Abstract: Ultra-small optical probes comprising a single-mode optical fiber and a lens which has substantially the same diameter as the optical fiber. The optical fiber and lens are positioned in a probe housing which is in the form of an insertional medical device such as a guidewire. Connector elements are provided to facilitate the attachment of the probe to an optical system and the quick disconnection of the probe from the optical system. The probe is used to obtain optical measurements in situ in the body of an organism and can be used to guide interventional procedures by a surgeon.

Abstract: A system for assessing organ function has a plurality of light emitters of distinct spectral characteristics are coupled into a percutaneous fiber delivery assembly with a tip extending to or into an internal organ to illuminate organ tissue. The assembly includes a delivery optical fiber, and a collection fiber that collects and returns light scattered, reflected or emitted by the surrounding tissue to a detector at the proximal end. The device also senses temperature at the tip. Control and processing modules drive the laser diodes and process the return signals. The instrument may assess general metabolic activity by detecting light absorption of a linked substance, for example at a peak attributed to deoxygenated hemoglobin and/or at one or more peaks attributed to oxygenated hemoglobin. Preferably, change of a parameter such as pulse oxygen saturation together with one or more other parameters such as temperature are detected to provide an indication of organ function, e.g., the onset of shock.

Abstract: A method and apparatus for analyzing a test material by inducing and detecting light-matter interactions. Particles of matter are introduced into a volume bounded by reflective surfaces wherein light of discrete frequencies can set up a standing wave mode of low loss. Light transported over a waveguide is introduced to induce a state change in the particles of matter and to cause the release of quantitized energy from the matter. A portion of the quantitized energy is captured and transported over a waveguide to a detector. The detector records a portion of the quantitized energy. Characteristics of the particles of matter may then be determined based upon the recorded portion of the quantitized energy.

Abstract: An apparatus for continuous cardiac output monitoring ascertains cardiac output by measuring the cross-sectional area of the vessel and the flow rate of fluid flowing through the vessel. The cross-sectional area is derived from the measured resistance within the vessel whereby a pair of signal electrodes injects a known electrical signal into the vessel and the resistance is derived from the known signal and the differential voltage between first and second measuring pairs of electrodes. Resistivity of the fluid is a component of the cross-sectional area derivation, and a temperature sensor is provided to allow for compensating for variations in resistivity with temperature. A velocity sensor is preferably of an optic fiber, Doppler shift type, and the accuracy of the velocity measurement is improved by focusing light emissions from the optic fiber(s) by either providing a Fresnel plate on the terminal end of the fiber or by forming the terminal end of the fiber in a generally conical shape.

Abstract: Device and method for measuring the absorption of radiation in a portion of tissue. For monitoring tissue and/or in order to permit medical indications, it is necessary to gather parameters allowing an assessement of the condition of the tissue, especially with regard to its oxygen supply. The disclosed invention provides a sensor carrier (1) at the loose end of which a sensor device (2) is mounted. This sensor device carries sensor areas (5, 6) which are connected to a measuring instrument (4). Light is emitted from a sensor area (5) and received by a sensor (6) after having transilluminated the tissue. The disclosed invention may be used for examining and controlling the tissue, for example, for perinatal measurement of arterial oxygen saturation of the fetus.

Abstract: Apparatus and method for measuring properties of certain analytes are provided. The apparatus includes a sensor capsule having a processing chamber defined by a wall which in one embodiment has a semi-permeable membrane permeable to the analyte as at least a portion thereof. Receptor material is disposed within the chamber and is capable of chemically interacting with the analyte. In one embodiment, at least a portion of the sensor is translucent. A light source, which may be an optical fiber, causes light to impinge on a translucent portion of the capsule and pass therethrough. Responsive fluorescent light is generated and emitted. This light may be received by detector means and processed in a conventional manner to determine concentration of the analyte. A dye-labelled analog-analyte may be provided within the chamber. Both the receptor material and analog-analyte are of such size that they will not pass through the semi-permeable membrane although the analyte can.

