Pulm-CCM attending here.

For understanding what's going on - how the vent "works" with the body, how to get the results you want, etc. requires some math, but no where near what you need/learn as an engineer. It's mostly simple math (algebraic at most), but understanding the implication is what confuses most people - such as understanding oxygen saturation curve, frank sterling curve, etc. Understanding dead space ventilation and how it is affected by vent changes, etc. Calculating anion gap, and even delta-gap (or delta-delta) on a patient, etc. and its implication. Medications are calculated per kg per unit time (min, hr)

Just like

@HuskyMD85 says, it's simple high school algebra mostly. You won't even be doing entry-level calculus. While understanding higher level math helps understand what's going on, and even how something works (ie MRI, PET, ultrasound, etc), or explaining to families/staff drug metabolism (zero order vs 1st order vs 2nd order) … or even understand how exponential growth works … in real life, the math is either elementary, or at most algebraic.

That's the clinical aspect. If you decide to do research, math plays a bigger role - whether it is the realm of physiology, or statistics and/or biostatistics. Then it's lots and lots of math.