Multispec Corporation

University of Southern California

Cedars-sinai Medical Center

Vasilis Z Marmarelis

Chrysostomos L Nikias

Warren S Grundfest

Ramez E N Shehada

David Sheby

Dae Cheol Shin

Theodore W Berger

Dong Song

Ramez E Shehada

Systems and techniques, including machine-readable instructions, for modeling of nonlinear systems. In one aspect, an apparatus includes a collection of two or more inputs configured and arranged to receive input signals, a collection of two or more outputs configured and arranged to output output signals, a processing unit configured to transform the input signals into the output signals, wherein the transformation is non-linear and treats the non-linear system as a collection of multiple input, single output non-linear systems, and a data storage that stores characteristics of the transformation.

Modeling nonlinear systems

The Laser Induced Fluorescence Attenuation Spectroscopy (LIFAS) method and apparatus preferably include a source adapted to emit radiation that is directed at a sample volume in a sample to produce return light from the sample, such return light including modulated return light resulting from modulation by the sample, a first sensor, displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor, displaced by a second distance from the sample volume, for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor associated with the first sensor and the second sensor and adapted to process the first and second signals so as to determine the modulation of the sample. The methods and devices of the inventions are particularly well-suited for determining the wavelength-dependent attenuation of a sample and using the attenuation to restore the intrinsic laser induced fluorescence of the sample. In turn, the attenuation and intrinsic laser induced fluorescence can be used to determined a characteristic of interest, such as the ischemic or hypoxic condition of biological tissue.

Method and devices for laser induced fluorescence attenuation spectroscopy

A system for providing high resolution imaging of objects having sub-millimeter dimensions comprised of at least one transmitter, at least one receiver, a coupling chamber, and a processor for recording attenuation and time of flight profiles of the transmitted signals. The signals are conditioned in a manner to provide high signal-to-noise ration (SNR) and minimal crosstalk and multipath effects at the receiver.

High-resolution 3D ultrasonic transmission imaging

Systems and methods for obtaining images of body organs or other tissue for each of their multiple characterizing aspects, and for classifying different tissue types within the images according to their characterizing aspects, are disclosed herein. The tissue may be irradiated with an ultrasonic signal, and an interaction signal received in return. Sinogram data may be constructed from the received interaction signal, and multiple characterizing data extracted therefrom. The multiple characterizing data representing multiple characterizing aspects may then be matched to tissue type within a database containing information correlating characterizing multi-aspect data with tissue type. Images of the tissue may then be presented with identifiers associating tissue portions with their matched tissue types.

Multi-mode processing for ultrasonic imaging

Methods and devices for Laser Induced Fluorescence Attenuation Laser Induced Fluorescence Attenuation Spectroscopy (LIFAS) Spectrocopy, including, in particular, methods and devices for the detection of ischemia and hypoxia in biological tissue. The LIFAS method and apparatus preferably include a source adapted to emit radiation that is directed at a sample volume in a sample to produce return light from the sample, such return light including modulated return light resulting from modulation by the sample, a first sensor, displaced by a first distance from the sample volume for monitoring the return light and generating a first signal indicative of the intensity of return light, a second sensor, displaced by a second distance from the sample volume for monitoring the return light and generating a second signal indicative of the intensity of return light, and a processor associated with the first sensor and the second sensor and adapted to process the first and second signals so as to determine the modulation of the sample. The methods and devices of the inventions are particularly well-suited for determining the wavelength-dependent attenuation of a sample and using the attenuation to restore the intrinsic laser induced fluorescence of the sample. In turn, the attenuation and intrinsic laser induced fluorescence can be used to determined a characteristic of interest, such as the ischemic or hypoxic condition of biological tissue.

Method and devices for laser induced fluorescence attenuation spectroscopy (LIFAS)

Method and devices for laser induced fluorescence attenuation

A signal processing method for use in echo-location systems (radar, sonar, laser radar) to obtain accurate estimates of the target reflectivity sequence in a random (non-Gaussian) noise environment, including ambient noise, reverberation, and clutter. The method derives the statistical characteristics of the random background environments and then constructs and maximizes the corresponding approximate likelihood function using iterative methods. The approximate maximum likelihood estimates are generated on the basis of an approximation of the ideal likelihood function which is maximized using computationally efficient algorithms.

Method and apparatus for situationally adaptive processing in

Automatic focusing of radar or sonar imaging systems, for example, synthetic aperture radar (SAR) or synthetic aperture sonar (SAS) systems, is accomplished by using high order measurements, such as the quadruple product of the range compressed signal g(x). The phase error is estimated by a recursive or non-recursive algorithm from the phase of the quadruple product. The estimated phase error is applied to the range-compressed SAR or SAS image data which is then azimuth compressed to obtain the focused image data.

Method for automatic focusing of radar or sonar imaging systems using

In echo-location and imaging systems, interference suppression is accomplished by shaping the transmitted signal waveform. Interference suppression permits more accurate range estimates or image formation, respectively. These specially shaped waveforms can also be used in communication systems to secure more accurate message transmission in the presence of interference. Shaping of the transmitted signal may be accomplished in two ways: (1) by convolving an elemental waveform with a multi-level pseudorandom sequence (i.e., binary, ternary, Poisson, etc.); or (2) by transforming nonlinearly the amplitude of the elemental waveform to give it high skewness. Interference suppression in the former case is achieved through matched filtering (replica correlation or pulse compression), and in the latter case it is accomplished by bispectrum-bicoherence processing.

Process and apparatus for improved interference suppression in

A method and apparatus for enhancing resolution of range estimates in all echo location systems and, specifically, such systems as Radar, Sonar, and Synthetic Aperture Radar (SAR), for example. The invention utilizes high order signal processing to 'sharpen' or contract the main lobe of the processing system ambiguity function and suppress its side lobes, for a given transmission pulse bandwidth. The method and apparatus may be implemented in the frequency domain or time domain. Enhanced resolution is achieved by using a filter (MSC filter), according to this invention, in the echo location data processing system so that the received echo data is processed by the MSC filter to produce a signal that exhibits enhanced range resolution. The MSC filter output, H(.omega.), which is specific to the transmitted pulse waveform, is the ratio of a high-order manipulation of the transmitted signal with its modified spectral profile.

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Irvine, CA, United States of America

Vasilis Z Marmarelis