Ravelijn

dr. D. Demirtas (Derya)

Associate Professor
BMS-HBE-IEBIS
Ravelijn 3420
d.demirtas@utwente.nl
+31534893184
Business card

A taste of the healthcare track of the UT IEM program and my research: https://youtu.be/CFS6F3gkCrY 

Academic profile

Derya Demirtas is an associate professor at the Center for Healthcare Operations Improvement & Research (CHOIR) in the Section of Industrial Engineering and Business Information Systems at the University of Twente. Her research focuses on operations research, optimization and data analytics, location theory and their applications to healthcare, emergency response, and public services.
 
Dr. Demirtas is a recipient of the Dutch Research Council (NWO) Veni talent grant, Top Sector Life Sciences & Health PPP Grant, and American Heart Association Young Investigator Award. She received the Best Poster Award by the National Association of EMS Physicians (2016) and won the second place in the INFORMS Section on Public Sector Operations Research best paper competition (2012) and second place in the INFORMS Case Competition (2020). Her research has been published in journals such as Management Science, European Journal of Operational Research, Journal of the American College of Cardiology, and Health Care Management Science (HCMS). She serves in several academic roles including co-chair of NWO Advisory Roundtable (Behaviour, Education  & Economic Sciences), chair of UT Examination Board Management Sciences, associate editor for HCMS, area editor for Health Systems and editorial board member of Operations Research for Health Care. She was a visiting faculty in the Industrial and Systems Engineering and in the Center for Health & Humanitarian Systems at Georgia Tech in 2018, where she worked on disaster response. 

Academic background

Dr. Demirtas received her BSc in Industrial Engineering with a double major in Computer Engineering from the Middle East Technical University, Turkey (2008). She then obtained her MMath in Combinatorics & Optimization from the University of Waterloo, Canada (2010), and her PhD in Industrial Engineering from the University of Toronto, Canada (2016).

In the media

Dr. Demirtas's research has been publicized by several media outlets, including RTV Oost, Reuters, Tubentia, Science Daily and Toronto Sun, and promoted by the University of Twente:

Expertise

  • Nursing and Health Professions

    • Out of Hospital Cardiac Arrest
    • Heart Arrest
    • Defibrillator
    • Radiotherapy
    • Time
    • Survival
    • Patient

  • Computer Science

    • Integer Programming

Organisations

Research interests

Operations research, optimization, spatial data analytics and their applications in healthcare and humanitarian sector: in particular, linear and integer programming, facility location under uncertainty, covering problems, spatiotemporal trend analysis, public health resource planning, post-disaster recovery and emergency service location problems.

For prospective students and researchers, please see Contact->Additional Contact Information. 

Publications

Jump to: 2024 | 2023 | 2022 | 2021 | 2020

2024

Strategic placement of volunteer responder system defibrillators (2024)Health care management science (E-pub ahead of print/First online). Buter, R., Nazarian, A., Koffijberg, H., Hans, E. W., Stieglis, R., Koster, R. W. & Demirtas, D.https://doi.org/10.1007/s10729-024-09685-4Increasing cost-effectiveness of AEDs using algorithms to optimise location (2024)Resuscitation, 201. Article 110300. Buter, R., van Schuppen, H., Stieglis, R., Koffijberg, H. & Demirtas, D.https://doi.org/10.1016/j.resuscitation.2024.110300Investigating Users’ Attitudes Toward Automated Smartwatch Cardiac Arrest Detection: Cross-Sectional Survey Study (2024)JMIR human factors, 11. Article e57574. van den Beuken, W. M. F., van Schuppen, H., Demirtas, D., van Halm, V. P., van der Geest, P., Loer, S. A., Schwarte, L. A. & Schober, P.https://doi.org/10.2196/57574

