1. |
Gambin B.J., Kruglenko E., Tymkiewicz R., Litniewski J., Heating efficiency of agarose samples doped with magnetic nanoparticles subjected to ultrasonic and magnetic field,
INTERNATIONAL JOURNAL OF HEAT AND MASS TRANSFER, ISSN: 0017-9310, DOI: 10.1016/j.ijheatmasstransfer.2024.125467, Vol.226, No.125467, pp.1-10, 2024Streszczenie: Recently, magneto-ultrasound heating of tissue in the presence of magnetic nanoparticles (NPs) has been studied due to its high potential for use in oncological hyperthermia. It has been published that a synergistic effect, generation of additional heat caused by magneto-ultrasonic coupling, was observed in a tissue-mimicking material (TMM) enriched with magnetic NPs. The specific absorption rate (SAR) was determined from the temperature rise measurements in a focus of the ultrasound beam. It is important to use precise measurement methods when considering medical applications, for which there are limitations to the power of each field, resulting from the prevention of biological phenomena dangerous to the patient. This study demonstrates that in magneto-ultrasonic heating SAR can be measured much more accurately if the ultrasonic field is almost uniform. Measurements were performed on TMM containing Fe3O4 NPs with a diameter of approximately 8 nm and superparamagnetic properties. Both, the measurement and simulation results showed that the errors resulting from the inaccuracy of placing the temperature probe are smaller than in the case of the focused ultrasound. At the same time, the temperature increase caused by the ultrasonic field is almost linear and the influence of heat convection on the SAR determination is negligible. The measurements showed that magneto-ultrasonic hyperthermia can provide the desired thermal effect at lower ultrasound powers and magnetic fields compared to ultrasonic or magnetic hyperthermia used alone. No synergy effect was recorded. Słowa kluczowe: Magnetic nanoparticle-mediated hyperthermia,Dual-mode ultrasonic-magnetic hyperthermia,Specific absorption rate,Hyperthermia efficiency Afiliacje autorów:
Gambin B.J. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Tymkiewicz R. | - | IPPT PAN | Litniewski J. | - | IPPT PAN |
| | 200p. |
2. |
Gambin B., Nowicki A., In Memoriam Janusz Wójcik Professor of the IPPT PAN,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/aoa.2023.146817, Vol.48, No.4, pp.463-464, 2023, EDITORIALStreszczenie: Janusz Wójcik was born in the heart of Poland near Czarnolas in August 1957. He obtained an M.Sc. Eng. degree at the Warsaw University of Technology in 1983. From 1984 until the last days of his life, he worked at the Institute of Fundamental Technological Research Polish Academy of Sciences in Warsaw. He received his doctoral degree on the basis of the dissertation “Nonlinear EnvelopeWaves in The Vlasov-Maxwell Plasma” in 1990. In 2004, he was given a permanent position of IPPT PAN professor and a year later he was appointed Head of the Ultrasound Introscopy Laboratory at the Department of Ultrasound. Słowa kluczowe: Janusz Wójcik Afiliacje autorów:
Gambin B. | - | IPPT PAN | Nowicki A. | - | IPPT PAN |
| |
3. |
Byra M., Klimonda Z., Kruglenko E., Gambin B., Unsupervised deep learning based approach to temperature monitoring in focused ultrasound treatment,
Ultrasonics, ISSN: 0041-624X, DOI: 10.1016/j.ultras.2022.106689, Vol.122, pp.106689-1-7, 2022Streszczenie: Temperature monitoring in ultrasound (US) imaging is important for various medical treatments, such as high-intensity focused US (HIFU) therapy or hyperthermia. In this work, we present a deep learning based approach to temperature monitoring based on radio-frequency (RF) US data. We used Siamese neural networks in an unsupervised way to spatially compare RF data collected at different time points of the heating process. The Siamese model consisted of two identical networks initially trained on a large set of simulated RF data to assess tissue backscattering properties. To illustrate our approach, we experimented with a tissue-mimicking phantom and an ex-vivo tissue sample, which were both heated with a HIFU transducer. During the experiments, we collected RF data with a regular US scanner. To determine spatiotemporal variations in temperature distribution within the samples, we extracted small 2D patches of RF data and compared them with the Siamese network. Our method achieved good performance in determining the spatiotemporal distribution of temperature during heating. Compared with the temperature monitoring based on the change in radio-frequency signal backscattered energy parameter, our method provided more smooth spatial parametric maps and did not generate ripple artifacts. The proposed approach, when fully developed, might be used for US based temperature. Słowa kluczowe: temperature monitoring, high intensity ultrasound, deep learning, transfer learning, ultrasound imaging Afiliacje autorów:
Byra M. | - | IPPT PAN | Klimonda Z. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 140p. |
4. |
Gambin B., Korczak-Ciegielska I.^{♦}, Secomski W., Kruglenko E., Nowicki A., Ultrasonic Experimental Evaluation of the Numerical Model of the Internal Fluid Flow in the Kidney Cooling Jacket,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/aoa.2022.142004, Vol.47, No.3, pp.389-397, 2022Streszczenie: Kidney Cooling Jacket (KCJ) preserves the kidney graft, wrapped in the jacket, against the too fast time of temperature rise during the operation of connecting a cooled transplant to the patient’s bloodstream. The efficiency of KCJ depends on the stationarity of the fluid flow and its spatial uniformity. In this paper, the fluid velocity field inside the three different KCJ prototypes has been measured using the 20 MHz ultrasonic Doppler flowmeter. The simplified 2D geometrical model of the prototypes has been presented using COMSOL-Multiphysics to simulate the fluid flow assuming the laminar flow model. By comparing the numerical results with experimental data, the simplified 2D model is shown to be accurate enough to predict the flow distribution of the internal fluid velocity field within the KCJ. The discrepancy between the average velocity measured using the 20 MHz Doppler and numerical results was mainly related to the sensitivity of the velocity measurements to a change of the direction of the local fluid flow stream. Flux direction and average velocity were additionally confirmed by using ommercial colour Doppler imaging scanner. The current approach showed nearly 90% agreement of the experimental results and numerical simulations. It was important for justifying the use of numerical modelling in designing the baffles distribution (internal walls in the flow space) for obtaining the
most spatially uniform field of flow velocity. Słowa kluczowe: multi-canal system; fluid flow prediction; cooling jacket; flow Doppler measurement Afiliacje autorów:
Gambin B. | - | IPPT PAN | Korczak-Ciegielska I. | - | inna afiliacja | Secomski W. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Nowicki A. | - | IPPT PAN |
| | 100p. |
5. |
Gambin B., Melnikova P.^{♦}, Kruglenko E., Strzałkowski R., Krajewski M., Impact of the agarose ferrogel fine structure on magnetic heating efficiency,
Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2021.169000, No.1690000, 169423, pp.1-10, 2022Streszczenie: Magnetic nanoparticles-mediated hyperthermia was widely studied in the last decades as applicable in cancer therapy. The majority of magnetic hyperthermia research was devoted to improvement of heating efficiency by application of various nanomaterials. The influence of biocompatibility, magnetic properties, sizes, composition, and concentration of magnetic nanoparticles (MNPs) on hyperthermia efficiency was extensively studied. Also, the limits preserving biological safety and the chemical stability of MNPs delivered to the tissue were established. However, much less research concerned the impact of the physical interactions between the closest MNPs on the hyperthermia efficiency. Our goal was to demonstrate the relationships between the internal structure of soft tissue containing MNPs, and the thermal effects of an alternating magnetic field. Because agarose-based gel exhibits a tissue-like internal structure, we performed hyperthermia experiments in two types of such gel containing bare and polyethylene glycol-coated Fe3O4 nanoparticles. We described the structural difference and we estimated the ferrogels specific absorption rate coefficients (SAR) from calorimetric experiments. Magnetic measurements showed 11% lower magnetic saturation of PEG-coated MNPs than of the bare MNPs. While the SAR of ferrogel with PEG-coated MNPs was 15% greater than bare MNPs. The structural characteristics calculated from TEM and SEM images were significantly different. Particularly, we observed the nanoparticle agglomeration in the gel with bare MNPs. The bare MNPs uniformly packed and located inside agarose double helices were observed for the first time. The distribution of MNPs and their spatial configuration in gel influenced strongly the strength of bonds blocking the movement of MNPs and determined the ferrogels heating efficiency. As the tissues to which we delivered MNPs were composed of agarose gel-like structures, our results may be useful in further research on hyperthermia in vivo. 10.1016/j.jmmm.2021.169000, 10.1016/j.jmmm.2022.169423 Słowa kluczowe: nanoparticle-mediated magnetic hyperthermia, ferrogel, nanoparticles distribution, double helices structure Afiliacje autorów:
Gambin B. | - | IPPT PAN | Melnikova P. | - | Politechnika Warszawska (PL) | Kruglenko E. | - | IPPT PAN | Strzałkowski R. | - | IPPT PAN | Krajewski M. | - | IPPT PAN |
| | 100p. |
6. |
Miklewska A., Tymkiewicz R., Kruglenko E., Krajewski M., Gambin B., Comparison of the influence of superparamagnetic nanoparticles concentration and coverage on the alternating magnetic field thermal effect,
Journal of Magnetism and Magnetic Materials, ISSN: 0304-8853, DOI: 10.1016/j.jmmm.2021.168918, Vol.550, pp.168918-1-6, 2022Streszczenie: Magnetic nanoparticles (MNP)s of Fe3O4 were synthesized in the co-precipitation reaction of iron chlorides dissolved in water and ammonia water. To produce polyethylene glycol (PEG) coatings of the NMPs, we added PEG to the ammonia water during the fabrication process. Magnetic fluids, ferrofluids, for research were prepared as oleic acid suspension of bare and PEG-coated nanoparticles at four concentrations. The results of the conducted calorimetric experiments confirmed that the efficiency of heating ferrofluids strongly depends on the concentration of nanoparticles in fluids. The results also indicate that the ferrofluids containing PEG-coated NPs heat up more than ferrofluids with bare nanoparticles. They are characterized by a higher specific absorption rate (SAR) value calculated from the initial slope of temperature versus time curve during heating. 10.1016/j.jmmm.2021.168918, 10.1016/j.jmmm.2022.169422 Słowa kluczowe: nanoparticle fluid hyperthermia, magnetite nanoparticles, PEG-coated nanoparticles, hyperthermia Afiliacje autorów:
Miklewska A. | - | IPPT PAN | Tymkiewicz R. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Krajewski M. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 100p. |
7. |
Majka K.^{♦}, Parol M.^{♦}, Nowicki A., Gambin B., Trawiński Z., Jaciubek M.^{♦}, Krupienicz A.^{♦}, Olszewski R., Comparison of the radial and brachial artery flow-mediated dilation in patients with hypertension,
Advances in Clinical and Experimental Medicine, ISSN: 1899-5276, DOI: 10.17219/acem/144040, Vol.31, No.3, pp.241-248, 2022Streszczenie: Background. Blood flow-mediated dilation (FMD) is a noninvasive assessment of vascular endothelial function in humans. The study of the FMD in hypertensive (HT) patients is an important factor supporting the recognition of the early mechanisms of cardiovascular pathologies, and also of the pathogenesis related to hypertension. Objectives. To investigate whether FMD measured on the radial artery (FMD-RA) using high-requency ultrasounds can be used asan alternative to FMD assessed with the lower frequency system onthe brachial artery in patients with HT. Materials and methods. The simultaneous measurements of FMD-RA and FMD measurements in the brachial artery (FMD-BA) were performed on 76 HT patients using 20 MHz and 7–12 MHz linear array probes, and were compared to the FMD measured in healthy groups. All quantitative data are presented as mean ± standard deviation (SD); the p-values of the normality and tests for variables comparisons are listed. The agreement of the FMD-RA and FMD-BA in HT patients was assessed with the Bland–Altman method, and using the intraclass correlation coefficient (ICC). In some statistical calculations, the FMD-RA values were rescaled by dividing them by a factor of 2. Results. The mean FMD-RA and FMD-BA in HT patients were 5.16 ±2.18% (95% confidence interval (95% CI): [4.50%, 5.82%]) and 2.13 ±1.12% (95% CI: [1.76%, 2.49%]), respectively. The FMD-RA and FMD-BA values of HT patients were significantly different than those in respective control groups. The p-values of Mann–Whitney–Wilcoxon tests were less than 0.05. The Bland–Altman coefficient for both measurement methods, FMD-RA and FMD-BA, was 3%, and the ICC was 0.69. Conclusions. Our findings show that FMD-RA, supplementary to FMD-BA measurements, can be used to assess endothelial dysfunction in the group of HT patients. In addition, the FMD-RA measurements met the criteria of high concordance with the FMD-BA measurements. Słowa kluczowe: hypertension, brachial artery, radial artery, endothelial function Afiliacje autorów:
Majka K. | - | Military Medical Institute (PL) | Parol M. | - | The John Paul’s II Western Hospital in Grodzisk Mazowiecki (PL) | Nowicki A. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Trawiński Z. | - | IPPT PAN | Jaciubek M. | - | Medical University of Warsaw (PL) | Krupienicz A. | - | Medical University of Warsaw (PL) | Olszewski R. | - | IPPT PAN |
| | 70p. |
8. |
Gambin B., Kruglenko E., Ultrasonic specific absorption rate in nanoparticle-mediated moderate hyperthermia,
BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.24425/bpasts.2021.137053, Vol.69, No.3, pp.e137053-1-18, 2021Streszczenie: Magnetic nanoparticle’s different applications in nanomedicine, due to their unique physical properties and biocompatibility, were intensively investigated. Recently, Fe3O4 nanoparticles, are confirmed to be the best sonosensitizers to enhance the performance of HIFU (high intensity focused ultrasound). They are also used as thermo-sensitizers in magnetic hyperthermia. A new idea of dual, magneto-ultrasound, coupled hyperthermia allows the ultrasound intensity to be reduced from the high to a moderate level. Our goal is to evaluate the enhancement of thermal effects of focused ultrasound of moderate intensity due to the presence of nanoparticles. We combine experimental results with numerical analysis. Experiments are performed on tissue-mimicking materials made of the 5% agar gel and gel samples containing Fe3O4 nanoparticles with φ = 100 nm with two fractions of 0.76 and 1.53% w/w. Thermocouples registered curves of temperature rising during heating by focused ultrasound transducer with acoustic powers of the range from 1 to 4 W. The theoretical model of ultrasound-thermal coupling is solved in COMSOL Multiphysics. We compared the changes between the specific absorption rates (SAR) coefficients determined from the experimental and numerical temperature rise curves depending on the nanoparticle fractions and applied acoustic powers.We confirmed that the significant role of nanoparticles in enhancing the thermal effect is qualitatively similarly estimated, based on experimental and numerical results. So that we demonstrated the usefulness of the FEM linear acoustic model in the planning of efficiency of nanoparticle-mediated moderate hyperthermia. Słowa kluczowe: ultrasonic hyperthermia, agar-based tissue mimicking phantom, magnetic nanoparticles, temperature, specific absorption rate (SAR) Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN |
| | 100p. |
9. |
Korczak I., Romowicz A.^{♦}, Gambin B., Palko T.^{♦}, Kruglenko E., Dobruch-Sobczak K., Numerical prediction of breast skin temperature based on thermographic and ultrasonographic data in healthy and cancerous breasts,
Biocybernetics and Biomedical Engineering, ISSN: 0208-5216, DOI: 10.1016/j.bbe.2020.10.007, Vol.40, pp.1680-1692, 2020Streszczenie: Breast cancer is one of the most common women's cancers, so an available diagnostic modality, particularly non-invasive, is important. Infrared thermography (IRT) is a supporting diagnostic modality. Until now, many finite element methods (FEM) numerical models have been constructed to evaluate IRT's diagnostic value and to relate breast skin temperature characteristics with breast structural disorder presence, particularly to distinguish between cancerous types and normal structures. However, most of the models were not based on any clinical data, except for several papers based on clinical magnetic resonance imaging (MRI) data, wherein a three-dimensional (3D) breast model was studied. In our paper, we propose a very simplified numerical two-dimensional FEM model constructed based on clinical ultrasound data of breasts, which is much cheaper and available in realtime as opposed to MRI data. We show that our numerical simulations enabled us to distinguish between types of healthy breasts in agreement with the clinical classification and with thermographic results. The numerical breast models predicted the possibility of differentiation of cancerous breasts from healthy breasts by significantly different skin temperature variation ranges. The thermal variations of cancerous breasts were in the range of 0.5 8C–3.0 8C depending on the distance of the tumor from the skin surface, its size, and the cancer type. The proposed model, due to its simplicity and the fact that it was constructed based on clinical ultrasonographic data, can compete with the more sophisticated 3D models based on MRI. Słowa kluczowe: non-invasive cancer detection, Pennes' bioheat transfer equation, finite element method, breast thermography, ultrasonography Afiliacje autorów:
Korczak I. | - | IPPT PAN | Romowicz A. | - | inna afiliacja | Gambin B. | - | IPPT PAN | Palko T. | - | inna afiliacja | Kruglenko E. | - | IPPT PAN | Dobruch-Sobczak K. | - | IPPT PAN |
| | 100p. |
10. |
Nowicki A., Gambin B., Secomski W., Trawiński Z., Szubielski M.^{♦}, Olszewski R., Does flow-mediated dilation normalization for base-scaled shear rate improve its value in coronary artery disease?,
ULTRASOUND IN MEDICINE AND BIOLOGY, ISSN: 0301-5629, DOI: 10.1016/j.ultrasmedbio.2020.05.018, Vol.46, No.9, pp.2551-2555, 2020Streszczenie: The article presents a new normalization of flow-mediated dilation (FMD) in the radial artery, taking into account the parameter BSSR being equal to the ratio of the basal shear rate (BS) measured before the cuff inflation and post occlusive shear rate (SR). The in vivo usefulness of the new normalization algorithm wasevaluated in two groups of patients. In group I, comprising 15 healthy volunteers, the normalized FMD/SR was(3.19 ± 1.4)*10^-4, while in group II, comprising 13 patients with stable coronary artery disease (CAD), it was(1.02 ± 0.76)*10^-4. We calculated almost 50% larger difference between the average values after normalizing FMD/BSSR. Specifically, the FMD/BSSR was equal to 28 ± 9.40 in group I and 6.01 ± 3.74 in group II. The prediction of CAD patients based on FMD/SR values had a sensitivity of 83.3% and a specificity of 84.6%, whereas the prediction of CAD patients based on the FMD/BSSR values revealed 100% sensitivity and specificity. These results confirm the usefulness of the novel normalization algorithm of the FMD in differentiation of normal patients from those with stable CAD. Słowa kluczowe: flow-mediated vasodilation, radial artery, shear rate, pulsed Doppler, ultrasonography, coronary artery disease
Afiliacje autorów:
Nowicki A. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Secomski W. | - | IPPT PAN | Trawiński Z. | - | IPPT PAN | Szubielski M. | - | Mazovia Regional Hospital in Siedlce (PL) | Olszewski R. | - | IPPT PAN |
| | 70p. |
11. |
Gambin B., Kruglenko E., Tymkiewicz R., Litniewski J., Ultrasound assessment of the conversion of sound energy into heat in tissue phantoms enriched with magnetic micro- and nanoparticles,
Medical Physics, ISSN: 0094-2405, DOI: 10.1002/mp.13742, Vol.46, No.10, pp.4361-4370, 2019Streszczenie: Purpose: Nowadays, the improvement of ultrasonic hyperthermia therapy is often achieved by adding hard particles to the sonicated medium in order to increase the heating efficiency. The explanation of the phenomenon of ultrasonic heating still requires testing on tissue mimicking materials (TMMs), enriched with particles of different sizes and physical properties. Our goal was to determine, by comparing their quantitative acoustic properties, which TMMs, with magnetic micro- or nanoparticles, convert more ultrasonic energy into heat or which of the particles embedded in the agar gel act as more effective thermal sonosensitizers. Methods: We manufactured a pure agar gel and an agar gel with the addition of magnetic micro- or nanoparticles in two proportions of 8 and 16 mg/ml. Ultrasound quantitative techniques, the broadband reflection substitution technique and backscattered spectrum analysis were used to characterize the samples by speed of sound (SOS), frequency-dependent attenuation, and backscattering coefficients. The integrated backscattering coefficients were also calculated. The quantitative parameters, scattering, and attenuation coefficients of ultrasound in phantoms with micro- and nanoparticles were estimated. Based on the attenuation and scattering of ultrasound in the samples, the ultrasonic energy absorption, which determines the heating efficiency, was evaluated. Additionally, the temperature increase during sonication of the phantoms by an ultrasonic beam was directly measured using thermocouples. Results: The density of the materials with nanoparticles was higher than for the materials with microparticles with the same fractions of particles. The SOS for all materials ranged from 1489 to 1499 m/s. The attenuation in the whole frequency range (3–8 MHz) was higher for the materials with nanoparticles than for the materials with microparticles. For the materials with the lower content (8 mg/ml) of particles, the attenuation coefficient was 0.2 dB/(MHz cm). For the 16 mg/ml concentration of nanoparticles and microparticles, the attenuation coefficients were 0.66 and 0.45 dB/(MHz cm), resectively. The value of backscattering coefficient in the whole frequency range was greater for the materials with microparticles than for the materials with nanoparticles. The values of the integrated backscattering coefficient were 0.05 and 0.08 1/m for the materials with nanoparticles and 0.46 and 0.82 1/m for the materials with microparticles and concentrations of 8 and 16 mg/ml, respectively. The rates of temperature increase in the first 3 s due to ultrasonic heating were higher for the materials with nanoparticles than for the materials with microparticles. Conclusions: Based on acoustical measurements, we confirmed that all materials can be used as tissue phantoms in the study of ultrasonic hyperthermia, as their properties were in the range of soft tissue properties. We found that the nanoparticle-doped materials had greater attenuation and smaller scattering of ultrasound than the materials with microparticles, so absorption in these materials is greater. Thus, the TMMs with nanoparticles convert more acoustic energy into heat and we conclude that magnetic nanoparticles are more effective thermal sonosensitizers than microparticles. This conclusion is confirmed by direct measurement of the temperature increase in the samples subjected to sonification. Słowa kluczowe: backscattering coefficient, frequency-dependent attenuation, hyperthermia TMM, magnetic particles, ultrasound absorption Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Tymkiewicz R. | - | IPPT PAN | Litniewski J. | - | IPPT PAN |
| | 100p. |
12. |
Nowicki A., Gambin B., Secomski W., Trawiński Z., Szubielski M.^{♦}, Tymkiewicz R., Olszewski R.^{♦}, Assessment of high frequency imaging and Doppler system for the measurements of the radial artery flow-mediated dilation,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.24425/aoa.2019.129276, Vol.44, No.4, pp.637-644, 2019Streszczenie: In the article we describe the new, high frequency, 20 MHz scanning/Doppler probe designed to measure the flow mediated dilation (FMD) and shear rate (SR) close to the radial artery wall. We compare two US scanning systems, standard vascular modality working below 12 MHz and high frequency 20 MHz system designed for FMD and SR measurements. Axial resolutions of both systems were compared by imaging of two closely spaced food plastic foils immersed in water and by measuring systolic/diastolic diameter changes in the radial artery. The sensitivities of Doppler modalities were also determined. The diagnostic potential of a high frequency system in measurements of FMD and SR was studied in vivo, in two groups of subjects, 12 healthy volunteers and 14 patients with stable coronary artery disease (CAD). Over three times better axial resolution was demonstrated for a high frequency system. Also, the sensitivity of the external single transducer 20 MHz pulse Doppler proved to be over 20 dB better (in terms of a signal-to-noise ratio) than the pulse Doppler incorporated into the linear array. Statistically significant differences in FMD and FMD/SR values for healthy volunteers and CAD patients were confirmed, p-values < 0:05. The areas under Receiver Operating Characteristic (ROC) curves for FMD and FMD/SR for the prediction CAD had the values of 0.99 and 0.97, respectively. These results justify the usefulness of the designed high-frequency scanning system to determine the FMD and SR in the radial artery as predictors of coronary arterial disease. Słowa kluczowe: low mediated dilation, shear rate, axial resolution, elevation resolution, pulsed Doppler, ultrasonic imaging Afiliacje autorów:
Nowicki A. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Secomski W. | - | IPPT PAN | Trawiński Z. | - | IPPT PAN | Szubielski M. | - | Mazovia Regional Hospital in Siedlce (PL) | Tymkiewicz R. | - | IPPT PAN | Olszewski R. | - | inna afiliacja |
| | 70p. |
13. |
Nowicki A., Trawiński Z., Gambin B., Secomski W., Szubielski M.^{♦}, Parol M.^{♦}, Olszewski R., 20-MHZ ultrasound for measurements offlow-mediated dilation and shear rate in the radialartery,