Abstract: The present invention provides low resolution Raman spectroscopic systems and methods for in-vivo detection and analysis of a lesion in a lumen of a subject. The system uses a multi-mode laser attached to a catheter in making in-vivo Raman spectroscopic measurements of the lumen. The system includes a light collector and/or a light dispersion element as well as a detector to measure spectral patterns that indicate the presence of the lesion. Based on the spectral response of the lumen, the presence (or absence) of a lesion can be determined. In addition, the components of the lesion can also be identified based on the unique Raman spectrum associated with each component.

Abstract: A device and method for imaging an object that is situated within a fluid environment having suspended particles uses infrared illumination. In a representative application, a catheter having fiber optics is inserted into the vasculature of a patient. The fiber optics transmits infrared light to an optical head at a distal end of the catheter, which transmits the light into a bloody environment to an object to be imaged. Light reflecting from the object is collected and transmitted throughout the fiber optic to an infrared camera, so that an image is formed. Proper selection of the wavelength of infrared illumination allows objects to be imaged through what would otherwise be an opaque liquid. The invention has particular utility in the field of medical imaging.

Abstract: The present invention provides in various embodiments novel, wearable systems for determining the metabolic condition of an aerobically stressed portion of tissue such as the muscle tissue of an exercising person. Generally, the systems comprise lightweight rugged detectors, worn adjacent the tissue being monitored. The system of the present invention thus minimizes any performance impairment. In preferred systems a wearable power pack and a wearable display means are provided for displaying information indicative of the aerobic metabolic condition of the region being monitored. In a preferred embodiment intended for use while running or engaged in similar athletic activities, the display is worn on the wrist and displays information from a leg-mounted detector. In another embodiment, intended to provide information to coaches, a telemetry system is employed to transmit a signal carrying the data from the detector to a remote location, for processing and display.

Abstract: A device and method are provided for assessing impairment of blood circulation in a patient, such as that in perfusion failure, wherein the patient requires mechanical ventilatory support. The invention involves measurement of PCO.sub.2 (partial pressure of carbon dioxide) within the lower respiratory tract of the patient, using a device that includes an endotracheal breathing tube for introducing air from an air supply pump into a patient's lungs, wherein a carbon dioxide sensor is provided as an integral part of that device, i.e., is physically connected to the endotracheal breathing tube in a manner that allows for PCO.sub.2 measurement along the sidewall of the patient's trachea.

Abstract: A multiple diameter fiber optic device comprises one or more optical fibers that are used to irradiate light onto a tissue and to detect light back-scattered by the tissue wherein each fiber is used for both irradiation and detection. In the case of multiple fibers, the fibers typically are bundled together at the probe end of the bundle. The diameters and/or numerical apertures of the one or more fibers are selected to provide different sampling volumes within the tissue. More specifically, the diameter and/or numerical apertures of the one or more fibers are chosen to emphasize differences in light penetration into the tissue such that the diameter and/or numerical aperture of each fiber is related to the scattering and absorption path lengths in the tissue.

Abstract: The detection method and apparatus detects abnormalities having a first signal propagation property within a host medium having a second signal propagation property based upon signals which have been reflected, scattered and/or absorbed by the host medium and any abnormalities therein. The detection apparatus includes a signal source for introducing a signal into the host medium which varies with respect to a predetermined signal parameter, such as time, frequency or source location. The detection apparatus also includes a plurality of detectors disposed along some or all of the boundary of the host medium for detecting the signal following propagation through the host medium and any abnormalities within the host medium. The detection apparatus further includes a signal processor for constructing at least one partial differential equation to describe the propagation of a regularized signal through a medium having the same shape as the host medium.

Abstract: Systems and methods for advancing a guide wire through body tissue are described. In one form, the guide wire includes an interferometric guidance system and a tissue removal member. The interferometric guidance system is coupled to the guide wire and includes a first optic fiber, a second optic fiber, and a detecting element. The first optic fiber includes a first end and a second end, and extends through a guide wire bore so that the second end is adjacent the guide wire second end. The second optic fiber of the guidance system similarly includes a first end and a second end, and a reference mirror is positioned adjacent the second optic fiber second end. The detecting element is configured to determine interference between a light beam propagating through the first optic fiber and a light beam propagating through the second optic fiber. The tissue removal member also is coupled to the guide wire and is configured to create a path through body tissue so that the guide wire may be advanced therethrough.