2023

Where do we need to improve resuscitation? Spatial analysis of out-of-hospital cardiac arrest incidence and mortality (2023)Scandinavian journal of trauma, resuscitation and emergency medicine, 31. Article 63. Buter, R., van Schuppen, H., Koffijberg, H., Hans, E. W., Stieglis, R. & Demirtas, D.https://doi.org/10.1186/s13049-023-01131-8Design of fork-join networks of First-In-First-Out and infinite-server queues applied to clinical chemistry laboratories (2023)European journal of operational research, 310(3), 1101-1117. Tsai, E. R., Demirtas, D., Tintu, A. N., de Jonge, R., de Rijke, Y. B. & Boucherie, R. J.https://doi.org/10.1016/j.ejor.2023.04.003Characterization of laboratory flow and performance for process improvements via application of process mining (2023)Applied Clinical Informatics, 14(1), 144-152. Tsai, E., Tintu, A., Boucherie, R., De Rijke, Y., Schotman, H. & Demirtas, D.https://doi.org/10.1055/a-1996-8479Wait!What does that mean?: Eliminating ambiguity of delays in healthcare from an OR/MS perspective (2023)Health systems, 12(1), 3-21. Van Zyl-Cillie, M., Demirtas, D. & Hans, E.https://doi.org/10.1080/20476965.2021.2018362Health Economic Evaluation of Data-driven AED Locations (2023)Resuscitation, 192(S1). Buter, R., Koffijberg, H., van Schuppen, H., Stieglis, R. & Demirtas, D.https://doi.org/10.1016/S0300-9572(23)00357-X

2022

Smartwatch based automatic detection of out-of-hospital cardiac arrest: Study rationale and protocol of the HEART-SAFE project (2022)Resuscitation Plus, 12. Article 100324. Schober, P., van den Beuken, W. M. F., Nideröst, B., Kooy, T. A., Thijssen, S., Bulte, C. S. E., Huisman, B. A. A., Tuinman, P. R., Nap, A., Tan, H. L., Loer, S. A., Franschman, G., Lettinga, R. G., Demirtas, D., Eberl, S., van Schuppen, H. & Schwarte, L. A.https://doi.org/10.1016/j.resplu.2022.100324Turnaround time prediction for clinical chemistry samples using machine learning (2022)Clinical Chemistry and Laboratory Medicine, 60(12), 1902-1910. Tsai, E. R., Demirtas, D., Hoogendijk, N., Tintu, A. N. & Boucherie, R. J.https://doi.org/10.1515/cclm-2022-0668Spatial risk analysis of out-of-hospital cardiac arrests in Amsterdam (2022)Resuscitation, 175(Suppl 1), S16-S17. Buter, R., van Schuppen, H., Stieglis, R., Hans, E. W., Koffijberg, H. & Demirtas, D.https://doi.org/10.1016/S0300-9572(22)00394-XStrategic placement of Citizen Responder System defibrillators (2022)Resuscitation, 175(Suppl 1), S3-S4. Buter, R., Hans, E. W., Koffijberg, H., Koster, R., Blom, M., Stieglis, R. & Demirtas, D.https://doi.org/10.1016/S0300-9572(22)00375-6

2021

Radiotherapy treatment scheduling: Implementing operations research into clinical practice (2021)PLoS ONE, 16(2). Article e0247428. Vieira, B., Demirtas, D., van de Kamer, J. B., Hans, E. W., Jongste, W. & van Harten, W. H.https://doi.org/10.1371/journal.pone.0247428

2020

Radiotherapy treatment scheduling considering time window preferences (2020)Health care management science, 23(4), 520-534. Vieira, B., Demirtas, D., B. van de Kamer, J., Hans, E. W., Rousseau, L.-M., Lahrichi, N. & van Harten, W. H.https://doi.org/10.1007/s10729-020-09510-8A Mathematical Programming Model for Radiotherapy Scheduling with Time Windows (2020)In Health Care Systems Engineering: HCSE, MontrĂ©al, Canada, May 30 - June 1, 2019 (pp. 241-249) (Springer Proceedings in Mathematics and Statistics; Vol. 316). Springer. Vieira, B., Demirtas, D., Kamer, J. B. v. d., Hans, E. W., Rosseau, L. M., Lahrichi, N. & van Harten, W. H.https://doi.org/10.1007/978-3-030-39694-7_19EURO 2018 — Innovative methods and uses of operations research in health and care applications (2020)Operations research for health care, 24. Article 100243. Marques, I., Demirtas, D., Rachuba, S. & Vasilakis, C.https://doi.org/10.1016/j.orhc.2019.100243

