{"bundle_type":"pith_open_graph_bundle","bundle_version":"1.0","pith_number":"pith:2026:4JPGVCJYR4QYXKFSW37EROPSIQ","short_pith_number":"pith:4JPGVCJY","canonical_record":{"source":{"id":"2606.07365","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-05T15:08:50Z","cross_cats_sorted":["cs.AI"],"title_canon_sha256":"5b7d6147f7254f644c53bf1a83fe6f4dbec3c94317d575727e4c7adfd5347faf","abstract_canon_sha256":"2b8c051d3d5745018aa85270b23dc23d244aadf2121ce37ea4b3f036a51f40c3"},"schema_version":"1.0"},"canonical_sha256":"e25e6a89388f218ba8b2b6fe48b9f2442be76d31a8285bdd7bccab76620f47da","source":{"kind":"arxiv","id":"2606.07365","version":1},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.07365","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"arxiv_version","alias_value":"2606.07365v1","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.07365","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"pith_short_12","alias_value":"4JPGVCJYR4QY","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"pith_short_16","alias_value":"4JPGVCJYR4QYXKFS","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"pith_short_8","alias_value":"4JPGVCJY","created_at":"2026-06-08T01:05:22Z"}],"events":[{"event_type":"record_created","subject_pith_number":"pith:2026:4JPGVCJYR4QYXKFSW37EROPSIQ","target":"record","payload":{"canonical_record":{"source":{"id":"2606.07365","kind":"arxiv","version":1},"metadata":{"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-05T15:08:50Z","cross_cats_sorted":["cs.AI"],"title_canon_sha256":"5b7d6147f7254f644c53bf1a83fe6f4dbec3c94317d575727e4c7adfd5347faf","abstract_canon_sha256":"2b8c051d3d5745018aa85270b23dc23d244aadf2121ce37ea4b3f036a51f40c3"},"schema_version":"1.0"},"canonical_sha256":"e25e6a89388f218ba8b2b6fe48b9f2442be76d31a8285bdd7bccab76620f47da","receipt":{"kind":"pith_receipt","key_id":"pith-v1-2026-05","algorithm":"ed25519","signed_at":"2026-06-08T01:05:22.272487Z","signature_b64":"owvLsRvcyazpG+DqzCGaY+FxlXrXtM4cZfOrWND/uMmlcDGa1GsDdp+YfoDOXy096pZZJo3/M+d7as2Rwq/XCQ==","signed_message":"canonical_sha256_bytes","builder_version":"pith-number-builder-2026-05-17-v1","receipt_version":"0.3","canonical_sha256":"e25e6a89388f218ba8b2b6fe48b9f2442be76d31a8285bdd7bccab76620f47da","last_reissued_at":"2026-06-08T01:05:22.271681Z","signature_status":"signed_v1","first_computed_at":"2026-06-08T01:05:22.271681Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"source_kind":"arxiv","source_id":"2606.07365","source_version":1,"attestation_state":"computed"},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-08T01:05:22Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"VvUUCXuUJ7aUT6gjzGhXVSvR8ThGEfibdcoGiq8pxQxGzAVVFaQiB6LxqrUPJqbTpskDNmLOmXJUJBvzOZPKDQ==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-03T00:56:43.393365Z"},"content_sha256":"e31499a9b9335455270f0efd8132cbaabcc2edb60051760c8b0f73206f09d639","schema_version":"1.0","event_id":"sha256:e31499a9b9335455270f0efd8132cbaabcc2edb60051760c8b0f73206f09d639"},{"event_type":"graph_snapshot","subject_pith_number":"pith:2026:4JPGVCJYR4QYXKFSW37EROPSIQ","target":"graph","payload":{"graph_snapshot":{"paper":{"title":"A robust PPG foundation model using multimodal physiological supervision","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","headline":"","cross_cats":["cs.AI"],"primary_cat":"cs.LG","authors_text":"Daniel P. Darcy, Eloy Geenjaar, Gouthaman KV, Lie Lu, Scott Daly, Trisha Mittal, Vince Calhoun","submitted_at":"2026-06-05T15:08:50Z","abstract_excerpt":"Photoplethysmography (PPG), a non-invasive measure of changes in blood volume, is widely used in both wearable devices and clinical settings. Recent PPG foundation models either use open-source ICU datasets with pretraining paradigms that require curated data and thus complicate generalization to field-like data, or use closed-source field-like PPG data. In contrast, we propose a PPG foundation model that does not require high-quality or field-like pretraining data, and instead leverages accompanying electrocardiogram and respiratory signals in ICU datasets to select contrastive samples