An adequate amount of supply of blood to the body organs is essential for the optimum survival and function of the cells. The Red Blood Cells (RBC) which are the most abundant cells of the blood transports hemoglobin which in turn carries oxygen from the lungs to the tissues. And hence its concentration in blood is an important factor. In this paper, we are presenting LAser Speckle Contrast Analysis (LASCA) as a tool for analyzing RBC concentration. Preliminary results obtained using body fluid such as blood mimicking phantoms are presented here. The technique described provides a non-contact, non-scanning and whole field method for assessing RBC concentration non-invasively. © 2010 Elsevier Ltd. All rights reserved.

Narayanan Unni Sujatha

Department of Applied Mechanics

M Ramasubba Reddy

anemia

FIELD METHODS

LASER SPECKLE CONTRAST

LASER SPECKLE CONTRAST ANALYSIS

NON-CONTACT

NON-INVASIVE ASSESSMENTS

RBC CONCENTRATION

RED BLOOD CELL

SCATTERER CONCENTRATIONS

blood

Concentration (process)

FLUIDS

Oxygen

Speckle

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Optics and Lasers in Engineering

Measuring microcirculatory tissue blood perfusion is of interest for both clinicians and researchers in a wide range of applications and can provide essential information of the progress of treatment of certain diseases which causes either an increased or decreased blood flow. Diabetic ulcer associated with alterations in tissue blood flow is the most common cause of non-traumatic lower extremity amputations. A technique which can detect the onset of ulcer and provide essential information on the progress of the treatment of ulcer would be of great help to the clinicians. A noninvasive, noncontact and whole field laser speckle contrast imaging (LSCI) technique has been described in this paper which is used to assess the changes in blood flow in diabetic ulcer affected areas of the foot. The blood flow assessment at the wound site can provide critical information on the efficiency and progress of the treatment given to the diabetic ulcer subjects. The technique may also potentially fulfill a significant need in diabetic foot ulcer screening and management. © 2014 SPIE.

Progress in Biomedical Optics and Imaging - Proceedings of SPIE

Non invasive blood flow assessment in diabetic foot ulcer using laser speckle contrast imaging technique

Blood flow velocity and red blood cell concentration are of vital importance in assessing tissue microcirculation. Laser speckle contrast analysis is being considered as a promising tool in the qualitative assessment of flow velocity as well as scatterer concentration in different body fluids, though the quantification part still remains challenging. The fractal-based spatial correlation analysis of speckle flow images along with the corresponding contrast analysis for the quantitative assessment of flow and scatterer concentration is investigated. In this study, phantom body fluid solution (intralipid 20%) of different concentrations is pumped at different flow rates through the designed flow channel using a syringe pump and the corresponding speckle images are acquired. The fractality of the acquired speckle images in response to the changes in concentration of the fluid as well as the variations in fluid flow is analyzed along with the corresponding contrast-based analysis. Following this qualitative analysis, an experimental model is attempted toward quantification of these parameters from a single acquired speckle image by considering the contrast and fractality changes together. © Society of Photo-Optical Instrumentation Engineers. © 2013 SPIE.

Journal of Biomedical Optics

Role of contrast and fractality of laser speckle image in assessing flow velocity and scatterer concentration in phantom body fluids

Imaging of tissue perfusion is a vital tool in assessing the status of various diseases that are reflected in the microcirculation. Different techniques developed for imaging microcirculation as well as assessing red blood cell (RBC) concentration are lacking quantitative flow information, whole field imaging capability and non invasiveness. This paper reports on a whole field, non invasive laser speckle imaging technique to quantitatively assess the capillary flow variations and scatterer concentration using microcirculation phantoms. A capillary phantom has been fabricated on two perspex sheets of 12mm thickness each. The flow channels of depth 0.7 and 2mm were machined in the sheets and blood mimicking phantom solution of desired concentration was pumped using a syringe infusion pump (RH-SY10, Ravel Hitecks, India) to get the desired flow rate. The phantom was illuminated with a He Ne laser (ThorLabs) and the resulting speckle pattern was captured using a CCD camera and frame grabber card and the images were analysed using the developed algorithm. The experimental set up is shown in Fig.1. © 2011 IEEE.

2011 Conference on Lasers and Electro-Optics Europe and 12th European Quantum Electronics Conference, CLEO EUROPE/EQEC 2011

Laser speckle contrast imaging for assessing flow velocities and scatterer concentration in capillary phantoms

Non-invasive assessment of static scatterer concentration in phantom body fluids using laser speckle contrast analysis technique

Diffuse reflectance spectroscopy and laser speckle imaging have been identified as an effective tool in characterizing/assessing tissue oxygenation and blood flow in real time tissues. In this paper we are exploring the possibility of finding out blood flow/oxygenation at different areas of feet of subjects with different levels of diabetes. Tissue blood flow is determined by assessing the contrast variations in the laser speckle image of the foot and tissue oxygenation is assessed by diffuse reflectance spectroscopy. A combination of both techniques offers an effective and purely non invasive mode of examination in the staging of Diabetes. © 2011 American Institute of Physics.

AIP Conference Proceedings

Non invasive assessment of tissue oxygenation and blood flow as a tool for staging diabetes

Microcirculation Imaging

Laser Speckle Contrast Analysis (LASCA) for Measuring Blood Flow

Pocket Companion to Guyton and Hall Textbook of Medical Physiology

Copyright

Applied Physics A

Illustration of a bimodal system in Intralipid-20% by polarized light scattering: experiments and modeling

Biofluid Dynamics

Biofluid Dynamics Concepts

Journal	Optics and Lasers in Engineering
ISSN	01438166
Open Access	No