Test of simulator-based assessment of psychomotor skill in transthoracic echo

We developed a transthoracic echo simulator that measures technical skill in image acquisition in terms of the deviation angle between an acquired image and the anatomically correct plane for that view. We studied whether this metric reflects the clinical experience of providers.

Attendees at an echo course or at the annual meeting of the Swedish Heart Association were invited to test themselves on the simulator by scanning a mannequin and acquiring four views in 15 min: parasternal long axis (pLAX) in patient 1, apical four chamber and apical long axis (aLAX) in patient 2 and pLAX in patient 3. Their experience with echo was assessed from duration in years and procedure volume in the past year. Image acquisition error was assessed from the deviation angle.

Of 61 participants, there were 37 physicians and 24 non-physicians (22 sonographers and two nurses). Non-physicians had higher procedure volume than physicians (850 ± 599 versus 312 ± 393 tests year^-1 , P<0·001); both had similar duration of experience (9 ± 8 versus 12 ± 11 years, P = NS). The deviation angle for aLAX (55 ± 37 degrees) was higher than for any other view (P<0·00001). aLAX was the only view whose deviation angle correlated significantly with experience and only with procedure volume (r = -0·357, P = 0·008).

These results demonstrate that deviation angle, a novel metric of technical skill in image acquisition, reflects clinical experience. Simulator-based testing provides objective and quantitative assessment that may be of value in the certification of trainees and for maintenance of certification.