Other contributions

EARLIER PUBLICATIONS:

  1. Vieira, B., Demirtas, D., van de Kamer, J.B, Hans, E.W., van Harten, W. “A mathematical programming model for optimizing the staïŹ€ allocation in radiotherapy under uncertain demand”, European Journal of Operational Research (EJOR), 270(2), 709-722, 2018.
  2. Lee, M., Demirtas, D., Buick, J.E., Ng A., Feldman, M.J., Cheskes S., Morrison, L.J., Chan, T.C.Y. “Increased cardiac arrest survival and bystander intervention in enclosed pedestrian walkway systems”, Resuscitation, 118, 1-7, 2017.
  3. Chan, T.C.Y., Demirtas, D., Kwon, R.H. “Optimizing the deployment of public access defibrillators”, Management Science, 62(12), 3617-3635, 2016 (Authors are listed alphabetically).
  4. Sun, C.L.F., Demirtas, D., Brooks, S.C., Morrison, L.J., Chan, T.C.Y. “Overcoming spatial and temporal barriers to public access defibrillators via optimization”, Journal of the American College of Cardiology, 68(8), 836–845, 2016.
  5. Barutçuoğlu, A., DemirtaƟ, D., Dilan, B., DĂŒzgĂŒn, R., Köksalan, M., SavaƟaneril S. “Vehicle dispatch and distribution center location problem for an automotive firm”, Journal of Industrial Engineering, 21(1), 4–16, 2010 (In Turkish,authors are listed alphabetically).

Research profiles

Supervision

PhD Student Supervision 

  • Robin Buter, "Strategic placement of Automated External Defibrillators under demand and supply uncertainty," expected to graduate in 2024
  • Maria van Zyl, "Process improvement in public hospitals in South Africa," expected to graduate in 2024
  • Eline Tsai, “Operations research from blood withdrawal to first results,” expected to graduate in 2024
  • Bruno Vieira, “Advanced Logistics Optimization of the Radiotherapy Treatment,” graduated in 2020

Graduate Student Awards Won by My Master and PhD Students

  • “Best of the Best” presentation finalist, European Resuscitation Conference, awarded to R. Buter, 2023. Title: “Health economic evaluation of data-driven AEDs”, (among 5 awardees out of 400+ submissions).
  • “Best of the Best” presentation finalist, European Resuscitation Conference, awarded to R. Buter, 2022. Title: “Strategic placement of citizen responder system defibrillators”, (among 7 awardees out of 200+ submissions).   
  • Operational Research Applied to Health Sciences (ORAHS) Gallivan Poster Awards, first place, awarded to R. Buter, 2022. Title: "Spatiotemporal Analysis of Out of Hospital Cardiac Arrests".
  • Bekader (IEM & IBA alumni association) Thesis Award for IEM, first place, awarded to S.Relijveld, 2021. Thesis title: "Analysis on the Costs of Care for Colorectal Cancer Patients Using Australian Multicentered Linked Data".
  • BMS faculty Graduation Award, first place, awarded to G. Holsbrink, 2021. Thesis title: "The Optimal Allocation of Casualties to Hospitals in case of a Mass-casualty Incidence".
  • KHMW Philips Graduation Award for Data Science and AI in Health Care, awarded to A. Nazarian, 2018. Thesis title: "Optimizing the Deployment of Automated External Defibrillators by a Data-driven Algorithmic Approach".

