fundus-camera-watchdog 0.5.0

File watchdog for fundus camera

Fundus Camera Watchdog

fundus-camera-watchdog monitors a folder on the fundus camera workstation and uploads files to a clinicedc project using the edc-retinopathy API.

It runs on the camera’s workstation. When the camera finishes an examination and writes files to disk, the watchdog detects them, confirms the subject has a camera session on the server, uploads each file, and moves the completed folder to an archive.

Prerequisites

1. A running clinicedc server with edc-retinopathy installed and an API token created.

2. The camera software must write its output into the watched folder using the expected layout (see Folder layout below).

Folder layout

The camera creates one subfolder per subject. Folder names follow a configurable pattern (see subject_folder_pattern). Filenames contain the eye laterality (OD for right, OS for left), extracted via filename_eye_pattern.

Combined report (default):

C:\RetCamOutput\
    105-10-0989-3_\
        105-10-0989-3_Retina_OD_20260602_121802.jpg
        105-10-0989-3_Retina_OS_20260602_121803.jpg
        105-10-0989-3_Retina_OD_20260602_121802.dcm
        105-10-0989-3_Retina_OS_20260602_121803.dcm
        105-10-0989-3_Report_20260602.html
    105-10-0001-2_\
        ...

Per-eye report:

C:\RetCamOutput\
    105-10-0989-3_\
        105-10-0989-3_Retina_OD_20260602_121802.jpg
        105-10-0989-3_Retina_OS_20260602_121803.jpg
        105-10-0989-3_Report_OD_20260602.html
        105-10-0989-3_Report_OS_20260602.html

Processing is triggered once a subject folder contains the expected number of files:

• Combined (default): at least 2 JPEG and 1 HTML file.

• Per-eye: at least 2 JPEG and 2 HTML files.

DICOM (.dcm) files are uploaded when present but are not required for triggering.

Quick start

1. Generate a sample config in the camera output folder:

   cd C:\RetCamOutput
   uvx fundus-camera-watchdog --create-config

   This creates fundus_camera_watchdog.json with sensible defaults.

2. Edit the config to fill in api_url, subject_folder_pattern, and optionally filename_eye_pattern, device_id, etc.

3. Set the API token as an environment variable (recommended):

   REM Windows (persists across reboots)
   setx FUNDUS_CAMERA_WATCHDOG_TOKEN "YOUR_DRF_TOKEN"

4. Start the watchdog:

   cd C:\RetCamOutput
   uvx fundus-camera-watchdog

Configuration

Settings are resolved in the following order (highest priority first):

1. CLI flags (e.g. --api-url)

2. JSON config file

3. FUNDUS_CAMERA_WATCHDOG_TOKEN environment variable (token only)

4. Built-in defaults

Config file discovery

If --config is not provided, the watchdog looks for fundus_camera_watchdog.json in the watch directory (or the current directory if --watch-dir is also omitted). Use --create-config to generate a sample.

Example fundus_camera_watchdog.json:

{
    "watch_dir": "C:\\RetCamOutput",
    "api_url": "https://edc.example.com",
    "device_id": "RET-CAM-001",
    "site_id": "40",
    "report_type": "combined",
    "subject_folder_pattern": "^(?P<subject_identifier>\\d{3}-\\d{2}-\\d{4}-\\d)_$",
    "filename_eye_pattern": "(?P<eye>OD|OS)"
}

Required settings

watch_dir

Folder the camera writes subject subfolders to. Defaults to the current directory if not provided.

api_url

Base URL of the EDC server (e.g. https://edc.example.com).

token

DRF authentication token. Can be provided via --token, the config file, or FUNDUS_CAMERA_WATCHDOG_TOKEN env var (recommended).

Optional settings

device_id

Identifier for this camera (sent to the server on resolve).

site_id

Study site identifier.

report_type

How the camera produces report files. combined (default) means a single HTML file covers both eyes; per_eye means one HTML per eye.

subject_folder_pattern

Regex to match subject folder names in the watch directory. Use a named group subject_identifier to extract the ID from the folder name. Default: ^(?P<subject_identifier>.+)$ (matches everything, folder name used as-is).

Example for folders like 105-40-1232-0_:

"subject_folder_pattern": "^(?P<subject_identifier>\\d{3}-\\d{2}-\\d{4}-\\d)_$"

This matches the folder and extracts 105-40-1232-0 as the subject identifier (stripping the trailing underscore).

filename_eye_pattern

Regex to extract eye laterality from filenames. Use a named group eye. Default: (?P<eye>OD|OS).

The extracted value is normalised automatically. All of the following are recognised:

• Left eye: L, LE, OS, LEFT

• Right eye: R, RE, OD, RIGHT

log_level

One of DEBUG, INFO (default), WARNING, ERROR.

Usage

Run from the camera output folder:

cd C:\RetCamOutput
uvx fundus-camera-watchdog

With an explicit config file:

uvx fundus-camera-watchdog --config C:\path\to\fundus_camera_watchdog.json

CLI flags override any value from the config file:

uvx fundus-camera-watchdog --log-level DEBUG --report-type per_eye

Without a config file:

uvx fundus-camera-watchdog ^
    --watch-dir C:\RetCamOutput ^
    --api-url https://edc.example.com ^
    --token YOUR_TOKEN ^
    --device-id RET-CAM-001 ^
    --subject-folder-pattern "^(?P<subject_identifier>\d{3}-\d{2}-\d{4}-\d)_$"

Stop with Ctrl+C.

What it does

The watchdog runs continuously and performs the following for each subject:

1. Detect – watches for new files in subject subfolders using filesystem events (watchdog), plus a periodic sweep every 60 seconds as a safety net.

2. Wait – each file is given up to 30 seconds to stabilise (stop growing) before being registered.

3. Classify – extracts eye laterality from each filename using the configured pattern. Maps files to API types:

   • *.jpg + OD -> right

   • *.jpg + OS -> left

   • *.dcm + OD -> right_dicom

   • *.dcm + OS -> left_dicom

   • *.html (combined) -> report

   • *.html + OD (per_eye) -> right_report

   • *.html + OS (per_eye) -> left_report

4. Resolve – POST /api/retinopathy/resolve/ confirms a CameraSession exists on the server for this subject.

5. Upload – sends each file to the server. Original filenames are preserved. Each upload includes a SHA-256 checksum. Multiple files per eye are supported.

6. Verify – GET .../status/ confirms the session received the expected files.

7. Archive – the subject folder is moved to <watch-dir>/processed/<subject_id>_<timestamp>/.

Error handling

• Retries – every API call is retried up to 3 times with a 5-second delay.

• Failed subjects – if any step fails, the subject is left in place and retried on the next 60-second sweep.

• Startup scan – on (re)start the watchdog scans all existing subject folders, picking up where it left off.

• Thread safety – file detection and upload run on separate threads with proper locking.