Detect point at which a value changes in a Timestream database

I need to get sample data for a period of at least 2 minutes after a state (on/off) has changed and remained stable.

I need to get the latest stable 2 minute+ period and and an average of all the 2 minute+ in a specified period.

My starting point is trying to identify all the points and which the state measure changed. How would I go about this with a Timestream query ?