Correlation analysis of laser Doppler flowmetry signals: a potential non-invasive tool to assess microcirculatory changes in diabetes mellitus

Abstract

Measurement and analysis of microcirculation is vital in assessing local and systemic tissue health. Changes in microvascular perfusion if detected can provide information on the development of various related diseases. Laser Doppler blood flowmetry (LDF) provides a non-invasive real-time measurement of cutaneous blood perfusion. LDF signals possess fractal nature that represents the correlation in the successive signal elements. Changes in the correlation of flow and its associated parameters could be used as a tool in differentiating the ailments at different stages or assessing the treatment effectiveness of a particular ailment. Spectral domain analysis of LDF signals reveals five characteristic frequency peaks corresponding to local and central regulatory mechanisms of the human body, namely metabolic, neurogenic, myogenic, respiration, and heart rate. This paper investigates the changes in the fractal nature and constituent frequency bands of laser Doppler signals in diabetic and healthy control subjects acquired from the glabrous skin of the foot so as to provide an assessment of microcirculatory dynamics. As a pilot study, it was attempted on a set of healthy control and diabetic volunteers, and the obtained results indicate that fractal nature of LDF signals is less in diabetic subjects compared to the healthy control. The wavelet analysis carried out on the set of signals reveals the dynamics of blood flow which may have led to the difference in correlation results.

Blood Flow Dynamics in Burns

“…Each such frequency band is also associated with a specific origin of the vasomotion activity [63,64]. The currently established frequency bands are as follows: cardiac activity (0.6-1.6 Hz), respiratory activity (0.15-0.4 Hz), myogenic activity (0.06-0.15 Hz), neurogenic activity (0.02-0.06 Hz), and endothelial activity (0.0095-0.02 Hz) [69]. These different bands have been established by abolishing certain pathways upon which the specific frequency band disappears.…”

Icrocirculatory changes in bulbar conjunctiva in various diseases

“…Для выражения результатов использу-ются относительные единицы [10,17]. Лазерная доппле-ровская флоуметрия является неинвазивным методом определения микроциркуляции, в том числе и кожной [18]. Данный метод получил широкое развитие благодаря циклу работ, выполненных в 1977-1985 гг.…”

The presence of synchronized perfusion dips in the microcirculation of the resting nail bed

“…By analyzing the frequency of vasomotion using LDF, different frequency bands have been established which are associated with different types of vasomotion activity [11,24,25].…”

“…These frequency bands are as follows: cardiac activity (0.6-1.6 Hz), respiratory activity (0.15-0.4 Hz), myogenic activity (0.06-0.15 Hz), neurogenic activity (0.02-0.06 Hz), and endothelial activity (0.0095-0.02 Hz) [25]. Vascular activity in the different frequency bands can be blocked by affecting the appropriate system [10,11,[19][20][21][22][23].…”