Skip to main page content
U.S. flag

An official website of the United States government

Dot gov

The .gov means it’s official.
Federal government websites often end in .gov or .mil. Before sharing sensitive information, make sure you’re on a federal government site.

Https

The site is secure.
The https:// ensures that you are connecting to the official website and that any information you provide is encrypted and transmitted securely.

Access keys NCBI Homepage MyNCBI Homepage Main Content Main Navigation
. 2017 Jul;4(3):035502.
doi: 10.1117/1.JMI.4.3.035502. Epub 2017 Aug 4.

Eye tracking in catheter-based cardiovascular interventions: early results

Peter Lanzer  1 , Mohammad Al-Naser  2   3 , Syed Saqib Bukhari  3 , Andreas Dengel  2   3 , Elizabeth A Krupinski  4
Affiliations

Eye tracking in catheter-based cardiovascular interventions: early results

Peter Lanzer et al. J Med Imaging (Bellingham). 2017 Jul.

Abstract

Visual x-ray image processing (XRIP) represents a fundamental component of catheter-based cardiovascular interventions (CBCVIs). To date, no data are available to define XRIP in this setting. To characterize CBCVI XRIP, we developed a computer-based method allowing continuous temporal-spatial analysis of data recorded by a head-mounted eye-tracking device. Quantitative analysis of gaze duration of an expert operator (EO) revealed that the average time in minutes spent viewing the images on the display screen was [Formula: see text] and [Formula: see text] of the total recorded time in coronary angiography (CA) and in CA followed by CBCVI, respectively. Qualitative analysis of gaze data of the EO revealed consistent focus on the center point of the screen. Only if suspicious findings were detected did gaze move toward the target. In contrast, a novice operator (NO) observing a subset of cases viewed coronary artery segments separately and sequentially. The developed methodology allows continuous registration and analysis of gaze data for analysis of XRIP strategies of EOs in live-cases scenarios and may assist in the transfer of experts' reading skills to novices.

Keywords: catheter-based cardiovascular interventions; eye tracking; perception; teaching.

PubMed Disclaimer

Figures

Fig. 1
Fig. 1
Operators with SMI ETG 2.7 eye trackers. Shown are the two operators participating in the study.
Fig. 2
Fig. 2
Video creation steps. The steps shown include both image acquisition and image processing.
Fig. 3
Fig. 3
(a) The view of the monitor in catheterization laboratory and (b) corresponding frame after the thresholding and morphological process.
Fig. 4
Fig. 4
Gaze mapping using homography transformation method. (a) A frame from the eye tracker with five markers detected (colored with red) and (b) the correspondent frame from the stationary camera video. In both images, the blue circle represents the gaze.
Fig. 5
Fig. 5
A scan path of the expert’s gaze in a single projection. Shown is a coronary angiogram in LAO cranial projection with operator’s gaze points centered on segment 7 stenosis (AHA/ACC nomenclature). The line shows fast movement between these fixations.
Fig. 6
Fig. 6
Bar diagram: summary of the on-screen time and off-screen time for all cases.
Fig. 7
Fig. 7
LAD intervention and gaze locations. Shown is a representative case gaze of an EO while performing PCI (case number 4). In cranial LAO projection, the LAD segment 7 lesion is projected approximately at the center of the screen. (a) The scan path, size of the circle corresponds to the dwell-time. (b) The heatmap of the scan path, the red color representing the most visited location on the x-ray image and the blue representing the least visited location.
Fig. 8
Fig. 8
The scan paths of the EO and NOs. Shown is a representative frame of cranial 4-deg LAO 15-deg CA projections (case number 14). While the EO focuses his gazes on the area of the missing LCx to discern traces of the vessel (a, arrows), the NO continues to focus his gazes on the LAD lesions already sufficiently documented in earlier cine-image series (b).
See this image and copyright information in PMC

References

    1. Cowen A. R., “Cardiovascular x-ray imaging: physics, equipment and techniques,” in Catheter-Based Cardiovascular Interventions; Knowledge-Based Approach, Lanzer P., Ed., pp. 203–260, Springer, Heidelberg, New York, Dordrecht: (2013).
    1. Preston K., Digital Processing of Biomedical Images, Springer, Heidelberg, New York, Dordrecht: (2013).
    1. Topol E., Nissen S. E., “Our preoccupation with coronary luminology. The dissociation between clinical and angiographic findings in ischemic heart disease,” Circulation 92, 2333–2342 (1995).CIRCAZ10.1161/01.CIR.92.8.2333 - DOI - PubMed
    1. Mintz G. S., et al. , “Limitations of angiography in the assessment of plaque distribution in coronary artery disease: a systematic study of target lesion eccentricity in 1446 lesions,” Circulation 93, 924–931 (1996).CIRCAZ10.1161/01.CIR.93.5.924 - DOI - PubMed
    1. Lanzer P., “Cognitive and decision-making skills in catheter-based cardiovascular interventions,” in Catheter-Based Cardiovascular Interventions; Knowledge-Based Approach, P. Lanzer, Ed., pp. 113–156, Springer, Heidelberg, New York, Dordrecht: (2013).