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1
Content available remote Towards in-vivo assessment of fluorescence lifetime: imaging using time-gated intensified CCD camera
Sawosz P., Wojtkiewicz S., Kacprzak M., Zieminska E., Morawiec M., Maniewski R., Liebert A.
Biocybernetics and Biomedical Engineering
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2018
|
Vol. 38, no. 4
966--974
EN
A novel technique for imaging of a small animal with application of time-gated intensified CCD camera was proposed. The time-resolved method based on emission of picosecond light pulses and detection of the light penetrating in tissues was applied. In this technique, the fluorescence photons, excited in the dye circulating in the tissue, that diffusely penetrate in the optically turbid medium are detected. The data acquired during measurements carried out on a rat was analyzed in order to estimate fluorescence life time which depends strongly on the environment in which the dye is distributed. In the life time estimation a special emphasis was put on compensation of influence of the instrumental response function of the setup on the measured quantity. The proposed optical system was validated in series of phantom experiments, in which estimates of fluorescence lifetime of inclusions containing indocyanine green (ICG) were obtained. ICG is a dye revealing florescence properties in near-infrared wavelength region. Images of the estimate of fluorescence lifetime of the ICG accumulated in tissues of a rat were successfully acquired around six circular spots of illumination of the diameter of 6mm. Larger lifetime values were observed in lung/heart region of the animal. Aspect of sampling rate of the fluorescence lifetime images optimization was finally discussed.
2
Content available remote Estimation of light detection efficiency for different light guides used in time-resolved near-infrared spectroscopy
Milej D., Kruczkowski M., Kacprzak M., Sawosz P., Maniewski R., Liebert A.
Biocybernetics and Biomedical Engineering
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2015
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Vol. 35, no. 4
227--231
EN
Time-resolved near-infrared spectroscopy is a technique enabling the assessment of changes in oxygenation and perfusion of tissue with depth discrimination. A challenge in time-resolved measurements remains to provide sufficiently high efficiency of photons detection together with high temporal resolution of the setup. The aim of this study was to compare the performance of different fiber bundles and liquid light guides which can be used in time-resolved near-infrared spectroscopy measurements. The comparison was carried out by measurements of the instrument response function and of the responsivity of the optical detection system equipped with different types of light guides. The responsivity was estimated employing a test phantom with known diffuse transmittance factor. The results suggest that application of liquid light guides provides higher efficiency of photon collection in comparison to fiber bundles which are typically used in tissue optics instrumentation.
3
Content available remote Time-resolved multi-channel optical system for assessment of brain oxygenation and perfusion by monitoring of diffuse reflectance and fluorescence
Milej D., Gerega A., Kacprzak M., Sawosz P., Weigl W., Maniewski R., Liebert A.
Opto-Electronics Review
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2014
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Vol. 22, No. 1
55-67
EN
Time-resolved near-infrared spectroscopy is an optical technique which can be applied in tissue oxygenation assessment. In the last decade this method is extensively tested as a potential clinical tool for noninvasive human brain function monitoring and imaging. In the present paper we show construction of an instrument which allows for: (i) estimation of changes in brain tissue oxygenation using two-wavelength spectroscopy approach and (ii) brain perfusion assessment with the use of single-wavelength reflectometry or fluorescence measurements combined with ICG-bolus tracking. A signal processing algorithm based on statistical moments of measured distributions of times of flight of photons is implemented. This data analysis method allows for separation of signals originating from extra- and intracerebral tissue compartments. In this paper we present compact and easily reconfigurable system which can be applied in different types of time-resolved experiments: two-wavelength measurements at 687 and 832 nm, single wavelength reflectance measurements at 760 nm (which is at maximum of ICG absorption spectrum) or fluorescence measurements with excitation at 760 nm. Details of the instrument construction and results of its technical tests are shown. Furthermore, results of in-vivo measurements obtained for various modes of operation of the system are presented.
4
Content available remote NMR-based metabonomics of cerebrospinal fluid applied to amyotrophic lateral sclerosis
Toczyłowska B., Jamrozik Z., Liebert A., Kwieciński H.
