How to use Parameters in Mechanism Measures?

Hi everyone,

Is it possible to refer any parameters which defined in Tools => Parameters, when I create user defined measures in Mechanism ( Analysis => Measures)? 

I have a sheave in the assembly and the diameter of the sheave is defined by a parameter. And I want to define a variable in the Mechanism which is related to the diameter parameter. But I don't know how to refer the parameter in the variable expression. I don't fine a way to define a variable to represent the diameter size in Mechanism Measures neither. 

Could you give me help?

Thanks,

ZR