Joanna Cheung Pui Ying 2004193805
Flexible Bronchoscope
Christine Ho Ka Man 2004032647
Veron Leung Ka Pik 2004125573
Eric Li Chun Hei 2004156871
Medical Engineering, Faculty of Engineering,
The University of Hong Kong, HKSAR
Introduction to Flexible Bronchoscope
Procedure of Bronchoscopy
In the diagnosis of pulmonary diseases,
radiography is usually used to identify the
problems. However, sometimes there maybe
cases that chest x-ray or thoracic CT scan give
us unclear or wrong information. In order to
improve the accuracy of diagnosis, bronchoscopy
is applied to identify the diseases and flexible
bronchoscope is commonly used (see fig. 1).
1.
2.
3.
Biopsy port
with cap
Video
connection
Insertion
tube
Suction
port
Working
channel
Eyepiece
Light
transmitting
glass fiber
bundle
Viewing
glass
fiber
bundle
Control
knob
Light source
and camera
Fig. 1 Different parts of flexible bronchoscope
Anesthetize the patient.
Inject a small amount of saline.
Insert the bronchoscope through the nasal
cavity (see fig. 5).
Fig. 5 A flexible bronchoscope is used to view the airway of the patient[4]
[1]
There are two types of flexible bronchoscope:
fiberoptic bronchoscope and videobronchoscope.
The former one was firstly introduced in 1960’s
and the latter one was developed in 1990’s.
Working principle of bronchoscope
Application of flexible bronchoscope
For diagnostic purpose:
1.
To visualize and to observe the lesions of
the tracheobronchial tree
2.
To collect specimen for biopsy and culture
(e.g. by curettage or brushing) (see fig. 6)
Transmission of light in bronchoscope is based on
total internal reflection.
When light is incident
upon a medium of lesser
index of refraction (ni>nt),
the ray is bent away from
the normal such reflection
Fig. 2 Internal reflection[2]
is commonly called "internal reflection" (see fig. 2).
The exit angle will
then approach 90°
for some critical
incident angle θc,
and for incident
angles
greater
than the critical
angle there will
be total internal
reflection[2] (see
Fig. 3 Total internal reflection[2]
fig. 3).
In flexible bronchoscope, light is delivered
distally by total internal reflection. (see fig. 4)
For fiberoptic bronchoscope, images are
brought back to eyepiece using this principle,
too.
6a
Fig. 6a Brush used for collecting cells from tracheobronchial tree
Fig. 6b Collecting cells by brushing[5]
For therapeutic purpose:
1.
For videobronchoscope, images are brought
back by a small charge-coupled device (CCD)
sensor in the tip part. Better image resolution
can be obtained[3].
To
remove
foreign
body
in
the
tracheobronchial tree by forceps or baskets
(see fig. 7)
Fig. 7 Forceps for removing foreign body in the
bronchus[6]
2.
3.
Fig. 4 Transmission of light within a optical fibre[2]
6b
4.
To remove malignant tumors by laser
(e.g. laser photoresection)
To frozen surface skin lesions
(e.g. cryotherapy)
To destroy malignant tumors by radiation
(e.g. brachytherapy), by electricity (e.g.
electrocautery) or by chemicals (e.g.
photodynamic therapy)[3]
Analysis of flexible bronchoscope
Pros of flexible bronchoscope
 Small and maneuverable[7]
Cons of flexible bronchoscope
 Difficult to keep the lens visualizing[7]
 Glass fiber is prone to damage[9]
- Easier to insert to the distal airway
- More comfortable for the patient
(see fig. 8)
 No internal recording system is available
 Need anesthetic
 Distal biopsy is easy
 Provide a better diagnosis than CT scan and X
ray

 Many doctors can see the screen at the same
time

Fig.8 The turning degree of a bronchoscope[8]
- May lead to allergy
Nose bleeding
The surgeon cannot look at the patient and the
screen at the same time
Link to a large set of monitor
(see fig. 9)
 Maintenance is expensive
Fig.9 The large set of monitor[10]
Overall, flexible bronchoscope is useful despite the disadvantages it has. It helps the doctors in
visualizing the tracheobronchial tree and this allows a better diagnosis for pulmonary diseases. In
addition, operations can be carried out through flexible bronchoscopy.
Further development of flexible bronchoscope
1. Internal recording device
3. Autofluorescence bronchoscopy
• Allow the bronchoscopist to check the
previous findings and operations.
• Enhance patient management.
• Make use of the characteristics of
autofluorescence on tumor to observe
carcinoma or dysplasia using special light
source and equipment[12] (see fig. 11).
2. More portable system
• Install more portable components, say a
smaller LCD monitor and a smaller image
processing machine. (see fig. 10)
11a
Fig. 10 A smaller LCD monitor is more
portable and convenient.[11]
11b
Fig. 11a White light image. No abnormal area visible.
Fig. 11b Autofluorescence image. Suspicious lung tissue
with significantly reduced fluorescence.[13]
Acknowledgements
We thank Dr. Ian Gibson and Dr. Nelson Yung for giving the engineering information and Ms. Miranda
Legg for the audio assistance. Special thanks to Dr. David Chong for showing us the demonstration of
using flexible bronchoscope.
References
[1] Emidicine consumer health website. Available at: http://www.emedicinehealth.com/. Accessed February 28, 2005.
[2] HyperPhysics Concepts website. Available at: http://hyperphysics.phy-astr.gsu.edu/. Accessed March 1, 2005.
[3] Bolliger C.T., Mathur P.N., ed. Interventional Bronchoscopy. Basel: Karger; 2000.
[4] Your Medical Source website. Available at: http://yourmedicalsource.com/. Accessed February 28, 2005.
[5] Tobacco Facts website. Available at: http://www.tobacco-facts.info/. Accessed March 1, 2005.
[6] Untitled. Available at: http://www.hyunjoo.co.kr/. Accessed February 28, 2005.
[7] Beamis J. F. Jr., Mathur P.N.. Interventional Pulmonology. The United States of America, the McGraw-Hill Companies, Inc.;
1999.
[8] Karl Storz Veterinary Endoscopy America Inc. website. Available at: http://www.karlstorz.com/. Accessed March 1, 2005.
[9] Cladonia Resources website. Available at: http://www.cladonia.co.uk/. Accessed March 2, 2005.
[10] Beth Israel Deaconess Medical Center. Available at: http://bidmc.harvard.edu/. Accessed February 28, 2005.
[11] LUXMA Manufacturer of Mobile Accessories website. Available at: http://www.luxmt.com/. Accessed March 1, 2005.
[12] J.A. Nakhosteen, B. Khanavkar. Autofluorescence Bronchoscopy: The Laser Imaging Fluorescence Endoscope. In:
Bolliger C.T., Mathur P.N., ed. Interventional Bronchoscopy. Basel: Karger; 2000:236-242.
[13] American College of Chest Physicians website. Available at: http://www.chestnet.org/. Accessed February 28, 2005.