Surgeons as Educators A Guide for Academic Development and Teaching Excellence

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Idle Time

While previous work has demonstrated that motion-based metrics provide reliable
and objective measures of surgical skill components [ 4 ], periods of nonmovement
(idle time) have been largely ignored. Recent surgical skills research has identified
a novel metric that focuses on periods during surgical task performance in which the
hands are not moving: idle time. Idle time is characterized as, “a lack of movement
of both hands and may represent periods of motor planning or decision making that
can be used to differentiate performance” [ 31 ]. Specifically, idle time may reflect
momentary pauses in task performance related to underlying cognitive, perceptual,
and psychomotor skill components. Preliminary analyses applying idle time as a
metric to existing data sets have revealed promising correlations between idle time
characteristics and independent variables such as level of expertise and task
difficulty.
Idle time as a metric of surgical assessment was initially defined through a
conference- based consensus effort of surgical trainers who were members of the
crucial surgical societies and boards responsible for the education, training, and
certification of surgeons [ 10 ]. Subsequently, this metric has been quantified using
tool/hand motion data and has been used to stratify surgical skills [ 5 , 11 – 15 ]. This
metric has been successfully used in analysis of performance on a suturing board [ 5 ]
dataset and assessment of performance in 5 of 10 needle insertion during subclavian
central line placement [ 15 ]. With these intriguing, preliminary results, further
exploration of “idle time” within surgeon speech is warranted as this potentially
may indicate cognitive overload, particularly in the case of novices.
More recently, Crochet et al. included a measure of idle time as one of several
metrics in an evaluation of the validity of a laparoscopic hysterectomy (LH) module
using the Lap Mentor VR simulator [ 32 ]. However, Crochet et al. refer to idle time

Novice

Expert

Left

Right

30

25

20

15

Grasp Force (N)

Grasp Force (N)

10

5

0

30

25

20

15

10

5

(^0020406080100)
050 100 150
Time (sec)
Time (sec)
200 250 300
a
b
Fig. 5.26 Novice (a) and
expert (b) grasp force over
time during FLS peg transfer
[ 27 ]
E.I. George et al.