TY  - CONF
AU  - Atanasoski, Vladimir
AU  - Lazović, Aleksandar
AU  - Ivanović, Marija
AU  - Hadžievski, Ljupčo
AU  - Bojović, Boško
AU  - Petrović, Jovana
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13045
AB  - Photoplethysmography (PPG) has become a standard method for assessment of blood volume changes in clinical care and heart rate in home care [1]. Besides the pulse rate, PPG pulse forms carry signatures of diagnostically relevant events in cardiac cycle and can be used to estimate arterial stiffness. Extraction of these features requires removal of noise, motion artifacts and the superimposed slow varying signals, such as that from breathing, from the signal while preserving pulse morphology. However, modern filtering methods often fail to reproduce all signal features. Here, we propose a novel noise–removal method based on autocorrelation. Autocorrelation is a well-known method used in optics, mainly for estimating the duration of ultrashort laser pulses. We used autocorrelation to remove the noise and baseline wander (BLW) from a set of bioelectrical signals, namely electrocardiogram (ECG) and PPG. These signals comprise pulses (or beats) repeated in time but with slight changes. When we record several such beats and by averaging them get a noise-free signal with distorted morphology. However, taking a few steps further, namely subtracting the average from the original signal and filtering the difference in the frequency domain, enables the noise and BLW extraction from the original signal and reproduction of a faithful noise-free signal. We tested this method on the private ECG database, where added BLW component is from public MIT-NST database, and on the private PPG signals. The results show the superiority of our approach compared to the conventional cubic spline (CSP) method.
PB  - Belgrade : Institute of Physics
C3  - 16th Photonics Workshop : Book of abstracts
T1  - Autocorrelation for denoising biomedical signals
SP  - 25
EP  - 25
UR  - https://hdl.handle.net/21.15107/rcub_vinar_13045
ER  - 

@conference{
author = "Atanasoski, Vladimir and Lazović, Aleksandar and Ivanović, Marija and Hadžievski, Ljupčo and Bojović, Boško and Petrović, Jovana",
year = "2023",
abstract = "Photoplethysmography (PPG) has become a standard method for assessment of blood volume changes in clinical care and heart rate in home care [1]. Besides the pulse rate, PPG pulse forms carry signatures of diagnostically relevant events in cardiac cycle and can be used to estimate arterial stiffness. Extraction of these features requires removal of noise, motion artifacts and the superimposed slow varying signals, such as that from breathing, from the signal while preserving pulse morphology. However, modern filtering methods often fail to reproduce all signal features. Here, we propose a novel noise–removal method based on autocorrelation. Autocorrelation is a well-known method used in optics, mainly for estimating the duration of ultrashort laser pulses. We used autocorrelation to remove the noise and baseline wander (BLW) from a set of bioelectrical signals, namely electrocardiogram (ECG) and PPG. These signals comprise pulses (or beats) repeated in time but with slight changes. When we record several such beats and by averaging them get a noise-free signal with distorted morphology. However, taking a few steps further, namely subtracting the average from the original signal and filtering the difference in the frequency domain, enables the noise and BLW extraction from the original signal and reproduction of a faithful noise-free signal. We tested this method on the private ECG database, where added BLW component is from public MIT-NST database, and on the private PPG signals. The results show the superiority of our approach compared to the conventional cubic spline (CSP) method.",
publisher = "Belgrade : Institute of Physics",
journal = "16th Photonics Workshop : Book of abstracts",
title = "Autocorrelation for denoising biomedical signals",
pages = "25-25",
url = "https://hdl.handle.net/21.15107/rcub_vinar_13045"
}

Atanasoski, V., Lazović, A., Ivanović, M., Hadžievski, L., Bojović, B.,& Petrović, J.. (2023). Autocorrelation for denoising biomedical signals. in 16th Photonics Workshop : Book of abstracts
Belgrade : Institute of Physics., 25-25.
https://hdl.handle.net/21.15107/rcub_vinar_13045

Atanasoski V, Lazović A, Ivanović M, Hadžievski L, Bojović B, Petrović J. Autocorrelation for denoising biomedical signals. in 16th Photonics Workshop : Book of abstracts. 2023;:25-25.
https://hdl.handle.net/21.15107/rcub_vinar_13045 .