Biocybernetics and Biomedical Engineering
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2013
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Vol. 33, no. 1
21--32
EN
The aim of this study was applications of cerebrospinal fluid (CSF) NMR-based metabolic fingerprinting to amyotrophic lateral sclerosis (ALS) as possible early diagnostic tool. Two CSF sample categories were collected: 9 ALS patients and 13 age-matched control patients (without neurological disease). Metabolic profile of the CSF was determined by high resolution proton NMR spectroscopy. For statistical analysis magnitudes of 33 signals of the NMR spectrum were selected. Partial least square discriminant analysis (PLS-DA) and orthogonal PLS-DA (OPLS-DA) modeling were used to find potential biomarkers of the disease. Those analyses showed that it was possible to distinguish the ALS patients from the control ones on the basis of the CSF metabolic profile. Significantly higher levels of metabolites observed in the patients with ALS may represent the state of anaerobic metabolism and excitotoxicity.
5
Content available Ocena stanu innowacyjności i warunków rozwoju przemysłu wyrobów medycznych w Polsce
Gacek A., Bąk P., Blacha-Stachowicz B., Augustyniak P., Liebert A., Podbielska H., Maniewski R.
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
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2013
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Vol. 19, nr 4
165--175
PL
W pracy podjęto próbę identyfikacji potencjału badawczego i technologicznego-produkcyjnego producentów wyrobów medycznych. Mając na względzie te grupę firm, przeprowadzono analizę SWOT, która była podstawą do oszacowania poziomu innowacyjności producentów wyrobów medycznych w Polsce. W tej analizie szczególną uwagę zwrócono na firmy z obszaru zaawansowanych technologii w dziedzinie inżynierii medycznej. Jako rezultat dokonanych analiz wskazano istotne bariery rozwoju innowacyjności w sektorze produkcji wyrobów medycznych. Określone zostały również uwarunkowania i perspektywy rozwojowe tego sektora w ciągu najbliższych lat.
EN
The presented work is an attempt to identify research and technological potential of Polish producers, active on market of medical products, especially specializing in the medical devices. The SWOT analysis was performed in order to estimate the innovation level in this sector. The special emphasis was placed on advanced technologies in the field of Biomedical Engineering. The limitations of the innovation development, were pointed out, along with perspectives and conditions for further expansion in the nearest future.
6
Content available remote Application of time-gated CCD camera with image intensifier in contactless detection of absorbing inclusions buried in optically turbid medium which mimics local changes in oxygenation of the brain tissue
Sawosz P., Zolek N., Kacprzak M., Maniewski R., Liebert A.
Opto-Electronics Review
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2012
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Vol. 20, No. 4
309-314
EN
The near infrared spectroscopy may be implemented using various optoelectronic techniques, however, most of them do not allow to carry out measurements at short source-detector separation. We propose a method, based on time-gated intensified CCD camera, which allows for contactless measurements and can be carried out at short source-detector separation. This technique was tested on a phantom with absorbing inclusions buried in an optically turbid medium which mimics local changes in oxygenation of the brain tissue.
7
Content available remote Time-resolved imaging of fluorescent inclusions in optically turbid medium : phantom study
Kacprzak M., Liebert A., Sawosz P., Żołek N., Milej D., Maniewski R.
Opto-Electronics Review
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2010
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Vol. 18, No. 1
37-47
EN
We present results of application of a time-resolved optical system for imaging of fluorescence excited in an inclusion containing indocyanine green (ICG), and located in optically turbid medium. The developed imaging system enabled simultaneous acquisition of fluorescence and diffusive reflectance. Eight independent time-resolved measurement channels based on time-correlated single photon counting technique were applied. In four of these channels, used for the fluorescence detection, sets of filters were applied in order to block the excitation light. Fast optomechanical switches allowed us to illuminate sequentially nine different spots on the surface of the studied object and finally 4×4 pixels maps at excitation and emission wavelengths were obtained. A liquid phantom used in this study consists of the fish tank filed with a solution ofmilk and water with black ink added to obtain optical properties in the range of the optical properties typical for the living tissue. A gel ball of a diameter of 5 mm with precisely controlled concentration of ICG was immersed in the liquid. The measurements were performed for inclusion located at different depths and for various ICG concentrations in the gel ball and in the surrounding liquid. The recorded distributions of times of arrival (DTA) of fluorescence photons and times of flight (DTOF) of diffusely reflected photons were analyzed by calculation of their statistical moments. We observed specific changes in moments of the measured DTAs as a function of depth of immersion of the fluorescent inclusion in the medium. We noted also that the changes of moments depend significantly on concentration of the dye in the fluorescence inclusion as well as in the surrounding liquid.
