Ocean Biomedical UltraSound Lab

Amidst growing animal rights movements, the release of captive cetaceans, particularly killer whales and dolphins, into their natural environments has gained increasing support from activists due to ethical concerns. However, there is a notable lack of quantitative studies on the interactions between wild and captive dolphins during rehabilitation before release. This study assesses the rehabilitation process of captive dolphin during its stay in the sea pen using advanced surveillance techniques. Methods including CCTV, hydrophone monitoring, and drone observations were utilized to document interactions between rehabilitating and wild dolphins. A convolutional neural network-based detector for dolphin whistle sound was used to automatically detect the whistle from underwater sound recorded at the rehabilitation site, which significantly expedited the identification of wild dolphin encounters compared to traditional manual methods. This technology also facilitated synchronized analysis of underwater sounds, CCTV footage, and drone videos, providing comprehensive visual and acoustic observations of captive and wild dolphins during encounters. This research offers insights that can guide future dolphin rehabilitation monitoring and release strategies.

Blood viscosity is inversely proportionate with shear rate mainly due to red blood cell (RBC) aggregation under steady flow. However, this inverse relation cannot explain the spatiotemporal variation of RBC dynamics under pulsatile flow. This study aimed to clarify the relationship between hemodynamics and hemorheology based on a novel computational model that couples RBC dynamics with blood viscosity under pulsatile flow. By integrating both whole-blood experiments with ultrasound imaging and numerical simulations, the spatiotemporal variations of local hematocrit were shown to drive local variations of blood viscosity under pulsatile flow. The results suggest that the local parabolic distribution of high hematocrit is influenced by RBC aggregation and pulsatile flow characteristics, which in turn affect blood viscosity. Computational analysis supports that local blood viscosity increased in regions with elevated hematocrit during the acceleration phase of pulsatile flow. Local hematocrit and RBC dynamics play critical roles in influencing blood viscosity under pulsatile flow, highlighting the importance of incorporating hemorheological and hemodynamic factors. These are crucial for understanding large arterial flow and potentially enhancing diagnostic and therapeutic approaches for cardiovascular diseases.