SONOSIM SUMMARY: This study is the first to employ hand motion analysis (HMA) for the evaluation of Focused Assessment with Sonography for Trauma (FAST) skills and techniques. HMA, originally designed to analyze surgical skills, has participants affix magnets to their hands while they perform a procedure in a magnetic field, then specialized hardware and software collects data and documents the motions of a participant’s hands while performing a task. This objective and automated metric was used for this study by second- and third-year surgical residents (novice ultrasound users) and attending-level physicians (expert ultrasound users) in the Trauma Surgery and Emergency Medicine departments. HMA provided feedback on their performance, and allowed for comparison between novice and expert completion of FAST.
Data analysis indicated a moderate correlation between quality of ultrasound images (via Quality of Ultrasound Imaging and Competence – QUICk) and the number of hand movements and total path length; as quality improved, the number of movements and lengths of paths decreased.
Overall, the study was able to evaluate novice and expert performances of FAST and indicate that HMA data has the potential to provide metrics for the development of evidence-based credentialing standards for ultrasound. However, since this was the first application of HMA on the evaluation of FAST, particular aspects of their study remain inconclusive. Thus, future studies might investigate the relationship between ultrasound knowledge and technical proficiency in the completion of FAST scans.
Ziesmann MT, Park J, Unger B, et al. Validation of hand motion analysis as an objective assessment tool for the Focused Assessment with Sonography for Trauma examination. J Trauma Acute Care Surg. 2015 Oct;79(4):631-637. doi: 10.1097/TA.0000000000000813.
Point-of-care ultrasonography is a standard part of trauma assessments, but there are no objective tools to assess proficiency and ensure high-quality examinations. Hand motion analysis (HMA) has been validated as a measure of surgical skill but has not previously been applied to ultrasonography. HMA was assessed for construct validity in Focused Assessment with Sonography for Trauma (FAST) performance.
Two cohorts of 12 expert and 12 novice ultrasonographers performed a FAST examination on a healthy volunteer. Hand motions were recorded with the trakSTAR 3D electromagnetic motion-tracking device (Ascension Technology) and analyzed using our custom-designed Motion Analysis and Recording System (MARS) software. Data were recorded at 240 Hz. Outcomes included time of examination, number of movements, and path length.
Time of examination was not different between cohorts (expert, 345.9 seconds; novice, 475.7 seconds; p = 0.12). Total path length of travel was shorter, and the number of discreet movements was less in the expert cohort for the left-hand (18.52 m vs. 28.01 m, p = 0.03, and 109.5 vs. 193.9, p = 0.027, respectively) and the right-hand performance (14.25 m vs. 32.09 m, p < 0.01, and 153.5 vs. 258.5, p = 0.03, respectively) versus the novice cohort. Both total path length traveled and total number of discreet movements were associated with expertise level in logistic regression modeling with areas under the receiver operating characteristic curves of 0.8269 and 0.8205, respectively.
This is the first study in the medical literature showing HMA as an objective, valid measure of FAST imaging performance. These objective, automated metrics can function as an adjunct measure to assess FAST performance as well as follow progress of and provide feedback to learners to improve future performances.
To read the article, visit the Journal of Trauma and Acute Care Surgery website.
SonoSim Keywords: Ultrasound Hand-Motion Analysis, FAST Scan, Ultrasound Education