Abstract: An erythema meter includes a probe, a light source of one or more specific probing and reference wavelengths, and an acoustic detector which determines the level of erythema present in the dental pulp chamber of a tooth. The probing and reference wavelengths are delivered in pulsed or amplitude modulated fashion through the probe, thereby permitting electronic identification and filtering of the received data. The absorption of the light wave raises the temperature of the material in the tooth and causes it to expand, thus creating tiny shockwaves which are picked up with the acoustic detector, revealing information on the location of blood and the quantity of blood inside the tooth. The erythema meter accurately measures the erythema, or inflammation, within the tooth in a qualitative and quantitative manner.

Abstract: A body or body structure may be examined by detecting radiation emitted from and/or reflected by the body or body structure, said radiation being in the terahertz frequency range. The detected radiation then is evaluated to obtain information concerning the body or body structure.

Abstract: Methods and systems for measuring volume and size of features such as lesions, tumors, sores, and wounds external to animal, human and plant skin, using 3D structured light scanners are provided. These methods and systems obtain a point cloud of the scanned feature, and employ algorithms to adjust the suggested feature geometry parameters to minimize deviations of the point cloud from suggested feature geometry. Obtained geometry parameters permit the calculation of the features' sizes and volumes.

Abstract: Disclosed are methods of determining long-term deposition pattern of a compound in tissue. The following steps can be followed: placing tissue against a receptor; directing mid-infrared electromagnetic radiation onto the tissue; quantifying the electromagnetic radiation that is reflected from the tissue to obtain a reflected amount; using a calibration equation to calculate the concentration of a compound from the reflected amount; and using the concentration of the compound to evaluate presence of a clinical condition in the tissue.

Abstract: The invention relates to a non-invasive method to diagnose the changes of molecular structures of organism tissues from body surface and a dedicated apparatus. The apparatus is comprised of a Fourier Transform infrared spectrometer and a set of additional accessories. Said additional accessories include a mid-IR fiber optics sampling attachment, a fiber coupling part, and an infrared detector part. The detection method is comprised of placing the ATR probe of the dedicated apparatus on the skin surface of a region to be tested, and scanning more than one time in which the resolution of the apparatus is 1-32 cm?1 and the range of the spectrum is 800-4000 cm?1. It is possible to detect changes in molecular structures of living biological tissues in the early stages of cancer, and testees will not feel uncomfortable during testing. The method is easy to operate, quick, accurate, and it doesn't harm the body.

Abstract: A method for detecting a complete or partial obstruction in a vessel through an intervening fluid includes receiving spectroscopic responses at different locations of a vessel wall, e.g., a vein or artery, through an intervening fluid, preferably blood. Spectroscopic responses are generated by irradiating the vessel wall at different locations and detecting spectra at those locations. In preferred embodiments, the radiation used is in the near infrared (NIR) region of the electromagnetic spectrum. The thrombus is located by determining whether fluctuations, spatial and/or spectral, of the spectral responses are indicative of thrombus.

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: A medical system includes a catheter having an elongated tubular member and an inner core slideably received within the elongated member. The inner core includes an imager on a distal end and is coupled with a control system and an imaging system. The inner core is configured to scan the interior of a lumen by radially rotating around a center axis and axially translating along the center axis while within the elongated member. The medical system is configured to dynamically image a body lumen at a high speed in order to allow for optical imaging in a safe manner without long durations of blood sequestration and displacement. The medical system is configured to obtain three dimensional images of the body lumen with as little as one dimensional scanning of the lumen. Images of the lumen can be stored and viewed at a desired rate after scanning.

Abstract: A system and method that enable real-time optical measurements of tissue reflection spectral characteristics while performing ablation, involves the radiation of tissue and recapturing of light from the tissue to monitor changes in the reflected optical intensity as an indicator of steam formation in the tissue for prevention of steam pop. The system includes a catheter adapted to collect light reflected from tissue undergoing ablation, a detection component that identifies and separates constituent wavelengths of collected light, a quantification apparatus for generating measured light intensity data for the collected light, and a processor that analyses the measured light intensity data in relation to time. The system may include a graphical display and/or an audio output (e.g., speaker) that provide visual and/or audio alarm when the system infers formation of a steam pocket in the tissue.

