May 2013- July 2013, Vol. 3, No. 3, 2124-2129.
E- ISSN: 2249 –1929
Journal of Chemical, Biological and Physical Sciences
An International Peer Review E-3 Journal of Sciences
Available online atwww.jcbsc.org
Section C: Physical Science
Research article
CODEN (USA): JCBPAT
Effect of He-Ne Laser Radiation on Viscometric
Behavior of Human Blood
Shikha Rathore1* and Basharath Ali 2
1
Department of Physics, Mahatma Gandhi Institute of Technology, Hyderabad, 500075, India
2
Department of Electronics, Anwar Ul-Ulloom College, Hyderabad, 500001, India
Received: 25 May 2013; Revised: 10 July 2013; Accepted: 18 July 2013;
Abstract: Laser-tissue interaction provides important information about the
characteristics and behavior of biological tissues and living cells. Low intensity laser
radiations are widely used in clinical practice since last 3 decades. The irradiation of
blood is considered as the most efficient method for the bio stimulation of biological
cells or living tissues. The purpose of this study is to investigate the effect of Low
Level Laser Radiation (LLLR) on viscometric behavior of human blood. Coefficient
of viscosity and size of erythrocytes are measured to understand the rheology of
blood. These rheological measurements in clinical studies are generally concerned
with the individual components of blood (erythrocytes, leucocytes, platelets and
plasma) which collectively influence blood viscosity. Therefore, it is appropriate to
measure the viscosity at three different levels- tissue level (whole blood), cellular
level (erythrocytes) and molecular level (plasma). To understand the viscometric
behavior of whole blood a systematic study has been done. A significant change in
the coefficient of viscosity and size of erythrocytes is observed with effect of laser
radiation.
Keywords: Viscosity, LLLR, Erythrocytes, Plasma, whole blood, Laser Diffraction.
INTRODUCTION
Laser diffraction which is alternatively referred as Low Angle Laser Light Scattering ( LALLS)
technique has emerged as one of the most important and effective techniques in the world of particle
2124 J. Chem. Bio. Phy. Sci.; Sec.C, 2013, Vol.3, No.3, 2124-2129.
Effect...
Shikha Rathore et.al.
size analysis. It is extensively used technique in medical research because of its ability to be fully
automated. Analysis of wet or dry samples can be done effectively by using laser diffraction. This
technique has non-destructive properties and suitable for a broad range of particle sizes which can
measure the size of particles ranging from 0.02 to 2000 micron. It has inherent advantages because of
properties associated with laser, which make it preferable to other techniques for many different
materials. In clinical research laser diffraction is considered as most suitable and effective technique
because of its reproducibility and repeatability. During the process of laser tissue interaction the
metabolic activities of the living organism changes which results in change in rheological parameters
of the human blood1.
Viscosity of blood is an important and common factor which ties blood pressure, cholesterol, ESR
erythrocyte sedimentation rate (ESR), hematocrit volume all together. Blood viscosity is measurement
of the thickness and stickiness of blood and is associated with various diseases either as a contributor
or an effect. The concentration of erythrocytes plays an important role in viscosity of blood. Besides
the effect of cell concentration, the viscosity of blood depends upon shear stress developed within the
fluid and also on the shear rate. At low shear rate viscosity is analogous to plasma viscosity whereas
at high shear rates measurement of viscosity will reflect the deformability of erythrocytes.
For plasma the viscosity is an inherent property and it will not be affected whether the fluid is flowing
slowly or quickly. This type of fluid with a constant velocity regardless of flow rate is called
Newtonian fluid. Plasma is homogeneous in nature whereas whole blood behaves as a non-Newtonian
fluid because of behavior of erythrocytes during flow2. The non-homogeneous behavior of whole
blood complicates the measurement of viscosity and put a restriction on use of viscometer which
measures it accurately.
In our study, we have measured the viscosity of blood using capillary tube viscometer which is
considered as more effective technique. To understand the impact of laser on blood viscosity, we have
performed experiments before and after laser radiation and analyzed the results. We have also
measured the size of erythrocytes at room temperature and after irradiating the samples. Results of
experiments are in line with the fact that size of erythrocytes has an important role in blood viscosity.
MATERIALS AND METHODS
The Laser Diffraction method of measuring particle size takes advantage of an optical principle of
scattering the light beam when it interacts with the particle. This diffraction pattern can be observed
on the screen. In this experiment, particle size is obtained by measuring the size of diffracted minima
with respect to angle of incident beam.
The pathological samples of normal human blood were obtained from healthy people those who were
not on any medication and were mixed with EDTA (Ethylene Diamine Tetra Acetic Acid) as an
anticoagulant. Each sample was divided into two parts for irradiation and control. The measurements
were taken immediately after collecting the blood. For separating the plasma from the whole blood,
the samples have been centrifuged at 4000 rpm at room temperature for 15 minutes. Viscosity for
whole blood and plasma has been measured at room temperature and after irradiating the sample. The
duration for irradiation was 30 minutes. At the same time for measurement of size of erythrocytes
slides were prepared before irradiating the sample and after irradiation.
For measurement of size of erythrocytes, He-Ne laser of 2 mW power with wavelength 632.8 nm and
beam spot size of 2 mm is used. By using the laser diffraction technique the size is measured for
human blood at room temperature and after irradiation.
2125 J. Chem. Bio. Phy. Sci. Sec.; C, 2013, Vol.3, No.3, 2124-2129.
Effect...
Shikha Rathore et.al.
