|
| 1 | +pyhealth.datasets.FHIRDataset |
| 2 | +===================================== |
| 3 | + |
| 4 | +A generic, config-driven NDJSON ingest for `HL7 FHIR |
| 5 | +<https://www.hl7.org/fhir/>`_ datasets. The whole pipeline is described by **a |
| 6 | +single YAML config** with three top-level sections — what files to read, how to |
| 7 | +turn each FHIR resource into a flat row, and how those rows appear as events |
| 8 | +downstream. A custom FHIR ingest is "point at a YAML" — no Python required. |
| 9 | + |
| 10 | +The bundled :class:`~pyhealth.datasets.MIMIC4FHIR` subclass uses this engine |
| 11 | +with the ``pyhealth/datasets/fhir/configs/mimic4fhir.yaml`` config tuned for |
| 12 | +PhysioNet's MIMIC-IV on FHIR export. See the sub-page below for the quick-start. |
| 13 | + |
| 14 | +.. contents:: On this page |
| 15 | + :local: |
| 16 | + :depth: 1 |
| 17 | + |
| 18 | + |
| 19 | +Quick start |
| 20 | +----------- |
| 21 | + |
| 22 | +.. code-block:: python |
| 23 | +
|
| 24 | + from pyhealth.datasets import MIMIC4FHIR, get_dataloader, split_by_patient |
| 25 | + from pyhealth.tasks.mpf_clinical_prediction import MPFClinicalPredictionTask |
| 26 | + from pyhealth.models import EHRMambaCEHR |
| 27 | + from pyhealth.trainer import Trainer |
| 28 | +
|
| 29 | + def main(): |
| 30 | + ds = MIMIC4FHIR(root="/data/mimic-iv-fhir") |
| 31 | + sample_ds = ds.set_task(MPFClinicalPredictionTask(), num_workers=1) |
| 32 | + train, val, test = split_by_patient(sample_ds, [0.7, 0.1, 0.2]) |
| 33 | + vocab_size = sample_ds.input_processors["concept_ids"].vocab.vocab_size |
| 34 | + model = EHRMambaCEHR(dataset=sample_ds, vocab_size=vocab_size) |
| 35 | + Trainer(model=model).train( |
| 36 | + train_dataloader=get_dataloader(train, batch_size=8, shuffle=True), |
| 37 | + val_dataloader=get_dataloader(val, batch_size=8), |
| 38 | + epochs=2, |
| 39 | + ) |
| 40 | +
|
| 41 | + if __name__ == "__main__": |
| 42 | + main() |
| 43 | +
|
| 44 | +(``if __name__ == "__main__":`` matters — :meth:`~pyhealth.datasets.BaseDataset.set_task` |
| 45 | +forks Dask workers; without the guard the workers re-import and re-spawn.) |
| 46 | + |
| 47 | + |
| 48 | +Pipeline at a glance |
| 49 | +-------------------- |
| 50 | + |
| 51 | +:: |
| 52 | + |
| 53 | + NDJSON shards on disk |
| 54 | + | |
| 55 | + | (Phase A) — stream line by line, route by resourceType, |
| 56 | + | project via the YAML's resource_specs |
| 57 | + v |
| 58 | + flattened_tables/<table>.parquet <- cache #1 |
| 59 | + | |
| 60 | + | (Phase B) — load_table, dd.concat, sort by patient_id (Dask) |
| 61 | + v |
| 62 | + global_event_df.parquet/part-*.parquet <- cache #2 |
| 63 | + | |
| 64 | + | (Phase C) — task_transform per-patient sample emit |
| 65 | + v |
| 66 | + task_df.ld/ <- cache #3a |
| 67 | + | |
| 68 | + | fit CehrProcessor vocab via SampleBuilder.fit(dataset) |
| 69 | + | proc_transform per-sample tensorisation |
| 70 | + v |
| 71 | + samples_*.ld/ <- cache #3b ──> SampleDataset |
| 72 | + |
| 73 | +Each of the three cache tiers has its own existence check; re-running with |
| 74 | +identical inputs skips every phase. Cache identity hashes the YAML byte digest, |
| 75 | +glob patterns, ``max_patients``, and engine schema version — any meaningful |
| 76 | +config change invalidates everything below it. See |
| 77 | +:class:`~pyhealth.datasets.BaseDataset` for the Phase B/C internals that are |