8
Content available remote Advantages of fluorescence over diffuse reflectance measurements tested in phantom experiments with dynamic inflow of ICG
Milej D., Kacprzak M., Żołek N., Sawosz P., Gerega A., Maniewski R., Liebert A.
Opto-Electronics Review
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2010
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Vol. 18, No. 2
208-213
EN
Time-resolved measurements of diffuse reflectance and fluorescence were carried out using phantom with dynamic inflow of indocyanine green (ICG) in tubes located at different depths. Better sensitivity of fluorescence signals related to the inflow of the dye was observed in comparison to simultaneously acquired diffuse reflectance. Obtained results can be referred to results of in-vivo measurements. We have observed much larger amplitude of changes in relative number of detected photons, mean time of flight and variance of the distributions of times of arrival of fluorescence photons than amplitudes of respective parameters measured from diffuse reflectance distributions of times of flight of photons. The constructed phantom allows us to study influence of concentration of the dye in the tube and the surrounding medium as well as temporal relation between appearance of the boli in deeper and superficial tube. Results of the study were used in optimization of the time-resolved multichannel system for simultaneous monitoring of fluorescence and reflectance.
9
Content available Wykorzystanie topografii optycznej w nieinwazyjnych badaniach ukrwienia mózgu i jej wstępna weryfikacja techniką SPECT
Kacprzak M., Liebert A., Mączewska J., Fronczewska K., Sawosz P., Toczyłowska B., Królicki L., Maniewski R.
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
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2010
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Vol. 16, nr 2
173-178
PL
Obserwacja zjawiska napływu i klirensu dożylnych środków kontrastujących jest techniką często stosowaną w diagnostyce medycznej. Zastosowanie w tym celu barwników, których widmo absorpcyjne leży w zakresie bliskiej podczerwieni, może być wykorzystane do badań hemodynamiki mózgu metodą optyczną. Opublikowane w ostatnich latach wyniki badań potwierdzają, że cyrkulacja barwnika ICG (zieleń indocjaninowa) w tkance mózgowej może być wykryta bezinwazyjnie metodą optyczną. W niniejszej pracy zostały przedstawione wstępne wyniki badań uzyskane z wykorzystaniem wielokanałowego sytemu do czasowo rozdzielczych pomiarów optycznych, skonstruowanego w IBIB PAN. Badania z zastosowaniem środka kontrastującego ICG przeprowadzono u osób zdrowych i w grupie pacjentów ze stwierdzonymi średnimi dolegliwościami neurologicznymi. Badania porównawcze zostały wykonane metodą radioizotopową SPECT używaną rutynowo w badaniach ukrwienia mózgu.
EN
Monitoring of inflow and washout of an exogenous contrast agent circulating in the human body is frequently utilized for medical diagnosis. Injection of a absorbing dye in near infrared wavelength region can be applied for estimation of cerebral blood flow or perfusion using optical method. It was reported that ICG (indocyanine green) circulating in the brain can be detected non-invasively on the surface of the human adult head. In the present paper we show results of analysis of time-resolved optical signals measured with the use of the self-constructed brain imager based on previously reported brain oxygenation topography system. The study were curried out on healthy volunteers and patients with mild cerebrovascular disorders after injections of the ICG contrast agent. Obtained results from optical measurements were compared with routinely used SPECT technique.
10
Content available Skomputeryzowany zestaw laserowo-dopplerowski do nieinwazyjnej diagnostyki mikrokrążenia krwi
Wojtkiewicz S., Liebert A., Badura G., Czerw M., Gacek A., Zbieć A., Obidzińska J., Staszkiewicz W., Maniewski R.
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
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2010
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Vol. 16, nr 2
138-144
PL
Opracowano i wykonano prototyp urządzenia laserowo-dopplerowskiego do nieinwazyjnych badań mikrokrążenia krwi. W odróżnieniu od rozbudowanych i drogich rozwiązań komercyjnych proponowany zestaw diagnostyczny jest urządzeniem mobilnym i ekonomicznym, głównie dzięki przeniesieniu, za pomocą interfejsu USB (Universal SerialBus), przetwarzania i analizy sygnałów pomiarowych do komputera osobistego wyposażonego w odpowiednie oprogramowanie. Urządzenie ma dwa niezależne kanały pomiarowe. Modułowa budowa umożliwia zmianę liczby kanałów. Źródłem światła z zakresu bliskiej podczerwieni jest dioda laserowa generująca falę o długości 780 nm. Zintegrowany moduł kalibracji optoelektronicznej eliminuje konieczność stosowania drogich i nietrwałych płynów kalibracyjnych oraz umożliwia automatyzację procesu kalibracji. Opracowany zestaw diagnostyczny przebadano na fantomach i zweryfikowano w warunkach klinicznych w trakcie pomiarów porównawczych z urządzeniami komercyjnymi u chorych z niewydolnością żylną oraz cukrzycą.
