Well, you would certainly get a better answer on the Venu forum, not here on the Garmin Connect Mobile Android forum, since unlike on the Venu forum, most users here are not familiar with Venu. However, if Venu supports alarms or alerts on the basis of breathing patterns or oximetry levels, you could use the feature of Activity Alerts - you could define a custom activity (for example called Sleep) and a custom alert to be triggered by an oximetry value or a breath frequency of your choice. You would then have to start the Sleep activity when going to bed, and stopping it when you wake up. Setting up custom alerts is described in the Venu User Manual here: https://www8.garmin.com/manuals/webhelp/venu/EN-US/GUID-D68697C7-D321-4B42-8A52-5C9D257B58CE.html
