Hi,
I think that it may be possible one day but for that there would have to be created an index that would specify for each element we dream, a specific chemical or electrical marker. I have a feeling we are still very far away from this achievement but anyhow I don't think I would buy such a machine.
The reason is that I enjoy my dreams while I dream them and after that, I enjoy the memory of them but I wouldn't want to see them again, for it would alter the recollection of my dream.
That's my opinion but I'm sure there would be many buyers for such a machine.
All the best