EN
Computerised laser-Doppler set-up for non-invasive measurements of blood microperfusion, was developed. The setup was equipped with two measurement channels allowing independent measurement in two position on the body. However, modular construction of the system enables easy increase of the channel number. Semi-conductor laser diode was used as the source of near infra-red light with wavelength of 780 nm. Integrated optoelectronic calibration module eliminates necessity of calibration with an expensive and non-persistent calibration liquids and makes the automatic calibration possible. In contrast to expensive commercial instruments the prototype is an economic and mobile device. It was achieved by USB (Universal Serial Bus) interface to PC computer responsible for signal processing and analysis. The developed laser-Doppler instrument was tested on the tissue phantoms and validated in clinical studies by comparison to commercial instruments.
11
Content available remote Correction of anisotropy coefficient in original Henyey Greenstein phase function for Monte Carlo simulations of light transport in tissue
Żołek N. S., Wojtkiewicz S., Liebert A.
Biocybernetics and Biomedical Engineering
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2008
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Vol. 28, no. 4
59-73
EN
In this paper, two different methods for calculation of polar deflection angle are compared. The scattering angle is defined by numerical inversion of cumulative distribution of the original Henyey-Greenstein phase function. Results of the Monte Carlo simulations obtained in this manner are compared with results of simulations in which the analytical inversion of the probability density for the cosine of the deflection angle is applied. Investigations are carried out for media with optical properties similar to these typical for living tissues as well for very small source detector separations (50-500 [\mi]m), i.e. in conditions, in which the diffusion theory can not be applied. The distributions of visiting probability of photons penetrating into the semi-infinite medium are obtained for various methods of phase function calculation. It can be observed that the methods of calculation of polar deflection angle influence significantly spatial distributions of reflectance and visiting probability obtained by Monte Carlo simulations. The approximated transformation of the anisotropy coefficient used in simulations carried out with the use of the original Henyey-Greenstein function to effective anisotropy coefficient is presented; that makes possible comparisons of the results of Monte Carlo simulations obtained by using different methods.
12
Content available Optyczne metody obrazowania molekularnego
Sołtysiński T., Liebert A., Zawicki I., Maniewski R.
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
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2008
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Vol. 14, nr 4
331--335
PL
Obrazowanie molekularne jest szybko rozwijającą się dziedziną badań w zakresie biotechnologii i inżynierii biomedycznej. W artykule przedstawiono przegląd technik stosowanych w obrazowaniu molekularnym, wykorzystujących metody medycyny nuklearnej oraz optyczne techniki oparte na analizie promieniowania fluorescencyjnego. W szczególności opisano metody optyczne obrazowania molekularnego stosowane w skali mikroskopowej (mikroskopia konfokalna, obrazowanie czasu relaksacji fluorescencyjnej, transfer energii Foerstera) oraz wykorzystywane w badaniach na zwierzętach doświadczalnych. Omówiono także potencjalne wykorzystanie technik optycznych w badaniach dużych objętości tkanek.
EN
Molecular imaging (MI) is a rapidly emerging field of biomedical, biotechnological and engineering research. This study provides a brief review of the state-of-the-art techniques and methods of MI based on nuclear physics and fluorescent agents. Special attention will be focused on optical methods of MI applied in microscopic scale (multiphoton confocal microscopy, fluorescence lifetime imaging, Forster energy transfer) and in experimental animals. Potential application of MI in large tissue volumes will be also discussed.
13
Content available remote Time-resolved reflectometry and spectroscopy for assessment of brain perfusion and oxygenation
Liebert A., Kacprzak M., Maniewski R.