Abstract: Apparatus and methods are provided for the imaging of structures in deep tissue within biological specimens, using spectral imaging to provide highly sensitive detection. By acquiring data that provides a plurality of images of the sample with different spectral weightings, and subsequent spectral analysis, light emission from a target compound is separated from autofluorescence in the sample. With the autofluorescence reduced or eliminated, an improved measurement of the target compound is obtained.

Abstract: A system for identifying vulnerable plaque includes an illumination subsystem for passing an illumination beam, modulated by a first modulation waveform, through a catheter. A receiving subsystem detects a collection beam, which is modulated by a second modulated waveform, from the catheter. A processing subsystem in communication with the receiving subsystem determines a relative phase difference between the first and second modulation waveforms.

Abstract: A non-invasive tool for skin disease diagnosis would be a useful clinical adjunct. The purpose of this study was to determine whether visible/near-infrared spectroscopy can be used to non-invasively characterize skin diseases. In-vivo visible- and near-infrared spectra (400-2500 nm) of skin neoplasms (actinic keratoses, basal cell carcinomata, banal common acquired melanocytic nevi, dysplastic melanocytic nevi, actinic lentigines and seborrheic keratoses) were collected by placing a fiber optic probe on the skin. Paired t-tests, repeated measures analysis of variance and linear discriminant analysis were used to determine whether significant spectral differences existed and whether spectra could be classified according to lesion type. Paired t-tests showed significant differences (p<0.05) between normal skin and skin lesions in several areas of the visible/near-infrared spectrum. In addition, significant differences were found between the lesion groups by analysis of variance.

Abstract: An imaging system illuminates body tissue with infrared light to enhance visibility of subcutaneous blood vessels, and generates a video image of the body tissue and the subcutaneous blood vessels based on reflected infrared light. The system includes an infrared light source for generating the infrared light and a structure for diffusing the infrared light. The diffusing structure includes one or more layers of diffusing material for diffusing the light. The system further includes a video imaging device for receiving the infrared light reflected from the body tissue and for generating a video image of the body tissue based on the reflected infrared light.

Abstract: A method of evaluating the surface of a material that has a distinguishable infrared spectrum comprising (a) positioning an infrared fiber optic probe to be in contact with a surface of the sample or material at a region of interest for detecting attenuated total reflectance or within a sufficient distance from the surface of the region for detecting reflection, (b) detecting mid- or near-infrared radiation attenuated total reflectance or reflection off of the surface of the sample or the material, (c) analyzing the infrared radiation from step (b) for at least one of peak height, peak area, frequency and chemometric parameters, and (d) actuating the removal device when a signal from the infrared fiber optic probe is between pre-selected values for at least one of peak height, peak area, frequency and chemometric parameters for the sample of the material.

Abstract: An imaging apparatus in which an imaging head having an observation hole for intaking images of an object to be observed formed at a top end is exchangeably mounted to a main body having an imaging device and an illumination light source wherein the imaging head is provided with a plurality of optical fibers for guiding a light from the illumination light source and illuminating the same to the object, light incident ends of respective optical fibers are disposed at positions opposing to emission ends of the illumination light source, and the light emission ends are circularly disposed around the image pick-up optical axis, whereby an appropriate illumination light in accordance with a magnifying ratio can be illuminated without disposing an illumination light source such as of LEDs to an imaging head such as an exchangeable lens unit.

