Infraredx, Inc.

Huwei Tan

Jay D Caplan

Barbara Marshik-Geurts

A multimodal intravascular analysis uses a structural intravascular analysis modality to compensate for a chemical analysis modality. Examples of structural analysis are IVUS, OCT, including optical coherence domain Reflectometry (OCDR) and optical frequency domain imaging (OFDI), and/or sonar rangefinding. Examples of chemical or functional analysis are optical, NIR, Raman, fluorescence and spectroscopy, thermography and reflectometry. In one example, the structural analysis is used to characterize the environment structurally, such as catheter head-vessel wall distance. This information is then used to select from two or more algorithms which are depth specific (e.g. shallow vs. deep), to achieve improved accuracy in the chemical or functional analysis.

System and method for intravascular structural analysis compensation of chemical analysis modality

A multimodal intravascular analysis uses a structural intravascular analysis modality to compensate for a chemical analysis modality. Examples of structural analysis are IVUS, OCT, including optical coherence domain Reflectometry (OCDR) and optical frequency domain imaging (OFDI), and/or sonar range finding. Examples of chemical or functional analysis are optical, NIR, Raman, fluorescence and spectroscopy, thermography and reflectometry. In one example, the structural analysis is used to characterize the environment structurally, such as catheter head-vessel wall distance. This information is then used to select from two or more algorithms which are depth specific (e.g. shallow vs. deep), to achieve improved accuracy in the chemical or functional analysis.

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. A demonstration of how the preprocessing methods impact a discrimination modeling technique is provided, how the blood filters were developed and optimized, and finally how the OSP and GLS blood filters correct the spectral signal and improve the discrimination results of the models.

Growing community of inventors

Needham, MA, United States of America

Huwei Tan