Atanasoski, Vladimir, Lazović, Aleksandar, Ivanović, Marija, Hadžievski, Ljupčo, Bojović, Boško, Petrović, Jovana, "Autocorrelation for denoising biomedical signals" in 16th Photonics Workshop : Book of abstracts (2023):25-25,
https://hdl.handle.net/21.15107/rcub_vinar_13045 .

TY  - CONF
AU  - Tadić, Predrag
AU  - Petrović, Jovana
AU  - Đorđević, Natalija
AU  - Ivanović, Marija
AU  - Lazović, Aleksandar
AU  - Vukčević, Vladan
AU  - Ristić, Arsen
AU  - Hadžievski, Ljupčo
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13044
AB  - We present our progress on the “Multi-SENSor SysteM and ARTificial intelligence in service of heart failure diagnosis (SensSmart)” project, which was introduced at the last year’s edition of the Workshop [1]. The goal of the SensSmart project is to enable early diagnosis of heart failure, through the development of: 1) a multi-sensor polycardiograph apparatus (PCG) that produces simultaneous acquisition of the subject’s electrocardiogram (ECG), photoplethysmogram (PPG), heart sounds, and heart movements, and 2) AI-assisted analysis of the acquired signals. This presentation is going to focus on the acquisition and processing of PPG signals. PPG is obtained by using a pulse oximeter which illuminates the skin and measures the changes in light absorption, thereby enabling the detection of blood volume changes in the vessels. Our PCG apparatus measures the blood flow through the brachial, radial, and carotid arteries. During each heartbeat, the generated waveform typically exhibits several characteristic points [2]. The magnitudes and time distances between these points are useful indicators of many cardiac conditions, including heart failure [3]. However, the inter-patient variability of the PPG waveform makes it challenging to derive simple rule-based diagnostic procedures. This has led many researchers to turn to statistical or machine learning methods for processing of PPG signals [4].  In this presentation, we give an overview of AI-based signal processing methods for PPG, and present some preliminary results and challenges in extracting features from real-world signals obtained using our PCG.
PB  - Belgrade : Institute of Physics
C3  - 16th Photonics Workshop : Book of abstracts
T1  - Photoplethysmogram as a source of biomarkers  for AI-based diagnosis of heart failure
SP  - 24
EP  - 24
UR  - https://hdl.handle.net/21.15107/rcub_vinar_13044
ER  - 

@conference{
author = "Tadić, Predrag and Petrović, Jovana and Đorđević, Natalija and Ivanović, Marija and Lazović, Aleksandar and Vukčević, Vladan and Ristić, Arsen and Hadžievski, Ljupčo",
year = "2023",
abstract = "We present our progress on the “Multi-SENSor SysteM and ARTificial intelligence in service of heart failure diagnosis (SensSmart)” project, which was introduced at the last year’s edition of the Workshop [1]. The goal of the SensSmart project is to enable early diagnosis of heart failure, through the development of: 1) a multi-sensor polycardiograph apparatus (PCG) that produces simultaneous acquisition of the subject’s electrocardiogram (ECG), photoplethysmogram (PPG), heart sounds, and heart movements, and 2) AI-assisted analysis of the acquired signals. This presentation is going to focus on the acquisition and processing of PPG signals. PPG is obtained by using a pulse oximeter which illuminates the skin and measures the changes in light absorption, thereby enabling the detection of blood volume changes in the vessels. Our PCG apparatus measures the blood flow through the brachial, radial, and carotid arteries. During each heartbeat, the generated waveform typically exhibits several characteristic points [2]. The magnitudes and time distances between these points are useful indicators of many cardiac conditions, including heart failure [3]. However, the inter-patient variability of the PPG waveform makes it challenging to derive simple rule-based diagnostic procedures. This has led many researchers to turn to statistical or machine learning methods for processing of PPG signals [4].  In this presentation, we give an overview of AI-based signal processing methods for PPG, and present some preliminary results and challenges in extracting features from real-world signals obtained using our PCG.",
publisher = "Belgrade : Institute of Physics",
journal = "16th Photonics Workshop : Book of abstracts",
title = "Photoplethysmogram as a source of biomarkers  for AI-based diagnosis of heart failure",
pages = "24-24",
url = "https://hdl.handle.net/21.15107/rcub_vinar_13044"
}

Tadić, P., Petrović, J., Đorđević, N., Ivanović, M., Lazović, A., Vukčević, V., Ristić, A.,& Hadžievski, L.. (2023). Photoplethysmogram as a source of biomarkers  for AI-based diagnosis of heart failure. in 16th Photonics Workshop : Book of abstracts
Belgrade : Institute of Physics., 24-24.
https://hdl.handle.net/21.15107/rcub_vinar_13044

Tadić P, Petrović J, Đorđević N, Ivanović M, Lazović A, Vukčević V, Ristić A, Hadžievski L. Photoplethysmogram as a source of biomarkers  for AI-based diagnosis of heart failure. in 16th Photonics Workshop : Book of abstracts. 2023;:24-24.
https://hdl.handle.net/21.15107/rcub_vinar_13044 .

