The most important thing: do NOT change your behavior towards the cat just because you have the baby. Do NOT shun away the cat with regard to the baby.
Instead, take your cat as an ally about everything you do:
- let's clean this plate;
- let's prepare some food for the baby;
- let's ... (you know what you need to do there).
Of course, you will have to introduce the cat to the new noisy "thingy" - otherwise the curiosity will not only kill the (legendary) cat, but also damage the "thingy" too. And as you noticed, "introduce" and "interact" are different words with different meanings. The cat should be allowed to see the baby from a distance - the mere observation is unlikely to change any state (and any diaper).
With fewer words: keep the cat away by being its friend, not by being the baby's protector against the monster. As much as possible, tend to the cat first, as a preparation to tending to the baby.
I am sure that more advice exists, but it is not currently in my possession.