Compact photoacoustic endoscopy by measuring initial photoacoustic pressure using phase-shift interferometry

Area of Science:

• Biomedical Optics
• Medical Imaging
• Photoacoustics

Background:

• Photoacoustic endoscopy (PAE) combines light and ultrasound for high-resolution imaging.
• Traditional PAE systems often require bulky components and acoustic coupling agents.
• Miniaturization and non-contact detection are key challenges for advanced endoscopic applications.

Purpose of the Study:

• To develop a novel photoacoustic endoscopy method utilizing phase-shift interferometry (PSI).
• To simplify PAE probe design and enable miniaturization through integrated optical structures.
• To achieve non-contact photoacoustic signal detection, eliminating the need for coupling agents.

Main Methods:

• Employed a three-step phase-shifting interferometry technique for photoacoustic signal detection.
• Utilized identical optical structures for both photoacoustic excitation and detection.
• Implemented PSI to mitigate environmental phase variations and ensure robust detection.
• Verified performance through endoscopic imaging of phantoms and biological tissues.

Main Results:

• Demonstrated a simplified and miniaturized photoacoustic endoscope probe design.
• Achieved non-contact photoacoustic signal detection.
• Successfully performed endoscopic imaging of carbon rods, leaf skeletons, and ex vivo mouse rectum tissues.
• Validated the effectiveness of PSI in mitigating environmental disturbances.

Conclusions:

• The novel PSI-based photoacoustic endoscopy method offers a simplified, miniaturized, and non-contact approach.
• This technique holds promise for improved endoscopic imaging in various biomedical applications.
• Further development could lead to more advanced in vivo diagnostic tools.