Abstract: Apparatus for high resolution imaging of a moving object comprises a source of low coherence light, an optical coherence tomography imaging instrument or a dual channel, optical coherence tomography/confocal imaging instrument, a transverse scanner, an interferometer, depth adjustment means, and interface optics. First and an optional second sensing blocks sense the axial and respectively the transverse position of the object. A splitting element is shared so that the interface optics and the sensing blocks have a common axis of light transmitted to and from the object. Timing means establishes a timing, and timing intervals and reference times for images as they are taken. The acceptability of each scanned image is determined according to predetermined criteria. A series of en-face OCT images, or of longitudinal OCT images of the object may be taken at different depths or transverse coordinates, and the stack of collected images is used to build 3D profiles of the object.

Abstract: A system for detecting and diagnosing ear related conditions. The system includes a device capable of obtaining a spectrum of reflected light from an ear of a subject and a processing unit in connection with the device, which is capable of translating the obtained spectrum of reflected light to one or more output values related to the condition of the ear. The invention further provides a method for detecting and diagnosing ear related conditions including the steps of illuminating inside the ear; inserting a device to the ear canal capable of conveying at least one spectrum of reflected light from the ear to a processing unit; and activating the processing unit thereby translating at least one spectrum of reflected light provided at the time of activating to one or more output values related to the condition of the ear.

Abstract: Apparatus for monitoring the presence of one or more chromophores in a tissue sample, comprises a light source for projecting light to illuminate an area of such tissue sample, a photo-receptor for receiving light remitted by the illuminated area of tissue, and spectroscopic analyser means for monitoring the remitted light, a comparator having means for comparing variations in the intensity and spectral characteristics of the remitted light with respect to the intensity and spectral characteristics of the projected light at different wavelengths and with a record of the intensity and spectral characteristics of light remitted by a reference sample of such tissue and means for emitting a control signal in response to any such variations. Methods of analyzing tissue histology, especially skin histology, are discussed, and a mathematical model is proposed for the analysis and comparison of the remitted light with a reference sample.

Abstract: A method and apparatus are provided for Raman imaging of carotenoids and related chemical substances in biological tissue, such as macular pigments. The method and apparatus utilize the technique of resonance Raman spectroscopy to produce an image of the levels of carotenoids and similar substances in tissue. In this technique, light is directed upon the area of tissue which is of interest such as the retina of an eye. A small fraction of the scattered light is scattered inelastically, producing a carotenoid Raman signal which is at a different frequency than the incident light. The Raman signal is collected, filtered, and analyzed to determine the spatial position and intensity of the Raman signals in the inelastically scattered light. An image of the Raman signals is then produced on an output device, with the image representing the spatial distribution and concentration level of carotenoids in the tissue.

Abstract: In photodynamic diagnosis and photodynamic therapy, the oscillating wavelength of laser light from a light source is fitted to a plurality of different kinds of photosensitizers and exciting conditions thereof. Moreover, diagnosis and treatment are achieved using concurrent diagnosis during treatment is realized as well. A semiconductor laser generates laser light having an oscillating wavelength which is variable and a full width at half maximum which is narrow. A light transmission line guides an irradiated laser light to the vicinity of a focus, an image transmission line observes the focus and the periphery thereof, a fluorescence light extracting device extracts only the fluorescence light emitted from a photosensitizer excited by the irradiated laser light, an image-pick-up/analyzing device picks up and analyzes an image of the extracted fluorescence light and an image display device displays the analyzing result.

Abstract: The invention features methods and systems for treating inflammatory, proliferative skin disorders, such as psoriasis, with ultraviolet phototherapy. The methods and systems use optical techniques to scan a patient's skin, designate areas of affected skin, and selectively deliver high doses of phototherapeutic ultraviolet radiation to the designated areas. To insure that only affected areas of skin affected are designated for the high doses of UV radiation, the methods and systems use one or more optical diagnostics that relate to independent physiological features of affected skin.

Abstract: A body fat measuring apparatus is provided with a light emitting device 1 for projecting light rays to a subject's tissue, light receiving devices 3 and 4 for detecting a transmitted light ray having passed through the subject's tissue and/or a reflected light ray reflected inside the subject's body, and a CPU 6 for calculating the subject's subcutaneous fat thickness and/or body fat percentage by performing an operation by use of the detection results of the light receiving devices 3 and 4. The light receiving devices 3 and 4 are situated at different distances from the light emitting device 1.

