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7 Light in Biology and Medicine
all within a flexible rod as thin as 1 mm in diameter.) This image is, in effect,
passively transported to the other end of the fiber tube, which has the individual
fibers arranged in the exact same pattern as the business end. The tube itself is
usually flexible, and therefore able to round gentle corners. The curvature can be
controlled by a thin metal wire with a curved end placed within the housing of
the endoscope, so the physician can steer the end. Additional manipulator wires
might be placed in the same housing. Note that no electronics or power is needed
at the business end.
• Information sharing: The availability of medical information makes it possible
to make medical diagnoses based on the full spectrum of study of diseases,
both rare and common, both past and newly emerging. Consultations can occur
across widely separated locations. Also, medical histories can be stored in ‘cloud
servers’ and retrieved from across the country when needed in an emergency.
• Distal examination and treatment: The transmission of high-resolution images
for patients some distance from a physician is possible.
• Laser-light therapy: Laser light can be redirected by passing the light through a
flexible optical fiber. In therapy, this allows laser light to be used for
– Removing Sun spots, birthmarks, tattoos, moles, warts, and unwanted hair;
– Surgical cutting and cauterizing;
– Killing cancer cells on the skin or in the body via endoscopy.
Depending on the application, intense laser light can be generated with a carbondioxide gas laser, argon gas laser, or Neodymium-doped yttrium aluminum
garnet (Y 3 Al 5 O 12 ) solid-state laser, with a frequency selected to give the greatest
light absorptivity in a given tissue.
7.29.7 Endoscopes
An endoscope is any device built to view interior regions of the body. Fiberoptic endoscopic imaging produces visual images using fiber conduits inserted into
cavities and organs. Note that glass fibers have a distinct advantage over other
endoscopic techniques because they are biologically inert, their light intensities and
frequencies are harmless to tissue, and they can produce highly localized images.
A capsule endoscope is an untethered enclosure holding a micro-CCD camera,
a radio transmitter, and a battery, together with optics, often including plastic light
pipes.
7.29.8 Image Intensifiers
When light levels are too low for effective viewing, an image intensifier may
be employed. The same kind of device may be used to make low-level infrared,
7 Light in Biology and Medicine
all within a flexible rod as thin as 1 mm in diameter.) This image is, in effect,
passively transported to the other end of the fiber tube, which has the individual
fibers arranged in the exact same pattern as the business end. The tube itself is
usually flexible, and therefore able to round gentle corners. The curvature can be
controlled by a thin metal wire with a curved end placed within the housing of
the endoscope, so the physician can steer the end. Additional manipulator wires
might be placed in the same housing. Note that no electronics or power is needed
at the business end.
• Information sharing: The availability of medical information makes it possible
to make medical diagnoses based on the full spectrum of study of diseases,
both rare and common, both past and newly emerging. Consultations can occur
across widely separated locations. Also, medical histories can be stored in ‘cloud
servers’ and retrieved from across the country when needed in an emergency.
• Distal examination and treatment: The transmission of high-resolution images
for patients some distance from a physician is possible.
• Laser-light therapy: Laser light can be redirected by passing the light through a
flexible optical fiber. In therapy, this allows laser light to be used for
– Removing Sun spots, birthmarks, tattoos, moles, warts, and unwanted hair;
– Surgical cutting and cauterizing;
– Killing cancer cells on the skin or in the body via endoscopy.
Depending on the application, intense laser light can be generated with a carbondioxide gas laser, argon gas laser, or Neodymium-doped yttrium aluminum
garnet (Y 3 Al 5 O 12 ) solid-state laser, with a frequency selected to give the greatest
light absorptivity in a given tissue.
7.29.7 Endoscopes
An endoscope is any device built to view interior regions of the body. Fiberoptic endoscopic imaging produces visual images using fiber conduits inserted into
cavities and organs. Note that glass fibers have a distinct advantage over other
endoscopic techniques because they are biologically inert, their light intensities and
frequencies are harmless to tissue, and they can produce highly localized images.
A capsule endoscope is an untethered enclosure holding a micro-CCD camera,
a radio transmitter, and a battery, together with optics, often including plastic light
pipes.
7.29.8 Image Intensifiers
When light levels are too low for effective viewing, an image intensifier may
be employed. The same kind of device may be used to make low-level infrared,