University of Michigan

Michael D Morris

Konan Peck

Steven A Goldstein

Benjamin Levi

Omer Berenfeld

Blake J Roessler

Barbara R McCreadie

Tso-Ching Chen

William F Finney

Matthew Schulmerich

Karen A Dehring

Tracey L Rapp

Shi-Duo G Huang

Chang-Yuh Chen

Tshengedzeni Demana

Patrick J Treado

Tsuey I Chen

Teng-Ke J Pang

A short wave infrared (SWIR) imaging system and method of using the same is provided for assessing a tissue damage depth and/or readiness for reconstruction and/or debridement. The SWIR imaging system includes a light source for illuminating the wound or burn, an image light-registering camera system having at least one narrow-band SWIR filter to image the wound or burn and output imaging information, and a detection system for receiving the imaging information and processing the imaging information to determine a tissue damage depth and/or readiness for reconstruction and/or debridement assessment.

Short wave infrared bedside or intra operative assessment of wound or burn depth at dry-wet layers and readiness for reconstruction

In a method for diagnosing or helping to diagnose a bone tissue condition of a patient, a portion of bone tissue of the patient is irradiated using a light source. The bone tissue may be irradiated in vivo through the skin or via an incision, for example. Alternatively, a biopsy of the bone tissue may be irradiated. Then, spectral content information for light scattered, reflected, or transmitted by the bone tissue is determined, and is used, at least in part, to determine whether the patient has a bone tissue condition.

Method and apparatus for diagnosing bone tissue conditions

In a method for measuring a composition of a sample, an illumination surface area of the sample is illuminated using a light source, and light from a plurality of emitting surface areas of the sample is received, each emitting surface area at a different location, the received light scattered by the sample. A cumulative area of the illumination surface area is greater than a cumulative area of two emitting surface areas of the plurality of emitting surface areas. For each emitting surface area, spectral content information associated with received light corresponding to that emitting surface area is determined, and composition information corresponding to a sub-surface region of the sample is determined based on the determined spectral content information. Different shapes of illumination surface areas as well as the plurality of emitting surface areas may advantageously be utilized for various specimen or sample geometries or illumination sources.

Method and system for measuring sub-surface composition of a sample

Methods and apparatus are provided for evaluating a connective tissue condition of a patient (e.g., a disease, a risk of developing a disease, a risk of developing a fracture, etc.). For example, an indicator associated with the connective tissue condition may be generated. First, tissue at a first location of the body of the patient is irradiated using a light source. The tissue may be irradiated in vivo through the skin or via an incision, for example. Alternatively, a biopsy of the tissue may be irradiated. Then, spectral content information for light scattered, reflected, or transmitted by the irradiated tissue is determined. The spectral content information may be used, at least in part, to generate an indicator associated with a condition of connective tissue at a second location of the body of the patient, the second location remote from the first location. The indicator may, for example, assist a physician in diagnosing or ruling out the connective tissue condition.

Method and apparatus for evaluating connective tissue conditions

A cooling means for a capillary electrophoresis system is described. The cooling means is designed for efficient heat dissipation and operates without arcing at voltages higher than 30 kV.

Heat sink for capillary electrophoresis

An imaging system for providing spectrographically resolved images. The system incorporates a one-dimensional spatial encoding mask which enables an image to be projected onto a two-dimensional image detector after spectral dispersion of the image. The dimension of the image which is lost due to spectral dispersion on the two-dimensional detector is recovered through employing a reverse transform based on presenting a multiplicity of different spatial encoding patterns to the image. The system is especially adapted for detecting Raman scattering of monochromatic light transmitted through or reflected from physical samples. Preferably, spatial encoding is achieved through the use of Hadamard mask which selectively transmits or blocks portions of the image from the sample being evaluated.

Spectrographic imaging system

A densitometer apparatus for evaluating electrophoresis gel samples based on photothermal techniques. In accordance with this invention, electrophoresis gels are characterized by passing a heating light beam through the gel at a particular location. Light absorbed by the presence of staining dyes in that area causes heat evolution which generates a local index of refraction variation or a 'thermal lens'. A probe beam is passed through the sample in the area of the thermal lens a predetermined period of time after it is generated and the modification to the beam caused by the thermal lens is evaluated. For example, defocusing of the probe beam can be sensed by a detector which receives transmitted light through a limiting aperture. Various means of separating the heating and probe beams are disclosed, including use of separate lasers, crossed beams, modulation by plane of polarization, etc. One embodiment of this invention is particularly adapted for characterizing dry gels in which the heating beam is absorbed by the sample and the probe beam passes across the sample and is modified by a thermal lens generated in the air above the sample. Several embodiments are related to means for offsetting the probe beam from the heating beam for use with samples that are swept by the photothermal techniques in accordance with this invention offer advantages in terms of sensitivity over conventional transmission-type densitometers. These advantages enable increased sensitivity and facilitate the use of simplified staining techniques.

Photothermal densitometer for reading electrophoresis gels

A capillary zone electrophoresis system with analyte velocity modulation is described. Velocity modulation of the analyte is provided through applying an AC component to the DC driving potential applied to the separation capillary. Typically modulation on the order of 20 to 30% is applied by a separate AC power supply or an integral DC/AC source. Numerous types of detector systems can be employed including refractive index detectors, conductance, fluorescence, etc. The output of the detector is demodulated using a synchronous demodulation. The velocity modulation generates a signal which is a derivative of the conventional concentration/time signal. The system vastly improves detector sensitivity in situations where limitations are imposed by the large and variable background signals which arise from the aqueous buffer itself. Numerous embodiments of means for applying the modulated driving potential are described along with several detectors which can be implemented in systems according to this invention.

Velocity modulated capillary electrophoresis analysis system

This invention relates to an absorbance detector particularly adapted to liquid chromatography testing. In modern chromatography techniques, light is focused within a small capacity test sample cell, and an optical system is provided to measure the absorbance of various frequencies of light to thereby identify the existence of selected compounds. Inaccuracies of presently available detecting devices result since localized heating within the test cell generates localized index of refraction variations which refract the light in a random fashion such that it is not sensed by the detector. Additional distorting effects are caused by imperfections in the optical surfaces of the system and turbulence due to fluid flow within the sample cell. In accordance with this invention, an appropriate phase conjugator in the form of a retroreflective array is placed in the path of light exiting the sample cell. The array redirects the light rays along their original paths such that they are again distorted but in a reverse sense from the original distortion. In this manner, all of the distorting effects are compensated for. In addition, various means are employed to eliminate the effects of specular reflection from the various optical elements within the system.

Liquid chromatography absorbance detector

A photothermal deflection detector for thin layer chromatography includes a translation means for holding and moving a thin layer chromatographic plate; a first impinging laser beam (e.g., 20 mW chopped argon laser) focused on the moveable thin layer chromatographic plate; a second probing laser beam (e.g., 2 mW He-Ne laser) intersecting the impinging laser beam directly above and parallel to the moveable thin layer chromatographic plate; and a laser deflection measuring means (e.g., knife edge, photodiode detector and lock-in amplifier demodulator) responsive to the thermal lens effect created by the absorption of the impinging laser beam by the separated compounds on the thin layer chromatographic plate. Such a system when applied to separated compounds (e.g., 1,2-napthaquinone, phenanthrenequinone and .alpha.-ionone) exhibits detection limits that range from 30 ng to 7.5 pg, depending upon the compounds's ability to absorb the impinging light.

Growing community of inventors

Ann Arbor, MI, United States of America

Michael D Morris