Improving the Quality of Fetal Heart Ultrasound Imaging With Multihead Enhanced Self-Attention and Contrastive Learning. - Yingying Zhang; Haogang Zhu; Jian Cheng 002; Jingyi Wang; Xiaoyan Gu; Jiancheng Han; Ye Zhang 025; Ying Zhao 026; Yihua He; Hongjia Zhang (IEEE J. Biomed. Health Informatics, 2023)