Tadić, Predrag, Petrović, Jovana, Đorđević, Natalija, Ivanović, Marija, Lazović, Aleksandar, Vukčević, Vladan, Ristić, Arsen, Hadžievski, Ljupčo, "Photoplethysmogram as a source of biomarkers  for AI-based diagnosis of heart failure" in 16th Photonics Workshop : Book of abstracts (2023):24-24,
https://hdl.handle.net/21.15107/rcub_vinar_13044 .

TY  - CONF
AU  - Nedić, Milica
AU  - Gligorić, Goran
AU  - Petrović, Jovana
AU  - Maluckov, Aleksandra
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13043
AB  - Photonic lattices of optical waveguides present a well-controlled platform for investigation of different phenomena associated with the topological characteristics of physical systems. Recently, the first experimental realization of a Majorana zero-mode bound at vortexlike distortion induced in the bulk of a 2D graphene-like photonic lattice is demonstrated in [1]. The observed modes lie mid-gap at zero energy and they are extremely robust to the perturbations to the underlying Hamiltonian. We use bipartite armchair hexagonal lattice and create a vortex topological defect by perturbing positions of the central waveguides and numerically examine how the eigenvalues spectrum depends on the distortion phase. The observed robustness of zero-mode is an indication that adding the saturable gain and linear loss to lattice can lead to efficient lasing. Starting from the noisy background, we achieve zero-mode lasing, shown in Figure 1. We further investigate its robustness to the changes in driving conditions and the vortex phase with the goal to find an efficeint and steady lasing regime. These results can be used to design a new topological laser.
PB  - Belgrade : Institute of Physics
C3  - 16th Photonics Workshop : Book of abstracts
T1  - Impact of the vortex distortion phase on the efficiency of lasing zero-mode
SP  - 23
EP  - 23
UR  - https://hdl.handle.net/21.15107/rcub_vinar_13043
ER  - 

@conference{
author = "Nedić, Milica and Gligorić, Goran and Petrović, Jovana and Maluckov, Aleksandra",
year = "2023",
abstract = "Photonic lattices of optical waveguides present a well-controlled platform for investigation of different phenomena associated with the topological characteristics of physical systems. Recently, the first experimental realization of a Majorana zero-mode bound at vortexlike distortion induced in the bulk of a 2D graphene-like photonic lattice is demonstrated in [1]. The observed modes lie mid-gap at zero energy and they are extremely robust to the perturbations to the underlying Hamiltonian. We use bipartite armchair hexagonal lattice and create a vortex topological defect by perturbing positions of the central waveguides and numerically examine how the eigenvalues spectrum depends on the distortion phase. The observed robustness of zero-mode is an indication that adding the saturable gain and linear loss to lattice can lead to efficient lasing. Starting from the noisy background, we achieve zero-mode lasing, shown in Figure 1. We further investigate its robustness to the changes in driving conditions and the vortex phase with the goal to find an efficeint and steady lasing regime. These results can be used to design a new topological laser.",
publisher = "Belgrade : Institute of Physics",
journal = "16th Photonics Workshop : Book of abstracts",
title = "Impact of the vortex distortion phase on the efficiency of lasing zero-mode",
pages = "23-23",
url = "https://hdl.handle.net/21.15107/rcub_vinar_13043"
}

Nedić, M., Gligorić, G., Petrović, J.,& Maluckov, A.. (2023). Impact of the vortex distortion phase on the efficiency of lasing zero-mode. in 16th Photonics Workshop : Book of abstracts
Belgrade : Institute of Physics., 23-23.
https://hdl.handle.net/21.15107/rcub_vinar_13043

Nedić M, Gligorić G, Petrović J, Maluckov A. Impact of the vortex distortion phase on the efficiency of lasing zero-mode. in 16th Photonics Workshop : Book of abstracts. 2023;:23-23.
https://hdl.handle.net/21.15107/rcub_vinar_13043 .

