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Inspector BIDS-physio + PRISM Studio Export Workflow

RRational supports two complementary standards for sharing cardiac recordings beyond the inspector:

  • BIDS-physio — the Brain Imaging Data Structure specification for physiological recordings, the de-facto standard for multi-modal (EEG / fMRI + cardiac) study packaging.
  • PRISM Studio biometrics — a single-row summary-metrics format used by the PRISM Studio framework for psychological-research workflows.

Both exporters live under the Tools menu and operate on the active recording (the dataset currently shown in the Participant tab).

Exporting to BIDS-physio

Step-by-step

  1. Load a recording into the inspector (see Inspector Workflows).
  2. Open the Tools menu and choose Export to BIDS-physio….
  3. In the dialog:
  4. Participant ID (sub-<id>) — required, alphanumeric.
  5. Session ID (ses-<id>) — optional, omit for single-session studies.
  6. Task name (task-<name>) — required, defaults to cardiac.
  7. Output directory — typically your BIDS root or a sourcedata/ subfolder.
  8. Anonymize — see below.
  9. Click Export. RRational writes two files into the chosen directory.

Output naming

sub-<pid>[_ses-<ses>]_task-<task>_recording-cardiac_physio.tsv.gz
sub-<pid>[_ses-<ses>]_task-<task>_recording-cardiac_physio.json

The .tsv.gz is a single-column gzipped TSV of RR intervals (ms). The .json sidecar carries the BIDS-required metadata for the recording.

Sidecar fields

Required (BIDS spec):

  • SamplingFrequency — populated with the mean beat rate (Hz, computed as 1 / mean(RR_seconds)) per the BIDS-spec documented workaround for event-spaced cardiac data.
  • StartTime — recording start, in seconds relative to the run start.
  • Columns — ["cardiac"].

Recommended:

  • Manufacturer — original device vendor when known.
  • RecordingDuration — in seconds.
  • RecordingType — "continuous".

Anonymize switch:

Ticking the Anonymize checkbox in the export dialog:

  • Shifts the acq_date field back by a configurable N days (DSGVO / HIPAA-style date offset).
  • Strips the experimenter and description fields from the sidecar.
  • Replaces participant-identifying free-text with the canonical sub-<id> token only.

For data-sharing in EU contexts, Anonymize is the recommended default.

Round-trip — re-importing your own BIDS export

The same .tsv.gz + .json pair produced by Tools → Export to BIDS-physio… can be re-loaded via File → Open recording… and picking the .tsv.gz. The importer:

  1. Reads the JSON sidecar for sampling-frequency hints and metadata.
  2. Treats the single column as the RR series (in ms).
  3. Reconstructs an internal annotation list with synthetic recording_start / recording_end events if the sidecar carries no event timing.

This round-trip is verified by the inspector test suite — see tests/inspector/test_bids_physio_round_trip.py.

PRISM Studio biometrics — for psych research

The PRISM Studio framework expects HRV summary metrics rather than the full time-series. To export:

  1. Run an analysis (Single Participant or Repeating Section) so metrics are computed.
  2. Open Tools → Export to PRISM biometrics….
  3. Choose an output directory. RRational writes:
  4. A single-row .tsv with the canonical HRV columns (MeanNN, SDNN, RMSSD, pNN50, LF, HF, LF/HF, SD1, SD2, SD1/SD2).
  5. A matching .json sidecar with PRISM's three required blocks:
    • Technical — sampling, detector version, correction flags.
    • Study — participant ID, group, session, condition.
    • Metadata — RRational version, export timestamp.

The PRISM exporter is summary-only by design — the time-series itself stays in your project as .rrational v2. If you need the time-series in a PRISM workflow, use the BIDS-physio exporter alongside.

See also