Abstract

Learning to perform ultrasound examinations requires extensive practice to master probe manipulation. Training is currently instructor-based or videobased. Research has also investigated various forms of automated visual guidance. Instructor guidance offers limited training time, whereas current automated approaches rely heavily on visual attention. Alternatively, leveraging touch through haptic guidance could support learning while limiting visual workload. Therefore, this paper proposes a wearable haptic ultrasound imaging guidance system wherein vibrotactile actuators spatially arranged to represent five key ultrasound probe movements (Slide, Sweep, Rotate, Tilt and Rock) deliver vibration sequences tangential to the intended motion. Experiments were conducted to assess user accuracy and confidence in identifying the location and direction of these vibrotactile cues as actuator parameters (vibration amplitude, inter-vibration delay and vibration duration) were varied. Overall, success rates above 90% were observed for the Slide, Sweep, and Rotate stimuli, indicating that they are easy to distinguish for most users. Success rates of 75% were obtained for Tilt and Rock, with parameter optimization leading to higher success rates. The users’ reported confidence levels were consistent with their performance. These results suggest that the proposed haptic cues are reliably distinguishable and could be used as guidance signals to assist novice sonographers.