Dániel András Drexler

Dániel András Drexler
Óbudai Egyetem · John von Neumann Faculty of Informatics

Doctor of Engineering

About

99
Publications
10,192
Reads
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814
Citations
Citations since 2016
60 Research Items
671 Citations
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
2016201720182019202020212022020406080100120
Additional affiliations
August 2016 - present
Óbuda University
Position
  • Professor (Assistant)
July 2015 - July 2016
Budapest University of Technology and Economics
Position
  • Professor (Assistant)
August 2012 - June 2015
Budapest University of Technology and Economics
Position
  • Research Assistant
Education
September 2012 - July 2014
Budapest University of Technology and Economics
Field of study
  • applied mathematics
September 2009 - August 2012
Budapest University of Technology and Economics
Field of study
  • Electrical Engineering
February 2008 - January 2011
Budapest University of Technology and Economics
Field of study
  • biomedical engineering

Publications

Publications (99)
Article
In this open letter, we give some insights on the potential use of mathematical modeling in understanding cancer research. The article is written in a form that can be understood by a larger public, not only by specialists.
Article
Full-text available
Cancer therapy optimization is an issue that can be solved using the control engineering approach. An optimal therapy generation algorithm is presented and tested using a tractable mouse model of breast cancer. The optimized therapeutic protocol is calculated in a closed-loop manner at fixed time instants, twice in a week. The controller consists o...
Conference Paper
Cyber-medical systems are revolutionizing medicine. Mathematical therapy optimization is one of the main pioneering results of cyber-medical system approach. Mathematical therapy optimization is based on a mathematical model. A reliable model with personalized model parameters is crucial for generating optimal treatment. We discuss algorithms for e...
Article
Derivation of the Robust Fixed Point Transformations based method is presented in both continuous and discrete time. Foundations of the method are built on the theory of the Input-Output linearization principle. The robustness of the controller is achieved by using fixed-point iterations on the difference between the inverse model and the true stru...
Conference Paper
Therapy optimization and personalization in cancer treatment requires reliable mathematical models. A key issue in personalization is the identification of the model parameters. We employ artificial neural networks to identify the model parameters based on few measurements using a priori information about the range of the parameters. The trainig da...
Article
Full-text available
Chemotherapy plays an important role in the treatment of cancer. While clinical chemotherapy protocols can lead to remission in some patients, in many cases tumor progression occurs despite continued treatment. In the present study we summarize mathematical approaches to model tumor growth and response to treatment, focusing on anticancer therapy r...
Conference Paper
This paper describes a Mass Ventilation System (MVS) which serves as a medical ventilator system. It can be used to ventilate large number of COVID-19 patients in parallel (5 – 50+) with personalized respiratory parameters. The system has been designed to be medically suitable for both non-invasive and invasive patient ventilation. It protects heal...
Conference Paper
Mathematical models of tumor growth and the effect of therapy is fundamental for personalizing and optimizing anticancer therapies. The aim of the research is to provide a good estimation of personalized tumor model parameters based on measurements carried out on the patient. We use in silico experiments to create a large set of training data in a...
Article
Therapeutic optimization is a promising direction of computer aided medicine. Optimization of chemotherapy based on mathematical models can result in lower doses, fewer side effects, a smaller chance of acquired drug resistance and more efficient personification. We explore model-based chemotherapy optimization for high frequency low dose therapies...
Article
A Moving Horizon Estimator (MHE) based Nonlinear Model Predictive Controller (NMPC) was designed for an impulsive minimal tumor growth model. The estimator computes the time-varying model parameters using mean square error with parameter deviation penalization and provides state estimations for the controller. The controller computes optimal doses...
Article
Full-text available
One challenging aspect of therapy optimization and application of control algorithms in the field of tumor growth modeling is the limited number of measurable physiological signals—state variables—and the knowledge of model parameters. A possible solution to provide such information is the application of observer or state estimator. One of the most...
Conference Paper
Enforcing system level safety is a key research domain within self-driving technology. Current general development efforts aim for Level 3+ autonomy, where the vehicle controls both lateral and longitudinal motion of the dynamic driving task, while the driver is permitted to divert their attention, as long as she/he is able to react properly to a h...
Article
Self-driving-car development on the global scale has reached a point where prototypes have proven the validity of the technology in various environments. Nevertheless, an increasing debate surrounds the serial production of these systems, with some experts arguing that real, trusted autonomous-driving capabilities may be at least a decade away, whi...
Article
A truly personalized cancer therapy demands the availability of models, of which tumor dynamics model is imperative. This paper presents a feasibility study of using a tumor growth model for lung cancer treatment planning. Recent developments in radiation therapy are outlined in this work, including target tumor based delivery of limited but highly...
