This document discusses infrared spectroscopy and its applications in medicine. It begins with an introduction that explains infrared spectroscopy involves light with wavelengths longer than visible light. It can be used to identify chemicals by producing absorption spectra using an infrared spectrometer. The document then discusses applications of infrared spectroscopy in medicine such as using near-infrared spectroscopy to non-invasively measure brain activity by detecting hemoglobin concentration changes associated with neural activity. Diagrams of typical measurement curves and Fourier-transform infrared spectroscopy systems are also included.

1. STUDY AND MEASUREMENT OF
INFRARED SPECTROSCOPY AND
ITS APPLICATIONS IN MEDICINE
Done by
Taif Alawsi

2. INTRODUCTION
• Infrared spectroscopy deals with the infrared region of
the electromagnetic spectrum, that is light with a
longer wavelength and lower frequency than visible light.
• It covers a range of techniques, mostly based on absorption
spectroscopy. As with all spectroscopic techniques, it can be
used to identify and study chemicals. For a given sample
which may be solid, liquid, or gaseous, the method or
technique of infrared spectroscopy uses an instrument called
an infrared spectrometer (or spectrophotometer) to produce
an infrared spectrum.

3. • A basic IR spectrum is essentially a graph of infrared
light absorbance (or transmittance) on the vertical axis vs.
frequency or wavelength on the horizontal axis.
• Typical units of frequency used in IR spectra are reciprocal
centimeter cm−1. Units of IR wavelength are commonly
given in micrometers μm, which are related to wave
numbers in a reciprocal way.
• A common laboratory instrument that uses this technique
is a Fourier transform infrared (FTIR) spectrometer.

4. APPLICATIONS
• The primary application of NIRS to the human body uses the
fact that the transmission and absorption of NIR light in human
body tissues contains information about hemoglobin
concentration changes. When a specific area of the brain is
activated, the localized blood volume in that area changes
quickly.
• Optical imaging can measure the location and activity of specific
regions of the brain by continuously monitoring blood
hemoglobin levels through the determination of optical
absorption coefficients.

5. •NIRS can be used for non-invasive
assessment of brain function through the
intact skull in human subjects by detecting
changes in blood hemoglobin
concentrations associated with neural
activity.

6. MEASUREMENTS
Typical measurement curve
FT-IR System diagram
FT-IR System device