Add DREAMT IBI Sleep Staging

[aasalaz2]

1. UIUC NetIDs

• Andrew Salazar (aas15)
• Sharon Lin (xinyiyl2)
• Soumya Mazumder (soumyam4)

2. Contribution Type

Task

3. High-Level Description

This PR adds a new PyHealth task that enables sleep stage classification using inter-beat interval (IBI) sequences extracted from the DREAMT wearable dataset.

4. Files to Look At

New Task Implementation

• pyhealth/tasks/dreamt_ibi_sleep_staging.py
  • Implements the DREAMT IBI sleep staging task
  • Windows the IBI signals, normalizes it, and aligns with stage labels

New Unit Test

• tests/test_dreamt_ibi_sleep_staging.py
  • Creates dummy DREAMT-like data
  • Validates task output formats, windowing, and sample generation

How to Run Unit Tests

From the project root:

pytest tests/test_dreamt_ibi_sleep_staging.py

The test does not depend on external data and runs self-contained.

Additional Note

• This task does not modify any existing datasets/models, so it should not affect existing PyHealth behavior.

[jhnwu3]

Nevermind, read through deeply. Nice task submission. Will look through this later lol