A Four-Level Translational Approach to Modeling Surgical Processes Goldstein D1, Loebe F2, Herre H3, Neumuth T1 1 Universität Leipzig, Innovation Center Computer Assisted Surgery (ICCAS), Leipzig, Germany 2 Universität Leipzig, Department of Computer Science 3 Universität Leipzig, Institute of Medical Informatics, Statistics and Epidemiology (IMISE), Research Group Ontologies in Medicine and Life Sciences (OntoMed)

Surgical Process Models and Surgical Workflows Presentation Outline Surgical Process Models and Surgical Workflows Objectives and requirements The Four-level approach Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Workflows in hospitals Workflows in the operating room Environment Workflows in hospitals Workflows in the operating room Surgical Process Models and Surgical Workflows Die Arbeit bewegt sich im Kontext der Prozess- und Workflowmodellierung. Heutzutage existiert eine Vielzahl von Prozessen oder Workflows im Krankenhausbereich. Es gibt Beispielsweise die Patientenpfade oder Workflows im Administrationsbereich, z. B. bei der Abrechnung von Leistungen. In den letzten Jahren wurde am ICCAS im Rahmen der Promotionsarbeit das Forschungsgebiet der chirurgischen Workflows weiterentwickelt. Hauptmethodik des Arbeitsgebietes ist die Modellierung und Analyse von Operationsverläufen als Teil der komplexen Prozesse im Operationssaal. Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Surgical Workflow Examples Workflows for ambulatory (n=51) and inpatient (n=54) cataract interventions (phase: Capsulorhexis) 34% START 5% paracentesis paracentesis knife cornea inject healon chamber ant capsulorhexis rhexis cannula capsula lentis 100% 93% 81% 100% 51% 83% 12% 84% 92% inject vision blue chamber ant cut lancet clear cut cornea Sie sehen hier ein Beispiel für zwei statistisch gemittelte OP-Verläufe, die aus verschiedenen Populationen erstellt wurden. Dem Beispiel liegen ambulante und stationäre Katarakteingriffe von je ca. 50 Patienten zugrunde. Am Beispiel dieser OP-Phase lässt sich recht gut erkennen, an welchen Stellen Stellen im OP-Verlauf es Abweichungen zwischen den einzelnen OPs gab. Beide Workflows verliefen generell zwischen dem START und dem STOP entlang des schwarzen Pfades, welcher die grauen Kästen verbindet. In 12% der stationären OPs wurden jedoch über diese beiden zusätzlichen Schritte ausgeführt, bzw. in 34% der stationären OPs musste dieser Arbeitsschritt wiederholt ausgeführt werden. Prinzipiell kann jedoch für jede Population von OP-Beschreibungen ein gemittelter Workflow mit detailierten Ausführungszeiten und Verlaufswahrscheinlichkeiten berechnet werden. 18% 99% 94% irrigate sauter cannula chamber ant excision material utrata‘s tweezers capsula lentis 86% END 19% 94% 6% 10% Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Requirements analyses and procedure optimization User Objectives Requirements analyses and procedure optimization Evaluation support for surgical instruments and devices Surgical education Workflow management in the digital operating room Die Ergebnisse der Arbeit können in vielen klinischen Anwendungsgebiete angewendet werden, z. B. für prospektive Anforderungsanalysen für chir. Instrumente oder Assistenzsysteme, für retrospektive Vergleiche zur Unterstützung von Evaluationen, Suche nach Optimierungsmöglichkeiten oder für den Einsatz in der chir. Ausbildung. Aus technischer Sicht bilden diese Schemata die Grundlage für den Einsatz von Workflowmanagementsystemen in Operationssälen. Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Objectives and Requirements Technical objectives facilitate comparability, interoperability, and uniform interpretation of process data providing a coherent conceptual and mathematical basis Requirements a common language measurement systems Situation description for surgical worksteps WHO, WHAT, WHEREWITH, WHERE, WHEN Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Available approaches Jannin et al. 2003 MacKenzie et al. 2001 EN 1828 Padoy et al. 2007 Neumuth et al. 2006 Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Four-Levels of the Approach Natural language level Conceptual / ontological level Formal / mathematical level Level 1: is related to the user, mostly medical personnel & engineers. Esp. the medical staff are not accustomed to dealing with formal representations or using formal methods to analyze surgical concepts.  natural language level is required to include the implicit knowledge and experience of the clinical users into our model. The natural language level further provides an interface for communicating the results of analyses, which are carried out in terms of the remaining levels, back to the users. Level 2 deals with the ontological analysis of domain knowledge, based on natural language expressions. Because natural language expressions usually allow for distinct interpretations depending on context, distinct ontologies may be derived. Linguistic patterns can be employed for ontological analysis, and existing bodies of real-world knowledge might be reused, for example, as represented in pre-existing ontologies. In particular, top-level ontologies can be used as a basis for developing domain-specific ontologies. This is the primary field of application of the method of ontological reduction (29,30). Level 3 provides for mathematical formalizations of domain knowledge dedicated to determinate purposes. Such formalizations must rest on the second – the conceptual – level, where different formalizations based on a single ontology may be useful for distinct purposes. Maintaining the link to the conceptual level allows for interoperability and comparability of different models, making cross-modeling approaches possible and thus the gathering of knowledge from different sources and from different points of view. Level 4 is concerned with the realization of formalizations from the previous level in languages with a practical orientation, primarily machine-processable languages. Here, another multiplication of representations arises due to multiple different implementations of a single formal model. Distinct implementations occur for different languages as well as for a single language. Several implementations may encode a formalization in progressively complex ways. Implementation level Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Conceptual level Carlson 1981 Bach 1986 Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Mathematical and Implementation level Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Clinical users request applications based on Surgical Process Models. Summary Clinical users request applications based on Surgical Process Models. Measuring of Surgical Processes is a challenging task due to a missing common language and missing measurement systems. The four-level approach considers theories from linguistics to capture knowlegde formally. An easy extendability towards top-level ontologies is expected. Neumuth T: A Four-Level Translational Approach to Modeling Surgical Processes GI-Workshop OBML, Leipzig, 25.-26.11.2009

Thank you. Thomas Neumuth Acknowledgement Thomas.neumuth@iccas.de The Innovation Center Computer Assisted Surgery (ICCAS) at the Faculty of Medicine at the University of Leipzig is funded by the German Federal Ministry for Education and Research (BMBF) and the Saxon Ministry of Science and the Fine Arts (SMWK) in the scope of the initiative “Unternehmen Region” with the grant numbers 03 ZIK 031 and 03 ZIK 032.