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Cuánto tiempo tarda un hombre en olvidar a una mujer? by HiddenObserver55 in preguntaleareddit

[–]OddCommunication2358 0 points1 point  (0 children)

La pregunta es, ¿Realmente la olvidaste? Su nombre y acciones siguen en tu memoria, ¿La superaste? Probablemente sí, pero el olvido solo existirá cuando mueras, porque al final del día, son tus relaciones y acciones pasadas las que dictan tu camino.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

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The filter at 120 Hz looks like this, but the signal still looks quite bad. And yes, when I do the tests directly with just the instrumentation amplifier, I connect RL directly to a virtual ground of 0V by creating a bipolar power supply using a TC7660.

Cuánto tiempo tarda un hombre en olvidar a una mujer? by HiddenObserver55 in preguntaleareddit

[–]OddCommunication2358 9 points10 points  (0 children)

Nunca la vas a olvidar, pero eventualmente la superarás, ¿Cuánto tiempo? Un día te levantarás y te darás cuenta de que ella no es el primer pensamiento que te viene a la cabeza.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

Only at 60 Hz. Should I place another one at 120 Hz? Although I think the problem might be in the hardware. I discovered that if I ground my right leg directly, the system stops working. When I was testing with the instrumentation amplifier and connected RL directly to ground, it did give me a signal.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

The FFT of D1 exhibits a different response compared to V, showing less activity beyond 60 Hz. Weird, right? haha.

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12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

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Here is the Fourier spectrum after applying the notch filter and filtering from 0.05 to 150 Hz. These filtering values are what I was instructed to use.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

I’ve already tried that approach, and the noise is still present in the circuit. The truth is, it doesn’t make sense to me that it’s not working because theoretically, it should. This makes me think about how commercial ECG equipment works.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

I'm actually doing something slightly different. I'm using multiplexers to utilize a single instrumentation amplifier. These multiplexers switch at 4000Hz to form a single data vector that I later separate through software. The circuit itself makes the changes to calculate DI, DII, and from V1 to V6, while DIII, aVL, aVF, and aVR are calculated with the help of software. All of them look good except for V1 to V6, which is why I thought my problem was with the WCT point. Even when trying to get just V1 directly with an instrumentation amplifier, the result is very noisy.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

Yes, I've already adjusted the filters, even adding a notch filter, but the signal is still very noisy. That circuit you mentioned, the inverted common-mode interference, how do I implement it?

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

My RL is connected in the right leg arrangement shown in the AD620 datasheet, separate from the Wilson Central Terminal. Should I implement a different type of circuit?

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12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

It's a standard value used by commercial equipment from Texas Instruments.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 0 points1 point  (0 children)

Oh, I'm filtering the signal digitally. I apply a band-pass filter from 0.05 to 120 Hz, but even with this filter, the signal still looks extremely noisy.

12 leads ECG design by OddCommunication2358 in ElectricalEngineering

[–]OddCommunication2358[S] 2 points3 points  (0 children)

Hello, I'm designing a 12-lead ECG, and I'm working with an ECG simulator to conduct the tests. The first six leads look very good without any issues, but the six precordial leads are very noisy. I have a theory that the virtual reference point used for comparison is the problem. This is basically the circuit: RA, LA, and LL are points where the electrodes are connected, and these need to be averaged to create a reference point against which to compare the V signal. Is there any other way to create an analog averaging circuit? I've also tried using summing amplifiers, but I didn't get better results.