Nedić, Milica, Gligorić, Goran, Petrović, Jovana, Maluckov, Aleksandra, "Impact of the vortex distortion phase on the efficiency of lasing zero-mode" in 16th Photonics Workshop : Book of abstracts (2023):23-23,
https://hdl.handle.net/21.15107/rcub_vinar_13043 .

TY  - CONF
AU  - Bugarski, Kolja
AU  - Petrović, Jovana
AU  - Maluckov, Aleksandra
PY  - 2023
UR  - https://vinar.vin.bg.ac.rs/handle/123456789/13040
AB  - One of the simplest [1] and nowadays hugely investigated models [2-5] for which topological features can be determined is the one-dimensional SSH (Su–Schrieffer–Heeger) model. In photonics, it can be realized as a waveguide array with alternating values of coupling between waveguides, Figure 1. While the linear regime has been investigated in great detail, the nonlinear regime leaves a number of questions open and is the subject of the work presented here. The light propagation through the waveguide array is mathematically modeled by the tight-binding differential-difference Schrödinger-like equation and numerically solved by the 4th order Runge-Kutta procedure. By tuning the ratio between the coupling constants of neighboring sites in the lattice, a topological phase transition can be induced. Boundary-bulk correspondence then provides creation of an integer number of edge states and the response of the bulk via integer value of the Zak-phase. We play with adding defects and inducing the nonlinear lattice response in order to confirm existing and find and manage new topological transitions in the system. This has potential applications in realization of the basic logic gates with controlled light (classical and quantum) beams which are necessary for solving quantum computing issues.
PB  - Belgrade : Institute of Physics
C3  - 16th Photonics Workshop : Book of abstracts
T1  - Localized modes in SSH photonic lattice in the presence of defects and local nonlinearity
SP  - 17
EP  - 17
UR  - https://hdl.handle.net/21.15107/rcub_vinar_13040
ER  - 

@conference{
author = "Bugarski, Kolja and Petrović, Jovana and Maluckov, Aleksandra",
year = "2023",
abstract = "One of the simplest [1] and nowadays hugely investigated models [2-5] for which topological features can be determined is the one-dimensional SSH (Su–Schrieffer–Heeger) model. In photonics, it can be realized as a waveguide array with alternating values of coupling between waveguides, Figure 1. While the linear regime has been investigated in great detail, the nonlinear regime leaves a number of questions open and is the subject of the work presented here. The light propagation through the waveguide array is mathematically modeled by the tight-binding differential-difference Schrödinger-like equation and numerically solved by the 4th order Runge-Kutta procedure. By tuning the ratio between the coupling constants of neighboring sites in the lattice, a topological phase transition can be induced. Boundary-bulk correspondence then provides creation of an integer number of edge states and the response of the bulk via integer value of the Zak-phase. We play with adding defects and inducing the nonlinear lattice response in order to confirm existing and find and manage new topological transitions in the system. This has potential applications in realization of the basic logic gates with controlled light (classical and quantum) beams which are necessary for solving quantum computing issues.",
publisher = "Belgrade : Institute of Physics",
journal = "16th Photonics Workshop : Book of abstracts",
title = "Localized modes in SSH photonic lattice in the presence of defects and local nonlinearity",
pages = "17-17",
url = "https://hdl.handle.net/21.15107/rcub_vinar_13040"
}

Bugarski, K., Petrović, J.,& Maluckov, A.. (2023). Localized modes in SSH photonic lattice in the presence of defects and local nonlinearity. in 16th Photonics Workshop : Book of abstracts
Belgrade : Institute of Physics., 17-17.
https://hdl.handle.net/21.15107/rcub_vinar_13040

Bugarski K, Petrović J, Maluckov A. Localized modes in SSH photonic lattice in the presence of defects and local nonlinearity. in 16th Photonics Workshop : Book of abstracts. 2023;:17-17.
https://hdl.handle.net/21.15107/rcub_vinar_13040 .

Bugarski, Kolja, Petrović, Jovana, Maluckov, Aleksandra, "Localized modes in SSH photonic lattice in the presence of defects and local nonlinearity" in 16th Photonics Workshop : Book of abstracts (2023):17-17,
https://hdl.handle.net/21.15107/rcub_vinar_13040 .