Virtual Biopsy and Physical Characterization of Tissues, Biofilms, Implants and Viscoelastic Liquids Using Vibrational Optical Coherence Tomography

Abstract

Tissue biopsies and implant analysis during animal testing or clinical studies are a requirement for development of new surgical materials and procedures. In this paper we report the use of vibrational OCT (VOCT) to evaluate the viscoelastic behavior of tissues, polymeric materials, biofilms, and viscoelastic solutions of macromolecules. Our results suggest that VOCT is a useful technique to characterize the behavior of cellular tissues and biofilms, polymeric implant materials and viscoelastic solutions used in medicine. It is demonstrated that the modulus and resonant frequency squared per unit thickness is a feature that can be used to characterize a variety of tissues. Further work is needed to understand the generalized behavior of synthetic polymers and viscoelastic solutions.

Comparative “virtual biopsies” of normal skin and skin lesions using vibrational optical coherence tomography

“…Vibrational optical coherence tomography (VOCT) is a new technique developed in the Department of Pathology at Robert Wood Johnson Medical School, Rutgers University. It uses near infrared light and audible sound applied transversely to the tissue surface to image and measure the resonant frequency of tissues . The resonant frequency is directly related to the tissue stiffness measured using conventional uniaxial tensile testing as described previously …”

“…OCT cross‐sectional images were obtained using an OQ Labscope (Lumedica Inc) and a laboratory spectral‐domain optical coherence tomography device (SD‐OCT) operating in the scanning mode …”

“…Transverse sample displacement was generated by placing a speaker next to the skin or under the excised lesion to be studied by spectral‐domain optical coherence tomography (SD‐OCT), a non‐contact, interferometric technique as discussed previously . The SD‐OCT system uses a fiber‐coupled superluminescent diode light source with an 810 nm center wavelength and 100 nm bandwidth (full‐width at half maximum) as described previously …”

“…The sound intensity was inaudible unless the speaker was placed near the subject's ear to make sure it was energized. In vitro measurements of excised verrucous carcinoma (a SCC subtype), a nodular basal cell carcinoma (subtype of BCC), an actinic keratosis, and a melanocytic nevus were made by placing the lesion on a glass slide and mounting the glass slide on a plastic support under which a speaker was placed to vibrate the tissue as discussed previously …”

“…Identification of tissue margins and tissue stiffness non‐invasively in conjunction with enhanced imaging techniques has the potential to facilitate detection of abnormal skin lesions and lead to early removal. We have developed at technique termed vibrational optical coherence tomography (VOCT) to image skin in three dimensions and measure the stiffness simultaneously, non‐invasively and non‐destructively to provide a “virtual biopsy” of skin and skin lesions …”