A Method and a Device Prototype for Noninvasive Measurements of Blood Perfusion in a Tissue

Lapitan, Denis G.; Разницын, О. А.

doi:10.1134/s0020441218050093

Cited by 13 publications

(4 citation statements)

References 18 publications

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“…The prototype device uses three LED emission sources operating in the wavelength range of 560–580 nm and one silicon photodiode in the optical sensor. The perfusion value calculated during signal processing is similar to that in laser Doppler flowmetry (LDF) [ 15 , 19 ]. The method allows the assessment of perfusion measured in perfusion units (PU).…”

Section: Methodsmentioning

confidence: 99%

Incoherent Optical Fluctuation Flowmetry: A New Method for the Assessment of Foot Perfusion in Patients with Diabetes-Related Lower-Extremity Complications

et al. 2022

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(1) Background: To date, there are no studies evaluating the ability of the incoherent optical fluctuation flowmetry (IOFF) method to assess foot tissue perfusion. The aim of this study was to evaluate the correlation between perfusion values measured by IOFF and TcPO2 in patients with diabetes-related lower-extremity complications. (2) Methods: This was an observational, cross-sectional, two-center study. Diabetic patients with peripheral artery disease and/or diabetic foot ulcers were studied (n = 27, examinations were carried out on 54 legs). Perfusion in the foot tissues was assessed using TcPO2 (reference standard for this study) and the IOFF method. (3) Results: High correlation coefficients of all perfusion parameters measured by IOFF with TcPO2 (Rs 0.7 to 0.76) were shown. The study demonstrated that the IOFF method allows, with a sensitivity of 85.7% and a specificity of 90.0%, the identification of patients with a critical decrease in TcPO2 < 20 mmHg. (4) Conclusions: The high correlation of IOFF parameters with TcPO2 and the moderately high sensitivity and specificity in detecting patients with severe ischemia of foot tissues shows the promise of the method for assessing a tissue perfusion in patients with diabetes-related lower-extremity complications.

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Section: Methodsmentioning

confidence: 99%

Incoherent Optical Fluctuation Flowmetry: A New Method for the Assessment of Foot Perfusion in Patients with Diabetes-Related Lower-Extremity Complications

et al. 2022

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“…It becomes more flexible with this cerebral channel design. In optical tissue oximeters as well as in pulse oximeters implementing several emission wavelengths, the most wellknown technical solution to avoid the simultaneous appearance of radiation at several wavelengths, as well as for eliminating the effect of ambient light, is the pulse-periodic separation of signals from LEDs in time [30,31]. This excludes the cross-illumination of the photodiode with different wavelengths and allows the level of ambient light during the period when all emitters are turned off to be measured.…”

Section: The System As a Wholementioning

confidence: 99%

Combined Non-Invasive Optical Oximeter and Flowmeter with Basic Metrological Equipment

2022

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Optical non-invasive diagnostic methods and equipment are used today in many medical disciplines. However, there is still no generally accepted and unifying engineering theory of such systems. Today, they are developed most empirically and do not always have the desired effectiveness in clinics. Among reasons for their insufficient clinical efficiency, we can claim the limited set of measured parameters, the poorly substantiated technical design parameters, and the lack of metrological certification, which all together lead to large uncertainties and inaccuracies in diagnostic data. The purpose of this study is to develop a new instrument for non-invasive optical oximetry by means of substantiating and creating amore informative tissue oximeter with an enhanced number of measured parameters and equipped with the basic metrological tools—imitational measures. The combination of two related optical diagnostic techniques—a tissue oximetry, including a cerebral one, and a fluctuation flowmetry on a single hardware platform—was used. Theoretical modeling of light transport in tissues was applied to substantiate the main technical design parameters of the device. For each measuring channel, relevant imitation measures for metrological verification and adjustment have been proposed. Some common principles for the operation of such equipment are described in the article, as well.

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“…The prototype has the external LEDs-based optical probe, the main electronic unit and a laptop with the data processing software. In the optical probe, six greenlight LEDs (L-7104GC, Kingbright, Taiwan) for illuminating the examined skin are placed radially around the silicon photodiode (TEFD4300, Vishay, USA) to provide a uniform illumination [44]. The photodiode registers backscattered radiation from a diagnostic volume of skin under the optical probe.…”

Section: Diagnostic Device Prototypementioning

confidence: 99%

“…It is useful to avoid a differential scheme, which is often used in LDF-meters to compensate ambient light and which is a source of the false spectra formation inside the instrument [23]. We used the pulsed switch-on/off regime for LEDs with 50% duty cycle [44]. The 320 Hz operating frequency was chosen to satisfy the Nyquist criterion with the 8-fold margin.…”

Section: Diagnostic Device Prototypementioning

confidence: 99%

Optical incoherent technique for noninvasive assessment of blood flow in tissues: Theoretical model and experimental study

Lapitan

Рогаткин

2021

Journal of Biophotonics

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Laser noninvasive methods for assessment of a tissue blood flow (BF), for example, the Laser Doppler Flowmetry (LDF), are well-known today. However, in such methods, low-frequency fluctuations (LFFs) in the registered optical signal caused by blood volume changes inside a tissue have not been studied in details until now. The aim of this study is to investigate the LFFs formation and to justify the LFFs-based diagnostic technique for cutaneous BF assessment. LFFs are theoretically described and experimentally shown in the input LDF signal inside the frequency range 0 to 10 Hz. They are substantiated as the basis of the new diagnostic method, in which BF is defined as the magnitude of blood volume changes in a tissue per unit time. The hand-made prototype of the promising diagnostic tool with light emitted diodes is used to validate the technique in experiments in vivo on 16 healthy volunteers in comparison with the LDF method. Experimental results show a good similarity of the recorded BF for both coherent and incoherent method. The proposed technique makes it possible the creation of inexpensive diagnostic equipment for assessment of cutaneous BF without using lasers and coherent light, completely and functionally comparable to LDF devices.

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A Method and a Device Prototype for Noninvasive Measurements of Blood Perfusion in a Tissue

Cited by 13 publications

References 18 publications

Incoherent Optical Fluctuation Flowmetry: A New Method for the Assessment of Foot Perfusion in Patients with Diabetes-Related Lower-Extremity Complications

Incoherent Optical Fluctuation Flowmetry: A New Method for the Assessment of Foot Perfusion in Patients with Diabetes-Related Lower-Extremity Complications

Combined Non-Invasive Optical Oximeter and Flowmeter with Basic Metrological Equipment

Optical incoherent technique for noninvasive assessment of blood flow in tissues: Theoretical model and experimental study

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