Multimodal optical diagnostics of the microhaemodynamics in upper and lower limbs

The introduction of optical non-invasive diagnostic methods into clinical practice can substantially advance in the detection of early microcirculatory disorders in patients with different diseases. This paper is devoted to the development and application of the optical non-invasive diagnostic approach for the detection and evaluation of the severity of microcirculatory and metabolic disorders in rheumatic diseases and diabetes mellitus. The proposed methods include the joint use of laser Doppler flowmetry, absorption spectroscopy and fluorescence spectroscopy in combination with functional tests. This technique showed the high diagnostic importance for the detection of disturbances in peripheral microhaemodynamics. These methods have been successfully tested as additional diagnostic techniques in the field of rheumatology and endocrinology. The sensitivity and specificity of the proposed diagnostic procedures have been evaluated.<br/

Evaluation of microvascular disturbances in rheumatic diseases by analysis of skin blood flow oscillations

Laser Doppler flowmetry (LDF), tissue reflectance oximetry (TRO) and pulse oximetry (PO) and cold pressor test (CPT) were used to assess the microcirculation parameters and the activation of regulatory mechanisms. LDF and TRO samples wavelet transform in the frequency bands 0.01-2 Hz was used to evaluate microvascular disturbances in rheumatic diseases and to assess the vascular involvement in the pathological process. The spectral components of LDF and TRO signals associated with endothelial, adrenergic, intrinsic smooth muscle, respiratory and cardiac activities were analyzed. Significant difference between healthy and rheumatology subjects was identified in perfusion parameters. Spectral analysis of the LDF signal revealed significant difference between two group of high (<0.1 Hz) frequency pulsations. Based on the analysed of the perfusion and amplitudes oscillation in the frequency band the decision rule for detection microvascular disturbances were synthesized. The perfusion parameter and amplitude oscillation associated with cardiac activities included in the decision rule. Based on the measured parameters and the result of wavelet transform LDF- and TRO-signals the parameters for detection of complications associated with microvascular disturbances and their possible causes were proposed

Detection of angiospastic disorders in the microcirculatory bed using laser diagnostics technologies

The evaluation of the microcirculatory bed functional state and the identification of angiospastic disorders with related complications, when the pathological changes are reversible, have an important role in medical practice. The aim of this study was to evaluate the possibility of using optical noninvasive methods and the cold pressor test to solve this problem. A total of 33 patients with rheumatological diseases and 32 healthy volunteers were included in the study. Laser Doppler flowmetry, tissue reflectance oximetry and pulse oximetry were used as optical noninvasive methods. The parameters were recorded before, immediately after and 20(Formula presented.)min after the cold pressor test. Based on the measured parameters, the complex parameters of the microcirculatory bed were calculated. A detailed statistical analysis of the parameter changes for each individual in the two groups displayed diverse microcirculatory bed parameter responses upon cold exposure, with differing recovery of parameters after CPT. New diagnostic criteria were proposed for the identification of angiospastic disorders. According to the proposed criteria, 27 people of the volunteers group were confirmed to not display any disorders. In the patient group, however, 18 people were observed to have a relatively normal functional state of the microcirculatory bed, while 15 people were observed to have a possible tendency to angiospasm. To highlight the differences between a relatively normal state and presence of angiospastic disorders, statistical analysis of experimental data was carried out, which revealed significant differences. Further analysis of data with angiospastic disorders identified a relationship between their diagnoses and the results of laboratory studies. Thus, the evaluation of combined noninvasive optical diagnostic method use, the cold pressor test and proposed diagnostic criteria showed a positive result. This approach can be used to detect the presence of possible angiospastic disorders and related complications, as well as microcirculatory bed disorders against the background of other diseases

Laser Doppler flowmetry in blood and lymph monitoring, technical aspects and analysis

The aim of this work was to study the possibilities of the laser Doppler flowmetry method for the joint study of microhaemo- and lymph circulation of human skin. Conducting a series of experimental studies allowed to trace the relationship of recorded signals of microcirculation of blood flow and lymph flow, as well as to study their oscillation nature by using wavelet analysis

Investigation of blood microcirculation parameters in patients with rheumatic diseases by videocapillaroscopy and laser Doppler flowmetry during cold pressor test

Videocapillaroscopy (VCS) and laser Doppler flowmetry (LDF) are non-invasive methods for evaluating microcirculation parameters. The VCS method is based on a high-speed video recording of capillaries in the nailfold. The recorded video frames are processed using a specialized algorithm to determine the red blood cells velocity. The LDF technique is based on the analysis of the Doppler shift of back-scattered laser radiation from moving red blood cells. In this work, simultaneous measurements of VCS and LDF have been performed in healthy volunteers and rheumatic patient. The study was conducted using a cold pressor test. Changes were recorded in response to cold exposure in rheumatic diseases