Biocybernetics and Biomedical Engineering
|
2007
|
Vol. 27, no. 1-2
217-225
EN
Time-resolved optical methods and instrumentation for non-invasive assessment of the cerebral cortex perfusion and oxygenation are presented. The oxygenation can be calculated using the moments of the distributions of times of flight of photons measured at two wavelengths in the near infrared region. For assessment of the brain perfusion, the kinetics of the inflow and washout of an exogenous dye injected intravenously is analyzed. The instrument developed at the Institute of Biocybernetics and Biomedical Engineering PAS is equipped with picosecond diode lasers, fast photodetectors and time correlated single photon counting electronics for acquisition of the distributions of times of flight of photons. This technique allows for a depth-resolved estimation of the changes of absorption and, in consequence, for an assessment of the changes occurring in the cerebral cortex. Combination of the data from multiple sources and detectors placed on the surface of the head with the depth-resolved analysis based on the moments enables to obtain images of the cortex perfusion and/or oxygenation. Potential applications of the instrument and its limitations are also discussed.
14
Content available remote Optymalizacja kodu Monte Carlo do symulacji czasu przelotu fotonów w strukturach tkankowych
Żółek N. S., Liebert A., Maniewski R.
Bio-Algorithms and Med-Systems
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2005
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Vol. 1, no. 1/2
277--280
PL
Symulacje Monte Carlo są często wykorzystywane w modelowaniu transportu światła w strukturach optycznie mętnych. Pozwalają uzyskać dokładny opis rozchodzenia się światła, ale wymagają dużej mocy obliczeniowej. Najbardziej czasochłonnymi operacjami podczas symulacji są: obliczanie wartości funkcji logarytmicznej i trygonometrycznej oraz generowanie liczb pseudolosowych. W tym artykule została przedstawiona weryfikacja i porównanie metody Monte Carlo wykorzystującej aproksymację funkcji logarytmicznej i trygonometrycznej z metodą klasyczną (z dokładnym obliczaniem logarytmu i funkcji cosinus) i z rozwiązaniami równania dyfuzji dla struktur jednorodnych.
EN
Monte Carlo simulations are frequently used in modeling of light transport in turbid media. They allow precise description of light transport, but require long computation time. Logarithmic and trigonometric functions evaluation, and generation of pseudorandom numbers are main-time consuming procedures in Monte Carlo calculations of light transport. In this paper, parallel Monte Carlo method with approximated logarithmic and trigonometric functions is analyzed, verified, and compared to the original one (with exact computation of logarithm and cosine functions) and with solution of diffusion equation for homogeneous media.
15
Content available remote Selected applications of near infrared optical methods in medical diagnosis
Maniewski R., Liebert A., Kacprzak M., Zbieć A.
Opto-Electronics Review
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2004
|
Vol. 12, No. 3
255-262
EN
Optical methods from the near infrared range, in particular the laser-Doppler flowmetry and the near infrared spectroscopy offer a new non-invasive, real-time technique for monitoring of the blood perfusion and oxygenation in a living tissue. In spite of some instrumental problems, e.g., relative calibration and unknown sampling measurement depth, these methods have been already used in clinical studies. In this paper, the principle of the methods and instrumentation have been described. The advantages and limitations of these techniques are also discussed and new trends in technical development of the laser-Doppler flowmetry and the near infrared spectroscopy, especially contactless perfusion scanning and photons time of flight measurement, have been shown. Finally, selected clinical applications of all presented methods have been described.
16
Content available remote Estimation of scattering volume in short distance reflectance measurements by Monte Carlo modelling
Liebert A., Terajewicz N., Maniewski R., Nilsson G., De Mul F.F.M.
Optica Applicata
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2002
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Vol. 32, nr 4
709-720
EN
The depth of light penetration is an interesting issue in various tissue optics experiments. The measurements of remitted light distribution was shown to allow for estimation of optical properties. However, in case of measurements with a short distance between the emitter and the detector, the diffusion equation fails, and the proposed methods cannot be applied. The aim of this study was to develop a simple method for estimation of the light penetration depth for short-distance measurements of remitted light. The idea is based on the analysis of the diffusely back-scattered light distribution adjacent to the emitter for the assessment of the scattering volume. The Monte Carlo method was used for theoretical estimation of the relationship between the light distribution around emitting fiber and the depth of light scattering volume. Two series of Monte Carlo simulations were performed: the first one with limited and the second one with unlimited scattering volume. In both series the values of absorption and scattering coefficients were altered within ranges typical of human tissues. The results of this study show that: the diffuse reflectance is strongly dependent on the absorption and scattering properties of the tissue and it is possible to estimate the depth of the scattering volume by use of the short distance profile of diffusely back-scattered light as measured at the surface of the tissue.
17
Content available remote Optical methods for tissue perfusion and oxygenation measurements
Maniewski R., Liebert A.