Article
Mathematical models of tumor growth in response to chemotherapy are crucial for therapy optimization and outcome. We create a relatively simple tumor growth model describing the antitumor effect of pegylated liposomal doxorubicin (PLD) validated with real experimental data obtained in a genetically engineered mouse model of breast cancer. We use fo...
Article
Control of physiological systems, like tumor growth dynamics, can contribute to modern medicine by designing optimized therapies or automating treatments. Typical challenges in physiological control are the positivity of the input and the interpatient variability of model parameters. We use positive dynamics extension to ensure the positivity of th...
Conference Paper
There are many parallelisms between autonomous medical robotics and autonomous vehicle technologies from the control design point of view. A key research interest in both domains is system safety. Current efforts target Level 3 (LoA 3) autonomy, where the system controls the robotic arms to perform section of a procedure autonomously, or in self-dr...
Article
Self-driving technologies introduced new challenges to the control engineering community. Autonomous vehicles with limited automation capabilities require constant human supervision, and human drivers have to be able to take back control at any time, which is called handover. This is a critical process in terms of safety, thus appropriate handover...
Article
There are many systems in practice that can have only positive (nonnegative) input, typical examples for such systems are physiological systems. Moreover, the parameters of these systems are usually not known exactly or may vary over time, thus application of robust controllers represents a reasonable possibility. Most model-based controller design...
Article
Full-text available
Tumor growth models are important to create an engineering background for cancer treatment either by using the models for simulations and evaluation of treatment protocols or, if combined with control engineering, by designing treatment protocols. A well-defined tumor growth model must describe the physiological processes and the measurements as we...
Conference Paper
Full-text available
Orienting manipulators in robotics are used to achieve the desired orientation of the end effector of the manip-ulator. These manipulators are composed of rotational joints, and thus inherently burdened with singularities. In singular configurations, the differential inverse orientation problem can not be applied since the Jacobian becomes singular...
Article
Full-text available
Inverse kinematics is a central problem in robotics, and its solution is burdened with kinematic singularities, i.e. the task Jacobian of the problem is singular. A subproblem of the general inverse kinematics problem, the inverse positioning problem is considered for spatial manipulators consisting of revolute joints, and a regularization method i...
Article
The efficiency of therapeutic cancer treatment protocols can be increased by incorporating knowledge about the underlying physiological processes into the design of the protocol. The aim of this work is to find the optimal protocol resulting in minimal drug usage for fixed resting time between measurements and treatments (the sampling time) and pre...
Article
The input of physiological control systems is positive in almost every case (i.e. it is the concentration of a drug), thus the application of controllers which guarantee positive input is crucial. However, most of the controller design methods can not incorporate the constraint that the input has to be positive. We propose a method based on the dyn...
Conference Paper
We introduce a controller design methodology for nonlinear systems via complementary Linear Parameter Varying (LPV) controller and observer structures. The recently developed method is able to control physiological systems even with complex nonlinearities – without using Linear Matrix Inequalities (LMI) or other techniques requiring iterations. The...
Conference Paper
Application of model-based control strategies for physiological control problems, like tumor therapy, may greatly improve the efficiency of clinical treatments. Our aim is to design a positive path tracking controller for a minimal model of tumor growth under angiogenic inhibition with bevacizumab treatment. We extend the dynamics of the system to...
Conference Paper
Modeling the tumor growth under angiogenic inhibition is an important step towards designing tumor treatment therapies based on mathematical tools. Our goal is to create a model for tumor growth that describes the underlying physiological processes adequately while being as simple as possible. We propose a second-order model containing linear terms...
Article
Full-text available
The closed-loop inverse kinematics algorithm is a numerical approximation of the solution of the inverse kinematics problem, which is a central problem of robotics. The accuracy of this approximation, i.e. the convergence of the numerical solution to the real solution can be increased by increasing the value of a feedback gain parameter. However, t...
Article
Full-text available
In medical practice, the effectiveness of fighting cancer is not only determined by the composition of the used drug, but determined by the administration method as well. As a result, having drugs with a suitable action profile is just a promising beginning, but without appropriate delivery methods, the therapy still can be ineffective. Finding the...
Conference Paper
A general approach to solve the inverse kinematics problem of series manipulators, i.e. finding the required joint motions for the desired end effector motions, is based on the linear approximation of the forward kinematics map and discretization of the continuous problem. Due to the linearization, first velocities are calculated, so numerical inte...
Conference Paper
