Developments in laser Doppler blood perfusion monitoring

Leahy, Martin J.; Mul, F.F.M. de; Nilsson, Gert; Maniewski, Roman; Liebert, Adam

doi:10.1117/12.475841

Cited by 5 publications

(4 citation statements)

References 42 publications

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“…The device then creates two‐dimensional, colour‐coded images representing various levels of the LDP of local tissue perfusion. The technique and its sensitivity have been described elsewhere (4,15,16). We have previously found an acceptable repeatability of the results obtained with the LDPI method on the identical subjects, under the same conditions on the same day, assessed with a coefficient of variation (CV) ranging from 7·9% to 9·5%.…”

Section: Methodsmentioning

confidence: 98%

Healing process of venous ulcers: the role of microcirculation

Ambrózy

Waczulíková

Willfort

et al. 2012

International Wound Journal

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In order to describe adequately the process of healing in the intermediate degrees, we investigated microcirculatory changes in the venous ulcers at well-defined stages of wound repair. We investigated dynamic changes in microcirculation during the healing process of venous ulcers. Ten venous ulcers were investigated in three consecutive clinical stages of wound healing: non granulation tissue (NGTA), GTA and scar. Subpapillary microcirculation was measured by laser Doppler perfusion (LDP) imaging and expressed using LDP values in arbitrary units. Nutritive perfusion by capillary microscopy and expressed as capillary density (CD) - the number of capillaries per square millimetre. Before the development of GTA the LDP was low (median 1·35; lower-upper quartiles 0·71-1·83) accompanied with zero CD in all but one patient who had a density of 1. With the first appearance of GTA in the same area, the LDP was improved (2·22; 1·12-2·33; P = 0·0024) when compared with NGTA, in combination with a significant increase in CD (1·75; 0-3; P = 0·0054). In scar, the LDP was similar to that in the NGTA (1·03; 0·77-1·83; P = 0·278), combined with the highest CD (5·75; 4·5-8) in comparison with the previous stages of the area (for both pairs, P < 0·0001). Venous ulcers are caused by poor nutritive and subpapillary perfusion. Subpapillary perfusion plays a major role in the formation of GTA. In a scar, the increased nutritive perfusion is sufficient to cover the blood supply and keep skin viable while subpapillary perfusion is low.

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Section: Methodsmentioning

confidence: 98%

Healing process of venous ulcers: the role of microcirculation

Ambrózy

Waczulíková

Willfort

et al. 2012

International Wound Journal

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“…The result of LDF measurements is formed as an index of microcirculation (perfusion) measured in perfusion (arbitrary) units. The method was first introduced over 40 years ago and has undergone continuous development since [11].…”

Section: Introductionmentioning

confidence: 99%

Sampling volume assessment for wearable multimodal optical diagnostic device

Zharkikh

Dremin

Dunaev

2023

Journal of Biophotonics

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The process and results of numerical Monte Carlo simulation of optical radiation propagation in laser Doppler flowmetry (LDF) and fluorescence spectroscopy (FS) channels of a wearable diagnostic multimodal device are described in this paper. To achieve the goal, a multilayer skin model with different parameters of blood and melanin content and different distances between sources and radiation receivers was designed. The changes in the sampling (diagnostic) volume depending on the anatomical features of the biological tissues, as well as on the technical parameters of the device were shown. Depending on the scattering media optical properties and the source‐detector configuration of the device, the diagnostic volume can range from 2 to 7 mm3. The obtained results allow the formation of specialized medical and technical requirements for wearable multimodal devices implementing LDF and FS channels.

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“…However, up to now, it has not been easy to determine whether the perfusion parameters measured by laser Doppler techniques relate to the nutritional, thermoregulatory or both types of flux [5].…”

Section: Introductionmentioning

confidence: 99%

Frequency weighted laser Doppler perfusion measurements in skin

et al. 2006

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Abstract:The laser Doppler (LD) technique has been applied to measurements of blood perfusion in a number of studies and is the most popular method for investigating microcirculation in patients. The skin is supplied with nutrients by the capillaries, the smallest blood vessels. The nutritive blood flow within the capillaries is very slow and should be distinguished from the blood flow of other vessels such as those in deeper layers of the skin. In this work, a novel laser Doppler flux meter was used. In contrast to the usual LD technique that only provides a mean flux value, partial flux values can be calculated which are correlated to different flow velocities by analyzing different Doppler frequencies. The influence of the changes in the microcirculation on the spectral LD signal was investigated on the inner part of the wrist to select frequency bands, which would allow the best discrimination of capillary blood flux. The LD measurements were performed during selective compression of the skin. Results were obtained from different volunteers and the Doppler signal intensity in a frequency range from 50 Hz to about 400 Hz was found to correlate best with the capillary blood flux of the skin.

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Developments in laser Doppler blood perfusion monitoring

Cited by 5 publications

References 42 publications

Healing process of venous ulcers: the role of microcirculation

Healing process of venous ulcers: the role of microcirculation

Sampling volume assessment for wearable multimodal optical diagnostic device

Frequency weighted laser Doppler perfusion measurements in skin

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