P = e(exp)(t /T+B) +C
The derivative of both sides:
dp = e(exp)(t /T+B) (1/T )dt or:
Since t starts from peak -dp/dt, when t=0, we have:
dp/dt max = e(exp)B (1/T ) = e(exp)B /Tau
Because e(exp)B is a constant, it means -dp/dt max and Tau share a relationship of one to one correspondence. We can draw the conclusion that -dp/dt max and Tau are equivalent indices in clinical significance.