Multimodality catheter composed of intravascular ultrasound imaging and polymer optical fiber FFR functions for the diagnosis of cardiac disease.

In this study, we developed a minimally invasive intravascular catheter integrating ultrasonic imaging with fiber Bragg grating (FBG)-based mechanical sensing. By co-integrating a high-frequency miniature ultrasound transducer and a ZEONEX-based polymer optical fiber Bragg grating at the tip of a 1.2 mm catheter, synchronized monitoring of vascular structure visualization and acquisition of hemodynamic pressure data was achieved. In vitro experiments demonstrated that the device attained an axial resolution of 50 µm and a pressure sensitivity of 6.81 pm/kPa when operating in an isotonic saline solution. This technology combines dynamic pressure sensing capabilities with ultrasonic structural imaging in a vascular interventional catheter to overcome the limitations of traditional single-modality catheters in assessing the extent of arterial stenosis. In vitro experiments demonstrated that the pressure sensitivity of this composite catheter was significantly higher than that of commercial pressure wires. Animal experiments successfully captured systolic pressure and diastolic pressure, confirming that the composite catheter is capable of detecting dynamic changes in intravascular stress, and therefore, facilitating a multimodal diagnostic approach for the diagnosis of cardiovascular diseases.