Dynamic optical coherence elastography for skin burn assessment: A preliminary study on mice model.

Skin burns that include tissue coagulation necrosis imply variations in stiffness. Dynamic phase-sensitive optical coherence elastography (OCE) is used to evaluate the stiffness of burned skin nondestructively in this paper. The homemade dynamic OCE was initially verified through tissue-mimicking phantom experiments regarding Rayleigh wave speed. After being burned with a series of temperatures and durations, the corresponding structure and stiffness variations of mice skin were demonstrated by histological images, optical coherence tomography B-scans, and OCE elastic wave speed maps. The results clearly displayed the variation in elastic properties and stiffness of the scab edge extending in the lateral direction. Statistical analysis revealed that murine skin burned at temperatures exceeding 100°C typically exhibited greater stiffness than skin burned at temperatures below 100°C. The dynamic OCE technique shows potential application for incorporating elasticity properties as a biomechanical extension module to diagnose skin burn injuries.

Low-cost, ultracompact handheld optical coherence tomography probe for in vivo oral maxillofacial tissue imaging.

SIGNIFICANCE: Optical coherence tomography (OCT) has proven useful for detecting various oral maxillofacial abnormalities. To apply it to clinical applications including biopsy guidance and routine screening, a handheld imaging probe is indispensable. OCT probes reported for oral maxillofacial imaging were either based on a bulky galvanometric mirror pair (not compact or long enough) or a distal-end microelectromechanical systems (MEMS) scanner (raised safety concerns), or adapted from fiber-optic catheters (ill-suited for oral cavity geometry). AIM: To develop a handheld probe featuring great compactness and excellent maneuverability for oral maxillofacial tissue imaging. APPROACH: A dual-axis MEMS scanner was deployed at the proximal end of the probe and the scanned beam was relayed to the distal end through a 4f configuration. Such design provides both a perfect dual-axis telecentric scan and excellent compactness. RESULTS: A handheld probe with a rigid part 70 mm in length and 7 mm in diameter and weighing 25 g in total was demonstrated through both ex vivo and in vivo experiments, including structural visualization of various oral maxillofacial tissues and monitoring the recovery process of an oral mucosa canker sore. CONCLUSIONS: The proposed probe exhibits excellent maneuverability and imaging performance showing great potential in clinical applications.