Not too sure whether it's the best one but you can run or on your Pixel 9 Pro

https://ollama.com/library/medllama2

How to is there:

https://www.androidauthority.com/install-deepseek-android-3521203/

And there is also meditron 7b (runs on earlier mentioned Pixel. More demanding model is 70b. Look it up on ollama library.