This article actually contains the link to the paper too: https://www.thelancet.com/journals/lancet/article/PIIS0140-6... — though behind a Lancet register-wall apparently

edit: though based on the abstract available at the URL, it's not clear to me which of the mentioned methods is the innovative one, if any (??)

edit 2: Found a youtube video with some actual description of how the machine is built, from the doctor himself, from 2015 (google keywords: "Chisti bubble CPAP"): https://www.youtube.com/watch?v=HM1E8yMJd5Q