Partner: P. Karłowicz |
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Recent publications
1. | Dobkowska-Chudon W.♦, Wrobel M.♦, Karłowicz P.♦, Dabrowski A.♦, Krupienicz A.♦, Targowski T.♦, Nowicki A., Olszewski R., Detecting cerebrovascular changes in the brain caused by hypertension in atrial fibrillation group using acoustocerebrography, PLOS ONE, ISSN: 1932-6203, DOI: 10.1371/journal.pone.0199999, Vol.13, No.7, pp.1-10, 2018 Abstract: Acoustocerebrography is a novel, non-invasive, transcranial ultrasonic diagnostic method based on the transmission of multispectral ultrasound signals propagating through the brain tissue. Dedicated signal processing enables the estimation of absorption coefficient, frequency-dependent attenuation, speed of sound and tissue elasticity. Hypertension and atrial fibrillation are well known factors correlated with white matter lesions, intracerebral hemorrhage and cryptogenic stroke numbers. The aim of this study was to compare the acoustocerebrography signal in the brains of asymptomatic atrial fibrillation patients with and without hypertension. The study included 97 asymptomatic patients (40 female and 57 male, age 66.26 +/- 6.54 years) who were clinically monitored for atrial fibrillation. The patients were divided into two groups: group I (patients with hypertension) n = 75, and group II (patients without hypertension) n = 22. Phase and amplitude of all spectral components for the received signals from the brain path were extracted and compared to the phase and amplitude of the transmitted pulse. Next, the time of flight and the attenuation of each frequency component were calculated. Additionally, a fast Fourier transformation was performed and its features were extracted. After introducing a machine learning technique, the ROC plot of differentiations between group I and group II with an AUC of 0.958 (sensitivity 0.99 and specificity 0.968) was obtained. It can be assumed that the significant difference in the acoustocerebrography signals in patients with hypertension is due to changes in the brain tissue, and it allows for the differentiating of high-risk patients with asymptomatic atrial fibrillation and hypertension. Keywords:changes in the brain, hypertension in atrial, acoustocerebrography Affiliations:
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2. | Lewandowski M., Walczak M., Karwat P., Witek B., Karłowicz P.♦, Research and Medical Transcranial Doppler System, ARCHIVES OF ACOUSTICS, ISSN: 0137-5075, DOI: 10.1515/aoa-2016-0074, Vol.41, No.4, pp.773-781, 2016 Abstract: A new ultrasound digital transcranial Doppler system (digiTDS) is introduced. The digiTDS enables diagnosis of intracranial vessels which are rather difficult to penetrate for standard systems. The device can display a color map of flow velocities (in time-depth domain) and a spectrogram of a Doppler signal obtained at particular depth. The system offers a multigate processing which allows to display a number of spectrograms simultaneously and to reconstruct a flow velocity profile. Doppler system, digital signal processing, hardware-software partitioning, field programmable gate arrays Affiliations:
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3. | Gawlikowski M.♦, Lewandowski M., Nowicki A., Kustosz R.♦, Walczak M., Karwat P., Karłowicz P.♦, The Application of Ultrasonic Methods to Flow Measurement and Detection of Microembolus in Heart Prostheses, ACTA PHYSICA POLONICA A, ISSN: 0587-4246, DOI: 10.12693/APhysPolA.124.417, Vol.124, No.3, pp.417-420, 2013 Abstract: For the last 20 years the world cardiosurgery has presented a considerable change of attitude to mechanical circulatory support. In spite of technological progress the main problems in ventricular assist devices are: thrombosis and low accuracy of flow measurements. In this paper the prototype of multi-gate Doppler flowmeter intended for cardiac assist system ReligaHeart EXT has been presented as well as the possibility of ultrasonic micro embolus detection. Keywords:artificial heart, microemboli, ultrasound Doppler Affiliations:
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List of chapters in recent monographs
1. 328 | Lewandowski M., Walczak M., Karwat P., Nowicki A., Karłowicz P.♦, Polskie protezy serca, opracowanie konstrukcji, badania kwalifikacyjne, przedkliniczne i kliniczne., rozdział: Wykonanie modelu i implementacja oprogramowania do ultradźwiękowego pomiaru przepływu krwi, FRK, Zabrze. Praca zbiorowa pod redakcją: Kustosz R., Gonsior M., Jarosz A., pp.3-21, 2013 |
