Development of optical sensor for soft tissue sarcoma boundary detection using optical coherence elastography

Intraoperative soft tissue tumor detection is of great importance for accurate delineation of the tumor margin during the surgical treatment of soft tissue sarcoma. Here we present an optical sensing method based on optical coherence elastography (OCE) for the detection of soft tissue tumor through noncontact assessment of the tissue mechanical properties. This method relies on an air-puff induced localized mechanical stimulation and the phase-resolved low-coherence interferometric measurement of the low-amplitude deformation from the tissue surface. The dominant frequency of the tissue surface response to the air-puff loading is quantified as the natural frequency of the soft tissue, which can be used for the differentiation of the pathological tissues from the normal ones. Our pilot experiments are performed on the tissue-mimicking phantoms and the human ex vivo soft tissue samples. The results demonstrate the feasibility of this OCE-based sensing method in noncontact assessment of tissue elasticity for the tumor detection. Also, the study on the amplitude attenuation of the induced mechanical wave suggests the potential of this method for the sensing of the tissue viscosity.