Opticalfibers used for minimally invasive surgery must be able to withstand
tight bends in order to have a light path with a very low bending-induced optical
power loss [ 21 ]. This characteristic allows the catheter to follow sinuous paths
through veins and arteries and around organs and bones as it moves toward its
destination. An important parameter is the NA of thefiber. This characteristic
influences how tightly the light is confined within the opticalfiber core and dictates
how much thefiber can be bent before optical bending loss becomes noticeable.
A number of high-NA single-mode and multimodefibers are commercially avail-
able, some of which can be bent to diameters as small as 3–4 mm with minimum
optical loss.
The overall opticalfiber size is another important characteristic [ 21 ]. Because the
fibers are inside of space-constrained catheters, the outerfiber diameter should be as
small as possible without sacrificing light transmission or mechanical durability.
Body region: knee,
shoulder, abdomenSurgical
instrumentOptical probeViewing
scopeMinor incisionsFig. 10.10Generic setup for
a minimally invasive surgery
procedure
Table 10.2 A selection of
minimally invasive surgical
procedures
Minimally invasive surgical procedure
Adrenalectomy to remove one or both adrenal glands
Colectomy to remove parts of a diseased colon
Colon and rectal surgery
Ear, nose and throat surgery
Endovascular surgery procedures (e.g., aneurysm repair)
Gallbladder surgery (cholecystectomy) to remove gallstones
Gastroenterologic and general surgery
Heart surgery, for example, to treat heart valve diseases
Hiatal hernia repair to relieve gastroesophageal reflux
Nephrectomy to remove a kidney or for donation
Neurosurgery to treatfluid buildup in the brain
Orthopedic surgery for a wide range of joint injuries and
disorders
Splenectomy to remove the spleen
Thoracic surgery: lung and esophageal tumors, cysts, or
diseases
Urologic surgery, such as prostate treatment306 10 Optical Imaging Procedures