Computer-based assessment of the operator’s experience in obstetric ultrasound examination based on hand movements and applied forces

Obstetric ultrasound (US) is widely used in prenatal diagnosis to monitor the development and growth of the embryo or fetus and to detect congenital anomalies. The benefits offered by US in terms of timely diagnosis are extensive, but the quality of the examination is closely linked to the experience of the clinician [1]. Although proper training and assessment of acquired skills are considered of paramount importance in order to ensure a quality exam, there is no European standard establishing a training path with an objective assessment of operator’s capabilities. In fact, the experience is often evaluated merely on the basis of the number of clinical tests performed. However, an operator with daily US examination experience may not perform as well as a true expert due to inadequate training [2]. Many studies have been conducted to assess hand ges- ture with the aim of establishing metrics to discriminate between experts and novice, which can also be used to study a specific training and objectively evaluate the acquired skills [3][4]. Inspired by these works, hand movement was also studied for fetal US on phantom [5] or in a virtual reality simulated scenario [6]. This paper presents a novel study for the objective assessment of the operator’s experience in obstetric US examinations based on hand gestures and forces applied with the US probe on the abdomen, during real obstetric US examinations. A Data Recording System was designed to collect this information during US examinations performed by clinician with 3 different levels of experience (expert, intermediate and novice) on pregnant women at the 2nd trimester. The results presented here focus on assessing a set of metrics with the potential to provide an objective discrimination of the operator’s level of experience. With respect to previous works, the novelty relies on validating the state-of-the-art discriminating metrics in a real scenario. Furthermore, this work includes as a novelty the measurement of the forces applied on the abdomen, which seems to be very relevant in the clinical practice. This study was approved by the Regional Ethics Commit- tee of Liguria (Italy) with the protocol number 379/2022 - DB id 12369.