A reconfigurable all-optical ultrasound transducer array for 3D endoscopic imaging

Area of Science:

• Biomedical Optics
• Medical Imaging
• Acoustic Engineering

Background:

• Miniature ultrasound probes are crucial for minimally invasive imaging.
• Existing probes face limitations in resolution and flexibility.
• All-optical methods offer potential for miniaturization and enhanced functionality.

Purpose of the Study:

• To develop and characterize a miniature all-optical ultrasound imaging system.
• To demonstrate the feasibility of reconfigurable acoustic source arrays for 3D imaging.
• To evaluate the system's performance for endoscopic and laparoscopic applications.

Main Methods:

• An all-optical system generated ultrasound photoacoustically using a scanned optical beam.
• A coherent fiber bundle transmitted the optical beam to an absorbing coating.
• A single fiber-optic detector captured ultrasound signals, achieving high resolution (97 μm x, 179 μm y, 110 μm z).

Main Results:

• The system achieved high on-axis resolutions in a 3.5 mm outer diameter probe.
• Reconfigurable optical scan patterns allowed for flexible acoustic source array geometries.
• Image quality demonstrated a strong dependency on the source location pattern.

Conclusions:

• A miniature all-optical ultrasound probe with arbitrary source array geometries was successfully fabricated.
• The system is suitable for 3D endoscopic and laparoscopic imaging.
• Demonstrated feasibility on ex vivo porcine cardiac tissue highlights clinical potential.