The PPG sawtooth sometimes stops¶
In some stretches, and some whole recordings, no frame slip comes although several were due. The delay there is flat and the frame clock keeps running; what stops the content's drift is not known.
| Status | open: seen, not explained. |
| Clocks | Pulse oximeter frame clock |
| Variables | Plethysmogram (SNUADC) |
What it means¶
A stretch without slips is not automatically safe: some show slow drift or fast ramps instead.
What is done about it¶
Stretches that pass the paused-sawtooth test are labelled N (offset only).
Evidence¶
| Study | Date | Status | Summary |
|---|---|---|---|
| Where the PPG sawtooth stops | 2026-10-11 | current | In some stretches no slip comes although several were due. The PPG delay there is flat, not hidden: the monitor keeps framing, and only the content's drift against the frames has stopped. |