20 MHz forward-imaging single-element beam steering with an internal rotating variable-angle reflecting surface: Wire...

Area of Science:

• Medical Imaging
• Acoustic Transducer Technology
• Biomedical Engineering

Background:

• Conventional endoscopic imaging is limited in scope and resolution.
• Developing novel beam-steering mechanisms is crucial for enhanced intra-cavity visualization.
• Acoustic imaging offers non-ionizing visualization capabilities.

Purpose of the Study:

• To demonstrate the feasibility of a forward-imaging acoustic system using a rotating variable-angle reflecting surface (VARS).
• To evaluate the imaging performance and resolution of the VARS-based system for intra-cavity applications.
• To explore the potential for 2D and 3D imaging using this novel beam-steering approach.

Main Methods:

• A single-element 20MHz PMN-PT press-focused angled-face transducer was integrated with a micro-machined VARS.
• The system was tested in water bath experiments using phantom wire structures and ex vivo cow eyes.
• Chirp coded excitation was employed to improve signal-to-noise ratio and penetration depth.

Main Results:

• The 2D imaging system achieved an axial resolution of 66μm and a lateral resolution of 520μm at a 10mm depth.
• Successful imaging of phantom wire structures and ex vivo cow eye samples was demonstrated.
• The system proved capable of generating 2D angular sector scans via VARS rotation.

Conclusions:

• The VARS-based forward-imaging system represents a feasible and novel approach for acoustic beam steering.
• This technology holds significant potential for improving intra-cavity imaging in medical diagnostics.
• Further development could enable 3D imaging by combining VARS and transducer rotations.