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48 | Chapter 3
al part of the cochlea were calcu-
sition of the electrode contact was
the cumulative angle between those
rdinate system, based on Chen et al.
strated in Figure 1E.
evels, and Dynamic Range
in this study used a CIS strategy.
patients in the P-group, who were
h a HiRes strategy, the first 3 mos the
833 pps/contact (75 sec/phase) was used. At 6 mos,
26 patients of the 45 patients used a HiRes strategy
programmed with the BEPS software package,
whereas 37 patients were using the HiRes strategy
at 1 yr of follow-up (1400 pps/contact, 21 sec/
phase, ranging from 8 to maximally 16 active
contacts). In the Discussion section, we argue that
HiRes experience is probably not a contributing
factor to any differences in speech perception
scores between the P- and NP-groups. For all
electrode contacts, the thresholds (T-levels) and
blique multi-
ructions of
mplanted co-
and without
a positioner
ly, a medial
sition of the
array. Three-
nstructions
MSCT scans,
epths of the
seen on A) of
de arrays dis-
B. The dia-
he coordinate
etermine the
The angle
sertion angle
contact ex-
rees, and d
distance from
e modiolus.
, V
OL
. 26 N
O
. 6
581
Fig. 1.
Typical oblique multiplanar reconstructions of MSCT scans of implanted cochleas with (A) and without (B) the use of a
positioner show, respectively, a medial and a lateral position of the basal electrode array. Three-dimensional-reconstructions (C & D),
using the MSCT scans, show insertion depths of the apical tips (not seen on A) of the same electrode arrays displayed in A and B. The
diagram (E) shows the coordinate system used to determine the insertion angle. The angle ð illustrates the insertion angle of an electrode
contact expressed in degr es, and d shows the radial distance from this contact to the modiolus.