Build an Activity To Monitor HR While Sleeping

I've got a very specific health issue and I need an activity to monitor my HR while sleeping. This would be for my Venue 3. Here's my requirements:

Settings
Data Screens
Screen 1
2 Fields Top: Time of day
Bottom: Heart rate
Screen 2
3 Fields Top: Time of day
Middle: Heart rate
Bottom: Countdown
Color
Red ONLY
Alerts
Heart Rate
High Alert
Countdown
Hours:Minutes:Seconds
Duration
Hours:Minutes:Seconds

Usage
Start activity with top right button
Screen 1 shows
Fit file created
If HR is ≥ High Alert for ≥ Duration:
Alert continues until bottom right button is pressed
Screen 2 shows
The Bottom data field (Countdown) displays a countdown timer that starts from the time the HR went over the High Alert (not the time the bottom right button was pressed).
When the Countdown reaches 0, an Alert continues until bottom right button is pressed

In words:

I've got a heart issue and I need my watch to monitor my HR while sleeping. Should my HR exceed the "High Alert" setting (say 100 bpm, for example) for the "Duration" setting (say 60 seconds, for example), a High Alert warning will sound and continue sounding unit a physical button is pressed. A countdown timer will also start (say 3 hours, for example) concurrent with the time of exceeding the "High Alert" setting. If the "High Alert" setting is exceeded but the "Duration" setting isn't exceeded, it wouldn't count.

I'm currently using the Cardio activity to test this out and it kind of works. It is missing the Duration setting so I get a lot of false positives. It also doesn't have the countdown timer which is critical as it represents when I need to wake and take specific medicine!

Thanks to anyone that is willing to take this on!


Doug