Analog Input. In this example we use a variable resistor (a potentiometer or a photoresistor), we read its value using one analog input of an Arduino or Genuino board and we change the blink rate of the built-in LED accordingly. The resistor's analog value is read as a voltage because this is how the analog inputs work.
For the Haigis formula, the a0 constant moves the power prediction curve up, or down, in much the same way that the SRK/T A-constant. The a1 constant is tied to the measured anterior chamber depth and the a2 constant is tied to the measured axial length.
The most commonly used formula is the 4-variable MDRD, which estimates GFR using four variables: serum creatinine, age, ethnicity, and gender. The original MDRD used six variables with the additional variables being the blood urea nitrogen and albumin levels.nother estimation tool to calculate GFR is the Mayo Quadratic formula. This formula was developed by Rule et al, in an attempt to better estimate GFR in patients with preserved kidney function. It is well recognized that the MDRD formula tends to underestimate GFR in patients with preserved kidney function.