03-10-2012, 03:58 PM
Design and Develo
pment of a Low Cost Video Bronchoscope
[attachment=35160]
Abstract
The aim of this project was to build a complete video bronchoscope system
without the use of fibre optic cables, thereby trying to make it both low-cost and
portable in nature. During the course of the project, the distal and the frontal
electronic modules were successfully built and tested. The primary idea of the
project is to build the electronics of a bronchoscope conforming to constraints
of size as required by commercial bronchoscopes while reducing the cost of the
unit device. The device also is needed to provide a real time clear video of the
insides of the human airways under conditions of very low illumination. The
system should also have the provision to record and store videos of the invasive
procedure for future diagnosis. For these purposes a very small video sensor
(about 2 mm in diameter) was accompanied by a small (1.5 mm) LED that
formed the distal tip of the bronchoscope, and the output video was compressed
to an mpeg4 format for efficient categorization. The bronchoscope was able to
provide a clear image of objects placed within a close range of the
bronchoscope. Image processing algorithms such as periodic noise reduction
were implemented to improve the quality of the video obtained from the distal
end of the bronchoscope.
Introduction:
A bronchoscope is a non-invasive device used to provide a clear image of
the internal respiratory system. The bronchoscope can be used for both
diagnostic purposes such as detection of pulmonary tumors and other diseases
or for surgical purposes like administration of general anesthesia and for
endoscopic surgeries. Bronchoscopes are of primarily two types viz. The fiberoptic
bronchoscope and the video bronchoscope. The former uses a fiber-optic
cable while the latter uses an electronic image sensor like CCD or CMOS
camera. The major disadvantage with the fiber-optic bronchoscope is that the
fiber-optic cable bundle used is extremely fragile and its cost is also high. Video
bronchoscopes, on the other hand provide a less-expensive but equally efficient
solution for imaging the airways. So, it was decided to build a low-cost video
bronchoscope which efficient and portable. A general schematic of the
conventional fibre optic bronchoscope is shown in Fig 1.
Motivation:
In the year 2009, Mr. Shankar, a Professor from the Physics Department of
College of Engineering, Guindy had a chance to meet a professor from the
department of anaesthesia from the Stanley Medical College, Chennai. The
doctor from Stanley had a brief discussion about the existing bronchoscopes and
their demerits. The doctor has told that there is a need for a device that is long
standing. So, Mr. Shankar brought this to the notice of Dr. P.V. Ramakrishna,
Professor Dept of Electronics and Communication Engineering at the College of
Engineering, Guindy. So, myself ( Hari Prasad) and Aravind Krishnan, who
were working in the Integrated Systems Laboratory were asked to make a brief
presentation at the Stanley Medical College before the team of doctors. We
were shown demonstrations on how does an actual bronchoscope used. The
doctor there told us that there were 5 bronchoscopes, of which only two were
working properly and had to be used for the entire hospital. The other three
bronchoscopes were useless because of the reason that the fibre inside was
broken. So the doctors told it would be good if the fibre were eliminated. Also
the doctors found it difficult with the existing system having only two degrees
of freedom. If the doctors wanted to navigate in the other two directions he must
turn it 90 degree. So, the doctors suggested a system with four degrees of
freedom rather than two. Also, they said that the Phlegm accumulates at the tip
and hampers the doctor’s vision so they said there is a need for a Wiper
arrangement. We were also shown some videos on the way doctors actually
navigate the device.
Design Concept:
The basic design concept of the system
includes the camera chip or the image sensor and an LED or light source only at
the distal tip with a diameter of 3mm. So that the device can penetrate upto the
second level of bronchi. The essential idea of our design is to minimize the
electronics at the distal tip. Thus the system consists of the CMOS Image sensor
OV6920 and White SMT LED for illumination. The video captured are sent via
very fine coax after preliminary processing. The output image appears to have
periodic noise along the x-axis and green colouration. Thus the video obtained
is made noise free with the help of DM355 processor programmed with iPIPE.
The final image obtained is viewed in a hand held LCD.
Designs Considered:
When the problem was defined, we considered some designs that were
similar to the existing ones. We tried to bring down the cost by actually not
replacing the fibres. But after meeting a team of doctors at the Department of
Anaesthesia, Stanley Medical College, Chennai, we found that fibres were
posing serious maintenance problems such as breakage. So , we decided to
replace it with electrical cables. The design consists of the tip with a CMOS
Image sensor for capturing real time video , an LED to illuminate the inside of
the trachea. Essentially we thought of placing the electronics at the tip, but later
we realised that it would increase the complexity of the system. So, we decided
to keep the electronics externally. So, this is indicated by the diagram shown
below.
