Controlled delivery of intravenous (IV) anesthetics aims at fast and safe achievement and maintenance of a suitable depth of hypnosis (DOH), by ensuring appropriate effect site (i.e. brain) exposure to the drug. Today, such drugs are regularly injected by Target Controlled Infusion (TCI) systems, piloted by an open-loop algorithm based on Pharmacokinetic (PK) models. Yet the inaccuracy of concentration prediction of current TCI can reach up to 100%. The situation could be improved by closing the loop with sensors providing regular real measurements of the anesthetic concentration in body fluids.
During this talk I will present two possible approaches for closing the control loop using plasma concentration measurements: one representing the classical method in pharmacokinetics based on the Bayesian inference and another one being an example of classical method in control theory based on Kalman filter. The first one performs the real-time re-estimation of the PK model parameters with each new measurement, while the latter one estimates the offset values for drug concentration adjustment. The updated concentration values are then used to compute the personalised delivery rate using the classical TCI algorithm.
To validate the algorithms robustness, we suggest to simulate measurements using the maximum inter- and intra-patient variability, for example, of the statistical Eleveld’s PK model. This allows one to stress the system to the maximum level prior to testing it on patients. We provide the robustness analysis of these algorithms by accounting for realistic measurement periods and delays.
From January 2017 Dr. Alena Simalatsar is a scientific collaborator of HES-SO Valais-Wallis. Her current work and interest is focused on development of novel medical devices including but not limited to closed-loop/autonomous devices, such as drug delivery systems. In parallel Dr. Simalatsar has a partial affiliation with the Division of Clinical Pharmacology of Centre Hospitalier Universitaire Vaudois (CHUV), Lausanne, Switzerland.
Dr. Alena Simalatsar received her Bachelor and masters degree from the Faculty of Radiophysics and Computer Technologies of Belarusian State University in 2005 and her PhD in Computer Science and Telecommunication Technologies in 2009 from the University of Trento, Italy. During her PhD she mainly working on system-level analysis methodologies for embedded systems. She has also spent six months as a Visiting Scholar at the Department of Electrical Engineering and Computer Sciences of the University of California at Berkeley, USA. In February 2011 Dr. Alena Simalatsar has joined the Ecole Polytechnique Fédéral de Lausanne (EPFL), Switzerland in a role of a scientific collaborator, where she conducted research on multiple medical technologies (MedTech) projects until September 2016 before moving to HES-SO Valais-Wallis.