Conference abstracts
1. | Olszewski R., Dobkowska-Chudon W.♦, Wrobel M.♦, Karlowicz P.♦, Dabrowski A.♦, Krupienicz A.♦, Targowski T.♦, Nowicki A., Is Acoustocerebrography a new noninvasive method for early detection of the brain changes in patients with hypertension?, ESC Congress 2017, European Society of Cardiology Congress 2017, 26-30 August, Barcelona, Spain, 2017-08-26/08-30, Barcelona (ES), DOI: 10.1093/eurheartj/ehx501.P190, Vol.38, No.suppl_1, pp.36, 2017 Abstract: Background: Hypertension (HT) is the leading cause of global disease burden and overall health loss. The brain is one of the main target organs affected by HT. HT is a potentially modifiable risk factor that leads to the formation of large vessel macroangiopathy, small vessel disease, microangiopathy, and microhemorrhages. Early detection of the brain changes (BC) gives a chance to receive appropriate treatment and protection from irreversible damage. Acoustocerebrography (ACG) is a set of techniques to capture the states of human brain tissue, and its changes on its molecular and cellular level. It is based on noninvasive measurements of various parameters obtained by analyzing an ultrasound pulse emitted across the human's skull. The main idea of this method relies in the relation between the tissue density, bulk modulus, and speed of propagation, for ultrasound waves in this medium. In our previous studies we showed that ACG is an effective method for detecting white matter lesions compared to the Magnetic Resonance Imaging. Additionally we showed that ACG allows to obtain a differentiated signal originates from atrial fibrillation (AF) patients and high-risk patients wit AF and HT.
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2. | Lewandowski M., Walczak M., Karwat P., Witek B., Nowicki A., Karłowicz P.♦, Research & Medical Doppler platform, 11th Congrès Français d'Acoustique, 2012 IOA annual meeting, 2012-04-23/04-27, Nantes (FR), pp.x1-x6, 2012 Abstract: A new ultrasound digital transcranial Doppler system (digiTDS) is introduced. The digiTDS enables diagnosis of intracranial vessels which are difficult to penetrate for standard systems. The device can display a color map of flow velocities in time-depth domain and a spectrogram of a Doppler signal received from a particular depth. The system offers a multigate processing that allows to display simultaneously a number of spectrograms and to reconstruct a flow velocity profile. The digital signal processing in digiTDS is partitioned between hardware and software parts. The hardware part (based on FPGA) executes a signal demodulation and reduces data stream. The software part (PC) performs the Doppler processing and display tasks. The hardware-software partitioning allowed to build a flexible Doppler platform at a relatively low cost. The digiTDS design fulfills all necessary medical standards being a new useful tool in transcranial field as well as in heart velocimetry research. Keywords:ultrasound transcranial Doppler, RF signal processing, DSP, FPGA Affiliations:
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Patents
Filing No./Date Filing Publication | Autor(s) Title Protection Area, Applicant Name | Patent Number Date of Grant | |
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277279 1989-01-20 BUP 15/1990 1990-07-23 | Marciniak A.♦, Nowicki A., Secomski W., Karłowicz P.♦, Piechocki M., Liwski J.♦Ultradźwiękowa głowica sektorowaPL, Instytut Podstawowych Problemów Techniki PAN | 157977 WUP 07/1992 1992-07-31 | |
255681 1985-10-08 - 1987-05-18 | Karłowicz P.♦, Liwski J.♦, Nowicki A.Sposób określania kierunku przepływu w cyfrowym pomiarze prędkości przepływu z zastosowaniem impulsowego przepływomierza dopplerowskiegoPL, Instytut Podstawowych Problemów Techniki PAN | 149954 - 1990-07-31 | |
247801 1984-05-23 - 1985-12-03 | Karłowicz P.♦, Nowicki A., Piechocki M., Secomski W.Ultradźwiękowy przepływomierz dopplerowski do rejestracji maksymalnej prędkości cieczyPL, Instytut Podstawowych Problemów Techniki PAN | 144601 - 1989-04-29 | |
239097 1982-11-18 - 1986-11-15 | Filipczyński L., Karłowicz P.♦, Nowicki A.Sposób i urządzenie do rozpoznania zaburzenia przepływu cieczy, zwłaszcza krwiPL, Instytut Podstawowych Problemów Techniki PAN | 136932 - 1984-12-03 | |
249124 1982-11-18 - 1985-03-12 | Filipczyński L., Karłowicz P.♦, Nowicki A.Sposób i urządzenie do rozpoznania zaburzenia przepływu cieczy, zwłaszcza krwiPL, Instytut Podstawowych Problemów Techniki PAN | 142585 - 1989-08-31 |