Biocybernetics and Biomedical Engineering
|
2002
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Vol. 22, no. 2-3
99-112
EN
Optical methods from the infrared range, especially Laser-Doppler flowmetry and near infrared spectroscopy offer a new non-invasive, real-time technique for monitoring of blood perfusion and oxygenation in living tissue. In spite of some instrumental problems e.g. relative calibration, unknown sampling measurement depth, these methods are already used in clinical studies. In the paper the methods principle, technical development and selected clinical applications have been described.
18
Content available remote Opracowanie i badania wielokanałowych sond laserowo-dopplerowskich
Tokarz A., Łukasiewicz P., Liebert A., Maniewski R.
Acta Bio-Optica et Informatica Medica. Inżynieria Biomedyczna
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2001
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Vol. 7, nr 3-4
115-122
PL
W pracy przedstawiono budowę sondy wielokanałowej laserowo-dopplerowskiej oraz modeli przepływu opracowanych w IBIB PAN. Opisano także układ pomiarowy i procedurę pomiarową, wykorzystaną do pomiaru indeksu ukrwienia LDP. Zbadano wpływ konfiguracji sondy laserowo-dopplerowskiej na wyniki pomiarów indeksu ukrwienia. Stwierdzono silną zależność zmierzonych sygnałów LDP od położenia kapilar w modelu, zależność selektywności pomiaru od odległości między światłowodem emisyjnym a detekcyjnym sondy, oraz liniowość algorytmów stosowanych do wyznaczania indeksu ukrwienia w funkcji prędkości przepływu.
EN
In this paper the construction of the multichannel Laser-Doppler probe and the flow model elaborated in the Institute of Biocybernetics and Biomedical Engineering PAS are presented. The experimental set-up and the method for the perfusion index LDP measurement are described. The influence of the configuration of the Laser-Doppler probe on measurements results is tested. The LDP signals levels depend significantly on the location of the capillaries of the model. The sensitivity of the measurement depends significantly on the distance between the emitting and detecting fiber of the probe. The perfusion index calculated with the use of the standard algorithm increases linearly due to the linear increase of flow velocity in the capillaries of the model.
19
Sondy laserowo-dopplerowskie do badań mikrokrążenia
Łukasiewicz P., Liebert A., Maniewski R.
Elektronizacja : podzespoły i zastosowania elektroniki
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2000
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nr 11
19-21
20
Content available remote Evaluation of integrating probes used in Laser-Doppler perfusion measurements
Łukasiewicz P., Liebert A., Zbieć A., Maniewski R.
Biocybernetics and Biomedical Engineering
|
2000
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Vol. 20, no. 4
77-88
EN
Laser-Doppler measurement is a clinically useful method for skin microperfusion assessment. The results of perfusion measurements depend significantly on the laser-Doppler probe geometry and the construction. Integrating probes are used by clinicians when the averaging of perfusion over a large volume of the tissue is needed. These probes allow to limit the influence of the skin blood perfusion inhomogenities. The aim of this study was to evaluate the effectiveness of the measurement performed with different types of integrating probes. The second aim was to compare two types of algorithms used in the Laser-Doppler signal processing for integrating probes. The study shows that the measurement results depend significantly on the area covered by the detecting fibres of the probe.
PL
Pomiary laserowo-dopplerowskie są klinicznie użyteczną metodą badania mikrokrążenia skórnego. Wyniki pomiarów mikrokrążenia uzależnione są w znacznym stopniu od geometrii i budowy sondy laserowo-dopplerowskiej. Jednym z typów sond laserowo-dopplerowskich jest sonda integrująca. Jest ona wykorzystywana przez klinicystów w przypadkach wymagających pomiarów ukrwienia uśrednianych z większych objętości tkanki. Stosowanie sond integrujących pozwala na ograniczenie wpływu niejednorodności mikrokrążenia na wynik pomiaru. Pierwszym celem podjętych badań była ocena efektywności pomiarów wykonywanych przy użyciu różnych typów sond integrujących. Drugim celem było porównanie dwóch różnych algorytmów obliczania sygnałów ukrwienia wykorzystywanych w przyrządach laserowo-dopplerowskich wyposażonych w sondy integrujące. Rezultaty przeprowadzonych badań pokazują istotną zależność wyników pomiarów laserowo-dopplerowskich od pola powierzchni obejmowanego przez światłowody detekcyjne sondy integrującej.
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