Question: User: Scene 7: Medical Application - Ultrasound Blood Flow Measurement Visual Prompt for AI Video Generator: Prompt: 3D medical cross-section inside a human blood vessel[cite: 14]. An ultrasound transducer probe on the skin sends high-frequency sound waves into flowing red blood cells[cite: 14]. Red blood cells moving toward the probe scatter the waves back[cite: 14]. The returning echo shifted to a higher frequency is detected by the sensor[cite: 14]. Graphical overlay demonstrates a double Doppler shift: first when cells receive the wave, second when scattering it back[cite: 14]. English Voiceover & Text: Voiceover: "In medicine, Doppler Ultrasound measures blood flow velocity[cite: 14]. Moving red blood cells experience a double Doppler shift—first as moving receivers, then as moving transmitters—allowing doctors to map arterial flow accurately[cite: 14]!"