Master’s and Bachelor Thesis Supervision (summary)

  • Healthcare logistics projects at Amsterdam University Medical Center (UMC); Radboud UMC; Utrecht UMC; RIVM; ZGT, Almelo; Sint Maartenskliniek, Nijmegen; St. Antonius Hospital, Utrecht; Rijnstate Hospital, Arnhem; MST, Enschede; Slingeland Hospital, Doetinchem; Boven Hospital, Amsterdam; Deventer Ziekenhuis; AcuteZorg Euregio, Enschede; StanCPR Network; Auckland City Hospital, New Zealand; University of Melbourne, Australia; Victoria Hospital, London, Canada;
  • Logistics projects at Albert Heijn, Voortman, Bol.com, Westphalia DataLab, Hema, Benchmark, Contour Covering Technology BV, PoolPlaza, Demcon Production, Royal Lemkes, CORE Chemistry.

Master’s Capita Selecta (Short-term Internship) Supervision (summary)

  • Healthcare logistics projects at UMC Utrecht, Netherlands Cancer Institute Antoni van Leeuwenhoek (NKI-AvL), Willem Kolff Stichting & Nierstichting

TEACHING

Instructor, Industrial Engineering & Management Bachelor and Master’s Program (2016 – present)

  • Operations Research Techniques 1 (1st quartile, yearly), ~75 students, 5 European Credits (5ECs)
  • Warehousing (4th quartile, yearly), ~75 students, 5 ECs
  • Professional Skills (2019 – 2020), 160 students
  • IEM Research Orientation (2017 – 2018), 60 students, 5 ECs

Coordinator & Instructor, Health Sciences Master's Program (2021 - present) 

  • Optimizing Healthcare Processes (2nd quartile, yearly), ~25 students, 5 ECs

Instructor, European Association of Hospital Managers (EAHM) (2018)

  • Crash course on operations management for hospital managers (together with Ines Marques)

Instructor, Global Faculty Program, Monterrey Inst. of Technology, Mexico (2018) 

  • Facilities Design and Materials Management, 20 students
  • Optimization Models, 20 students
  • Applications of Optimization in Healthcare, 30 students 

Instructor, Health Sciences Bachelor Program (2016) 

  • Operations Management (OM) in Healthcare (in Module 4: Optimization of Care), 50 students, 3 ECs 
  • OM Practicum (in Module 4), 50 students, 3 ECs       
  • Project: Optimization of Healthcare Processes (in Module 4), 50 students, 1 EC 

Miscellaneous

  • Guest lecturer, Instituto Superior TĂ©cnico, Portugal (2018)
  • Author, Case Study on Maximizing Team Diversity in a First-year Engineering Course, University of Toronto (2015)
  • Guest Lecturer, MIE 258 Engineering Economics and Accounting, University of Toronto (2015)
  • Certificate in Prospective Professors in Training, University of Toronto (2014)
  • Guest Lecturer, MIE 468 Facility Planning, University of Toronto (2013)
  • Teaching Assistant, Dept. of Mechanical and Industrial Engineering, University of Toronto (2010 – 2015)
  • Teaching Assistant, Division of Engineering Science, University of Toronto (2011)
  • Teaching Assistant, Dept. of Combinatorics and Optimization, University of Waterloo (2008 – 2010)

Committee work

  • Chair, Examination Board, TBK/IEM, 2022 – present
  • Member, Young Academy Twente, 2022 – present
  • Member, Examination Board, TBK/IEM, 2021 – present
  • Member, OLC (Opleidingscommissie – Program Committee), TBK/IEM, 2017 – 2021

Affiliated study programs

Courses academic year 2024/2025

Courses in the current academic year are added at the moment they are finalised in the Osiris system. Therefore it is possible that the list is not yet complete for the whole academic year.

