Simulation for competency assessment in vascular and cardiac ultrasound

Abstract

Healthcare providers who use peripheral vascular and cardiac ultrasound require specialized training to develop the technical and interpretive skills necessary to perform accurate diagnostic tests. Assessment of competence is a critical component of training that documents a learner's progress and is a requirement for competency-based medical education (CBME) as well as specialty certification or credentialing. The use of simulation for CBME in diagnostic ultrasound is particularly appealing since it incorporates both the psychomotor and cognitive domains while eliminating dependency on the availability of live patients with a range of pathology. However, successful application of simulation in this setting requires realistic, full-featured simulators and appropriate standardized metrics for competency testing. The principal diagnostic parameter in peripheral vascular ultrasound is measurement of peak systolic velocity (PSV) on Doppler spectral waveforms, and simulation of Doppler flow detection presents unique challenges. The computer-based duplex ultrasound simulator developed at the University of Washington uses computational fluid dynamics modeling and presents real-time color-flow Doppler images and Doppler spectral waveforms along with the corresponding B-mode images. This simulator provides a realistic scanning experience that includes measuring PSV in various arterial segments and applying actual diagnostic criteria. Simulators for echocardiography have been available since the 1990s and are currently more advanced than those for peripheral vascular ultrasound. Echocardiography simulators are now offered for both transesophageal echo and transthoracic echo. These computer-based simulators have 3D graphic displays that provide feedback to the learner and metrics for assessment of technical skill that are based on transducer tracking data. Such metrics provide a motion-based or kinematic analysis of skill in performing cardiac ultrasound. The use of simulation in peripheral vascular and cardiac ultrasound can provide a standardized and readily available method for training and competency assessment.

Keywords: Doppler ultrasound; duplex scanning; echocardiography; medical education; simulation.

Figure 1.

Computer display of the interface for the duplex ultrasound simulator developed at the University of Washington showing an examination of a dialysis access fistula in the left arm. (A) Left panel: duplex display showing the B-mode image with color-flow Doppler on top and Doppler spectral waveforms on the bottom. The Doppler spectral waveform has been acquired at a beam angle of 60 degrees and the cursor has been placed on the waveform for measurement of peak systolic velocity. Middle panel: controls for the ultrasound display mode and Doppler settings (including Doppler beam angle, sample volume depth, sample volume size, and PRF or scale). Right panel: the 3D display shows the locations of the transducer (‘star’ and cone) and B-mode image (translucent rectangle) on the vessel in the mannequin; this display can be zoomed. (B) Report page. The learner performs a scan and measures velocities that are entered on this table. When the learner ‘submits’ his/her answers, the cells are colored to indicate whether each response is correct (green), close (yellow), or definitely wrong (red). As the mouse is hovered over each cell, the correct value is displayed for feedback. In practice mode, the learner can ‘unsubmit’ the answers and try again. (Note: figure is in color online.)

Figure 2.

User interface for the echocardiography simulator developed at the University of Washington. (A) The image ‘acquired’ by the trainee appears in a dual display (upper inset) and appears side by side and beating in synchrony with the anatomically correct view. The angular deviation and other metrics are displayed for additional feedback (arrow indicates the enlarged metrics in the inset). This image was very close to correct. (B) Acquisition of a poorly positioned image in which the aortic valve is obscured and the left ventricle is foreshortened; note the difference in visualization of anatomy and the magnitude of the angular deviation.

Figure 3.

Kinematic metrics of skill in transesophageal echo (TEE) in the HeartWorks simulator. Probe tip trajectory and depth of the transesophageal echo probe are smoother and more fluid for the expert than for the novice. Reproduced from ref. 61 (© Springer International Publishing Switzerland 2016) with permission of Springer.