ULTRASOUND IN MEDICINE AND BIOLOGY, ISSN: 0301-5629, DOI: 10.1016/j.ultrasmedbio.2018.02.011, Vol.44, No.6, pp.1187-1197, 2018Streszczenie: A high-frequency scanning system consisting of a 20-MHz linear array transducer combined with a 20-MHz pulsed Dopplerprobe was introduced to evaluate the degree of radial artery ﬂow-mediated dilation (FMD [%]) in two groups of patients after5 min of controlled forearm ischemia followed by reactive hyperemia. In group I, comprising 27 healthy volunteers, FMD (mean ± standard deviation) was 15.26 ± 4.90% (95% confidence interval [CI]: 13.32%–17.20%); in group II, comprising 17 patients with chronic coronary artery disease, FMD was significantly less at 4.53 ± 4.11% (95% CI: 2.42%–6.64%). Specifically, the ratio FMD/SR (mean ± standard deviation),wasequalto5.36×10−4±4.64×10−4 (95%CI:3.54×10−4 to7.18×10−4)ingroupIand1.38×10−4±0.89×10−4 (95% CI: 0.70 × 10−4 to 2.06 × 10−4) in group II. Statistically significant differences between the two groups were confirmed by a Wilcoxon–Mann–Whitney test for both FMD and FMD/SR (p < 0.01). Areas under receiver operating characteristic curves for FMD and FMD/SR were greater than 0.9. The results confirm the usefulness of the proposed measurements of radial artery FMD and SR in differentiation of normal patients from those with chronic coronary artery disease. (E-mail: ) © 2018 World Federation for Ultrasound in Medicine & Biology. All rights reserved. Słowa kluczowe: Flow-mediated vasodilation, Radial artery, Shear rate, Reactive hyperemia, Endothelium, Pulsed doppler, Ultrasonography Afiliacje autorów:
Nowicki A. | - | IPPT PAN | Trawiński Z. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Secomski W. | - | IPPT PAN | Szubielski M. | - | Mazovia Regional Hospital in Siedlce (PL) | Parol M. | - | The John Paul’s II Western Hospital in Grodzisk Mazowiecki (PL) | Olszewski R. | - | IPPT PAN |
| | 40p. |
14. |
Wójcik J., Gambin B., Theoretical and numerical aspects of nonlinear reflection–transmission phenomena in acoustics,
Applied Mathematical Modelling, ISSN: 0307-904X, DOI: 10.1016/j.apm.2016.10.026, Vol.42, pp.100-113, 2017Streszczenie: Equations of nonlinear acoustic wave motion in a non-classical lossy medium are used to derive generalised formulas describing the phenomena of reflection and transmission. Integral, non-local operators that are caused by the nonlinear effects in wave propagation and occur in reflection and transmission formulas are given in a form in which classical linear reflection and transmission coefficients are explicitly separated. Numerical calculations are performed for a simplified, one-dimensional wave travelling in a lossless medium. These simplifications reveal the pure effect of the impact of nonlinearities on the reflection and transmission phenomena. We consider adjacent media with different properties to illustrate various aspects of the problem. In particular, even if two media have the same linear impedance and the same material modules of the third order, we observe an explicit effect of the nonlinearity on the reflection phenomenon. The theoretical predictions are confirmed qualitatively by numerical calculations based on the finite difference time domain method. Słowa kluczowe: non-linear sound wave, non-linear reflection, non-classical absorption, soft tissues Afiliacje autorów:
Wójcik J. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 35p. |
15. |
Byra M., Kruglenko E., Gambin B., Nowicki A., Temperature Monitoring during Focused Ultrasound Treatment by Means of the Homodyned K Distribution,
ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.131.1525, Vol.131, No.6, pp.1525-1528, 2017Streszczenie: Temperature monitoring is essential for various medical treatments. In this work, we investigate the impact of temperature on backscattered ultrasound echo statistics during a high intensity focused ultrasound treatment. A tissue mimicking phantom was heated with a spherical ultrasonic transducer up to 56 _C in order to imitate tissue necrosis. During the heating, an imaging scanner was used to acquire backscattered echoes from the heated region. These data was then modeled with the homodyned K distribution. We found that the best temperature indicator can be obtained by combining two parameters of the model, namely the backscattered echo mean intensity and the effective number of scatterers per resolution cell. Next, ultrasonic thermometer was designed and used to create a map of the temperature induced within the tissue phantom during the treatment Słowa kluczowe: Temperature monitoring, homodyned K distribution, focused ultrasound Afiliacje autorów:
Byra M. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Nowicki A. | - | IPPT PAN |
| | 15p. |
16. |
Karwat P., Kujawska T., Lewin P.A.^{♦}, Secomski W., Gambin B., Litniewski J., Determining temperature distribution in tissue in the focal plane of the high (>100 W/cm2) intensity focused ultrasound beam using phase shift of ultrasound echoes,
Ultrasonics, ISSN: 0041-624X, DOI: 10.1016/j.ultras.2015.10.002, Vol.65, pp.211-219, 2016Streszczenie: In therapeutic applications of High Intensity Focused Ultrasound (HIFU) the guidance of the HIFU beam and especially its focal plane is of crucial importance. This guidance is needed to appropriately target the focal plane and hence the whole focal volume inside the tumor tissue prior to thermo-ablative treatment and beginning of tissue necrosis. This is currently done using Magnetic Resonance Imaging that is relatively expensive. In this study an ultrasound method, which calculates the variations of speed of sound in the locally heated tissue volume by analyzing the phase shifts of echo-signals received by an ultrasound scanner from this very volume is presented. To improve spatial resolution of B-mode imaging and minimize the uncertainty of temperature estimation the acoustic signals were transmitted and received by 8 MHz linear phased array employing Synthetic Transmit Aperture (STA) technique. Initially, the validity of the algorithm developed was verified experimentally in a tissue-mimicking phantom heated from 20.6 to 48.6°C. Subsequently, the method was tested using a pork loin sample heated locally by a 2 MHz pulsed HIFU beam with focal intensity ISATA of 129 W/cm2. The temperature calibration of 2D maps of changes in the sound velocity induced by heating was performed by comparison of the algorithm-determined changes in the sound velocity with the temperatures measured by thermocouples located in the heated tissue volume. The method developed enabled ultrasound temperature imaging of the heated tissue volume from the very inception of heating with the contrast-to-noise ratio of 3.5–12 dB in the temperature range 21–56°C. Concurrently performed, conventional B-mode imaging revealed CNR close to zero dB until the temperature reached 50°C causing necrosis. The data presented suggest that the proposed method could offer an alternative to MRI-guided temperature imaging for prediction of the location and extent of the thermal lesion prior to applying the final HIFU treatment. Słowa kluczowe: Ultrasonic temperature imaging, HIFU, Echo phase shift, Velocity image contrast Afiliacje autorów:
Karwat P. | - | IPPT PAN | Kujawska T. | - | IPPT PAN | Lewin P.A. | - | Drexel University (US) | Secomski W. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Litniewski J. | - | IPPT PAN |
| | 30p. |
17. |
Gambin B., Byra M., Kruglenko E., Doubrovina O.^{♦}, Nowicki A., Ultrasonic Measurement of Temperature Rise in Breast Cyst and in Neighbouring Tissues as a Method of Tissue Differentiation,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.1515/aoa-2016-0076, Vol.41, No.4, pp.791-798, 2016Streszczenie: Texture of ultrasound images contain information about the properties of examined tissues. The analysis of statistical properties of backscattered ultrasonic echoes has been recently successfully applied to differentiate healthy breast tissue from the benign and malignant lesions. We propose a novel procedure of tissue characterization based on acquiring backscattered echoes from the heated breast. We have proved that the temperature increase inside the breast modifies the intensity, spectrum of the backscattered signals and the probability density function of envelope samples. We discuss the differences in probability density functions in two types of tissue regions, e.g. cysts and the surrounding glandular tissue regions. Independently, Pennes bioheat equation in heterogeneous breast tissue was used to describe the heating process. We applied the finite element method to solve this equation. Results have been compared with the ultrasonic predictions of the temperature distribution. The results confirm the possibility of distinguishing the differences in thermal and acoustical properties of breast cyst and surrounding glandular tissues. Słowa kluczowe: medical ultrasound, temperature changes in vivo, breast tissue, ultrasonic temperature measurement Afiliacje autorów:
Gambin B. | - | IPPT PAN | Byra M. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Doubrovina O. | - | Belarussian State University (BY) | Nowicki A. | - | IPPT PAN |
| | 15p. |
18. |
