I'm running my dissertation project using Biopac MP150, collecting ECG and ICG. Our lab is using EL500 for ICG and EL513 for ECG. Is it possible to find an off-brand replacement for these or a cheaper version that would be as effective? For the number of participants I need, Biopac electrodes come up to about $1000, which is a bit much for a grad student budget in addition to other costs associated with the project. Any thoughts would be greatly appreciated! Thank you!