Batteries
Categories:
INSTRUMENTARIUM
Sources:
A Manual Of Peroral Endoscopy And Laryngeal Surgery
The simplest, best, and safest source of current is a
double dry battery arranged in three groups of two cells each,
connected in series (Fig. 8). Each set should have two binding posts
and a rheostat. The binding posts should have double holes for two
additional cords, to be kept in reserve for use in case a cord becomes
defective.* The commercial current reduced through a rheostat should
never be used, because there
s always the possibility of grounding
the circuit through the patient; a highly dangerous accident when we
consider that the tube makes a long moist contact in tissues close to
the course of both the vagi and the heart. The endoscopist should
never depend upon a pocket battery as a source of illumination, for it
is almost certain to fail during the endoscopy. The wires connecting
the battery and endoscopic instrument are covered with rubber, so that
they may be cleansed and superficially sterilized with alcohol. They
may be totally immersed in alcohol for any length of time without
injury.
* When this is done care is necessary to avoid attempting to use
simultaneously the two cords from one pair of posts.
[FIG 8.--The author's endoscopic battery, heavily built for
reliability.
It contains 6 dry cells, series-connected in 3 groups of 2 cells each.
Each group has its own rheostat and pair of binding posts.]