So I do not have a medical background. I have however worked a number of Industrial Control Systems (ICS) projects, and what you describe kind of sounds like a PID control loop, which also is not a simple push up/down approach.

From Wikipedia:"A proportional–integral–derivative controller (PID controller or three-term controller) is a control loop mechanism employing feedback that is widely used in industrial control systems and a variety of other applications requiring continuously modulated control. A PID controller continuously calculates an error value e(t) as the difference between a desired setpoint (SP) and a measured process variable (PV) and applies a correction based on proportional, integral, and derivative terms (denoted P, I, and D respectively), hence the name."

Getting PID control loops to work has a lot of research behind it, but it's still hard to get right with new hardware. I would imagine a PID control loop involving organics (wetware) would be much order, and harder still a PID control loop in organics with life-threatening failures possible.