In the medical practice, there are several methods to administer anti-cancer drugs. A commonly used method is the intermittent bolus doses (BD) administration when the patient receives drug on given days and the therapy has rest periods between the injections. The amount of bolus doses can be the maximum tolerated dose (MTD) or less. Anti-cancer dr...
Article
Full-text available
Controllability of chemical reactions is an important problem in chemical engineering science. In control theory, analysis of the controllability of linear systems is well-founded, however the dynamics of chemical reactions is usually nonlinear. Global controllability properties of chemical reactions are analyzed here based on the Lie-algebra of th...
Conference Paper
The closed-loop inverse kinematics algorithm is a numerical method used to approximate the solution of the inverse kinematics problem of robot manipulators based on the explicit Euler integration, that is a simple numerical integration technique. It is known from the theory of numerical techniques that the Crank-Nicolson method gives results with b...
Article
Full-text available
Background: Bevacizumab is an exogenous inhibitor which inhibits the biological activity of human VEGF. Several studies have investigated the effectiveness of bevacizumab therapy according to different cancer types but these days there is an intense debate on its utility. We have investigated different methods to find the best tumor volume estimat...
Conference Paper
Full-text available
Tumor growth model identification under antiangio-genic therapy is a very current issue since the existing models in the literature have some limitations and usually they are not clinically validated. We have carried out animal experiments to observe valid data; mice were transplanted with C38 colon adenocarcinoma and they were treated with bevaciz...
Article
Every therapy that fights against cancer aims to reduce the tumor volume as far as possible. However, the price of low tumor volume has to be paid twice: as financial cost and also as side effect cost. In this article, we present qualitative correlation between the steady-state tumor volume and inhibitor serum concentration based on the tumor growt...
Conference Paper
Full-text available
Tumor cells need a set of functional capabilities for development and growth. One of these capabilities is angiogenesis; tumor cells have to become able to force new vessel formation to ensure oxygen and nutrient supply. In the literature, there are several different growth models which aim to describe the growth characteristics. The model creation...
Conference Paper
Solution of the differential inverse positioning sub-task is an important problem in robotics, that is burdened with kinematic singularities. This problem can be handled by regularizing the task Jacobian, however this requires the knowledge of the regularization vector. A candidate for the regularization vector for an elbow manipulator is given, an...
Thesis
Full-text available
The dissertation is about the solution of the differential inverse kinematics problem of serial manipulators. The differential solution of the inverse kinematics problem exists generally for serial open-chain manipulators with arbitrary number of joints and arbitrary geometry, opposed to the explicit inverse of the forward kinematics map, that is w...
Article
Full-text available
Graph decomposition is a key process in system-level synthesis, even if it is used for allocation (e.g. hardware-software partitioning) or simple decomposition as a preprocessing step (e.g. for pipelining). Acyclic graphs are usually desirable in the design processes, thus preserving the acyclicity during decomposition is crucial. We propose a modi...
Article
Full-text available
Model identification allows to design different control strategies for antiangiogenic cancer therapy, and create model-based treatment protocols. These model-based protocols can be more effective than the current ones, since they provide individual treatment for the patients. The aim of this paper is to investigate C38 colon adenocarcinoma growth i...
Article
Full-text available
Solution of the inverse orientation problem of robot manipulators is encumbered with singularities. The solution of the differential inverse orientation problem requires the inverse of the task Jacobian, however in singularities the inverse does not exist. The differential inverse orientation problem is transformed into a new representation called...
Conference Paper
Full-text available
Cancer treatment is one of the most important research fields of modern medicine. In the last decades, targeted molecular therapies showed prosperous results. These treatments achieve tumor regression with limited side-effects. Mathematical models were posed which describe the dynamics of tumor regression under the applied control. The current pape...
Conference Paper
Full-text available
Following the tradition established at previous IEEE INES conferences, this paper presents the results achieved by the Physiological Controls Group of Óbuda University in the field of physiological control last year (2013). The application target was focused on diabetes (artificial pancreas), tumor (antiangiogenic therapy), and hemodialysis (contro...
Conference Paper
Singular configurations arise in the kinematics of revolute joint manipulators, and complicates the solution of the inverse kinematics problem or detoriates motion planning. Singularities arise when solving inverse positioning and inverse orientation as well. In this work the differential inverse orientation problem is transformed into an inverse p...
Conference Paper
In system-level synthesis, the graph describing the task may consist of a great number of vertices, thus the design algorithms (e.g. hardware-software partitioning, pipeline synthesis, etc.) may become extremely complicated. This difficulty is relaxed by decomposing the task description graph that is usually unavoidable in system-level synthesis. T...