Abstract: A method for the evaluation of the ultrastructure of connective tissue, such as cartilage, including (a) providing a probe operative in the near-infrared or mid-infrared region of the electromagnetic spectrum, (b) positioning the probe either to be in contact with the connective tissue (for detecting attenuated total reflectance) or within a sufficient distance from the surface of the connective tissue (for detecting reflection), (c) detecting infrared radiation which penetrates the surface of the connective tissue for detecting attenuated total reflectance or which reflects off the surface of the connective tissue and (d) analyzing the infrared radiation from step (c) for at least one of peak height, peak area and frequency, and comparing at least one of the peak height, the peak area and the frequency for established values for at least one of peak height, peak area and frequency for normal connective tissue to detect a modification in the molecular structure of the connective tissue.

Abstract: Systems and methods for spectroscopic diagnosis and treatment are employed which utilize molecular spectroscopy to accurately diagnose the condition of tissue. Infrared Raman spectroscopy and infrared attenuated total reflectance measurements are performed utilizing a laser radiation source and a fourier transform spectrometer. Information acquired and analyzed in accordance with the invention provides accurate details of biochemical composition and pathologic condition.

Abstract: A device and method in accordance with the invention for determining the oxygen partial pressure (PO2) of a tissue by irradiating the tissue with optical radiation such that the light is emitted from the tissue, and by collecting the reflected or transmitted light from the tissue to form an optical spectrum. A spectral processor determines the PO2 level in tissue by processing this spectrum with a previously-constructed spectral calibration model. The tissue may, for example, be disposed underneath a covering tissue, such as skin, of a patient, and the tissue illuminated and light collected through the skin. Alternatively, direct tissue illumination and collection may be effected with a hand-held or endoscopic probe. A preferred system also determines pH from the same spectrum, and the processor may determine critical conditions and issue warnings based on parameter values.

Abstract: A system and method is disclosed for helping determine a condition of selected tissue of a patient based on a set of thermal images of the selected tissue acquired over a time period. The image set has image regions with corresponding characteristics indicative of a temperature condition of an associated part of the selected tissue, which had been subjected to a thermal challenge during part of the image acquisition time period. Feature values are determined based on the characteristics of selected image regions. A classifier is applied to the features to provide an indication of the condition of the selected tissue, such as indicating a likelihood of malignancy.

Abstract: Prolonged and severe tissue hypoxia results in tissue necrosis in pedicled flaps. We demonstrate the potential of near-infrared spectroscopy for predicting viability of compromised tissue portions. This approach clearly identifies tissue regions with low oxygen supply, and also the severity of this challenge, in a rapid and non-invasive manner, with a high degree of reproducibility. Tissues remaining below a certain hemoglobin oxygen saturation threshold (oxygen saturation index <1) for prolonged periods (>6 h) became increasingly dehydrated, eventually becoming visibly necrotic. Tissues above this threshold (oxygen saturation index >1), despite being significantly hypoxic relative to the pre-elevation saturation values, remained viable over the 72 h post-elevation monitoring period. The magnitude of the drop in tissue oxygen saturation, as observed immediately following surgery, correlated with the final clinical outcome of the flap tissue.

Abstract: A time-varying modulating signal is used as a plethysmography signal, rather than a time-varying detected optical power. The time-varying detected optical power is used (e.g., in a feedback loop) to adjust the source intensity. Light is transmitted from a light source, wherein an intensity of the transmitted light is based on a light control signal. A portion of the light transmitted from the light source is received at a light detector, the portion having an associated detected light intensity. A feedback signal is produced based the portion of light received at the light detector, the feedback signal indicative of the detected light intensity. The feedback signal is compared to a reference signal to produce a comparison signal. The light control signal is then adjusted based on the comparison signal, wherein at least one of the comparison signal and the light control signal is representative of volume changes in blood vessels.

