Abstract: The invention relates to methods and devices for characterizing tissue in vivo, e.g., in walls of blood vessels, to determine whether the tissue is healthy or diseased, and include methods of displaying results with or without thresholds.

Abstract: Spectral variation contributed from the absorbance of unwanted correlated signals, such as blood at variable pathlengths between an in vivo catheter optic probe and a coronary vessel wall is an obstacle in the detection of vulnerable plaque. Preprocessing methods are described to reduce the impact of blood upon the spectral signal, based on the principles of Orthogonal Subspace Projection (OSP) and Generalized Least Square (GLS). The multivariate discrimination models used on the processed spectral information reduce the number of independent factors that include contributions from blood. The disclosed chemometric processing including preprocessing methods provide for in vivo spectral detection of medical analytes within the human body and in particular within the coronary vessel wall.

Abstract: A method and apparatus is disclosed for signal spectrometry using an improved apodization function. Such method and apparatus involve (i) obtaining sample and reference time domain waveforms; (ii) applying sample and reference apodization waveforms to the sample and reference time domain waveforms, such that substantially same weight is applied to corresponding substantially coextensive regions of the sample and reference time domain waveforms, (iii) transforming the sample and reference apodized waveforms from the time domain into the frequency domain; and (iv) generating referenced spectral analysis waveform for signal analysis from a ratio of the transformed sample and reference frequency spectra, the spectral analysis waveform substantially excluding frequencies associated with the corresponding substantially coextensive regions of the apodized sample and reference time domain waveforms.

Abstract: A method for improving the treatment and/or examination of vessel walls through fluid, such as blood, functions by identifying the points in time when the catheter is closest to the vessel wall or farthest from the vessel wall. Identification of this relative location enables improved spectral readings in larger vessels. In short, instead of trying to overcome motion (e.g., by centering the catheter), this approach takes advantage of motion by identify times when the catheter is closer to the vessel wall, in order to gather more useful spectral information or improve the efficacy of the treatment of the vessel walls. In the specific example, the invention is used for near infrared (NIR) spectroscopy. In some embodiments, the catheter head is designed to induce relative movement between the head and the vessel walls.

Abstract: The invention relates to methods and devices for characterizing tissue in vivo, e.g., in walls of blood vessels, to determine whether the tissue is healthy or diseased.

Abstract: The invention relates to methods and devices for characterizing tissue in vivo, e.g., in walls of blood vessels, to determine whether the tissue is healthy or diseased, and include methods of displaying results with or without thresholds.

Abstract: The invention relates to methods and devices for characterizing tissue in vivo, e.g., in walls of blood vessels, to determine whether the tissue is healthy or diseased, and include methods of displaying results with or without thresholds.

Abstract: The invention relates to methods and devices for characterizing tissue in vivo, e.g., in walls of blood vessels, to determine whether the tissue is healthy or diseased, and include methods of displaying results with or without thresholds.

Abstract: Spectral variation contributed from the absorbance of unwanted correlated signals, such as blood at variable pathlengths between an in vivo catheter optic probe and a coronary vessel wall is an obstacle in the detection of vulnerable plaque. Preprocessing methods are described to reduce the impact of blood upon the spectral signal, based on the principles of Orthogonal Subspace Projection (OSP) and Generalized Least Square (GLS). The multivariate discrimination models used on the processed spectral information reduce the number of independent factors that include contributions from blood. The disclosed chemometric processing including preprocessing methods provide for in vivo spectral detection of medical analytes within the human body and in particular within the coronary vessel wall.

Abstract: The invention relates to methods and devices for characterizing tissue in vivo, e.g., in walls of blood vessels, to determine whether the tissue is healthy or diseased.