Laser Doppler flowmetry of blood perfusion in mucoperiosteal flaps covering membranes in bone augmentation and implant procedures. A pilot study in dogs.

1993 ◽  
Vol 4 (1) ◽  
pp. 35-38 ◽  
Author(s):  
D. Zanetta-barbosa ◽  
B. Klinge ◽  
H. Svensson
Keyword(s):  
Pilot Study ◽  
Laser Doppler Flowmetry ◽  
Blood Perfusion ◽  
Laser Doppler ◽  
Bone Augmentation ◽  
Doppler Flowmetry

scholarly journals Laser Doppler Flowmetry versatile acquisition system with low quantization error

2018 ◽  
Vol 4 (1) ◽  
pp. 25
Author(s):  
Francesco Marrazzi ◽  
Frederic Truffer ◽  
Martial Geiser
Keyword(s):  
Laser Doppler Flowmetry ◽  
Analog Circuit ◽  
Scattered Light ◽  
Blood Perfusion ◽  
Electrical Signal ◽  
Laser Doppler ◽  
Physical Models ◽  
Acquisition System ◽  
Invasive Technique ◽  
Doppler Flowmetry

The Laser Doppler Flowmetry (LDF) is a non-invasive technique used to evaluate blood perfusion of various human tissues like the skin or the fundus of the eye. It is based on the scattering of light on moving red blood cells in tissue. Frequency shifted scattered light is detected and provide an electrical signal. Physical models for LDF use the DC and AC components of this signal. If AC is small relative to the DC, digitalization becomes an issue, and if more than two LDF signal acquisitions and analysis have to be done simultaneously, the device becomes expensive and bulky. We propose here a versatile and inexpensive acquisition system, which overcomes quantization errors issue by first separating DC from AC, then amplifying AC and finally recombining both signals before digitalization. We designed an analog circuit combined with a 12 bit analog-to-digital converter, a microcontroller unit and a Raspberry Pi2 (Rpi2) for the signal processing. Results are accessed remotely from the Rpi2 through HTTP protocol. Multiple systems can easily be used simultaneously for multichannel acquisitions.

scholarly journals Identification of Gingival Microcirculation Using Laser Doppler Flowmetry in Patients with Orthodontic Treatment—A Longitudinal Pilot Study

Medicina ◽  
2021 ◽  
Vol 57 (10) ◽  
pp. 1081
Author(s):  
Martha Alicia Laredo-Naranjo ◽  
Nuria Patiño-Marín ◽  
Gabriel Alejandro Martínez-Castañón ◽  
Carlo Eduardo Medina-Solís ◽  
Carolina Velázquez-Hernández ◽  
...  
Keyword(s):  
Pilot Study ◽  
Laser Doppler Flowmetry ◽  
Orthodontic Treatment ◽  
Tooth Movement ◽  
Inflammatory Responses ◽  
Laser Doppler ◽  
Time Intervals ◽  
Depth Level ◽  
Doppler Flowmetry ◽  
Basal Flow

Background and Objectives: Orthodontic tooth movement is associated with inflammatory responses. The aim of this study was to identify gingival microcirculation using laser Doppler flowmetry in patients with orthodontic treatment. Materials and Methods: A longitudinal pilot study was performed. The participants were selected using a non-probability consecutive sampling. Of the twenty-five subjects, a total of six (four women and two men) complied with the criteria. Before and during the treatment, the oral hygiene index, gingival index, probing depth, level of epithelial attachment, and gingival microcirculation were evaluated with laser Doppler flowmetry (integrated parameters: 1. integrated primary basal flow (IPBF), 2. integrated total secondary real flow (ITSRF), and 3. difference between integration (DBI)) in all of the participants). Results: (a) An increase in gingival blood flow was identified at all time intervals with different arches during orthodontic treatment. (b) The IPBF and ITSRF (with treatment) identified after 20 min (treatment initial stage) were compared with the different time intervals, and we observed an increase in gingival perfusion at the 24th, 48th, and 72nd hours in some arches. (b) In the DBI, we found statistically significant differences (p < 0.005) in the Nitinol group of 0.016 inches among all the time intervals (24 h, 48 h, and 72 h) within the 30-day interval, observing a flow increase three times greater than the basal flow after 30 days. Conclusions: Healthcare professionals must identify the inflammatory processes in treatment to observe and discontinue use of harmful methods in clinical practice.

scholarly journals Laser doppler flowmetry for human blood microcirculation assessment

2014 ◽  
Vol 95 (1) ◽  
pp. 63-69 ◽  
Author(s):  
I V Barhatov
Keyword(s):  
Blood Flow ◽  
Frequency Analysis ◽  
Laser Doppler Flowmetry ◽  
Maximum Amplitude ◽  
Blood Perfusion ◽  
Laser Doppler ◽  
Doppler Flowmetry ◽  
Functional Changes ◽  
Microcirculatory Disorders ◽  
The Impact

The prevention and treatment of various microcirculation disorders are one of the most important problems of medical practice. The difficulties of studying the microcirculation are related to the blood vessels small size and extensive branching within organ tissues. At present, various methods of microcirculation assessment using the laser Doppler flowmetry are applied in active clinical practice in our country. The review covers the main methods of laser Doppler flowmetry used for the diagnosis of various microcirculation disorders. The method is based on the determination of tissue blood perfusion by measuring the Doppler frequency shift while tissue is illuminated by a laser beam, followed by the registration of the reflected radiation from moving and stationary tissue components. Microcirculatory oscillation rhythm plays an important role, especially in early diagnosis of many diseases. The loss of certain types of oscillations at laser Doppler flowmetry is interpreted as «spectral narrowing» and serves as a diagnostic criterion for microcirculation deregulation, which is directly related to decreased blood perfusion and tissue hypotrophy. The use of amplitude-frequency analysis of blood flow oscillations can non-invasively evaluate the impact of the various components of microvascular tone, allowing to calculate an index of neurogenic and myogenic tone and bypass index. The amplitude-frequency analysis of the laser Doppler flowmetry spectrum uses normalized parameters determining the maximum amplitude of the blood flow oscillation in different bands, as well as their ratio - microcirculation effectiveness index. Hyperemic, spastic, spastic-atonic, structural and degenerative, congestive and stasic forms of various microcirculation disorders are marked out. Each of these microcirculatory disorders is characterized by a certain ratio of structural and functional changes and changes in blood velocity, as well as impaired barrier function. The main principles of the microcirculatory disorders are described.

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