Page 20 - Clinical Manual of Small Animal Endosurgery

8 Clinical Manual of Small Animal Endosurgery

Fig. 1.8 Combined CCU, light source and monitor. This unit combines the
light source, CCU, monitor and image capture in a single package.
Photograph courtesy of Karl Storz GmbH & Co. KG, Tuttlingen, Germany.

components. Additionally, the light intensity from these units is lower
than is obtained with a separate light source. Although adequate for most
applications, the image may be poor in large cavities (e.g. in laparoscopy
of giant-breed dogs).
All the components of the video system are arranged in a video cart
(called a tower) to minimise space and set-up times. The cart should have
a large-wheeled base with lockable wheels in order for it to be moved
around the surgical suite easily. The cart usually also accommodates the
insufflator and the light source, and should have drawers for cables and
equipment not in use, and the capability to secure a carbon dioxide
canister for insufflation. Some carts are also equipped with a power strip
with electrical surge protection, which allows the various devices to be
plugged in and enables use of a single mains cable. The video monitor
is usually located on the top shelf of the cart, at the surgeon’s eye level;
to allow more versatility in its position, some surgeons prefer to have it
on a mechanical arm.

Light source

Since the development of fibre-optic cables in 1960, light has been trans-
mitted to the endoscope from a remote source. Two main different types
of high-intensity light source are in use: xenon and halogen. The intensity
of light from different technology types cannot be compared accurately
using wattage, as this measures how much power the bulb consumes,
rather how much light it produces. Light output is measured in lumens: