4 research outputs found
Motion Magnification in Robotic Sonography: Enabling Pulsation-Aware Artery Segmentation
Ultrasound (US) imaging is widely used for diagnosing and monitoring arterial
diseases, mainly due to the advantages of being non-invasive, radiation-free,
and real-time. In order to provide additional information to assist clinicians
in diagnosis, the tubular structures are often segmented from US images. To
improve the artery segmentation accuracy and stability during scans, this work
presents a novel pulsation-assisted segmentation neural network (PAS-NN) by
explicitly taking advantage of the cardiac-induced motions. Motion
magnification techniques are employed to amplify the subtle motion within the
frequency band of interest to extract the pulsation signals from sequential US
images. The extracted real-time pulsation information can help to locate the
arteries on cross-section US images; therefore, we explicitly integrated the
pulsation into the proposed PAS-NN as attention guidance. Notably, a robotic
arm is necessary to provide stable movement during US imaging since magnifying
the target motions from the US images captured along a scan path is not
manually feasible due to the hand tremor. To validate the proposed robotic US
system for imaging arteries, experiments are carried out on volunteers' carotid
and radial arteries. The results demonstrated that the PAS-NN could achieve
comparable results as state-of-the-art on carotid and can effectively improve
the segmentation performance for small vessels (radial artery).Comment: Accepted Paper IROS 202
Adaptive dynamic programming-based controller with admittance adaptation for robot–environment interaction
The problem of optimal tracking control for robot–environment interaction is studied in this article. The environment is regarded as a linear system and an admittance control with iterative linear quadratic regulator method is obtained to guarantee the compliant behaviour. Meanwhile, an adaptive dynamic programming-based controller is proposed. Under adaptive dynamic programming frame, the critic network is performed with radial basis function neural network to approximate the optimal cost, and the neural network weight updating law is incorporated with an additional stabilizing term to eliminate the requirement for the initial admissible control. The stability of the system is proved by Lyapunov theorem. The simulation results demonstrate the effectiveness of the proposed control scheme