A Neurosymbolic Approach for Constructing Planning Domain Models from Clinical Narratives
Authors: Ranveer Singh, Saurabh Mathur, Michael Skinner, Prasad Tadepalli, Kristian Kersting, Sriraam Natarajan
Organizations: The University of Texas at Dallas, Richardson, TX, USA · Technical University of Darmstadt, Darmstadt, Germany · Oregon State University, Corvallis, OR, USA · Hessian Center for Artificial Intelligence (hessian.ai), Darmstadt, Germany · German Research Center for AI (DFKI)
Surgical procedures such as laparoscopic appendectomy are complex, high-stakes processes, yet formalizing their workflows for decision support remains a significant challenge. Inducing probabilistic planning domain models in this setting is particularly difficult due to the lack of structured event data and the prevalence of implicit actions in clinical narratives, which neither empirical symbolic methods nor Large Language Models (LLMs) can adequately address on their own. We introduce NSPIN, a neurosymbolic framework for inducing probabilistic planning domain models from unstructured clinical narratives. Our method extracts and imputes structured event sequences from raw text using a pretrained LLM, then induces a PPDDL model and refines its preconditions with LLM-proposed revisions, guided by empirical validation. We evaluate the approach on 2,660 laparoscopic appendectomy notes written by 9 surgeons. NSPIN yields models that generalize to unseen notes, and expert clinical review indicates its induced knowledge is largely consistent with surgical practice.
Figures & tables
Figure 1: The NSPIN framework for inducing probabilistic planning models from clinical narratives. Our neurosymbolic approach extracts structured predicates from unstructured surgical notes using an LLM. It uses this structured information to synthesize a planning model that generalizes across diverse surgical workflows. Using an LLM to ground each action and observation in the text allows NSPIN to account for both explicit and implicitly mentioned information.
Figure 2: A partial surgical sequence sampled using an action-transition model and NSPIN. NSPIN learns action preconditions that constrain the set of possible next actions, along with observational effects each action probabilistically produces. These emitted observations provide context for a simple data-driven action-transition model used for sampling candidate actions. Blue nodes represent sampled actions, gray nodes represent emitted observations, orange arrows indicate candidate precondition relationships, and gray arrows indicate observation flow. In this example, port placement is followed by the observation of adhesions, which then provides contributing context for performing an adhesiolysis.
Figure 3: Surgical Note lengths and counts across surgeons
Dataset
Top-1 Acc
Top-3 Acc
Avg NLL
↑ is better
↑ is better
↓ is better
Imputed
0.32±0.07
0.51±0.10
9.33±2.35
Non-Imputed
0.24±0.09
0.39±0.12
11.85±2.85
Table 1: Action set prediction performance comparison across imputed and non-imputed datasets
Method
Top-1 Acc
Top-3 Acc
Avg NLL
↑ is better
↑ is better
↓ is better
NSPIN (w/wo) Refinement
0.88±0.03
0.93±0.03
1.67±0.60
LLM with Example
0.56±0.23
0.56±0.23
9.22±4.76
LLM only
0.78±0.09
0.78±0.09
4.72±1.80
Table 2: Observation prediction performance comparison on the imputed dataset across different methods
Method
Top-1 Acc
Top-3 Acc
Avg NLL
TADR
↑ is better
↑ is better
↓ is better
↓ is better
NSPIN
0.42±0.07
0.64±0.08
6.08±1.57
0.16±0.06
NSPIN w/o Refinement
0.32±0.07
0.51±0.09
9.33±2.22
0.36±0.12
LLM with Example
0.09±0.16
0.19±0.27
16.28±6.34
0.74±0.36
LLM only
0.20±0.13
0.27±0.16
15.05±3.49
0.68±0.19
Table 3: Action prediction performance comparison on the imputed dataset across different methods
Robotics and Autonomous Systems (AI), Arizona State University, Tempe, USA · Department of Artificial Intelligence, Kyungpook National University, Daegu, South Korea