| 78 | +shared with all other PyHealth datasets. |
| 79 | + |
| 80 | + |
| 81 | +The unified YAML config |
| 82 | +----------------------- |
| 83 | + |
| 84 | +A FHIR ingest YAML has three top-level sections. The bundled |
| 85 | +``mimic4fhir.yaml`` is the canonical worked example; what follows is the |
| 86 | +section-by-section reference. |
| 87 | + |
| 88 | +Section 1: ``glob_patterns:`` (which files to read) |
| 89 | +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 90 | + |
| 91 | +.. code-block:: yaml |
| 92 | +
|
| 93 | + glob_patterns: |
| 94 | + - "**/MimicPatient*.ndjson.gz" |
| 95 | + - "**/MimicEncounter*.ndjson.gz" |
| 96 | + # ... one pattern per resource-type shard family |
| 97 | +
|
| 98 | +Defaults to ``["**/*.ndjson.gz"]`` when omitted. Only worth setting when your |
| 99 | +export has a per-resource-type file-naming convention you want to exploit for |
| 100 | +speed — PhysioNet MIMIC-IV FHIR ships shards as ``MimicPatient*.ndjson.gz``, |
| 101 | +``MimicEncounter*.ndjson.gz``, etc., and filtering at the file level avoids |
| 102 | +decompressing ~10% of the export that contains only unconfigured resource |
| 103 | +types. For a generic export where everything is in ``bundles.ndjson.gz``, omit |
| 104 | +this block and the streamer will filter by ``resourceType`` after parsing. |
| 105 | + |
| 106 | +Override at runtime via ``MIMIC4FHIR(glob_pattern=...)`` or |
| 107 | +``MIMIC4FHIR(glob_patterns=[...])``. |
| 108 | + |
| 109 | +Section 2: ``resource_specs:`` (how to project JSON into rows) |
| 110 | +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 111 | + |
| 112 | +Keys are FHIR ``resourceType`` strings. For each, declare a ``table`` name and |
| 113 | +an ordered ``columns`` mapping: |
| 114 | + |
| 115 | +.. code-block:: yaml |
| 116 | +
|
| 117 | + resource_specs: |
| 118 | +
|
| 119 | + Patient: |
| 120 | + table: patient |
| 121 | + columns: |
| 122 | + patient_id: { locate: ["id"], required: true } |
| 123 | + birth_date: { locate: ["birthDate"] } |
| 124 | + gender: { locate: ["gender"] } |
| 125 | + deceased_boolean: { locate: ["deceasedBoolean"], transform: bool_norm } |
| 126 | +
|
| 127 | + Observation: |
| 128 | + table: observation |
| 129 | + columns: |
| 130 | + patient_id: { locate: ["subject.reference"], transform: ref_id, required: true } |
| 131 | + resource_id: { locate: ["id"] } |
| 132 | + encounter_id: { locate: ["encounter.reference"], transform: ref_id } |
| 133 | + event_time: { locate: ["effectiveDateTime", "effectivePeriod.start", "issued"] } |
| 134 | + concept_key: { locate: ["code"], transform: coding_key } |
| 135 | +
|
| 136 | +Each column entry has three fields: |
| 137 | + |
| 138 | +``locate`` *(required, list of dotted paths)* |
| 139 | + Ordered JSON paths into the resource; the first that resolves to a non-null |
| 140 | + value wins. This is how FHIR choice-types (``onset[x]``, ``effective[x]``, |
| 141 | + ``performed[x]``, …) are handled — list every variant explicitly. A single |
| 142 | + string is accepted as shorthand for a one-element list. |
| 143 | + |
| 144 | +``transform`` *(optional, name of a built-in transform, default ``identity``)* |
| 145 | + Maps the located leaf to a flat scalar string. See the registry below. |
| 146 | + |
| 147 | +``required`` *(optional, bool, default false)* |
