Specifies requirements for the development (analysis, design, verification and validation) of a physiologic closed-loop controller (PCLC) as part of a physiologic closed-loop control system (PCLCS) in medical electrical equipment and medical electrical systems to control a physiologic variable. This collateral standard applies to various types of PCLC, e.g. linear and non-linear, adaptive, fuzzy, neural networks. This collateral standard applies to a closed-loop controller that sets the controller output variable in order to adjust (i.e., change or maintain) the measured physiologic variable by relating it to the reference variable.