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: Tissue types (e.g. tumorous or normal) are determined using optical spectroscopy. Autofluorescence and diffuse reflectance spectra are generated by separately illuminating a tissue surface area with monochromatic light and white light. A peak in autofluorescence intensity (F) is provided around 460 nm from both from normal and tumorous human brain tissue with 337 nm monochromatic light excitation. Separation between white/gray matter and brain tumors is provided by certain combined F-Rd spectrum numerical values, especially certain ratios of F and Rd between 400 nm-600 nm. Numerical values based on certain combinations of unequal exponential powers of F and Rd are essentially unaffected by the superficial blood contamination. In addition, diffuse reflectance intensity (Rd) between 650 nm and 800 nm from white/gray matter was significantly stronger than that from primary and secondary brain tumors and is used with the combined spectrum numerical value to enhance accurate determinations.

Abstract: Systems and methods for spectroscopic diagnosis and treatment are employed which utilize molecular spectroscopy to accurately diagnose the condition of tissue. Infrared Raman spectrscopy and infrared attenuated total reflectance measurements are performed utilizing a laser radiation source and a fourier transform spectrometer. Information acquired and analyzed in accordance with the invention provides accurate details of biochemical composition and pathologic condition.

Abstract: Systems and methods for spectroscopic diagnosis and treatment are employed which utilize molecular spectroscopy to accurately diagnose the condition of tissue. Infrared Raman spectroscopy and infrared attenuated total reflectance measurements are performed utilizing a laser radiation source and a fourier transform spectrometer. Information acquired and analyzed in accordance with the invention provides accurate details of biochemical composition and pathologic condition.

Abstract: A novel approach to measuring the overall and layer-by-layer thickness of in vivo skin tissue based on near infrared absorbance spectra is described. The different biological and chemical compounds present in the various layers of a tissue sample have differing absorbance spectra and scattering properties that enable them to be discerned and quantified, thus allowing an estimate of the thickness of the tissue being sampled. The method of the invention also yields the chemical composition of the absorbing and/or scattering species of each layer. Additionally, a method of path length normalization for the purpose of noninvasive analyte prediction on the basis of skin thickness and layer constituents is provided.

Abstract: Method and apparatus for imaging objects in turbid media. In one embodiment, the method comprises illuminating at least a portion of the turbid medium with substantially monochromatic light of at least two wavelengths in the 600-1500 nm spectral range. A first of the at least two wavelengths is equal to a resonance wavelength for an optical property of an object in the illuminated portion of the turbid medium but is not equal to a resonance wavelength for the turbid medium. A second of the at least two wavelengths is not equal to a resonance wavelength for either the object or the turbid medium. Light emergent from the turbid medium following each of the foregoing illuminations comprises a ballistic component, a snake component and a diffuse component. A direct shadowgram image may be obtained by preferentially passing from the emergent light, following each illumination. the ballistic and snake components thereof and detecting the preferentially passed light.

Abstract: An apparatus for obtaining a cellular image to be used in performing a test for pathology of the sentinel lymph node, which is the first lymph node a cancer metastasizes to. The gamma radiation emitted from a near-infrared fluorescent colorant injected in advance into the vicinity of a tumor is detected by use of a gamma-probe. A fiber coupler separates the low-coherence light emitted from the light source of an OCT portion (Optical Coherence Tomography) into a signal-light to be projected onto the sentinel lymph node and a reference-light whose wavelength is slightly shifted. The signal-light is projected onto the sentinel lymph node, and interference is caused between the signal-light reflected from a predetermined depth within the sentinel lymph node and the reference-light. A balance differential detector measures the intensity of the interference-light, and a cellular level ultra high-resolution optical tomographic image of the sentinel lymph node is obtained.