| 148 | + When ``true``, a resource whose ``locate`` cannot be resolved is **dropped** |
| 149 | + (and logged) rather than emitted with a null. Use this on the patient |
| 150 | + reference column so events without a discoverable patient never reach the |
| 151 | + global event frame. |
| 152 | + |
| 153 | +Transform registry |
| 154 | +^^^^^^^^^^^^^^^^^^ |
| 155 | + |
| 156 | +Available transforms (defined in |
| 157 | +``pyhealth/datasets/fhir/utils.py`` ``TRANSFORMS`` dict): |
| 158 | + |
| 159 | +================== =========================================================== |
| 160 | +``identity`` Pass the value through. Stringifies non-string scalars. |
| 161 | +``ref_id`` Reference object or ``"Patient/p1"`` -> ``"p1"``. |
| 162 | +``coding_key`` CodeableConcept -> ``"system|code"`` of its first coding. |
| 163 | +``bool_norm`` JSON boolean / ``"true"``/``"false"`` -> ``"true"``/``"false"``/None. |
| 164 | +``med_concept`` MedicationRequest medication[x] -> codeable-concept or |
| 165 | + ``"MedicationRequest/reference|<id>"`` fallback. |
| 166 | +================== =========================================================== |
| 167 | + |
| 168 | +Adding a new transform is a one-liner: register a callable in ``TRANSFORMS`` |
| 169 | +in ``utils.py`` and reference it by name from the YAML. |
| 170 | + |
| 171 | +Section 3: ``tables:`` (how rows are exposed as events) |
| 172 | +~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 173 | + |
| 174 | +Keys here must match the ``table:`` values from Section 2. Each entry tells |
| 175 | +:meth:`~pyhealth.datasets.BaseDataset.load_table` how to read the flat parquet: |
| 176 | + |
| 177 | +.. code-block:: yaml |
| 178 | +
|
| 179 | + tables: |
| 180 | + patient: |
| 181 | + file_path: "patient.parquet" |
| 182 | + patient_id: "patient_id" |
| 183 | + timestamp: "birth_date" |
| 184 | + attributes: ["birth_date", "gender", "deceased_boolean"] |
| 185 | +
|
| 186 | + observation: |
| 187 | + file_path: "observation.parquet" |
| 188 | + patient_id: "patient_id" |
| 189 | + timestamp: "event_time" |
| 190 | + attributes: ["resource_id", "encounter_id", "event_time", "concept_key"] |
| 191 | +
|
| 192 | +``file_path`` is the parquet filename inside the cached |
| 193 | +``flattened_tables/`` directory. ``patient_id`` and ``timestamp`` name the |
| 194 | +columns to surface as the normalised ``patient_id`` and ``timestamp`` on each |
| 195 | +event. ``attributes`` is the list of columns surfaced as event attributes — in |
| 196 | +the global event frame they're renamed to ``{table}/{attr}`` and later show up |
| 197 | +on ``patient.get_events(event_type=...).attr_name``. |
| 198 | + |
| 199 | +Cross-section validation |
| 200 | +~~~~~~~~~~~~~~~~~~~~~~~~ |
| 201 | + |
| 202 | +At load time the dataset checks that every ``table:`` value declared in |
| 203 | +Section 2 has a matching ``tables.<name>`` block in Section 3. Typos surface |
| 204 | +as a config error at startup, not silent empty parquets. |
| 205 | + |
| 206 | + |
| 207 | +Customising for a non-MIMIC FHIR export |
| 208 | +--------------------------------------- |
| 209 | + |
| 210 | +Step 1 — write your YAML. |
| 211 | +~~~~~~~~~~~~~~~~~~~~~~~~~ |
| 212 | + |
| 213 | +Copy ``pyhealth/datasets/fhir/configs/mimic4fhir.yaml`` and adapt the |
| 214 | +``resource_specs:`` and ``tables:`` blocks for the resources you care about. |
| 215 | +For an export that adds Immunizations: |
