Dear Vicki: My staff check their phones during our meetings. How can I get them to engage?

Q: I am a hands-on SME owner with a packed schedule. I’m starting to have a real problem with office meetings, and I need your help. I believe they are using up too much of my time and not leading to meaningful progress. Discussions go round in circles, as many participants come unprepared and quickly become disengaged, openly checking their phone notifications when others are speaking.