Page 213 - Academic Press Encyclopedia of Physical Science and Technology 3rd BioTechnology

P1: GTV/MBR P2: GSS Final Pages
Encyclopedia of Physical Science and Technology EN011L-523 August 10, 2001 11:17

Optical Fiber Techniques for Medical Applications 333

Robot–assistedendoscopicoperationshavealsobeenused
in gynecology, for the reconnection of fallopian tubes, and
in general surgery, for the laparoscopic removal of gall-
bladders (rigid).
Thin fiberscopes of diameter 2–3 mm have been in-
serted into blood vessels and used to visualize atheroscle-
rotic plaque within the coronary arteries, or to view the
inner parts of a fetus inside the womb. There has been
further progress in the development of ultrathin flexible
fiberscopes whose outer diameter is less than 1 mm. With
further development, such fiberoptic endoscopes will un-
doubtedly have a growing role in medicine.
Optical fibers can be used for diagnosis by inserting
them into the body and making physical and chemical FIGURE 13 A compound endoscope, which includes a fiber-
scope, a fiberoptic diagnostic system, a power fiber, and an ancil-
measurements through them. As direct sensors, the fibers
lary channel for irrigation or suction.
serve simply as light guides for transmitting laser light
into the body and back. Such direct sensors have been
used for measuring blood flow or for the early detection of liquids or drugs, for inserting pressurized gases, or for
of cancer. In a different mode of operation, tiny trans- sucking out debris. Similar endoscopes may be used in a
ducers (optodes) are attached to the fibers to form indirect multitude of applications. In the future, laser endoscope
sensors. With these optodes, physical measurements, such systems may be inexpensive and simple to use, and they
as blood pressure and temperature, or chemical measure- may even be used in small clinics.
ments, such as pH or pO 2 , can be carried out. Currently, No doubt fiberoptic techniques will replace more tradi-
blood samples are extracted from a patient and sent to the tional procedures in the coming years.
laboratory for chemical analysis. Fiberoptic techniques
may bring the laboratory closer to the patient. They may
also enable fast and repetitive chemical analysis to be per- SEE ALSO THE FOLLOWING ARTICLES
formed at the patient’s bedside or during an operation. The
use of optical fibers as sensors may simplify some of the
GLASS • IMAGE-GUIDED SURGERY • LASER-MATERIALS
diagnostic techniques and make them more reliable and
INTERACTIONS • LASERS,OPTICAL FIBER • LIGHT SOUR-
less costly.
CES • MICROOPTICS • OPTICAL FIBER COMMUNICATIONS
Recently there has also been progress in the devel-
• OPTICAL FIBERS,FABRICATION AND APPLICATIONS
opment of power fibers, which could transmit relatively
high laser power. Pure silica fibers have been used for the
transmission of Nd:YAG, GaAs, Ar-ion, and excimer laser
beams, and hollow or crystalline IR fibers for the deliv- BIBLIOGRAPHY
ery of CO 2 laser beam. Power fibers would undoubtedly
replace articulating arms in surgical laser systems. Such Carruth,J.A.S.,andMcKenzie,A.L.(1984).“MedicalLasers—Science
fibers, inside laser catheters, may be inserted into the body and Clinical Practice,” Adam Hilger, Bristol and Boston.
Katzir, A., ed. (2000). “Proceedings of the Biomedical Optics Symposia
and used to perform surgical operations, without necessi-
1984–2000.”
tating a large incision. The enormous advantages of using Katzir, A. (1997). “Lasers and Optical Fibers in Medicine (Physical
fiberoptic delivery systems for surgical operations inside Techniques in Biology and Medicine),” Academic Press, San Diego.
the body are obvious. Inserting the fibers inside the body is Katzir, A., ed. (1990). “Selected Papers on Optical Fibers in Medicine,”
a minimally invasive surgical procedure and the need for a Spie Milestone Series, Vol. MS 11, SPIE Press.
Niemz, M. H. (1996). “Laser–Tissue Interactions: Fundamentals and
major surgical operation may be eliminated in many cases.
Applications,” Springer Verlag.
Finally, one may consider a compound laser endoscope Puliafito, C. A., ed. (1996). “Laser Surgery and Medicine: Principles
(Fig. 13) that would contain several channels. One would and Practice,” John Wiley & Sons, New York.
be a fiberscope that enables the physician to see what Sivak, M. V. (1987). “Gastroenterologic Endoscopy,” Saunders,
he/she is doing. A second channel would be a fiberoptic Philadelphia.
Welch, A. J., and Van Gemert, J. C., ed. (1995). “Optical-Thermal Re-
sensor, for diagnostic purposes. A third channel would be
sponse of Laser-Irradiated Tissue,” Plenum, New York.
occupied by a power fiber for transmitting high-intensity Wolf, H. F., ed. (1984). “Handbook of Fiber Optics: Theory and Appli-
laser beams. Other channels would be used for injection cations,” Granada Publishing, Great Britain.