Multimodal optical measurement for study of lower limb tissue viability in patients with diabetes mellitus

According to the International Diabetes Federation, the challenge of early stage diagnosis and treatment effectiveness monitoring in diabetes is currently one of the highest priorities in modern healthcare. The potential of combined measurements of skin fluorescence and blood perfusion by the laser Doppler flowmetry method in diagnostics of low limb diabetes complications was evaluated. Using Monte Carlo probabilistic modeling, the diagnostic volume and depth of the diagnosis were evaluated. The experimental study involved 76 patients with type 2 diabetes mellitus. These patients were divided into two groups depending on the degree of complications. The control group consisted of 48 healthy volunteers. The local thermal stimulation was selected as a stimulus on the blood microcirculation system. The experimental studies have shown that diabetic patients have elevated values of normalized fluorescence amplitudes, as well as a lower perfusion response to local heating. In the group of people with diabetes with trophic ulcers, these parameters also significantly differ from the control and diabetes only groups. Thus, the intensity of skin fluorescence and level of tissue blood perfusion can act as markers for various degrees of complications from the beginning of diabetes to the formation of trophic ulcers

Multimodal Optical Diagnostics of the Microhaemodynamics in Upper and Lower Limbs

The introduction of optical non-invasive diagnostic methods into clinical practice can substantially advance in the detection of early microcirculatory disorders in patients with different diseases. This paper is devoted to the development and application of the optical non-invasive diagnostic approach for the detection and evaluation of the severity of microcirculatory and metabolic disorders in rheumatic diseases and diabetes mellitus. The proposed methods include the joint use of laser Doppler flowmetry, absorption spectroscopy and fluorescence spectroscopy in combination with functional tests. This technique showed the high diagnostic importance for the detection of disturbances in peripheral microhaemodynamics. These methods have been successfully tested as additional diagnostic techniques in the field of rheumatology and endocrinology. The sensitivity and specificity of the proposed diagnostic procedures have been evaluated

Multimodal optical diagnostics of the microhaemodynamics in upper and lower limbs

Abstract The introduction of optical non-invasive diagnostic methods into clinical practice can substantially advance in the detection of early microcirculatory disorders in patients with different diseases. This paper is devoted to the development and application of the optical non-invasive diagnostic approach for the detection and evaluation of the severity of microcirculatory and metabolic disorders in rheumatic diseases and diabetes mellitus. The proposed methods include the joint use of laser Doppler flowmetry, absorption spectroscopy and fluorescence spectroscopy in combination with functional tests. This technique showed the high diagnostic importance for the detection of disturbances in peripheral microhaemodynamics. These methods have been successfully tested as additional diagnostic techniques in the field of rheumatology and endocrinology. The sensitivity and specificity of the proposed diagnostic procedures have been evaluated

Evaluation of microvascular disturbances in rheumatic diseases by analysis of skin blood flow oscillations

Abstract Laser Doppler flowmetry (LDF), tissue reflectance oximetry (TRO) and pulse oximetry (PO) and cold pressor test (CPT) were used to assess the microcirculation parameters and the activation of regulatory mechanisms. LDF and TRO samples wavelet transform in the frequency bands 0.01–2 Hz was used to evaluate microvascular disturbances in rheumatic diseases and to assess the vascular involvement in the pathological process. The spectral components of LDF and TRO signals associated with endothelial, adrenergic, intrinsic smooth muscle, respiratory and cardiac activities were analyzed. Significant difference between healthy and rheumatology subjects was identified in perfusion parameters. Spectral analysis of the LDF signal revealed significant difference between two group of high (&lt;0.1 Hz) frequency pulsations. Based on the analysed of the perfusion and amplitudes oscillation in the frequency band the decision rule for detection microvascular disturbances were synthesized. The perfusion parameter and amplitude oscillation associated with cardiac activities included in the decision rule. Based on the measured parameters and the result of wavelet transform LDF- and TRO-signals the parameters for detection of complications associated with microvascular disturbances and their possible causes were proposed

Investigation of blood microcirculation parameters in patients with rheumatic diseases by videocapillaroscopy and laser Doppler flowmetry during cold pressor test

Abstract Videocapillaroscopy (VCS) and laser Doppler flowmetry (LDF) are non-invasive methods for evaluating microcirculation parameters. The VCS method is based on a high-speed video recording of capillaries in the nailfold. The recorded video frames are processed using a specialized algorithm to determine the red blood cells velocity. The LDF technique is based on the analysis of the Doppler shift of back-scattered laser radiation from moving red blood cells. In this work, simultaneous measurements of VCS and LDF have been performed in healthy volunteers and rheumatic patient. The study was conducted using a cold pressor test. Changes were recorded in response to cold exposure in rheumatic diseases