High-Speed Schlieren Imaging of Shock Waves for the Study of Tympanic Membrane’s Response

Abstract The mechanics of tympanic membrane (TM) fractures resulting from exposure to high-pressure blasts are not yet fully understood. To investigate TM responses to such events, shock tubes can be utilized as loading devices. The effective use of these devices requires proper characterization. One appropriate method for visualizing the shock waves produced by a shock tube is high-speed Schlieren imaging, which can provide both qualitative and quantitative information. In this paper, we present a shock tube integrated with a high-speed Schlieren system and high-speed dynamic pressure transducers. The highspeed Schlieren system allowed us to observe the shock waves emitted from the shock tube and characterize the Mach number of each wave. The flow structures generated from the tube exit were identified and synchronization between Schlieren images and pressure data was achieved. The shock tube showed good repeatability and generated supersonic blasts capable of rupturing TM samples, with a shock Mach number of up to 1.4. The versatile and cost-effective nature of the shock tube opens new possibilities for understanding the real-time mechanics of TM fractures and investigating their dynamic response in the future, when even more sophisticated quantitative optical techniques will be used to investigate the TM’s behavior in these conditions.