2.Methods and materials
2.1.Target examination
In this study,
we collected operator's gaze for CT contrast 1-phase examination from chest to pelvis.69 cases were collected,
37 cases with CAN 4 and 32 cases without CAN 4.
2.2.
Target and equipment
Five medical radiological technicians (working experience 3 to 11 years,
average 8 years) who understood the operation contents and the flow of the inspection operated.
Combinations of CT scanner and injector are Aquilion ONE Vision (ver.
7.0: Canon Medical Systems,
Inc.,
Nasu,
Japan) and GX 7 (Nemoto Kyorindou,
Tokyo,
Japan) with CAN 4,
Aquilion ONE (ver.
6.0: Canon Medical Systems,
Inc.,
Nasu,
Japan) and GX 7 (Nemoto Kyorindou,
Tokyo,
Japan) without CAN 4.
The two CT systems have the same basic performance other than the CAN 4 connection function,
and the layout of the operation monitor,
the controller and the injector are almost the same.
In addition,
the chief scientist fully explained the significance and method of this research to the operator,
observation tests were conducted after obtaining consent from the operator.
2.3.
Gaze Analysis System
Pro Glasses 2 (Tobii Pro,
Tokyo,
Japan) was used as a gaze analyzer.
Numerical Analysis of the gaze data,
the accompanying software: Pro Lab (Tobii Pro,
Tokyo,
Japan) was used.
Pro Lab sets the region of interest (ROI) on the collected moving image,
it is possible to extract the time the line of sight stayed in that rang.
It is also possible to visualize the distribution in which the line of sight has stayed for a certain time or longer.
2.4.
Definition of gaze and feature quantity
Among the collected line-of-sight data,
the data used for the analysis is the range (total analysis range) in which the setting of the scan plan is completed from the time when the scan protocol is selected on the CT operation monitor (S-con monitor).
Fig.3 shows the layout of angle of view.
Seven ROIs were set on the angle of view.
The ROI is an S-con monitor,
a CT image processing / analysis monitor (D-con monitor),a radiological information system(RIS)monitors,an injector monitor,
a patient monitoring monitor,
a laboratory directional line of sight range,
and ranges that do not fall under these ranges.We defined the time of sight line data in the total analysis range as total gaze time and extracted the gaze time of each ROI.Then,
the relative gaze time ratio of each range to total gaze time was calculated.
2.5.
Statistical analysis of gaze collection data.
Excel statistics (ver.
2.15,
Bell Cave,
Tokyo,
Japan),
which is an add-in application of Microsoft Excel,
was used for statistical analysis.
A statistically significant difference test was performed using the Mann-Whitney U test.
The significance level was set at 5%.