学术交流英语PPT讲稿
深圳人事考试网-昆山一中
30s
Good afternoon, everyone. The
title of the paper is Visible Microspectroscopy
for
Diagnosis of Gastric Precancer. Its author
is Liu Yong from Department of Physics, Zhao
qing University. It’s presented by Li Mengfan
from CAS, Hefei Institutes of Physical
Science. You can know more about cancer and
the new method to diagnose gastric
precancer
after reading this paper.
58s
Cancer is very common among human beings. It
is mostly related to the habit of the
patients, the job, the environment, the
drinking water and the soil matters, too. If a
person
is affected by certain bacteria, he may
also get gastric cancer. Bad habits like smoking,
drinking, mental tension, eating improperly
and living irregularly increase the possibility of
having cancer. Before specific treatment, the
doctor should make sure whether the patient
has cancer and where the focus is. The method
used to diagnose cancer and locate the
cancerous area is very important.
42s
Before we design a
method to diagnose cancer, we should know more
about cancer like
where it starts and what it
causes.
Firstly, about 90% of the human’s
cancer start from the epithelial layer of skin,
internal
organs and tubular organs in the
body. Secondly ,
cancer usually accompanied by
the
changes of organization structure in the
cell level.
So,
the changes which appear
in the
structure of organization and chemical
composition provides important evidence for
diagnosis
of precancer.
42s
Normal method to diagnose gastric
precancer is
Reflectance spectroscopy. It’s
very
prospective in early diagnosis of cancer
and is commonly used these years.
One of
the most common technology is
diffuse
reflectance visible spectroscopy, it can
acquire the approximate information of the
target tissue. This method is low cost, fast and
non-invasive, it provides important means for
diagnosis of malignant damage of
organization
of human organs. However, there are also some
disadvantages of this
method which need to be
improved.
55s
This is the
system of diffuse reflectance spectroscopy, the
light beam emitted from the tungsten
halogen
lamp is guided into the integral ball by the
source fiber. The light come out of the integral
ball irradiate the standard board, the
reflected light of the standard board is treated
as the
background. Then take target tissue
substitute for the standard board, and scan the
reflected light
of it. The reflected light
spectra of the gastric tissue mucosal layer and
the submucosa layer is
guided into the
spectrometer by the collector fiber. The
spectrometer and the computer is
connected by
USB, spectrum can be processed using computer.
36s
First of all, only
average visible spectrum of the target tissue
can be acquired, it means that the
docters
cannot make out the location of the cancerous
tissue precisely.
What’s more, the device
is easy to be affected by changes of optical path
length induced by
different set-up of prober
and the variation of hemoglobin concentration due
to the
pressure between prober and tissue.
50s
To avoid the problems of the
commonly used techniques, diffuse reflectance
visible
spectroscopy, scientists do a lot of
researches to find out a new way to diagnose
precancer.
The new method is Visible
Microspectroscopy. The visible microspectroscopic
measurement device is accomplished on the
basis of fiber confocal microscope, its 3-d
imaging principle devote to the optical
tomography ability of the system.
The visible
microspectrum of cancerous and normal tissue can
be analysed and
contrasted, so it’s more
useful than the normal method.
45s
This is the structure of the visible
microspectroscopy device .
The fiber coupler
can separate the lighting beams from the signal
beam. The two lens can
focus the light on the
tissue ,
The 3-D electronic controlled
platform move along the direction of optic axis,
so that the
device can acquire the visible
microspectroscopy signal of the sample in
different depth,
precisely locate the boundary
of the cancerous signal measured from different
position can be stored in the computer after
analysed by the spectrometer.
31s
This is the spectrum chart of the normal
tissue and cancerous tissue, they are analyzed by
the spectrometer before being transmitted to
the computer. The upper chart is the visible
spectrum of normal tissue, it is regular.
Contrasting to this, in the nether chart, the
spectrum of the cancerous area shows that the
strength of reflected light grows as the
wave
length grows.
49s
In
comparison with the normal method, there are a lot
of advantages of the new
method.
Firstly,
the structure of visible microspectroscopy device
is very simple. The main parts
consist of
source, fiber coupler, 3-D electronic controlled
platform, spectrometer and the
computer.
Secondly, the 3-D space microspectrum can be
acquired , which can help the doctors
efficiently make out whether the gastric
tissue is cancerous.
What’s more, the optical
tomography ability enabled the device to precisely
locate the
edge of the cancerous area.
32s
i.
ii.
iii.
In
conclusion, the main goal of this research is to
find a new way to diagnose the
gastric
precancer.
The spectrum of the normal and
cancerous gastric tissues which can be
measured by visible microspectroscopy in cell
level is the central idea .
This new method
can obtain the cell level information, and is not
affected by
changes of optical path
length and hemoglobin concentration.
50s
i. The device is very simple, so it can
have a small size, which can reduce the
sufferings of can efficiently make out
whether the tissue is canceration.
ii.
Besides, the 3-D space microspectrum and optical
tomography ability can make
the device
accurately distinguish the cancerous tumor area
from the normal tissue in cell
level, thus the
boundary of the cancerous tissue can be
ascertained accurately.
iii. The result of
the research shows that this device may be used to
non-invasively
diagnosis of early gastric
cancer.
20s
This device is only
researched in the lab, there are still a lot of
works to do to make this device
applied into
practice. So, special design of this device should
be made which can be applied
to the medical
diagnosis.