Abstract: Methods and apparatus for non-invasive tissue urea concentrations during or subsequent to hemodialysis using near-infrared spectroscopy are discussed. Near-infrared tissue spectra can be obtained by projecting near-infrared radiation into skin on the underside of human forearms and capturing the light reflected back and out through the tissue. An index matching medium is used to couple the tissue to the analyzer. The tissue spectrum collected preferably includes primarily diffuse reflected light reflected from the inner dermis. Multiple tissue spectra of known urea concentration are used to build a model from which the urea concentration of an unknown sample can be devised. The model is based on a partial least squares algorithm applied to multiple tissue scans and concomitant blood sample urea measurements. This model is then applied to an unknown tissue spectra.

Abstract: This invention teaches a method to identify cellular abnormalities which are associated with disease states. The method utilizes infrared (IR) spectra of cell samples which are dried on an infrared-transparent matrix and scanned at the frequency range from 3000-950 cm−1. The identification of samples is based on establishing a reference using a representative set of spectra of normal and/or diseased specimens. During the reference assembly process, multivariate techniques such as Principal Component Analysis (PCA) and/or Partial Least Squares (PLS) are used. PCA and PLS reduce the data based on maximum variations between the spectra, and generate clusters in a multidimensional space representing the different populations. The utilization of Mahalinobis distances, or linear regression (e.g., Principle Component Regression on the reduced data from PCA) form the basis for the discrimination.

Abstract: A diagnostic monitor for classifying biological tissue in which a light emitter (102) is optically coupled to the tissue to be diagnosed (145) and a light detector (174) is optically coupled to the tissue to detect a portion of the light which passes through the tissue. The tissue classifier (184) receives a signal from the detector and provides an optical classification output signal (195), wherein the tissue is classified by type or state, either for detection, localization, or imaging. A method of classifying tissue is also described.

Abstract: A body fat measuring apparatus is provided with a light emitting device 1 for projecting light rays to a subject's tissue, light receiving devices 3 and 4 for detecting a transmitted light ray having passed through the subject's tissue and/or a reflected light ray reflected inside the subject's body, and a CPU 6 for calculating the subject's subcutaneous fat thickness and/or body fat percentage by performing an operation by use of the detection results of the light receiving devices 3 and 4. The light receiving devices 3 and 4 are situated at different distances from the light emitting device 1.

Abstract: The invention relates to a method of using diffuse optical tomography and oxygen in a stroke patient, or a patient suspected of having a stroke, to detect ischemic events or bleeds in the brain.

Abstract: A non-invasive method for analyzing the blood-brain barrier includes obtaining a Raman spectrum of a selected portion of the eye and monitoring the Raman spectrum to ascertain a change to the dynamics of the blood brain barrier. Also, non-invasive methods for determining the brain or blood level of an analyte of interest, such as glucose, drugs, alcohol, poisons, and the like, comprises: generating an excitation laser beam (e.g., at a wavelength of 600 to 900 nanometers); focusing the excitation laser beam into the anterior chamber of an eye of the subject so that aqueous humor, vitreous humor, or one or more conjunctiva vessels in the eye is illuminated; detecting (preferably confocally detecting) a Raman spectrum from the illuminated portion of the eye; and then determining the blood level or brain level (intracranial or cerebral spinal fluid level) of an analyte of interest for the subject from the Raman spectrum.

Abstract: A method and system for examining biological materials using low-power cw excitation Raman spectroscopy. A low-power continuous wave (cw) pump laser beam and a low-power cw Stokes (or anti-Stokes) probe laser beam simultaneously illuminate a biological material and traverse the biological material in collinearity. The pump beam, whose frequency is varied, is used to induce Raman emission from the biological material. The intensity of the probe beam, whose frequency is kept constant, is monitored as it leaves the biological material. When the difference between the pump and probe excitation frequencies is equal to a Raman vibrational mode frequency of the biological material, the weak probe signal becomes amplified by one or more orders of magnitude (typically up to about 104-106) due to the Raman emission from the pump beam.