Karwat P., Kujawska T., Secomski W., Gambin B., Litniewski J., Application of ultrasound to noninvasive imaging of temperature distribution induced in tissue,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.19, pp.219-228, 2016Streszczenie: Therapeutic and surgical applications of High Intensity Focused Ultrasound (HIFU) require monitoring of local temperature rises induced inside tissues. It is needed to appropriately target the focal plane, and hence the whole focal volume inside the tumor tissue, prior to thermo-ablative treatment, and the beginning of tissue necrosis. In this study we present an ultrasound method, which calculates the variations of the speed of sound in the locally heated tissue. Changes in velocity correspond to temperature change. The method calculates a 2D distribution of changes in the sound velocity, by estimation of the local phase shifts of RF echo-signals backscattered from the heated tissue volume (the focal volume of the HIFU beam), and received by an ultrasound scanner (23). The technique enabled temperature imaging of the heated tissue volume from the very inception of heating. The results indicated that the contrast sensitivity for imaging of relative changes in the sound speed was on the order of 0.06%; corresponding to an increase in the tissue temperature by about 2 °C. Słowa kluczowe: HIFU, echo phase shift, parametric imaging, velocity/brightness CNR Afiliacje autorów:
Karwat P. | - | IPPT PAN | Kujawska T. | - | IPPT PAN | Secomski W. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Litniewski J. | - | IPPT PAN |
| | 6p. |
19. |
Gambin B., Wójcik J., Doubrovina O.^{♦}, Differentiation of random structure properties using wavelet analysis of backscattered ultrasound,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.19, pp.121-128, 2016Streszczenie: The aim of this work was to find the differences between random media by analyzing the properties of the ultrasound signals backscattered from the inhomogeneities. A numerical model is used to generate two types of random media. The first has the randomness in scatterers’ positions and the second has the randomness in the size and acoustical properties of scatterers. The numerical model of wave scattering has been used to simulate the RF (radio frequency) signals caused by the incident pulse traveling as a plane wave. The markers of randomness type differences between the scattering media were obtained with the help of the spectral and wavelet analysis. The effect of differences in randomness type is more spectacular when the wavelet analysis is performed. Słowa kluczowe: spectrogram, scalogram, wavelets, random scattering structure Afiliacje autorów:
Gambin B. | - | IPPT PAN | Wójcik J. | - | IPPT PAN | Doubrovina O. | - | Belarussian State University (BY) |
| | 6p. |
20. |
Gambin B., Kruglenko E., Byra M., Relationships between Acoustical Properties and Stiffness of Soft Tissue Phantoms,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.19, pp.111-120, 2016Streszczenie: Polyvinyl-alcohol cryogel is commonly used for soft tissue phantom manufacture. The gel formation from an aqueous solution of polyvinyl-alcohol takes place during the freezing and thawing cycle. The aim of this work was to assess the degree of gel solidification, hence the material stiffness, by means of quantitative ultrasound. We manufactured three phantoms which differed in the number of freezing/thawing cycles. First, tissue phantoms were examined with an elastography technique. Next, we measured the speed of sound and the attenuation coefficient. What is more, the inter structure variations in phantoms were assessed with the Nakagami imaging which quantifies the scattering properties of the backscattered ultrasound echo. Obtained results confirmed the connection between the number of freezing/thawing cycles and the solidification process. We defined the boundary layer as a region which has a different structure than the sample interior. Next, for each phantom this layer was extracted based on a Nakagami parameter map. We calculated that the thickness of the boundary layer was lower in samples which were subjected to a larger number of freezing/thawing cycles. Słowa kluczowe: soft tissue phantoms, elastography, ultrasound attenuation, speed of sound, Nakagami maps, stiffness Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Byra M. | - | IPPT PAN |
| | 6p. |
21. |
Ivanova J.^{♦}, Nikolova G.^{♦}, Becker W.^{♦}, Gambin B., Interface behavior of a bi-material plate under dynamic loading. Cohesive interface debonding,
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, ISSN: 0044-2267, DOI: 10.1002/zamm.201300119, Vol.95, No.11, pp.1190-1201, 2015Streszczenie: The paper deals with the elastic and cohesive interface behavior of pre-cracked bi-material ceramic-metal structures under dynamic time harmonic load. The shear lag model as well as the Fourier method is applied to find the dynamic response of the considered bi-material structure, assuming the cohesive interface behaviour, accompanied before of the elastic-brittle one. In both cases, the growth of debond length is not considered, e.g. at a given loading condition the only corresponding debond length is found. The inertia forces of the already elastic debond parts of the bi-material structure are neglected. Appropriate contact conditions are proposed in order to fit together both elastic and cohesive solutions. The numerical predictions for the cohesive debond length of the bi-material structures is calculated by the aid of the corresponding value of the elastic debond length at the same loading condition. The influence of loading characteristics i.e. frequencies and amplitude fluctuations on the debond length and the interface shear stress distribution is discussed. The parametric analysis of the results obtained is illustrated by examples of the modern ceramic-metal composites on metal substrates and is depicted in figures. Słowa kluczowe: Dynamic behaviour of bi-material structure, cracked plate, shear lag model, elastic-brittle and cohesive interface delamination, debond length Afiliacje autorów:
Ivanova J. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Nikolova G. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Becker W. | - | Technische Universität Darmstadt (DE) | Gambin B. | - | IPPT PAN |
| | 25p. |
22. |
Gambin B., Kruglenko E., Temperature Measurement by Statistical Parameters of Ultrasound Signal Backscattered from Tissue Samples,
ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.128.A-72, Vol.128, No.1-A, pp.A-72-78, 2015Streszczenie: A novel estimation of temperature changes inside soft tissues has been proposed in sub-ablation range, i.e. 20°C-48°C. This estimation has been obtained by studying statistical properties of backscattered ultrasonic signals. Two different procedures of heating/cooling have been performed in which the RF echoes have been registered from soft tissue phantom in the first procedure, and from soft tissue in vitro in the second one. Calculated envelopes of signals registered in time points during heating/cooling experiments have been treated as a statistical sample drawn from a random variable with three different distributions, namely the Rayleigh distribution, the Nakagami distribution, and the K-distribution. The histograms obtained in subsequent time moments have been fitted to the three distributions. Dependencies of their shape and scale parameters on temperature have been calculated. It is concluded that the shape parameter of the K-distribution can be chosen as the best marker of temperature changes in both experiments. The choice of the marker has been made by analysis of temperature dependencies of all calculated parameters and by comparing the quality of fitting all histograms to the considered distributions. Besides, the chosen marker as a function of temperature exhibits the closest shape to temperature/time function experimentally measured. Słowa kluczowe: therapeutic applications, ultrasonics, medical imaging Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN |
| | 15p. |
23. |
Gambin B., Kruglenko E., Gałka A.A.^{♦}, Wojnar R., Macroscopic thermal properties of quasi-linear cellular medium on example of the liver tissue,
COMPUTER ASSISTED METHODS IN ENGINEERING AND SCIENCE, ISSN: 2299-3649, Vol.22, No.4, pp.329-346, 2015Streszczenie: There are two main topics of this research: (i) one topic considers overall properties of a nonlinear cellular composite, treated as a model of the liver tissue, and (ii) the other topic concerns the propagation of heat in the nonlinear medium described by the homogenised coefficient of thermal conductivity.
For (i) we give a method and find the effective thermal conductivity for the model of the liver tissue, and for the point (ii) we present numerical and analytical treatment of the problem, and indicate the principal difference of heat propagation in linear and nonlinear media. In linear media, as it is well known, the range of the heat field is infinite for all times t > 0, and in nonlinear media it is finite.
Pennes’ equation, which should characterize the heat propagation in the living tissue, is in general a quasi-nonlinear partial differential equation, and consists of three terms, one of which describes Fourier’s heat diffusion with conductivity being a function of temperature T. This term is just a point of our analysis.
