[SOLVED] Qustion about ECG cable resistance.

[Mryemeni]

Hello guys!

First I'm not sure if this thread should be here, if it's not accept my apologies.

My question is regarding an ECG cable I bought for my father "he's a doctor" that didn't work on the device, after checking with the one that works it seems that the difference between the two is the presence of resistance between the two sides of the leads on the one that I bought.

Knowing that I opened the case of the cable and found resistors connected between the two sides of the cable as shown in the picture, my question now is if i removed the resistors and resoldered the leads will that work on the device safely?

If it was another devicec I would have done it since I already measured the one that works and it shows no resistance, but since it's a medical instrument I hesitated, so I need your opinion guys.

Thanks in advance.

 

[crutschow]

What is the value of the resistance? Since the EEG signal is going into the high impedance of the EEG amplifier the resistors shouldn't have any effect on the signal unless the resistors are a very high value. The resistors may be for safety to limit any current to the patient in case the amplifier end of the leads would come in contact with a high voltage, such as to the power line, by some sort of equipment failure.

 

[Mryemeni]

Thanks crutschow for your response, the resistors measure 4.7K ohms

 

[andre_luis]

Some medical probes, although mechanically complying with standard connections, are designed to be employed strictly with equipments from which belongs, and you must inspect if such cable conform with this condition.


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[Mryemeni]

OK, it turns out that the resistances are not the problem as crutschow said, the two cables have different order of the pins and that what gives wrong readings.

Thanks guys.