Laser induced surface acoustic wave combined with phase sensitive optical coherence tomography for superficial tissue...

Area of Science:

• Biomedical Engineering
• Biophysics
• Materials Science

Background:

• Tissue mechanical properties are crucial for assessing physiological condition and aiding disease diagnosis and treatment.
• Laser-induced surface acoustic waves (SAWs) offer a non-invasive, non-contact method for characterizing tissue elasticity.
• Direct laser application to tissue poses a risk of thermal damage due to energy deposition.

Purpose of the Study:

• To investigate the thermal effects of laser-induced SAWs on biological tissue.
• To propose and validate a protective solution to mitigate laser-induced thermal damage.
• To enable accurate in vivo measurement of tissue mechanical properties for clinical applications.

Main Methods:

• Development of transient thermal analysis to study laser-tissue interaction.
• Experimental verification of thermal analysis using a high-energy Nd:YAG laser pulse.
• Implementation of a thin agar membrane as a surface shield to protect the tissue.
• Validation of the approach by measuring skin mechanical properties in a Thiel mouse model.

Main Results:

• The study successfully analyzed the thermal effects of laser pulses on the agar surface shield.
• The agar shield effectively protected the underlying tissue from thermal damage.
• The laser-induced SAW method, with the agar shield, accurately measured skin mechanical properties in a mouse model.
• Demonstrated feasibility for in vivo elasticity measurements.

Conclusions:

• The proposed agar membrane shielding is an effective solution to prevent thermal damage during laser-induced SAW measurements.
• This approach significantly advances the clinical applicability of laser-induced SAWs for non-invasive tissue elasticity assessment.
• The method holds promise for diagnosing and characterizing various surface epithelia conditions in dermatology and beyond.