Spectroscopic unwanted signal filters for discrimination of vulnerable plaque and method therefor

A system for analyzing blood vessels in the presence of intervening fluid, the system comprising:

• a source of radiation;
• a catheter for directing the radiation at blood vessel walls through intervening fluid and collecting radiation from the blood vessel walls;
• a detector system of monitoring the collected radiation;
• a controller for generating spectral responses from the collected radiation detected by the detector system;
• an analyzer for determining spectral responses of the blood vessel walls from the collected spectral responses from the controller and generating information for assessment of the blood vessel walls in response to the determined spectral responses of the blood vessel walls, wherein the analyzer determines the spectral responses of the blood vessel walls by applying a filter generated in response to spectra of the fluid to remove a contribution of the fluid.

A system for spectrally analyzing interior structures of animals in the presence of unwanted spectral signal sources, the system comprising:

• a source of radiation;
• a catheter for directing the radiation at the interior structures through intervening medium and collecting radiation returning from the interior structures;
• detector system of monitoring radiation from the interior structures;
• a spectrometer controller for generating spectral responses from the monitored radiation detected by the detector system;
• an analyzer for determining spectral responses of the interior structures from the generated spectral responses from the spectrometer controller by removing a contribution of the medium by applying a filter generated using a spectral response of the medium to remove or deemphasize a contribution of the medium relative to a signal from the interior structures and generating an assessment of a state of the internal structures in response to the determined spectral responses of the internal structures.

A blood vessel analysis method comprising:

• collecting spectral responses of the blood vessels, the spectral responses including unwanted spectral signals caused by irradiating the blood vessel through an intervening fluid;
• processing the spectral responses by applying a filter generated from the unwanted spectral signals to reduce the unwanted spectral signals relative to the blood vessel responses to generate determined spectral responses of the blood vessels;
• and
• using the determined spectral responses to analyze the blood vessels.