2.3. Outcome measures
Intra- and post-operative complications were recorded. The 3D image
quality was assessed in terms of the spatial orientation and visibility
of the middle ear anatomy. More specifically, we looked at three
parameters: stereoscopy, lighting, and focusing during posterior
tympanotomy and electrode insertion. Surgeon comfort was assessed in
terms of physical discomfort and eye strain. Staff comfort was assessed
in terms of equipment ergonomics and eye strain. All parameters were
rated on a 5-point Likert scale, where 5 meant “very good”, 4 –
“good”, 3 – “neutral”, 2 – “bad”, and 1 – “very bad”. The
assessment was performed by the chief surgeon immediately after each
surgery. The mode of the answers by the scrub nurse, circulating nurse,
and three residents was used as a measure of staff comfort. The
percentage of surgeries falling under each Likert category was
calculated.