to collect…
Asinine
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