Fiber Optic Essentials

9. Medical Applications 193

Detector-optics

Source

Signal

Detector

Coupling optics

Light guide

Reference detector

Object

Light

interacts

with object

Optics for illuminating and

detecting light from object

Figure 9.5 Configuration of a fiber optic sensor system.

microtube, tilted surface, moving mechanical part, etc.) [15]. Microbial

biosensors may also incorporate transducers which convert biochemical

signals into electrical or optical signals. Some sensors place immobilized

micro-organisms close to a thermistor which measures the metabolic heat

they produce; calorimetry may be applied to measure a large variety of

substances based on thermal reactions such as this. Some sensors work in

conjunction with microchips. For example, Oak Ridge National Labora-

tory has developed an infrared microspectrometer. It can be used for blood

chemistry analysis, gasoline octane analysis, environmental monitoring,

industrial process control, aircraft corrosion monitoring, and detection of

chemical warfare agents. It uses a light source to excite chemicals in

its environment, then channels the emitted light into an optical fiber for

external analysis. The measured wavelengths are fed into a microchip,

which identifies and determines the concentrations of chemicals in a sam-

ple. These miniaturized devices can be as accurate as standard laboratory

procedure, with a large number of additional applications [17]. Finally,

we should note that there are many other types of biosensors that use

microchips, or illuminate using fluorescence, which do not require optical

fibers.

References

[1] Hecht, J. (1999) City of Light: The story of Fiber Optics, Oxford University Press.

[2] Winawer, S.J., Fletcher, R.H., Miller, L., Godlee, F., Stolar, M.H., Mulrow, C.D.,

et al. (1997) “Colorectal Cancer Screening: Clinical Guidelines and Rationale”. Gas-

troenterology, 112: 594–642 (Published erratum in Gastroenterology 1997;112:1422).

[3] Bongsoo, L. (2004) Fiberoptic Tutorial, Nanoptics Inc. May 6.

194 Fiber Optic Essentials

[4] Dennis C. Leiner (2002) Miniature Optics in the Hospital Operating Room, Light-

house Imaging Corporation.

[5] Johnson, B.A. (1999) “Flexible Sigmoidoscopy: Screening for Colorectal Cancer”,

American Family Physician, January 15. American Academy of Family Physicians.

p. 313.

[6] Reinhard, J. (2000) Fundamentals of Fiber Optics (for Illumination), Volpi AG.

[7] Jerome D. Waye (2001) The Evolution of Gastrointestinal Endoscopy at The Mount

Sinai Hospital, The Mount Sinai Journal of Medicine, 68 (2), March.

[8] Nathan, R., Annetine C. Gelijns, and Holly, D. (1995) Sources of Medical Technol-

ogy: Universities and Industry, National Academy Press.

[9] Basil I. Hirschowitz (2000) “Endoscopy – 40 Years since Fiber Optics”, Digestive

Surgery, 17:115–117.

[10] Gregory, A., Michael, K., Harvey, W., Thomas Cox, J., Elliott, L., Jame McCaughan

Jr., Brian, S., Raymond, L., Overview of Clinical Laser Applications, The Laser

Training Institute, www.lasertraining.org/Clinical Laser Applications.PDF.

[11] For lasers in eye surgery, see http://www.lasersite.com/lasik/index.htm.

[12] For lasers in dental surgery, see http://www.dentalfind.com/laser_gum_surgery/.

[13] Website for Clark Equine Clinic, http://www.clarkequine.com/surgery.htm.

[14] Alison, P. (2004) “KTP laser shows high efficacy in men with retention”, Urology

Times, January 1.

[15] “Breakthrough Treatment for Enlarged Prostate”, Surgical Center of Central Florida,

website feature article, http://www.thesurgicalcenter.net/Feature.html.

[16] McLeish, T. (2000) “Devices Detect Salmonella, E. Coli, Other Bacteria”, News-

wise, June 26. University of Rhode Island, Kingston R. I.

[17] Bruce, J.K. (1996) “Biosensors and Other Medical and Environmental Probes”,

ORNL Rev., 29 (3), Oak Ridge National Laboratory. http://www.ornl.gov/info/ornl-

review/rev29_3/text/biosens.htm; also, see http://www.microfab.com/technology/

biomedical/biomed.html.