Skills Classification in Cardiac Ultrasound with Temporal Convolution and Domain Knowledge Using a Low-Cost Probe Tracker

[State of the art: Simulation in US]

Technical simulation of diagnostic and therapeutic procedures is of growing relevance for student education and advanced medical training and has already been introduced in the field of ultrasound. This review gives a broad overview on different levels of simulation for ultrasound diagnostics and highlights the technical background of the methodology. A critical review of the literature reveals recommendations for implementing simulation techniques in medical studies and professional ultrasound training. An analysis of strengths and weaknesses shows the advantages of simulation especially in the context of individual learning situations and COVID-19-related restrictions for personal interaction. However, simulation techniques cannot replace the experiences of complex clinical examinations with direct interaction to real patients. Therefore, future applications may focus on repetition and assessment of achieved competencies by using standardized feedback mechanisms in order to preserve the limited resources for practical medical training.

Development and preliminary testing of a prior knowledge-based visual navigation system for cardiac ultrasound scanning

Purpose

Ultrasound is widely used to diagnose disease and guide surgery because it is versatile, inexpensive and radiation-free. However, image acquisition is dependent on the operation of a professional sonographer, which is a difficult skill to learn for a wider range of non-sonographers.

Methods

We propose a prior knowledge-based visual navigation method to obtain three important standard ultrasound views of the heart, based on the sonographer's skill learning and augmented reality prompts. The key information about the probe movement was captured using vision-based tracking and normalisation methods on 14 volunteers, based on a professional sonographer's practice. An augmented reality-based navigation method was then proposed to guide operators with no ultrasound experience to find standard views of the heart in a second set of three volunteers.

Results

Through quantitative analysis and qualitative scoring, the results showed that the proposed method can effectively guide non-sonographers to obtain standard views with diagnostic value.

Conclusion

It is believed that the method proposed in this paper has clear application value in primary care, and expansion of the data will allow the accuracy of the navigation to be further improved.

Change in economy of ultrasound probe motion among general medicine trainees

OBJECTIVES

To observe change in economy of 9 ultrasound probe movement metrics among internal medicine trainees during a 5-day training course in cardiac point of care ultrasound (POCUS).

METHODS

We used a novel probe tracking device to record nine features of ultrasound probe movement, while trainees and experts optimized ultrasound clips on the same volunteer patients. These features included translational movements, gyroscopic movements (titling, rocking, and rotation), smoothness, total path length, and scanning time. We determined the adjusted difference between each trainee's movements and the mean value of the experts' movements for each patient. We then used a mixed effects model to trend average the adjusted differences between trainees and experts throughout the 5 days of the course.

RESULTS

Fifteen trainees were enrolled. Three echocardiographer technicians and the course director served as experts. Across 16 unique patients, 294 ultrasound clips were acquired. For all 9 movements, the adjusted difference between trainees and experts narrowed day-to-day (p value < 0.05), suggesting ongoing improvement during training. By the last day of the course, there were no statistically significant differences between trainees and experts in translational movement, gyroscopic movement, smoothness, or total path length; yet on average trainees took 28 s (95% CI [14.7-40.3] seconds) more to acquire a clip.

CONCLUSIONS

We detected improved ultrasound probe motion economy among internal medicine trainees during a 5-day training course in cardiac POCUS using an inexpensive probe tracking device. Objectively quantifying probe motion economy may help assess a trainee's level of proficiency in this skill and individualize their POCUS training.