We show that a nonlinear character of the medium (heat conductivity dependent on the temperature) changes in qualitative manner the nature of heat transfer. It is proved that for the heat source concentrated initially (t = 0) at the space point, the range of heated region (for t > 0) is finite. The proof is analytical, and illustrated by a numerical experiment. Słowa kluczowe: heat transport, asymptotic homogenisation, effective heat conductivity Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Gałka A.A. | - | inna afiliacja | Wojnar R. | - | IPPT PAN |
| | 14p. |
24. |
Wójcik J., Gambin B., Litniewski J., Theoretical results and numerical study on the nonlinear reflection and transmission of plane sound waves,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.18, pp.181-192, 2015Streszczenie: The comparison between theoretical and numerical solutions of the reflection/transmission problem for the acoustic plane wave normally incident on the discontinuity surface between two nonlinear lossy media was presented. Numerical calculations made under the assumption that the two media have the same impedance, allow to single out the effect of nonlinearities in the description of the reflection and transmission phenomena, so they agreed with theoretical predictions. It was shown that theoretically obtained and numerically calculated results mutually confirmed themselves Słowa kluczowe: Nonliear reflection, transmission, Riccati equation Afiliacje autorów:
Wójcik J. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Litniewski J. | - | IPPT PAN |
| | 6p. |
25. |
Gambin B., Kruglenko E., Wójcik J., Relationship between thermal and ultrasound fields in breast tissue in vivo,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.18, pp.53-58, 2015Streszczenie: The study shows the direct relationship between the temperature field and the parallel changes that are taking place in backscattered ultrasonic signals from the breast tissue in vivo when heated to the temperature of approximately 42 o C. The non-uniform temperature field inside the heating tissue was determined by the numerical model using FEM. It is shown that the spatial distribution of intensities of the backscattered signals coincides with the temperature distribution field predicted by the numerical model in some areas. The result indicates the possibility of the indirect measurement of the temperature rise in the breast tissue in vivo by measuring the intensity variations of the ultrasound echo. Słowa kluczowe: temperature field, backscattered ultrasonic signals, breast tissue in vivo, FEM model Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Wójcik J. | - | IPPT PAN |
| | 6p. |
26. |
Byra M., Gambin B., Temperature detection based on nonparametric statistics of ultrasound echoes,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.18, pp.17-23, 2015Streszczenie: Different ultrasound echoes properties have been used for the noninvasive temperature monitoring. Temperature variations that occur during heating/cooling process induce changes in a random process of ultrasound backscattering. It was already proved that the probability distribution of the backscattered RF (radio frequency) signals is sensitive to the temperature variations. Contrary to previously used methods which explored models of scattering and involved techniques of fitting histograms to a special probability distribution two more direct measures of changes in statistics are proposed in this paper as temperature markers. They measure the ”distance” between the probability distributions. The markers are the Kolmogorov Smirnov distance and Kulback-Leiber divergence. The feasibility of using such nonparametric statistics for noninvasive ultrasound temperature estimation is demonstrated on the ultrasounds data collected during series of heating experiments in which the temperature was independently registered by the classical thermometer or thermocouples. Słowa kluczowe: ultrasoud echoes, non-invasive temperaturę monitoring, Kolmogorov Smirnov distance, Kulback-Leiber divergence Afiliacje autorów:
Byra M. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 6p. |
27. |
Nowicki A., Gambin B., Ultrasonic Synthetic Apertures: Review,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.2478/aoa-2014-0047, Vol.39, No.4, pp.427-438, 2014Streszczenie: In the paper the concept of synthetic aperture used for high resolution/high frame rate ultrasonic imaging is reviewed. The synthetic aperture technique allows building extended “virtual” apertures, synthesized from smaller real aperture resulting in improved lateral resolution along full penetration depth without sacrificing the frame rate.
Especially, four methods, synthetic aperture focusing (SAF), multi-element synthetic aperture focusing (M-SAF), synthetic receive aperture (SRA) and synthetic transmit aperture (STA) are addressed. The effective aperture function, describing two-way, far field radiation is a useful tool in beam pattern analysis. Some basic notations, which are used to calculate the effective aperture are introduced in Appendix. Słowa kluczowe: synthetic aperture, effective aperture, ultrasonography Afiliacje autorów:
Nowicki A. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 15p. |
28. |
Kruglenko E., Gambin B., RF signal amplitude statistics during temperature changes in tissue phantoms,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.17, pp.115-122, 2014Streszczenie: Two heating protocols for soft tissue phantoms have been performed. An Agar-Gel-Oil (AGO) mixture has been heated locally by applying ultrasonic beams and a Poly Vinyl Alcohol-cryogel (PVA-c) has been heated “globally” by a water bath with a controlled temperature rise. The RF signals were collected during heating by an ultrasound transducer to ensure no interference from waves from the heating transducer. Independently, the thermocouples' measurement has been used to obtain temperature as a function of time in the AGO case. At first, a compensation of attenuation was performed and normalized envelopes of signals were used as data for statistical analysis. It is shown that random the values of the backscattered amplitude are close to Rayleigh and K-distributed random variables for AGO and PVA-c, respectively. Temperature is linked to the scale parameter of Rayleigh distribution for the AGO, and the shape parameter of K-distribution for PVA-c were calculated and discussed in the context of their suitability for the acoustic measurement of temperature. Słowa kluczowe: Agar-Gel_Oil soft tissue phantom, K-distribution shape parameter, temperaturę measurements Afiliacje autorów:
Kruglenko E. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 7p. |
29. |
Doubrovina O.^{♦}, Gambin B., Kruglenko E., Temperature level and properties of wavelet approximations of back scattered ultrasound,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.17, pp.37-46, 2014Streszczenie: The aim of the paper is to find links between the dynamics of changes of statistical parameters and changes in spectral properties of the signal envelope of backscattered RF signals during the thermal process. We have shown previously that by using wavelet approximations these tendencies are better recognized in the case of the heating of a phantom sample than in the parallel analysis performed for a full signal envelope. Here we are currently expanding this statement to the case of heating a soft tissue sample in vitro. The shape parameter of the K- distributed random variable is considered as a statistical marker of temperature level changes. Additionally, the spectral properties of different levels of wavelet approximations are calculated and their sensitivity to temperature increase and decrease is demonstrated. Both approaches registering changes in temperature, are used in the case of the pork loin tissue sample in vitro, heated by an ultrasound beam with a different power. Słowa kluczowe: ultrasound echoes, soft tissue sample in vitro, statistical marker of temperaturę rise Afiliacje autorów:
Doubrovina O. | - | Belarussian State University (BY) | Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN |
| | 7p. |
30. |
Gambin B., Bielski W.^{♦}, Incompressible limit for a magnetostrictive energy functional,
BULLETIN OF THE POLISH ACADEMY OF SCIENCES: TECHNICAL SCIENCES, ISSN: 0239-7528, DOI: 10.2478/bpasts-2013-0110, Vol.61, No.4, pp.320-326, 2013Streszczenie: The modern materials undergoing large elastic deformations and exhibiting strong magnetostrictive effect are modelled here by free energy functionals for nonlinear and non-local magnetoelastic behaviour. The aim of this work is to prove a new theorem which claims that a sequence of free energy functionals of slightly compressible magnetostrictive materials with a non-local elastic behaviour, converges to an energy functional of a nearly incompressible magnetostrictive material. This convergence is referred to as a Γ -convergence. The non-locality is limited to non-local elastic behaviour which is modelled by a term containing the second gradient of deformation in the energy functional. Słowa kluczowe: gamma-convergence, incompressibility, magnetostrictive material, second gradient of deformation, existence of minimizers Afiliacje autorów:
Gambin B. | - | IPPT PAN | Bielski W. | - | Institute of Geophysics (PL) |
| | 25p. |
31. |
Gambin B., Doubrovina O.^{♦}, Statistical properties of wavelet transform coefficients of backscattering signal from soft tissues and their phantoms,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.16, pp.59-66, 2013Streszczenie: The paper contains the wavelet approach to registered backscattered RF signals from two different cases. First, the wavelet analysis has been performed for RF signals registered from soft tissue phantoms. The second case is the wavelet analyses of RF scattered signals from regions of healthy and BCC changed human skin. The three phantoms made from tissuemimicking material with different structures have been measured. We claim that there are visible differences in the statistical parameters of wavelets coefficients of signals between healthy and BCC changed skin regions as well as between phantoms without scatterers and with different number of strong small scatterers. Słowa kluczowe: backscattered RF signals, skin cancer differentiation, scatterers numer, wavelet approximations Afiliacje autorów:
Gambin B. | - | IPPT PAN | Doubrovina O. | - | Belarussian State University (BY) |
| | 7p. |
32. |
Kruglenko E., Gambin B., Cieślik L., Soft Tissue-Mimicking Materials With Various Number of Scatterers and Their Acoustical Characteristics,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.16, pp.121-128, 2013Streszczenie: For the study of the temperature increase in the soft tissues irradiated by a low-power ultrasound [1], soft tissue-mimicking materials can be used. The phantoms have been produced based on an aqueous solution of agar, oil, and glass beads microparticles. The RF signals collected in the experiments enabled evaluation of the acoustic properties of phantoms with different number of strong scatterers (concentration varied from 0 to 30 pcs/mm3). Speed of sound (SOS) determined for the phantoms was similar to the value typical of soft tissue (about 1540 m/s). To determine attenuation coefficient the semi-transmission method has been used. Attenuation coefficient value varied from 0.5 to 1.1 dB/(MHz cm), depending on the number of scatterers. It was shown that the phantoms stored for 6 months preserved their acoustical properties and were usable for further experiments. It was found that within the total attenuation, the part corresponding to scattering can be distinguished. Słowa kluczowe: acoustical characteristics, soft tissue mimicking material, scatterers number Afiliacje autorów:
Kruglenko E. | - | IPPT PAN | Gambin B. | - | IPPT PAN | Cieślik L. | - | IPPT PAN |
