Felix Nensa
Author directory2026
Configurable Clinical Information Extraction with Agentic RAG: What Works, What Breaks, and Why
Osman Alperen Çinar-Koraş | Marie Bauer | Sameh Khattab | Merlin Engelke | Moon Kim | Stephan Settelmeier | Shigeyasu Sugawara | Fabian Freisleben | Felix Nensa | Jens Kleesiek
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Osman Alperen Çinar-Koraş | Marie Bauer | Sameh Khattab | Merlin Engelke | Moon Kim | Stephan Settelmeier | Shigeyasu Sugawara | Fabian Freisleben | Felix Nensa | Jens Kleesiek
Proceedings of the 2026 Conference on Empirical Methods in Natural Language Processing: Industry Track
Patient contexts span hundreds of heterogeneous documents and thousands of structured data points, yet the document-level metadata that AI systems need for retrieval and triage is absent or incomplete. Standard retrieval-augmented generation fails on this data, mishandling temporal reasoning, cross-document dependencies, and missing metadata. We report on the deployment of ACIE (Agentic Clinical Information Extraction) at University Medicine Essen: an on-premise agentic RAG pipeline that reasons over complete patient contexts and grounds every answer in source passages for clinician verification. We quantify the metadata gap, trace the architectural decisions it shaped, and evaluate extraction alongside an independent retrospective lymphoma registry study, in which nuclear-medicine physicians verify every extracted value against its cited sources. Across 7,326 clinician judgments on this lymphoma-registry workflow, 96.5% of extractions were accepted, with per-type acceptance ranging from 80% to 99%.
WisPerMed at ArchEHR-QA 2026: Retrieval-Augmented Prompting for Grounded EHR Question Answering
Jan-Henning Büns | Tabea Margareta Grace Pakull | Hendrik Damm | Bohao Chu | Christoph M. Friedrich | Felix Nensa | Elisabeth Livingstone | Peter A. Horn | Norbert Fuhr
Proceedings of the Third Workshop on Patient-Oriented Language Processing (CL4Health) @ LREC 2026
Jan-Henning Büns | Tabea Margareta Grace Pakull | Hendrik Damm | Bohao Chu | Christoph M. Friedrich | Felix Nensa | Elisabeth Livingstone | Peter A. Horn | Norbert Fuhr
Proceedings of the Third Workshop on Patient-Oriented Language Processing (CL4Health) @ LREC 2026
ArchEHR-QA is a grounded question-answering (QA) task for electronic health records (EHRs) comprising four subtasks: (1) question rewriting, (2) evidence identification, (3) grounded answer generation, and (4) answer-evidence alignment. In this work, we present a modular pipeline centered on retrieval-augmented generation (RAG). For Subtask 1, RAG few-shot prompting outperformed both PEFT and prompt-only baselines on the development set; however, Claude few-shot proved substantially more robust on the test set, ranking 6th out of 13 participating teams (score: 26.94). For Subtask 2, a union ensemble of open-weight LLMs (GPT-OSS-120B and Qwen3-30B-A3B) achieved a 56.7 micro-F1, rivaling the proprietary Claude Opus 4.6 while demonstrating higher recall (53.6). For Subtask 3, our RAG few-shot approach using Claude Opus 4.5 achieved the 1st place out of 13 participating teams (score: 36.33). Finally, for Subtask 4, a zero-shot Claude Opus 4.6 configuration ranked 2nd out of 16 participating teams (score: 81.3).
2025
WisPerMed at ArchEHR-QA 2025: A Modular, Relevance-First Approach for Grounded Question Answering on Eletronic Health Records
Jan-Henning Büns | Hendrik Damm | Tabea Pakull | Felix Nensa | Elisabeth Livingstone
Proceedings of the 24th Workshop on Biomedical Language Processing (Shared Tasks)
Jan-Henning Büns | Hendrik Damm | Tabea Pakull | Felix Nensa | Elisabeth Livingstone
Proceedings of the 24th Workshop on Biomedical Language Processing (Shared Tasks)
2024
Comprehensive Study on German Language Models for Clinical and Biomedical Text Understanding
Ahmad Idrissi-Yaghir | Amin Dada | Henning Schäfer | Kamyar Arzideh | Giulia Baldini | Jan Trienes | Max Hasin | Jeanette Bewersdorff | Cynthia S. Schmidt | Marie Bauer | Kaleb E. Smith | Jiang Bian | Yonghui Wu | Jörg Schlötterer | Torsten Zesch | Peter A. Horn | Christin Seifert | Felix Nensa | Jens Kleesiek | Christoph M. Friedrich
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Ahmad Idrissi-Yaghir | Amin Dada | Henning Schäfer | Kamyar Arzideh | Giulia Baldini | Jan Trienes | Max Hasin | Jeanette Bewersdorff | Cynthia S. Schmidt | Marie Bauer | Kaleb E. Smith | Jiang Bian | Yonghui Wu | Jörg Schlötterer | Torsten Zesch | Peter A. Horn | Christin Seifert | Felix Nensa | Jens Kleesiek | Christoph M. Friedrich
Proceedings of the 2024 Joint International Conference on Computational Linguistics, Language Resources and Evaluation (LREC-COLING 2024)
Recent advances in natural language processing (NLP) can be largely attributed to the advent of pre-trained language models such as BERT and RoBERTa. While these models demonstrate remarkable performance on general datasets, they can struggle in specialized domains such as medicine, where unique domain-specific terminologies, domain-specific abbreviations, and varying document structures are common. This paper explores strategies for adapting these models to domain-specific requirements, primarily through continuous pre-training on domain-specific data. We pre-trained several German medical language models on 2.4B tokens derived from translated public English medical data and 3B tokens of German clinical data. The resulting models were evaluated on various German downstream tasks, including named entity recognition (NER), multi-label classification, and extractive question answering. Our results suggest that models augmented by clinical and translation-based pre-training typically outperform general domain models in medical contexts. We conclude that continuous pre-training has demonstrated the ability to match or even exceed the performance of clinical models trained from scratch. Furthermore, pre-training on clinical data or leveraging translated texts have proven to be reliable methods for domain adaptation in medical NLP tasks.
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Co-authors
- Marie Bauer 2
- Jan-Henning Büns 2
- Hendrik Damm 2
- Christoph Friedrich 2
- Peter A. Horn 2
- Jens Kleesiek 2
- Elisabeth Livingstone 2
- Kamyar Arzideh 1
- Giulia Baldini 1
- Jeanette Bewersdorff 1
- Jiang Bian 1
- Bohao Chu 1
- Amin Dada 1
- Merlin Engelke 1
- Fabian Freisleben 1
- Norbert Fuhr 1
- Max Hasin 1
- Ahmad Idrissi-Yaghir 1
- Sameh Khattab 1
- Moon Kim 1
- Osman Alperen Koraş 1
- Tabea Pakull 1
- Tabea Margareta Grace Pakull 1
- Jörg Schlötterer 1
- Cynthia S. Schmidt 1
- Henning Schäfer 1
- Christin Seifert 1
- Stephan Settelmeier 1
- Kaleb E Smith 1
- Shigeyasu Sugawara 1
- Jan Trienes 1
- Yonghui Wu 1
- Torsten Zesch 1