Measurement of viscosity is done by using the viscometer. There are three types of viscometer
generally used for clinical applications. These are capillary viscometer, falling ball viscometer and
rotational viscometer. Here capillary tube viscometer was used. Very less quantity of blood is allowed
to flow through a known length of column. Measurement of viscosity is performed by measuring the
time for blood to flow a predefined distance along the tube. The experiment is repeated after
irradiating the blood. Same procedure is used to measure the viscosity of plasma. The radius of the
capillary tub was 0.5 mm. The capillary tube viscometer has several features which makes it more
efficient for clinical applications. It gives rapid and precise measurement of very less quantity of
blood or plasma.
The He- Ne Laser of 632.8nm wavelength and 100 mW output power with beam spot size of 5 mm
was used for irradiation of blood samples. The volume of blood was 3 to 5 ml and maximum
irradiation time was 30 min. Figure-1 indicates the experimental setup used to perform the
experiments
Fig.1: Experimental arrangement for irradiating the blood samples
RESULTS AND DISCUSSION
In this section, data points obtained through various experiments are analyzed and observations are
presented in a graphical manner. Following major observations are being discussed here:
•
Impact of laser radiation on viscosity of whole blood and plasma
•
Impact of laser radiation on size of erythrocytes
Viscosity of whole blood shows a remarkable variation with and without effect of laser radiation as
shown in Figure-2.
The reason for such variation is understandable as various activities take place during the interaction
of laser radiation with blood. The first activity is based on photodynamic action of laser radiation
where the energy is transferred to oxygen present in the whole blood. Than with respect to the time
duration of irradiation, photo dissociation starts, this indicates interaction of radiation with
hemoglobin. And finally a part of radiation converted into heat that is referred as local heating of cell
which causes change in temperature at local site3. However because of intensive blood circulation,
there is no significant change in the temperature of the whole blood but the viscometric behavior of
whole blood changed. No significant impact of laser interaction was observed on plasma.
2126 J. Chem. Bio. Phy. Sci. Sec.; C, 2013, Vol.3, No.3, 2124-2129.
Effect...
Shikha Rathore et.al.
The possible explanation for decrease in viscosity of whole blood is either because of decrease in
concentration of erythrocytes per unit volume i.e. heamatocrit (HCT) value or change in size and
shape of erythrocytes. Change in size has been observed with effect of laser radiation as shown in
Figure-4. A significant difference between controlled and irradiated blood samples is found. The laser
radiation reduces the viscosity of whole blood by 12 to 30 %.
Fig.2: Chart presenting coefficient of viscosity of human blood before and after
radiation for 30 minutes
Further, blood samples have been irradiated for different time duration with laser radiation to see the
characteristic behavior of whole blood and viscosity is being measured. The decrease in viscosity with
different time duration of interaction for 15 minutes, 30 minutes, 45 minutes, and 60 minutes is shown
in Figure-3. This result indicates that viscosity of whole blood decreases as time of interaction
increases.
Fig. 3: Data on Coefficient of Viscosity of human blood after radiating the
samples for different time duration
2127 J. Chem. Bio. Phy. Sci. Sec.; C, 2013, Vol.3, No.3, 2124-2129.
Effect...
Shikha Rathore et.al.
For measurement of size of erythrocytes, Laser diffraction technique is used. The slides were prepared
by smears of blood before effect of radiation and kept in the path of laser radiation. Diffraction pattern
is observed on the screen. Further blood sample has been irradiated for 30 minutes and again slides
were prepared. The experiment has been repeated for measurement of size of erythrocytes. 0 to 7 % of
decrease in size is observed as presented in Figure 4.
Fig. 4: Data on size of human erythrocytes before and after radiation for 30 minuets
CONCLUSION
The impact of laser interaction with whole blood or living cells is influenced by reaction of individual
components of blood i.e. erythrocytes, thrombocytes, leucocytes and plasma. And it is also not
surprising that effect of environment and weather condition also has its effect on the circulation of
blood. This study investigated the effect of Low Level Laser Radiation (LLLR) on rheological
parameters of the human blood. Results of our experiments indicates that laser radiation act both at
tissue level and molecular level which results in change of viscosity and size of erythrocytes. This
study uses the capillary tube viscometer for performing measurement to obtain accurate and effective
results on multiple blood samples. Experimental results provide useful insight in role of laser
interaction with biological tissues which may help in dealing with some medical challenges.
ACKNOWLEDGMENT
The author expresses thanks to pathology laboratories for providing the samples, biophysics
department Nizam College and Globe Research Laboratory for providing research facilities.
REFERENCES
1. G.Dan, Siposan and AdalbertLukacs. Journal of Clinical Laser Medicine & Surgery. April 2001, 19(2):
89-103.
2. A.Yu. A.N.Vladimirov, G.I.Osipov, KlebanovBiochemistry (Moscow), Photobiological Principles of
Therapeutic Applications of Laser Radiation, 2004, 69, 81-90.
3. G.Dan Siposan and Adalbert Lukacs. Journal of Clinical Laser Medicine & Surgery.
2000, 18(4):
185-195.
2128 J. Chem. Bio. Phy. Sci. Sec.; C, 2013, Vol.3, No.3, 2124-2129.
Effect...
Shikha Rathore et.al.
4. Sehyun Shin, Yunhee Ku, Myung-Su Park and Jang-Soo Suh1, Korea-Australia Rheology Journal,
2004. 16, 2, 85-90.
5. G. A. Zalesskaya* and E. G. Sambor Journal of Applied Spectroscopy, 2005,72, 2, 242-248.
Corresponding author: Shikha Rathore; Department of Physics, Mahatma Gandhi
Institute of Technology, Hyderabad, 500075, India
2129 J. Chem. Bio. Phy. Sci. Sec.; C, 2013, Vol.3, No.3, 2124-2129.