Courses academic year 2023/2024

The focus of Dr. Demirtas’s research is on data-driven decision making aimed at improving healthcare and humanitarian systems. Her projects include:

1. Optimizing the locations of public access defibrillators to improve survival from out-of-hospital cardiac arrest (OHCA): In this research, we develop a comprehensive data-driven modeling framework for emergency facility deployment, leveraging optimization, metaheuristics and data science. Our models analyze the spatiotemporal trends in demand (OHCA) and supply (citizen volunteers), estimate citizen volunteer response rates using machine learning and historical data, and optimize locations of emergency facilities under both demand and supply uncertainty.

In collaboration with: UMC Amsterdam (location Amsterdam), HartslagNu, Dutch Heart Foundation

2. Smart watch to detect unwitnessed OHCAs: Our consortium will develop a smart wearable to automatically and reliably detect OHCA, and to trigger an immediate emergency response. Our work package will test the effectiveness of the proposed platform using simulation models and measure the impact on survival and response time.

In collaboration with: UMC Amsterdam (location VUmc), Stan B.V., 111 B.V., Wavy Assistant B.V.

3. Improving citizen volunteer response to OHCA: In the Netherlands, an innovative app, HartslagNu, alerts registered volunteers when an OHCA occurs nearby, and dispatches them either to the victim for CPR, or to an AED and then to the patient. In this research, we investigate potential improvement in HartslagNu’s dispatch strategy by creating simulation models to test various volunteer assignment strategies. Moreover, we investigate effects of mobile AEDs and targeted volunteer recruitment in terms of response time and survival. 

In collaboration with: Stan B.V., HartslagNu

4. Optimizing the staff allocation in radiotherapy: The goal of this project is to maximize the number of patients completing the pre-treatment stage in radiotherapy (RT) within the waiting time targets. We focus on the tactical planning of radiation therapy technologists (RTTs) throughout the pre-treatment process of the RT treatment chain considering stochastic patient arrivals.

In collaboration with: Netherlands Cancer Institute, Antoni van Leeuwenhoek (NKI-AvL) hospital, Polytechnique Montreal

5. Process optimization in clinical chemistry laboratories: The focus of this project is to assess the operations from blood withdrawal to first results, and investigate different configurations and prioritization rules in order to reduce diagnostics turnaround time and improve the laboratory performance.

In collaboration with: UMC Amsterdam (location VUmc), UMC Amsterdam (location Amsterdam), Erasmus MC

6. Post-disaster recovery: The aim of this research is to create efficient models to help decision making in debris collection. We focus on partitioning the affected area into zones and assigning these to contractors while minimizing costs, maximizing societal benefits and maintaining contiguity of zones.

In collaboration with: Georgia Institute of Technology

7. Process improvement in private hospitals in South Africa: This research aims to investigate what constitutes problematic waiting times, the causes of these waiting times, and possible interventions to be designed to reduce these waiting times in a private hospital in South Africa.

In collaboration with: North-West University, South Africa

Address

University of Twente

Ravelijn (building no. 10), room 3420
Hallenweg 17
7522 NH Enschede
Netherlands

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Organisations

Additional contact information

For prospective students and researchers

PhD applicants and visiting PhD students: If you are interested in joining our group as a PhD student or visiting PhD student, please email me your CV and an up-to-date transcript (grade list). Indicate your research interests and whether you have your own funding.

PhD applicants from under-represented groups: If you have obtained your BA or MA in the Netherlands and have a migration background from Africa, Asia, the Caribbean, Central and South America and Turkey, you might be eligible for the Mosaic 2.0 program of NWO (https://www.nwo.nl/en/researchprogrammes/mosaic). Please mention this in your email and I would be happy to explore this opportunity with you.

UT master students with strong research interest: Internal research-based master theses and capita selecta projects are regularly available. If you are interested in getting research experience, please email me your CV and an up-to-date transcript (grade list). Indicate your research interests and your timeline.

Postdoc applicants: If you have your own funding or willing to apply for Marie Curie fellowship (https://marie-sklodowska-curie-actions.ec.europa.eu/actions/postdoctoral-fellowships) or similar, please email me your CV and your recent papers I would be happy to explore MSCA opportunity with you.

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