Future Trends:
The present system can be used to for clinical purposes after it meets the
standards of the medical engineering. The presently built system is a far cry
from the device required. It is but a starting point in realization of the vision that
any small time pulmonary clinic must possess a bronchoscope. The casing of
the bronchoscope is to be made of a biocompatible material that does not cause
any harm to the subject. It must be easily sterilizable. Some additional features
can be added such as wipers for actually removing the red effect caused due to
the phlegm. Also the device can be enabled with four degrees of freedom unlike
the conventional device with two degrees of freedom. The CMOS Image sensor
can also be re fabricated into a flexible cylindrical one.
pment of a Low Cost Video Bronchoscope
[attachment=35160]
Abstract
The aim of this project was to build a complete video bronchoscope system
without the use of fibre optic cables, thereby trying to make it both low-cost and
portable in nature. During the course of the project, the distal and the frontal
electronic modules were successfully built and tested. The primary idea of the
project is to build the electronics of a bronchoscope conforming to constraints
of size as required by commercial bronchoscopes while reducing the cost of the
unit device. The device also is needed to provide a real time clear video of the
insides of the human airways under conditions of very low illumination. The
system should also have the provision to record and store videos of the invasive
procedure for future diagnosis. For these purposes a very small video sensor
(about 2 mm in diameter) was accompanied by a small (1.5 mm) LED that
formed the distal tip of the bronchoscope, and the output video was compressed
to an mpeg4 format for efficient categorization. The bronchoscope was able to
provide a clear image of objects placed within a close range of the
bronchoscope. Image processing algorithms such as periodic noise reduction
were implemented to improve the quality of the video obtained from the distal
end of the bronchoscope.
Introduction:
A bronchoscope is a non-invasive device used to provide a clear image of
the internal respiratory system. The bronchoscope can be used for both
diagnostic purposes such as detection of pulmonary tumors and other diseases
or for surgical purposes like administration of general anesthesia and for
endoscopic surgeries. Bronchoscopes are of primarily two types viz. The fiberoptic
bronchoscope and the video bronchoscope. The former uses a fiber-optic
cable while the latter uses an electronic image sensor like CCD or CMOS
camera. The major disadvantage with the fiber-optic bronchoscope is that the
fiber-optic cable bundle used is extremely fragile and its cost is also high. Video
bronchoscopes, on the other hand provide a less-expensive but equally efficient
solution for imaging the airways. So, it was decided to build a low-cost video
bronchoscope which efficient and portable. A general schematic of the
conventional fibre optic bronchoscope is shown in Fig 1.
Motivation:
In the year 2009, Mr. Shankar, a Professor from the Physics Department of
College of Engineering, Guindy had a chance to meet a professor from the
department of anaesthesia from the Stanley Medical College, Chennai. The
doctor from Stanley had a brief discussion about the existing bronchoscopes and
their demerits. The doctor has told that there is a need for a device that is long
standing. So, Mr. Shankar brought this to the notice of Dr. P.V. Ramakrishna,
Professor Dept of Electronics and Communication Engineering at the College of
Engineering, Guindy. So, myself ( Hari Prasad) and Aravind Krishnan, who
were working in the Integrated Systems Laboratory were asked to make a brief
presentation at the Stanley Medical College before the team of doctors. We
were shown demonstrations on how does an actual bronchoscope used. The
doctor there told us that there were 5 bronchoscopes, of which only two were
working properly and had to be used for the entire hospital. The other three
bronchoscopes were useless because of the reason that the fibre inside was
broken. So the doctors told it would be good if the fibre were eliminated. Also
the doctors found it difficult with the existing system having only two degrees
of freedom. If the doctors wanted to navigate in the other two directions he must
turn it 90 degree. So, the doctors suggested a system with four degrees of
freedom rather than two. Also, they said that the Phlegm accumulates at the tip
and hampers the doctor’s vision so they said there is a need for a Wiper
arrangement. We were also shown some videos on the way doctors actually
navigate the device.
Design Concept:
The basic design concept of the system
includes the camera chip or the image sensor and an LED or light source only at
the distal tip with a diameter of 3mm. So that the device can penetrate upto the
second level of bronchi. The essential idea of our design is to minimize the
electronics at the distal tip. Thus the system consists of the CMOS Image sensor
OV6920 and White SMT LED for illumination. The video captured are sent via
very fine coax after preliminary processing. The output image appears to have
periodic noise along the x-axis and green colouration. Thus the video obtained
is made noise free with the help of DM355 processor programmed with iPIPE.
The final image obtained is viewed in a hand held LCD.
Designs Considered:
When the problem was defined, we considered some designs that were
similar to the existing ones. We tried to bring down the cost by actually not
replacing the fibres. But after meeting a team of doctors at the Department of
Anaesthesia, Stanley Medical College, Chennai, we found that fibres were
posing serious maintenance problems such as breakage. So , we decided to
replace it with electrical cables. The design consists of the tip with a CMOS
Image sensor for capturing real time video , an LED to illuminate the inside of
the trachea. Essentially we thought of placing the electronics at the tip, but later
we realised that it would increase the complexity of the system. So, we decided
to keep the electronics externally. So, this is indicated by the diagram shown
below.
Future Trends:
The present system can be used to for clinical purposes after it meets the
standards of the medical engineering. The presently built system is a far cry
from the device required. It is but a starting point in realization of the vision that
any small time pulmonary clinic must possess a bronchoscope. The casing of
the bronchoscope is to be made of a biocompatible material that does not cause
any harm to the subject. It must be easily sterilizable. Some additional features
can be added such as wipers for actually removing the red effect caused due to
the phlegm. Also the device can be enabled with four degrees of freedom unlike
the conventional device with two degrees of freedom. The CMOS Image sensor
can also be re fabricated into a flexible cylindrical one.