Massachusetts Institute of Technology

Tufts University

Lahey Clinic, Inc.

Martin Hunter

Michael S Feld

Irene Georgakoudi

David L Kaplan

Ramachandra Rac Dasari

Wei-Chuan Shih

Thomas Scecina

Luis H Galindo

Jason T Motz

Thomas Schnelldorfer

Robert Michael Trout

Sharad Gupta

Annika Enejder

Methods and apparatus for improved imaging of internal tissue structures, such as lesions in the peritoneum, are disclosed employing Differentially Polarized Light (DPL) imaging. The optical system can include a laparoscope having at least one optical illumination waveguide for directing illuminating radiation and an optical collection waveguide having an aperture for collecting and transmitting radiation backscattered from a tissue region to a detector. The system further can include a polarizer for polarizing the illuminating radiation and a second analyzing polarizer disposed in the optical return path, whereby backscattered radiation of differing polarizations can be passed to the detector. End cap assemblies are also disclosed that that can be fitted to conventional laparoscopes, e.g., by a threaded connection or the like, to facilitate DPL imaging by polarizing the illuminating light of the laparoscope. For example, the end cap can include a polarizing film within a stainless steel housing. The polarizing film can be shaped to cover of the illumination outputs of the laparoscope, while leaving clear the aperture for collection of reflected or scattered radiation.

Laparoscopic imaging using polarized light

In one aspect, the present invention generally provides methods for characterizing mineralization of a material, e.g., a biomaterial, by illuminating the material with radiation and analyzing radiation scattered from the material in response to the illumination. For example, in some embodiments, a material can be illuminated with polarized radiation at a plurality of wavelengths and the elastically scattered radiation corresponding to two or more of those wavelengths can be collected at two polarizations: one parallel and the other perpendicular to the illumination polarization. A differential intensity of the scattered radiation at the two polarizations can be analyzed as a function of wavelength to obtain information regarding the morphology of mineral deposits in the sample. Further, the total scattered radiation can be analyzed to derive information regarding the level of mineralization.

Non-invasive optical characterization of biomaterial mineralization

The present invention relates to the use of Raman spectroscopy for quantitative, non-invasive transcutaneous measurement of blood analytes, such as glucose. Raman spectroscopy is used to measure glucose transcutaneously, in patients whose blood glucose levels were monitored. Raman spectra were collected transcutaneously along with glucose reference values provided by standard capillary blood analysis. A partial least squares calibration was created from the data from each subject and validated using leave-one-out cross validation.

Raman spectroscopy for non-invasive glucose measurements

The system and method of the present invention relates to using spectroscopy, for example, Raman spectroscopic methods for diagnosis of tissue conditions such as vascular disease or cancer. In accordance with a preferred embodiment of the present invention, a system for measuring tissue includes a fiber optic probe having a proximal end, a distal end, and a diameter of 2 mm or less. This small diameter allows the system to be used for the diagnosis of coronary artery disease or other small lumens or soft tissue with minimal trauma. A delivery optical fiber is included in the probe coupled at the proximal end to a light source. A filter for the delivery fibers is included at the distal end. The system includes a collection optical fiber (or fibers) in the probe that collects Raman scattered radiation from tissue, the collection optical fiber is coupled at the proximal end to a detector. A second filter is disposed at the distal end of the collection fibers. An optical lens system is disposed at the distal end of the probe including a delivery waveguide coupled to the delivery fiber, a collection waveguide coupled to the collection fiber and a lens.

Systems and methods for spectroscopy of biological tissue

Growing community of inventors

Bradford, MA, United States of America

Martin Hunter