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Utveckling av en multikanal near infrared spectroscopy (NIRS) givare

Abdi, Aydin LU (2011) EEM820 20111
Department of Biomedical Engineering
Abstract
Near-Infrared Spectroscopy (NIRS) has become popular in many research fields for
the past two decades. NIRS technology uses near infrared light for measuring changes
in the concentration of deoxygenated hemoglobin and oxygenated hemoglobin. Noninvasive
near-infrared absorption measurements in tissue have many invaluable
applications in the medical field. Today NIRS is a very attractive technique within for
example brain research and studies of neurological and psychiatric diseases.
The purpose of this thesis is to develop a handheld, multi-channel, low cost and
compact Continuous Wave NIRS system. The system will non-invasively monitor
blood oxygenation and total hemoglobin level in the frontal lobe of the brain by
measuring... (More)
Near-Infrared Spectroscopy (NIRS) has become popular in many research fields for
the past two decades. NIRS technology uses near infrared light for measuring changes
in the concentration of deoxygenated hemoglobin and oxygenated hemoglobin. Noninvasive
near-infrared absorption measurements in tissue have many invaluable
applications in the medical field. Today NIRS is a very attractive technique within for
example brain research and studies of neurological and psychiatric diseases.
The purpose of this thesis is to develop a handheld, multi-channel, low cost and
compact Continuous Wave NIRS system. The system will non-invasively monitor
blood oxygenation and total hemoglobin level in the frontal lobe of the brain by
measuring changes in blood absorption with near-infrared light through tissue. With
LabView 8.6 the NIRS probe was programmed for data processing and thereafter was
analyzed data using MatLab 2007.
For building the NIRS system I utilized eight phototransistors with their own
PCBs (Printed Circuits Board), three LEDs (Light-Emitting Diode), one FPC
(Flexible Printed Circuit) and one computer board. Two wavelengths of 735nm and
850nm were considered due to the different optical properties of oxygenated and
deoxygenated hemoglobin at near-infrared region. This system can measure the
intensity of light scattering through the tissue and from this value and the absorption
coefficients of hemoglobin; the concentrations of the oxygenated and deoxygenated
hemoglobin (Hb and HbO2) can be calculated. The device's possible clinical
application, i.e., as a screening tool for the detection of sleep apnea, was explored
using the breath holding protocol. In persons with sleep apnea there is a reduction in
their oxy-hemoglobin saturation (O2 saturation) due to the cessation of airflow. This is
simulated using the breath holding protocol. With the prototype I built I was able to
show that the total hemoglobin concentration (in proportion to blood volume) within
the detected region increases during the breath holding period, reaches a peak after
the start of re-breathing, and gradually comes back to normal. The results obtained
proved that the device was able to detect the hemodynamic changes during the breath
holding tests.
This project has had many limitations mainly due to time-limit but despite this
the results are clear and show that the device works properly. The NIRS system is a
relatively new technique with many possibilities in the future but much research needs to be done and the knowledge about NIRS still has to be more widespread
before we will see it being used as a tool in the clinical medical field. (Less)
Please use this url to cite or link to this publication:
author
Abdi, Aydin LU
supervisor
organization
course
EEM820 20111
year
type
H2 - Master's Degree (Two Years)
subject
language
Swedish
additional info
2011-03
id
2786718
date added to LUP
2012-06-12 11:33:04
date last changed
2014-10-08 14:47:03
@misc{2786718,
  abstract     = {Near-Infrared Spectroscopy (NIRS) has become popular in many research fields for
the past two decades. NIRS technology uses near infrared light for measuring changes
in the concentration of deoxygenated hemoglobin and oxygenated hemoglobin. Noninvasive
near-infrared absorption measurements in tissue have many invaluable
applications in the medical field. Today NIRS is a very attractive technique within for
example brain research and studies of neurological and psychiatric diseases.
The purpose of this thesis is to develop a handheld, multi-channel, low cost and
compact Continuous Wave NIRS system. The system will non-invasively monitor
blood oxygenation and total hemoglobin level in the frontal lobe of the brain by
measuring changes in blood absorption with near-infrared light through tissue. With
LabView 8.6 the NIRS probe was programmed for data processing and thereafter was
analyzed data using MatLab 2007.
For building the NIRS system I utilized eight phototransistors with their own
PCBs (Printed Circuits Board), three LEDs (Light-Emitting Diode), one FPC
(Flexible Printed Circuit) and one computer board. Two wavelengths of 735nm and
850nm were considered due to the different optical properties of oxygenated and
deoxygenated hemoglobin at near-infrared region. This system can measure the
intensity of light scattering through the tissue and from this value and the absorption
coefficients of hemoglobin; the concentrations of the oxygenated and deoxygenated
hemoglobin (Hb and HbO2) can be calculated. The device's possible clinical
application, i.e., as a screening tool for the detection of sleep apnea, was explored
using the breath holding protocol. In persons with sleep apnea there is a reduction in
their oxy-hemoglobin saturation (O2 saturation) due to the cessation of airflow. This is
simulated using the breath holding protocol. With the prototype I built I was able to
show that the total hemoglobin concentration (in proportion to blood volume) within
the detected region increases during the breath holding period, reaches a peak after
the start of re-breathing, and gradually comes back to normal. The results obtained
proved that the device was able to detect the hemodynamic changes during the breath
holding tests.
This project has had many limitations mainly due to time-limit but despite this
the results are clear and show that the device works properly. The NIRS system is a
relatively new technique with many possibilities in the future but much research needs to be done and the knowledge about NIRS still has to be more widespread
before we will see it being used as a tool in the clinical medical field.},
  author       = {Abdi, Aydin},
  language     = {swe},
  note         = {Student Paper},
  title        = {Utveckling av en multikanal near infrared spectroscopy (NIRS) givare},
  year         = {2011},
}