Abstract: A fiber optic sensor for D dimer (a fibrinolytic product) can be used in vivo (e.g., in catheter-based procedures) for the diagnosis and treatment of stroke-related conditions in humans. Stroke is the third leading cause of death in the United States. It has been estimated that strokes and stroke-related disorders cost Americans between $15-30 billion annually. Relatively recently, new medical procedures have been developed for the treatment of stroke. These endovascular procedures rely upon the use of microcatheters. These procedures could be facilitated with this sensor for D dimer integrated with a microcatheter for the diagnosis of clot type, and as an indicator of the effectiveness, or end-point of thrombolytic therapy.

Abstract: A catheter tube carries an imaging element for visualizing tissue. The catheter tube also carries a support structure, which extends beyond the imaging element for contacting surrounding tissue away from the imaging element. The support element stabilizes the imaging element, while the imaging element visualizes tissue in the interior body region. The support structure also carries a diagnostic or therapeutic component to contact surrounding tissue.

Abstract: An apparatus and method for transilluminating a tubular tissue within the body. The apparatus comprises an elongate catheter having a fiber optic substantially coextensive with the length thereof which provides diffuse illumination laterally along at least a portion of the length of the catheter. The fiber optic terminus at the proximal end of the catheter is flared to form a light receiving aperture for collecting illuminating light. The flared proximal end of the optical fiber presents an effectively greater light input aperture and enables the fiber to conduct more light to the distal delivery end than would otherwise be possible with a fiber having a flat cut end and receiving light from a divergent light source. The distal end of the catheter is dimensioned to fit within a tubular tissue and be advanced therethrough.

Abstract: A physical-information-image displaying apparatus for use with an endoscope including an image pick-up which picks up an endoscopic image from a living subject and produces an endoscopic-image signal representing the picked-up endoscopic image, and a display which displays the picked-up endoscopic image represented by the endoscopic-image signal, the apparatus including a physical-information obtaining device which obtains a physical information from the subject and produces a physical-information signal representing the obtained physical information, a physical-information-image-signal producing device which produces, based on the physical-information signal produced by the physical-information obtaining device, a physical-information-image signal representing a physical-information image corresponding to the obtained physical information, and a superimposing device which superimposes the physical-information-image signal produced by the physical-information-image-signal producing device, on the endoscopic-i

Abstract: An apparatus for informing an operator of an abnormality of a physical information obtained from a living subject, including a physical-information obtaining device which obtains the physical information from the subject via an endoscope and outputs a physical-information signal representing the obtained physical information, a signal converting device which converts the physical-information signal into an analog speech signal having a waveform representing a speech corresponding to the obtained physical information, a speech outputting device which outputs the speech represented by the speech signal, a judging device for judging whether the obtained physical information represented by the physical-information signal is abnormal, and a frequency shifting device which shifts, when the judging means makes a positive judgment, frequencies of the speech output by the speech outputting device, so that the operator is informed of the abnormality of the physical information obtained from the subject.

Abstract: Optical localization fiber embodiments (200, 260, 270, 290, 310, 330, and 350) suitable for preoperative localization of soft tissue lesions by X-ray mammography, CT MRI, ultrasonography or nuclear medicine are provided. In these embodiments at least one hook is carried by an optical fiber for retention in soft tissue. The tip of the optical fiber is visible through the soft tissue when the origin of the optical fiber is attached to a light source. Embodiments include dual hooks (224, 226) attached through a hole (214) in the tip portion (206), a hook (262) fused to the tip (264), a hook (272) glued to the tip (274), a hook (292) held on by a cap (294), a hook (312) screwed into the tip (320), a hook (340) held in a bore in the tip portion (336) by cement, and a hook (358) in a groove (352). A supplemental optical fiber probe (250) provides a method for locating the fibers inside soft tissue.