| 216 | + |
| 217 | +.. code-block:: yaml |
| 218 | +
|
| 219 | + resource_specs: |
| 220 | + Patient: |
| 221 | + table: patient |
| 222 | + columns: |
| 223 | + patient_id: { locate: ["id"], required: true } |
| 224 | + birth_date: { locate: ["birthDate"] } |
| 225 | + Immunization: |
| 226 | + table: immunization |
| 227 | + columns: |
| 228 | + patient_id: { locate: ["patient.reference"], transform: ref_id, required: true } |
| 229 | + resource_id: { locate: ["id"] } |
| 230 | + event_time: { locate: ["occurrenceDateTime", "recorded"] } |
| 231 | + concept_key: { locate: ["vaccineCode"], transform: coding_key } |
| 232 | +
|
| 233 | + tables: |
| 234 | + patient: |
| 235 | + file_path: "patient.parquet" |
| 236 | + patient_id: "patient_id" |
| 237 | + timestamp: "birth_date" |
| 238 | + attributes: ["birth_date"] |
| 239 | + immunization: |
| 240 | + file_path: "immunization.parquet" |
| 241 | + patient_id: "patient_id" |
| 242 | + timestamp: "event_time" |
| 243 | + attributes: ["resource_id", "event_time", "concept_key"] |
| 244 | +
|
| 245 | +Step 2 — instantiate |
| 246 | +~~~~~~~~~~~~~~~~~~~~ |
| 247 | + |
| 248 | +Either pass ``config_path=...`` directly: |
| 249 | + |
| 250 | +.. code-block:: python |
| 251 | +
|
| 252 | + from pyhealth.datasets import FHIRDataset |
| 253 | +
|
| 254 | + ds = FHIRDataset( |
| 255 | + root="/data/my_fhir_export", |
| 256 | + config_path="/path/to/my_export.yaml", |
| 257 | + ) |
| 258 | +
|
| 259 | +or write a 3-line subclass that bundles your config: |
| 260 | + |
| 261 | +.. code-block:: python |
| 262 | +
|
| 263 | + from pyhealth.datasets import FHIRDataset |
| 264 | +
|
| 265 | + class MyFHIR(FHIRDataset): |
| 266 | + DEFAULT_CONFIG_PATH = "/path/to/my_export.yaml" |
| 267 | +
|
| 268 | + ds = MyFHIR(root="/data/my_fhir_export") |
| 269 | +
|
| 270 | +Step 3 — that's it. |
| 271 | +~~~~~~~~~~~~~~~~~~~ |
| 272 | + |
| 273 | +Everything downstream — :meth:`~pyhealth.datasets.BaseDataset.set_task`, |
| 274 | +:meth:`~pyhealth.datasets.BaseDataset.iter_patients`, |
| 275 | +:meth:`~pyhealth.datasets.BaseDataset.get_patient` — works the same as for any |
| 276 | +other PyHealth dataset. |
| 277 | + |
| 278 | + |
| 279 | +Notes on resource use |
| 280 | +--------------------- |
| 281 | + |
| 282 | +Streaming ingest avoids loading the whole NDJSON corpus into RAM, but downstream |
| 283 | +steps still scale with cohort size. For a **smoke run** the bundled example |
| 284 | +fixtures fit on any laptop. For a **laptop-scale real subset**, set |
| 285 | +``max_patients=`` and/or narrow ``glob_patterns`` to keep cache and task passes |
| 286 | +manageable; ≥16 GB system RAM is a comfort target for Polars + the trainer. |
| 287 | +For the **full PhysioNet export**, prefer fast SSD, large disk, and plenty of |
| 288 | +RAM — total work scales with the corpus size even if RAM ingest is bounded. |
| 289 | + |
| 290 | + |
| 291 | +Bundled FHIR datasets |
| 292 | +--------------------- |
| 293 | + |
| 294 | +.. toctree:: |
| 295 | + :maxdepth: 1 |
| 296 | + |
| 297 | + pyhealth.datasets.MIMIC4FHIR |
| 298 | + |
| 299 | + |
| 300 | +API reference |
| 301 | +------------- |
| 302 | + |
| 303 | +.. autoclass:: pyhealth.datasets.FHIRDataset |
| 304 | + :members: |
| 305 | + :undoc-members: |
| 306 | + :show-inheritance: |
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