Abstract: A set of reference moisture value of the plurality of sample skin is measured with conventional skin moisture measuring device. Then a set of standard calibration equation is provided from calculating a set of measured reflectance spectra of calibration and the set of reference moisture value by using the multivariate regression, and it is stored at a memory. The next steps are to measure skin moisture of test skin with reference to the set of standard calibration equation stored at the memory. By radiating near infrared on the test skin and sensing a set of reflectance spectra with the portable skin moisture measuring apparatus by using near infrared reflectance spectroscopy system, the skin moisture is measured at a repeatable and stable way, regardless of the variation of temperature or humidity of the external circumstance.

Abstract: A multitasking optical fiber probe for collecting dosimeter information from more than one position in a sample. The basic principle of the present invention involves using one or more different sensor zones along the length of the fiber each with a different photoactive constituent having a sufficiently unique emission spectra (spectral or temporal) to enable deconvolution of the emission spectra by the computer and therefore correlation of the detected parameter with the position of the sensor zone along the length of the optical fiber. In the broadest form of the invention the probe is embodied by only one sensor zone located at some point along the length of the fiber spaced away from the end face of the fiber.

Abstract: An optical scanning spectroscopic apparatus includes a light source and optics to direct light into a region of interest. Means for detecting autofluorescent emissions at a plurality of detectably distinct wavelengths are also provided. A processor receives data corresponding to the autofluorescence and compares the data to a control data set. The light source may alternately include any source of suitable light such as an arc lamp, a laser, or a pulsed laser each controlled to produce a defined wavelength. The comparison of autoflourescent emissions collected at different wavelengths is claimed as a means for diagnosing various retinal diseases.

Abstract: Noninvasive instrumentation and procedures have been developed for estimating the apparent age of human and animal subjects based on the irradiation of skin tissue with near-infrared light. The method of age estimation provides additional information about primary sources of systematic tissue variability due to chronological factors and environmental exposure. Therefore, categorization of subjects on the basis of the estimated apparent age is suitable for further spectral analysis and the measurement of biological and chemical compounds, such as blood analytes. Furthermore, age determination of subjects has particular benefit in assessment of therapies used to reduce the effects of ageing in tissue and measurement of tissue damage.

Abstract: In a method, a device and a computer program for determining the blood flow in a tissue or organ region, the fluorescence intensity of an exogenous chromophore is measured as a function of time in the tissue region to be examined and from this the permeation rate of the chromophore is calculated, from which the blood flow can be derived.

Abstract: A method and a system is provided for discriminating between healthy cervical tissue and pathologic cervical tissue based on the fluorescence response of the tissue to laser excitation (LIF) and the backscatter response to illumination by white light (in the spectral range of 360 to 750 nm). Combining LIF and white light responses, as well as evaluating a spatial correlation between proximate cervical tissue sites in conjunction with a statistically significant “distance” algorithm, such as the Mahalanobis distance between data sets, can improve the discrimination between normal and abnormal tissue. The results may be displayed in the form of a map of the cervix representing the suspected pathology.

Abstract: Extravasation of a fluid applied to a patient is determined by monitoring light transmitted through the tissue of the patient in proximity to a site at which the fluid is being injected. Light is radiated from a plurality of light sources in an encoded manner into the body part at the site at which the fluid is injected and the light that is reflected, scattered, diffused or otherwise emitted from the body part is detected individually by a plurality of light detectors. Signals representative of the detected light are developed and, prior to injection of the fluid, references are developed against which measurements made during injection of the fluid are compared. New light signals having an improved signal-to-noise ratio are developed from the comparisons of the detected light signals with the associated reference signals.

Abstract: A novel approach to measuring the overall and layer-by-layer thickness of in vivo skin tissue based on near infrared absorbance spectra is described. The different biological and chemical compounds present in the various layers of a tissue sample have differing absorbance spectra and scattering properties that enable them to be discerned and quantified, thus allowing an estimate of the thickness of the tissue being sampled. The method of the invention also yields the chemical composition of the absorbing and/or scattering species of each layer. Additionally, a method of path length normalization for the purpose of noninvasive analyte prediction on the basis of skin thickness and layer constituents is provided.