during"},"claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.07365","kind":"arxiv","version":1},"verdict":{"id":null,"model_set":{},"created_at":null,"strongest_claim":"","one_line_summary":"","pipeline_version":null,"weakest_assumption":"","pith_extraction_headline":""},"integrity":{"clean":true,"summary":{"advisory":0,"critical":0,"by_detector":{},"informational":0},"endpoint":"/pith/2606.07365/integrity.json","findings":[],"available":true,"detectors_run":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938"},"references":{"count":0,"sample":[],"resolved_work":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","internal_anchors":0},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"author_claims":{"count":0,"strong_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"builder_version":"pith-number-builder-2026-05-17-v1"},"verdict_id":null},"signer":{"signer_id":"pith.science","signer_type":"pith_registry","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54"},"created_at":"2026-06-08T01:05:22Z","supersedes":[],"prev_event":null,"signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"LehydpnrLCNg5CNmzY113Y48tRamFDynpkz5KEBDbSh3p0r5otdY+AxB66Po2yE4vcNiTr1MWE4gcz/8ifKCBw==","signed_message":"open_graph_event_sha256_bytes","signed_at":"2026-07-03T00:56:43.393761Z"},"content_sha256":"64155ab51150390af59595884395ece53a25959783478fba3f54b75268a3b554","schema_version":"1.0","event_id":"sha256:64155ab51150390af59595884395ece53a25959783478fba3f54b75268a3b554"}],"timestamp_proofs":[],"mirror_hints":[{"mirror_type":"https","name":"Pith Resolver","base_url":"https://pith.science","bundle_url":"https://pith.science/pith/4JPGVCJYR4QYXKFSW37EROPSIQ/bundle.json","state_url":"https://pith.science/pith/4JPGVCJYR4QYXKFSW37EROPSIQ/state.json","well_known_bundle_url":"https://pith.science/.well-known/pith/4JPGVCJYR4QYXKFSW37EROPSIQ/bundle.json","status":"primary"}],"public_keys":[{"key_id":"pith-v1-2026-05","algorithm":"ed25519","format":"raw","public_key_b64":"stVStoiQhXFxp4s2pdzPNoqVNBMojDU/fJ2db5S3CbM=","public_key_hex":"b2d552b68890857171a78b36a5dccf368a953413288c353f7c9d9d6f94b709b3","fingerprint_sha256_b32_first128bits":"RVFV5Z2OI2J3ZUO7ERDEBCYNKS","fingerprint_sha256_hex":"8d4b5ee74e4693bcd1df2446408b0d54","rotates_at":null,"url":"https://pith.science/pith-signing-key.json","notes":"Pith uses this Ed25519 key to sign canonical record SHA-256 digests. Verify with: ed25519_verify(public_key, message=canonical_sha256_bytes, signature=base64decode(signature_b64))."}],"merge_version":"pith-open-graph-merge-v1","built_at":"2026-07-03T00:56:43Z","links":{"resolver":"https://pith.science/pith/4JPGVCJYR4QYXKFSW37EROPSIQ","bundle":"https://pith.science/pith/4JPGVCJYR4QYXKFSW37EROPSIQ/bundle.json","state":"https://pith.science/pith/4JPGVCJYR4QYXKFSW37EROPSIQ/state.json","well_known_bundle":"https://pith.science/.well-known/pith/4JPGVCJYR4QYXKFSW37EROPSIQ/bundle.json"},"state":{"state_type":"pith_open_graph_state","state_version":"1.0","pith_number":"pith:2026:4JPGVCJYR4QYXKFSW37EROPSIQ","merge_version":"pith-open-graph-merge-v1","event_count":2,"valid_event_count":2,"invalid_event_count":0,"equivocation_count":0,"current":{"canonical_record":{"metadata":{"abstract_canon_sha256":"2b8c051d3d5745018aa85270b23dc23d244aadf2121ce37ea4b3f036a51f40c3","cross_cats_sorted":["cs.AI"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-05T15:08:50Z","title_canon_sha256":"5b7d6147f7254f644c53bf1a83fe6f4dbec3c94317d575727e4c7adfd5347faf"},"schema_version":"1.0","source":{"id":"2606.07365","kind":"arxiv","version":1}},"source_aliases":[{"alias_kind":"arxiv","alias_value":"2606.07365","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"arxiv_version","alias_value":"2606.07365v1","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"doi","alias_value":"10.48550/arxiv.2606.07365","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"pith_short_12","alias_value":"4JPGVCJYR4QY","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"pith_short_16","alias_value":"4JPGVCJYR4QYXKFS","created_at":"2026-06-08T01:05:22Z"},{"alias_kind":"pith_short_8","alias_value":"4JPGVCJY","created_at":"2026-06-08T01:05:22Z"}],"graph_snapshots":[{"event_id":"sha256:64155ab51150390af59595884395ece53a25959783478fba3f54b75268a3b554","target":"graph","created_at":"2026-06-08T01:05:22Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"graph_snapshot":{"author_claims":{"count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57","strong_count":0},"builder_version":"pith-number-builder-2026-05-17-v1","claims":{"count":0,"items":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"formal_canon":{"evidence_count":0,"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"integrity":{"available":true,"clean":true,"detectors_run":[],"endpoint":"/pith/2606.07365/integrity.json","findings":[],"snapshot_sha256":"c28c3603d3b5d939e8dc4c7e95fa8dfce3d595e45f758748cecf8e644a296938","summary":{"advisory":0,"by_detector":{},"critical":0,"informational":0}},"paper":{"abstract_excerpt":"Photoplethysmography (PPG), a non-invasive measure of changes in blood volume, is widely used in both wearable devices and clinical settings. Recent PPG foundation models either use open-source ICU datasets with pretraining paradigms that require curated data and thus complicate generalization to field-like data, or use closed-source field-like PPG data. In contrast, we propose a PPG foundation model that does not require high-quality or field-like pretraining data, and instead leverages accompanying electrocardiogram and respiratory signals in ICU datasets to select contrastive samples during","authors_text":"Daniel P. Darcy, Eloy Geenjaar, Gouthaman KV, Lie Lu, Scott Daly, Trisha Mittal, Vince Calhoun","cross_cats":["cs.AI"],"headline":"","license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-05T15:08:50Z","title":"A robust PPG foundation model using multimodal physiological supervision"},"references":{"count":0,"internal_anchors":0,"resolved_work":0,"sample":[],"snapshot_sha256":"258153158e38e3291e3d48162225fcdb2d5a3ed65a07baac614ab91432fd4f57"},"source":{"id":"2606.07365","kind":"arxiv","version":1},"verdict":{"created_at":null,"id":null,"model_set":{},"one_line_summary":"","pipeline_version":null,"pith_extraction_headline":"","strongest_claim":"","weakest_assumption":""}},"verdict_id":null}}],"author_attestations":[],"timestamp_anchors":[],"storage_attestations":[],"citation_signatures":[],"replication_records":[],"corrections":[],"mirror_hints":[],"record_created":{"event_id":"sha256:e31499a9b9335455270f0efd8132cbaabcc2edb60051760c8b0f73206f09d639","target":"record","created_at":"2026-06-08T01:05:22Z","signer":{"key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signer_id":"pith.science","signer_type":"pith_registry"},"payload":{"attestation_state":"computed","canonical_record":{"metadata":{"abstract_canon_sha256":"2b8c051d3d5745018aa85270b23dc23d244aadf2121ce37ea4b3f036a51f40c3","cross_cats_sorted":["cs.AI"],"license":"http://creativecommons.org/licenses/by-nc-nd/4.0/","primary_cat":"cs.LG","submitted_at":"2026-06-05T15:08:50Z","title_canon_sha256":"5b7d6147f7254f644c53bf1a83fe6f4dbec3c94317d575727e4c7adfd5347faf"},"schema_version":"1.0","source":{"id":"2606.07365","kind":"arxiv","version":1}},"canonical_sha256":"e25e6a89388f218ba8b2b6fe48b9f2442be76d31a8285bdd7bccab76620f47da","receipt":{"algorithm":"ed25519","builder_version":"pith-number-builder-2026-05-17-v1","canonical_sha256":"e25e6a89388f218ba8b2b6fe48b9f2442be76d31a8285bdd7bccab76620f47da","first_computed_at":"2026-06-08T01:05:22.271681Z","key_id":"pith-v1-2026-05","kind":"pith_receipt","last_reissued_at":"2026-06-08T01:05:22.271681Z","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","receipt_version":"0.3","signature_b64":"owvLsRvcyazpG+DqzCGaY+FxlXrXtM4cZfOrWND/uMmlcDGa1GsDdp+YfoDOXy096pZZJo3/M+d7as2Rwq/XCQ==","signature_status":"signed_v1","signed_at":"2026-06-08T01:05:22.272487Z","signed_message":"canonical_sha256_bytes"},"source_id":"2606.07365","source_kind":"arxiv","source_version":1}}},"equivocations":[],"invalid_events":[],"applied_event_ids":["sha256:e31499a9b9335455270f0efd8132cbaabcc2edb60051760c8b0f73206f09d639","sha256:64155ab51150390af59595884395ece53a25959783478fba3f54b75268a3b554"],"state_sha256":"7e859b50a400d319bd6d0bb22d887356b87302c7958f121ec57153af71b2b5c9"},"bundle_signature":{"signature_status":"signed_v1","algorithm":"ed25519","key_id":"pith-v1-2026-05","public_key_fingerprint":"8d4b5ee74e4693bcd1df2446408b0d54","signature_b64":"gqzbaQSyEtJ8vHtxy8VstYRDd/J7aTobik4zM8ikpvUKCF7RIDf0MXYMdcwQvBZoIeOilM+jCewo/MJeHbfaAA==","signed_message":"bundle_sha256_bytes","signed_at":"2026-07-03T00:56:43.396218Z","bundle_sha256":"4b7721c71ba756cdf1bf4b02e1321b24d6da6a2bda181e2461f5068ca64240e2"}}