Author, Institution: Vilma Putnynaitė, Kaunas University of Technology
Science area, field of science: Technological Sciences, Measurement Engineering, T010
Research Supervisor: Chief Researcher Dr. Vytautas Petkus (Kaunas University of Technology, Measurement Engineering, T010)
Research Consultant: Prof. Dr. Arminas Ragauskas (Kaunas University of Technology, Electrical and Electronics Engineering, T001)
Dissertation Defence Board of Measurement Engineering Science Field:
Prof. Dr. Renaldas Raišutis (Kaunas University of Technology, Technological Sciences, Measurement Engineering, T010) – chairperson
Assoc. Prof. Dr. Magdalena Kasprowicz (Wroclaw University of Science and Technology, Poland, Technological Sciences, Measurement Engineering, T010)
Prof. Dr. Vaidotas Marozas (Kaunas University of Technology, Technological Sciences, Measurement Engineering, T010)
Prof. Dr. Kęstutis Petrikonis (Lithuanian University of Health Sciences, Medical and Health Sciences, Medicine, M001)
Prof. Dr. Algimantas Valinevičius (Kaunas University of Technology, Technological Sciences, Measurement Engineering, T010)
Dissertation defence meeting will be at Rectorate Hall of Kaunas University of Technology (K. Donelaičio 73-402, Kaunas)
The doctoral dissertation is available at the library of Kaunas University of Technology (Gedimino 50, Kaunas) and on the internet: V. Putnynaitė el. dissertation.pdf
© V. Putnynaitė, 2025 “The text of the thesis may not be copied, distributed, published, made public, including by making it publicly available on computer networks (Internet), reproduced in any form or by any means, including, but not limited to, electronic, mechanical or other means. Pursuant to Article 25(1) of the Law on Copyright and Related Rights of the Republic of Lithuania, a person with a disability who has difficulties in reading a document of a thesis published on the Internet, and insofar as this is justified by a particular disability, shall request that the document be made available in an alternative form by e-mail to doktorantura@ktu.lt.”
Annotation: Cardiovascular diseases remain a leading cause of morbidity and mortality worldwide. Despite advances in cardiac surgery, neurological complications such as postoperative cognitive dysfunction (POCD) and delirium remain common following coronary artery bypass grafting (CABG) with cardiopulmonary bypass (CPB). The underlying pathophysiological mechanism involves impairment of cerebral autoregulation (CA), which predisposes the brain to ischemic or hyperemic injury. This dissertation introduces and experimentally validates a novel methodology for real-time detection of CA impairment based on periodic rectangular modulation of arterial blood pressure (ABP), integrated into the CPB system. A prospective clinical study was conducted at the Hospital of the Lithuanian University of Health Sciences Kaunas Clinics to assess multimodal physiological monitoring data, including transient responses of cerebral blood flow velocity (CBFV) and non-invasive intracranial pressure (nICP) to artificially induced changes in blood flow. Newly proposed Steady-Level (SL) indices enabled identification of CA impairment with a delay of less than one minute. Prolonged episodes of CA impairment lasting more than 3–4 minutes were found statistically significantly associated with postoperative cognitive dysfunction and delirium. This research demonstrates that integrating blood pressure modulation and real-time CA monitoring directly into the cardiopulmonary bypass system enables individualized, closed-loop arterial pressure management aligning with the principles of precise and personalized medicine.