| | 7p. |
33. |
Ivanova J.^{♦}, Nikolova G.^{♦}, Gambin B., Interface delamination of bi-material structure under time harmonic load. Cohesive behaviour of the interface,
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, ISSN: 0044-2267, DOI: 10.1002/zamm.201000210, Vol.92, No.1, pp.41-51, 2012Streszczenie: The interface cohesive behaviour and interface delamination in a bi-material structure consisting of two plates and material interface with zero thickness under time harmonic load is studied. Previously, the authors studied the elasto-brittle interface behaviour, from both sides of a crack, initially normal to the interface, when the elastic-brittle interface debonding appeared. Now, it is again assumed that the restriction for the ratio of energy release rates of the second plate and interface allowing the occurrence of an interface cohesive delamination before the initiation of the normal crack in the second plate is satisfied. The shear lag model is adopted and applied to find the dynamic response of the considered structure, assuming the cohesive interface behaviour, accompanied before of the elastic-brittle one. In both cases, the growth of debond length is not considered e.g. at a given loading condition the corresponding single debond length is found. The inertia forces of the already debonded interface elasto-brittle cracks (mode II) are neglected. The appropriate contact conditions are proposed in order to fit together both elastic and cohesive solutions. The Laplace inverse transform is applied to obtain the original of cohesive debond length by the aid of the already obtained elastic value of debond length at the same loading condition. Parametric analysis of the results obtained is illustrated by examples of the modern ceramic-metal composite on metal substrate. The influence of frequencies and amplitude fluctuations on the cohesive debond length and the interface shear stress distribution are discussed. Słowa kluczowe: dynamic behaviour of bi-material structure, cracked plate, shear lag model, Laplace transform, cohesive interface delamination, cohesive debond length Afiliacje autorów:
Ivanova J. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Nikolova G. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Gambin B. | - | IPPT PAN |
| | 20p. |
34. |
Mizera A., Gambin B., Modelling of ultrasound therapeutic heating and numerical study of the dynamics of the induced heat shock response,
COMMUNICATIONS IN NONLINEAR SCIENCE AND NUMERICAL SIMULATION, ISSN: 1007-5704, DOI: 10.1016/j.cnsns.2010.04.056, Vol.16, No.5, pp.2342-2349, 2011Streszczenie: In this presentation we consider hyperthermia, a procedure of raising the temperature above 43 C, as a treatment modality. To this purpose, a numerical model of in vivo soft tissue ultrasound heating is proposed by extending a previously presented in vitro model. Based on the numerical simulations, a heating scheme satisfying some constraints related to potential clinical applications is established, and the resulting temperature time-course profile is composed with the temperature-dependent protein denaturation formula of a recently published mathematical model for the eukaryotic heat shock response. The obtained simulation results of the combined models are discussed in view of potential application of ultrasound soft tissue heating in clinical treatment. Słowa kluczowe: Hyperthermia, Heat Shock Response dynamics, Ultrasound therapeutic treatment, mathematical modelling Afiliacje autorów:
Mizera A. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 40p. |
35. |
Gambin B., Ivanova J.^{♦}, Valeva V.^{♦}, Nikolova G.^{♦}, Precracking and interfacial delamination in a bi-material structure: Static and dynamic loadings,
ACTA MECHANICA SINICA, ISSN: 0567-7718, DOI: 10.1007/s10409-011-0414-3, Vol.27, No.1, pp.80-89, 2011Streszczenie: The behavior of a precracked bi-material structure interface under given static and dynamic axial loading is an interest object in the present paper. Firstly, it is shown that the shear-lag model is a proper tool to analyze a delamination process in a precracked bi-material structure undergoing static loading. Secondly, the “shear-lag model” is applied to the structure under dynamic loading. To solve the problem for an interface delamination of the structure and to determine the debond length along the interface, our own 2D boundary element method (BEM) code is proposed in the case of static loading, and the shear-lag model together with the Laplace transforms and half-analytical calculations are used in the case of dynamic loading. The interface layer is assumed as a very thin plate compared with the other two. The parametric (geometric and elastic) analysis of the debond length and interface shear stress is done. The results from the 2D BEM code proved the validity of analytical solutions to the shear-lag model. In the dynamic case, the influence of loading characteristics, i.e., frequencies and amplitude fluctuations on the shear stress and the value of debond length for an interval of time, is discussed. The analysis of the obtained results is illustrated by an example of the modern ceramic-metal composite, namely cermet, and depicted in figures. Słowa kluczowe: Debond length, Precracked bi-material structure, Shear-lag model, Delamination, BEM Afiliacje autorów:
Gambin B. | - | IPPT PAN | Ivanova J. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Valeva V. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Nikolova G. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) |
| | 25p. |
36. |
Ivanova J.^{♦}, Nikolova G.^{♦}, Gambin B., Interface delamination of bi-material structure under dynamic time harmonic loading,
ZAMM-ZEITSCHRIFT FUR ANGEWANDTE MATHEMATIK UND MECHANIK, ISSN: 0044-2267, DOI: 10.1002/zamm.200900369, Vol.91, No.2, pp.146-154, 2011Streszczenie: The interface behaviour between two layers of 2D elastic structure under dynamic time-harmonic load is studied. The “shear lag model” is adopted and applied to the dynamic response of bi-material structure, assuming the elastic-brittle behaviour of the interface. The Laplace transforms together with half-analytical calculations are used to obtain the shear stress and elastic debond lengths along the interface at sinusoidal load. Parametric analysis of the obtained results is illustrated by an example of the modern ceramic-metal composite, so called cermet, and depicted in figures. The influence of loading characteristics, i.e. frequencies and amplitude fluctuations on the shear stress and the value of debond length for a small interval of time, is discussed. Słowa kluczowe: Dynamic behaviour of bi-material structure, cracked plate, shear lag model, elastic-brittle interface delamination, debond length Afiliacje autorów:
Ivanova J. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Nikolova G. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Gambin B. | - | IPPT PAN |
| | 20p. |
37. |
Gambin B., Kruglenko E., Kujawska T., Michajłow M.^{♦}, Modeling of tissues in vivo heating induced by exposure to therapeutic ultrasound,
ACTA PHYSICA POLONICA A, ISSN: 0587-4246, Vol.119, pp.950-956, 2011Streszczenie: The aim of this work is mathematical modeling and numerical calculation in space and time of temperature fields induced by low power focused ultrasound beams in soft tissue in vivo after few minutes exposure time. These numerical predictions are indispensable for planning of various ultrasound therapeutic applications. Both, the acoustic pressure distribution and power density of heat sources induced in tissue, were calculated using the numerical solution to the second order nonlinear differential wave equation describing propagation of the high intensity acoustic wave in three-layer structure of nonlinear attenuating media. The problem of the heat transfer in living tissues is modelled by the Pennes equation, which accounts for the effects of heat diffusion, blood perfusion losses and metabolism rate. Boundary conditions and geometry are chosen according to the anatomical dimensions of a rat liver. The obtained results are compared with those calculated previously and verified experimentally for temperature elevations induced by ultrasound in liver samples in vitro. The analysis of the results emphasizes the value of the blood perfusion and the values of heat conductivity on the temperature growth rate. The numerical calculations of temperature fields were performed using the ABAQUS FEM software package. The thermal and acoustic properties of the liver and water being the input parameters to the numerical model were taken from the published data in cited references. The range of thermal conductivity coefficient of living tissue is obtained from the model of two-phase composite medium with given microstructure. The first component is a “solid” tissue and the second one corresponds to blood vessels area. The circular focused ultrasonic transducer with a diameter of 15 mm, focal length of 25 mm and resonance frequency of 2 MHz has been used to generate the pulsed ultrasonic beam in a very introductory experiment in vivo, which has been performed. Numerical prediction confirms qualitatively its results. Słowa kluczowe: focused ultrasound, soft tissues, local thermal fields, numerical modelling Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Kujawska T. | - | IPPT PAN | Michajłow M. | - | inna afiliacja |
| | 15p. |
38. |
Valeva V.^{♦}, Ivanova J.^{♦}, Gambin B., BEM and Shear lag method for interface problem of bi-material structure under static loading,
JOURNAL OF THEORETICAL AND APPLIED MECHANICS, ISSN: 1429-2955, Vol.41, No.9, pp.17-29, 2011Streszczenie: The behaviour of the interface of a pre-cracked bi-material ceramic-metal structure under static axial loading is an object of interest in the present paper. To solve the problem for interface delamination of the structure and to determine the debond length along the interface, a 2D BEM code was created and applied. The interface plate is assumed as a very thin plate comparing with the others two. The parametric (geometric and elastic) analysis of the debond length and interface shear stress is done. First, the obtained numerical results are compared with analytical ones from 1D. Shear lag analysis of the considered structure. The respective comparison is illustrated in figures and shows a good agreement. The comparison between the calculated using 2D BEM code elastic-brittle debond lengths with Song's experimental data for the bi-material structure Zinc/Steel as well as with respective results from FEM simulation shows good coincidence. Słowa kluczowe: BEM, Shear lag analysis, bi-material structure, debond length Afiliacje autorów:
Valeva V. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Ivanova J. | - | Institute of Mechanics, Bulgarian Academy of Science (BG) | Gambin B. | - | IPPT PAN |
| | 15p. |
39. |
Wójcik J., Litniewski J., Nowicki A., Gambin B., Applying crystallography in analysis of trabecular bone backscatter,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.14, pp.255-266, 2011Streszczenie: Some important details of the Backscatter Effective Cross-Sections (BECS) obtained for random scattering structures (like trabecular bone) are explain by comparison with the results obtained by means of the simplified theoretical model. The simplified model was (establish) and justified on the basis of the structural analysis of the results obtained for exact model of the field scattering on complex structures. The simplified model is commonly used in description of the scattering on the regular structures like crystal. Comparison with experimental results for the trabecular bone is also presented. The results allowed to conclude that crystallographic methods could be potentially useful for extracting characteristic features of trabecular bone.
