Publications by Year: 2014

L. Lim, Nichols, B., Migden, M. R., Rajaram, N., Reichenberg, J. S., Markey, M. K., Ross, M. I., and Tunnell, J. W., “Clinical study of noninvasive in vivo melanoma and nonmelanoma skin cancers using multimodal spectral diagnosis,” Journal of Biomedical Optics, vol. 19, pp. 117003, 2014. Publisher's VersionAbstract
Abstract.  The goal of this study was to determine the diagnostic capability of a multimodal spectral diagnosis (SD) for in vivo noninvasive disease diagnosis of melanoma and nonmelanoma skin cancers. We acquired reflectance, fluorescence, and Raman spectra from 137 lesions in 76 patients using custom-built optical fiber-based clinical systems. Biopsies of lesions were classified using standard histopathology as malignant melanoma (MM), nonmelanoma pigmented lesion (PL), basal cell carcinoma (BCC), actinic keratosis (AK), and squamous cell carcinoma (SCC). Spectral data were analyzed using principal component analysis. Using multiple diagnostically relevant principal components, we built leave-one-out logistic regression classifiers. Classification results were compared with histopathology of the lesion. Sensitivity/specificity for classifying MM versus PL (12 versus 17 lesions) was 100%/100%, for SCC and BCC versus AK (57 versus 14 lesions) was 95%/71%, and for AK and SCC and BCC versus normal skin (71 versus 71 lesions) was 90%/85%. The best classification for nonmelanoma skin cancers required multiple modalities; however, the best melanoma classification occurred with Raman spectroscopy alone. The high diagnostic accuracy for classifying both melanoma and nonmelanoma skin cancer lesions demonstrates the potential for SD as a clinical diagnostic device.
R. Hennessy, Goth, W., Sharma, M., Markey, M. K., and Tunnell, J. W., “Effect of probe geometry and optical properties on the sampling depth for diffuse reflectance spectroscopy,” Journal of Biomedical Optics, vol. 19, pp. 107002, 2014. Publisher's VersionAbstract
Abstract.  The sampling depth of light for diffuse reflectance spectroscopy is analyzed both experimentally and computationally. A Monte Carlo (MC) model was used to investigate the effect of optical properties and probe geometry on sampling depth. MC model estimates of sampling depth show an excellent agreement with experimental measurements over a wide range of optical properties and probe geometries. The MC data are used to define a mathematical expression for sampling depth that is expressed in terms of optical properties and probe geometry parameters.
B. Yang and Tunnell, J. W., “Real-time absorption reduced surface fluorescence imaging,” Journal of Biomedical Optics, vol. 19, pp. 090505, 2014. Publisher's VersionAbstract
Abstract.  We introduce a technique that limits absorption effects in fluorescence imaging and does not require extensive imaging processing, thus allowing for video rate imaging. The absorption minimization is achieved using spatial frequency domain imaging at a single high spatial frequency with standard three-phase demodulation. At a spatial frequency f=0.5  mm−1, we demonstrated in both in-vitro phantoms and ex-vivo tissue that the absorption can be significantly reduced. In the real-time implementation, we achieved a video rate of 19  frames/s. This technique has potential in cancer visualization and tumor margin detection.
M. Sharma, Marple, E., Reichenberg, J., and Tunnell, J. W., “Design and characterization of a novel multimodal fiber-optic probe and spectroscopy system for skin cancer applications,” Review of Scientific Instruments, vol. 85, pp. -, 2014. Publisher's Version
I. K. Ilev, Tunnell, J., Chen, Y., Hildebrandt, N., Dholakia, K., and Vo-Dinh, T., “Introduction to the Issue on Nanobiophotonics,” Selected Topics in Quantum Electronics, IEEE Journal of, vol. 20, pp. 3-6, 2014.
S. F. Bish, Sharma, M., Wang, Y., Triesault, N. J., Reichenberg, J. S., Zhang, J. X. J., and Tunnell, J. W., “Handheld Diffuse Reflectance Spectral Imaging (DRSi) for in-vivo characterization of skin.,” Biomed Opt Express, vol. 5, no. 2, pp. 573-86, 2014.Abstract
Diffuse reflectance spectroscopy provides a noninvasive means to measure optical and physiological properties of tissues. To expand on these measurements, we have developed a handheld diffuse reflectance spectral imaging (DRSi) system capable of acquiring wide field hyperspectral images of tissue. The image acquisition time was approximately 50 seconds for a 50x50 pixel image. A transport model was used to fit each spectra for reduced scattering coefficient, hemoglobin concentration and melanin concentration resulting in optical property maps. The system was validated across biologically relevant levels of reduced scattering (5.14% error) and absorption (8.34% error) using tissue simulating phantoms. DRSi optical property maps of a pigmented skin lesion were acquired in vivo. These trends in optical properties were consistent with previous observations using point probe devices.
M. Fitzmaurice, Pogue, B. W., Tearney, G. J., Tunnell, J. W., and Yang, C., “Advances in optics for biotechnology, medicine and surgery.,” Biomed Opt Express, vol. 5, no. 2, pp. 560-1, 2014.Abstract
The guest editors introduce a Biomedical Optics Express feature issue that includes contributions from participants at the 2013 conference on Advances in Optics for Biotechnology, Medicine and Surgery XIII.