Electrodes

Making your own electrodes

For best results it is advisable that you make your own electrodes with a linked reference. But this will require some soldering skills. You can see such cables on the picture below.

Don't feel like making such electrodes yourself? A few cable sets are available for purchase. Send an inquiry here.

For making the electrode cables with linked reference you will need the following:

• 5 crocodile clips
• 5 male stereo phone connectors 3.5 mm
• 6 meters of microphone cable (you can use thin coaxial cable as well)
• some electrical tape or shrinking tubes
• soldering iron

Save about 40 cm section of the microphone cable for connecting the two mastoids. The rest of the cable you can cut into five pieces of equal length. These five pieces will make five passive electrodes. On one side of the cable you will have the audio connector, on the other side you will have the crocodile clip. Make sure to connect the middle section of the phone connector via one of the inner wires of the cable to the crocodile clip. The innermost section of the phone connector is the ground, which is connected to the cable shield. Make sure that this shield is not connected to the crocodile clip. After you have created five such passive electrodes, connect two of them together with the remaining cable section, like on the illustration below.

The two electrodes are connected at the crocodile end. The shields of all the three cables are linked together. Also the two crocodile clips are linked together with the central wire of the connecting cable (this means that the middle sections of both the phone connectors are linked together).

Such electrodes with crocodile clips can be used together with disposable ECG electrodes. You will probably want ECG electrodes with a smaller diameter, which are easier to place on the mastoid bone. Or the references could be placed on the earlobes. It is advisable to use disposable ECG electrodes with a wet gel for a good contact. Below is an example of such electrodes.