Weakly guided attention model with hierarchical interaction for brain CT report generation.

Brain Computed Tomography (CT) report generation, which aims to assist radiologists in diagnosing cerebrovascular diseases efficiently, is challenging in feature representation for dozens of images and language descriptions with several sentences. Existing report generation methods have achieved significant achievement based on the encoder-decoder framework and attention mechanism. However, current research has limitations in solving the many-to-many alignment between the multi-images of Brain CT imaging and the multi-sentences of Brain CT report, and fails to attend to critical images and lesion areas, resulting in inaccurate descriptions. In this paper, we propose a novel Weakly Guided Attention Model with Hierarchical Interaction, named WGAM-HI, to improve Brain CT report generation. Specifically, WGAM-HI conducts many-to-many matching for multiple visual images and semantic sentences via a hierarchical interaction framework with a two-layer attention model and a two-layer report generator. In addition, two weakly guided mechanisms are proposed to facilitate the attention model to focus more on important images and lesion areas under the guidance of pathological events and Gradient-weighted Class Activation Mapping (Grad-CAM) respectively. The pathological event acts as a bridge between the essential serial images and the corresponding sentence, and the Grad-CAM bridges the lesion areas and pathology words. Therefore, under the hierarchical interaction with the weakly guided attention model, the report generator generates more accurate words and sentences. Experiments on the Brain CT dataset demonstrate the effectiveness of WGAM-HI in attending to important images and lesion areas gradually, and generating more accurate reports.

Directional droplet bouncing on a moving superhydrophobic surface.

Droplets directionally bouncing off moving superhydrophobic solid surfaces are universal in nature and are crucial in many biological, sustainable, environmental, and engineering applications. However, their underlying physics and regulation strategies remain relatively unknown. This paper demonstrates that the maximum directional acceleration of a post-impact droplet mainly occurs in the spreading stage and that the orientational velocity of the droplet mainly originates in the early impingement process. Furthermore, it clarifies the underlying physics based on momentum transfer process imposed by the boundary layer of impacts and proposes a strategy for regulating the directional droplet velocity using a comprehensive formula. Finally, it shows that directional bouncing reduces the flight momentum of a small flying device by 10%-22%, and the experimental values agree closely with the predicted values. This study reveals the droplet bounce orientation mechanism imposed by moving substrates, provides manipulation methods, and makes positive and meaningful discussions of practical applications.

[Application study of gait analysis on different syndrome types based on musculature zones of the knee osteoarthritis].

OBJECTIVE: To study the gait characteristics of different syndrome types based on musculature zones of the knee osteoarthritis (KOA) and to discuss the application of modern biomechanical technology in objective study on syndrome differentiation which is based on musculature zones. METHODS: Thirty knees out of 19 patients suffering from KOA with the different musculature zone syndrome types were measured the step angle, the heel impulse, the internal and external rotation figures and the percentage of the maximum vertical ground reaction time in the total time of the supporting period by using the Plantar Pressure Measurement System. RESULTS: In the knees with abnormal musculature zones, the figures of step angle and the heel impulse of Foot Shaoyang Meridian and three foot yin meridians were significantly increased than normal (all P<0.05), while those figures of Foot Yangming Meridian were normal; in the knees of Foot Yangming Meridian with abnormal musculature zones, the external rotation mean figure in the midstance was significantly increased than normal (P<0.05); in the knees of Foot Shaoyang Meridian with abnormal musculature zones, the internal rotation mean figure in the propulsion was significantly increased than normal (P<0.05); in the knees of the three foot yin meridians with abnormal musculature zones, the mean external rotation figure in propulsion was significantly increased than normal (P<0.05); in the knees of the Foot Yangming Meridian with abnormal musculature zones, the time of maximum vertical ground reaction was significantly delayed (P<0.05). CONCLUSION: The figures of the gait index in KOA patients with different musculature zone types are different, including the step angle, heel impulse, the internal and external rotation figures, the time of the maximum vertical ground reaction and so on, which could be used as the objective basis of syndrome differentiation based on musculature zones for KOA patients. Therefore, biomechanical technology can be applied in the syndrome differentiation based on musculature zones for KOA patients.