Multiple regression? how to get a formula

Hi everyone,

i'm trying to figure out how to approach my problem.. I want to find a formula that shows me when the transmembrane pressure (TMP) is rising due to clotting and not by other factors like viscosity or temperature or flow or ..?.. . The setup is as followed: blood is pumped through a membrane (large surface) over which the TMP is measured. TMP, viscosity, temperature and flow are measured also the inlet pressure and outlet pressure, from these last two the TMP is measured ofcourse.

I was thinking of a formula that includes all the factors and than sort of normalize it and if is changes it should be because of clotting. but should I look at each factor independently and than use multiple regression?

If you have any idea that could help me out, or put me in the right direction that would be so great! I'm really struggling with this one.

Thanks in advance,

Paul