Słowa kluczowe: Multi scattering, Random structures Afiliacje autorów:
Wójcik J. | - | IPPT PAN | Litniewski J. | - | IPPT PAN | Nowicki A. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 4p. |
40. |
Kruglenko E., Gambin B., Some aspects of numerical modeling of temperature increase due to ultrasound beam irradiation of rat liver,
HYDROACOUSTICS, ISSN: 1642-1817, Vol.14, pp.99-110, 2011Streszczenie: Some aspects of FEM modeling of hyperthermia, the procedure of tissue temperature rise above 37 oC inside the living organism, as a treatment modality, are studied. Low intensity focused ultrasound (LIFU) beam has been used as a source of temperature rise in the liver tissue during performed experiments in vitro. The comparison of the FEM model of the corresponding heating process and the experimental results has been presented in [1]. In the paper, the FEM model of heating scheme of the rat liver tissue in vivo irradiated by the same ultrasound transducer is formulated. At first, the existence of blood perfusion is taken into account in the model equation. Secondly, the thermal and acoustical properties, which are the input parameters of the numerical model, are taken from the published data in literature. Here, the size and the intensity of heat sources are modeled in two ways on the basis of acoustic nonlinear equation solutions in 3 layers attenuating medium. We demonstrate how the results of FEM model in the case of in vitro and in vivo heating, depend on the assumed power density of heat sources, as well as on the size of the heated area. The results are compared and discussed. The influence of different models on temperature rise profiles are demonstrated. Afiliacje autorów:
Kruglenko E. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 4p. |
41. |
Mizera A., Gambin B., Stochastic modeling of the eukaryotic heat shock response,
JOURNAL OF THEORETICAL BIOLOGY, ISSN: 0022-5193, DOI: 10.1016/j.jtbi.2010.04.029, Vol.265, No.3, pp.455-466, 2010Streszczenie: The heat shock response (HSR) is a highly evolutionarily conserved defence mechanism allowing the cell to promptly react to elevated temperature conditions and other forms of stress. It has been subject to intense research for at least two main reasons. First, it is considered a promising candidate for deciphering the engineering principles underlying regulatory networks. Second, heat shock proteins (main actors of the HSR) play crucial role in many fundamental cellular processes. Therefore, profound understanding of the heat shock response would have far-reaching ramifications for the cell biology.
Recently, a new deterministic model of the eukaryotic heat shock response has been proposed in the literature. It is very attractive since it consists of only the minimum number of components required by any functional regulatory network, while yet being capable of biological validation. However, it admits small molecule populations of some of the considered metabolites. In this paper a stochastic model corresponding to the deterministic one is constructed and the outcomes of these two models are confronted. The aim with this comparison is to show that, in the case of the heat shock response, the approximation of a discrete system with a continuous model is a reasonable approach. This is not always the truth, especially when the numbers of molecules of the considered species are small. By making the effort of performing and analysing 1000 stochastic simulations, we investigate the range of behaviour the stochastic model is likely to exhibit. We demonstrate that the obtained results agree well with the dynamics displayed by the continuous model, which strengthens the trust in the deterministic description. A proof of the existence and uniqueness of the stationary distribution of the Markov chain underlying the stochastic model is given. Moreover, the obtained view of the stochastic dynamics and the performed comparison to the outcome of the continuous formulation provide more insight into the dynamics of the heat shock response mechanism. Słowa kluczowe: Stochastic model, Computer simulations, Markov chain, Gillespie algorithm, Stationary distribution Afiliacje autorów:
Mizera A. | - | IPPT PAN | Gambin B. | - | IPPT PAN |
| | 32p. |
42. |
Bielski W.^{♦}, Gambin B., Relationship between existence of energy minimizers of incompressible and nearly incompressible magnetostrictive materials,
REPORTS ON MATHEMATICAL PHYSICS, ISSN: 0034-4877, Vol.66, No.2, pp.147-157, 2010Streszczenie: Models of incompressible and slightly compressible magnetostrictive materials are introduced. They are given by the free energy functionals which depend on magnetization and elastic deformation as well as on their gradients. We demonstrate the existence of minimum of an energy functional for a slightly compressible material. We also prove a theorem on convergence of a sequence of minimizers of less and less compressible material energy functionals to a minimize of energy of incompressible material. Besides the existence of solution of the incompressible magnetostrictive problem is obtained. Słowa kluczowe: micromagnetics, magnetostrictive material, incompressible, nearly incompressible materials, existence problem Afiliacje autorów:
Bielski W. | - | Institute of Geophysics (PL) | Gambin B. | - | IPPT PAN |
| | 13p. |
43. |
Gambin B., Kujawska T., Kruglenko E., Mizera A., Nowicki A., Temperature fields induced by low power focused ultrasound during gene therapy. Numerical predictions and experimental results,
ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, Vol.34, No.4, pp.445-460, 2009Streszczenie: The aim of this work is twofold. Firstly, to verify a theoretical model which is capable of predicting temperature fields appearing in soft tissues during their ultrasound treatment. Secondly, to analyze some aspects of the dynamics of Heat Shock Response induced by the heating process in the context of therapeutic treatment. The theoretical investigations and quantitive analysis of temperature increments at any field point versus time of heating process, depending on the heat source power, spatial distribution and duration as well as on the tissue thermal properties, has been carried out by Finite Element Method (FEM). The validation of the numerical model has been performed by comparison of the calculation results with the experimental data obtained by measuring in vitro of the 3D temperature increments induced in samples of the turkey and veal liver by the circular focused transducer with the diameter of 15 mm, focal length of 25 mm and resonance frequency of 2 MHz. Various ultrasonic regimes were considered. They were controlled by adjusting ultrasound power and exposure time. The heat shock proteins (HSP) and misfolded proteins (MFP) levels during the proposed cyclic sonification are presented. Słowa kluczowe: heat-responsive gene therapy, temperature field, low-power focused ultrasound, soft tissues, ultrasonic regime control, heat sources distribution, heat shock proteins Afiliacje autorów:
Gambin B. | - | IPPT PAN | Kujawska T. | - | IPPT PAN | Kruglenko E. | - | IPPT PAN | Mizera A. | - | IPPT PAN | Nowicki A. | - | IPPT PAN |
| | 9p. |
44. |
Gambin B., Gałka A.^{♦}, Telega J.J., Tokarzewski S., Influence of anisotropy induced by microcracks on effective elastic properties,
ENGINEERING TRANSACTIONS (ROZPRAWY INŻYNIERSKIE), ISSN: 0867-888X, Vol.53, No.4, pp.409-420, 2005 | |
45. |
Gambin B., Trzęsowski A., Probabilistyczne przestrzenie metryczne,
Prace IPPT - IFTR Reports, ISSN: 2299-3657, No.60, pp.1-48, 1972 | |