7018 results about "Wavelength band" patented technology

A photosensitizer together with complementary light energy are used to prevent the development of infection associated with an indwelling medical catheter or device. Light of a selected wavelength or wavelength band is coupled to the catheter or device and transmitted by a wall or walls thereof to one or both of the external and internal surfaces thereof. The catheter or device also incorporates at least one photosensitizer which releases a toxic substance when activated by the light energy which destroys bacteria on or around the catheter or device. A method of preventing infection using photosensitizers and complementary light energy is also disclosed.

Apparatus, method, logic arrangement and storage medium are provided for increasing the sensitivity in the detection of optical coherence tomography and low coherence interferometry (“LCI”) signals by detecting a parallel set of spectral bands, each band being a unique combination of optical frequencies. The LCI broad bandwidth source can be split into N spectral bands. The N spectral bands can be individually detected and processed to provide an increase in the signal-to-noise ratio by a factor of N. Each spectral band may be detected by a separate photo detector and amplified. For each spectral band, the signal can be band p3 filtered around the signal band by analog electronics and digitized, or, alternatively, the signal may be digitized and band pass filtered in software. As a consequence, the shot noise contribution to the signal is likely reduced by a factor equal to the number of spectral bands, while the signal amplitude can remain the same. The reduction of the shot noise increases the dynamic range and sensitivity of the system.

A device and a method to provide a more reliable and accurate measurement of hematocrit (Hct) by noninvasive means. The changes in the intensities of light of multiple wavelengths transmitted through or reflected light from the tissue location are recorded immediately before and after occluding the flow of venous blood from the tissue location with an occlusion device positioned near the tissue location. As the venous return stops and the incoming arterial blood expands the blood vessels, the light intensities measured within a particular band of near-infrared wavelengths decrease in proportion to the volume of hemoglobin in the tissue location; those intensities measured within a separate band of wavelengths in which water absorbs respond to the difference between the water fractions within the blood and the displaced tissue volume. A mathematical algorithm applied to the time-varying intensities yields a quantitative estimate of the absolute concentration of hemoglobin in the blood. To compensate for the effect of the unknown fraction of water in the extravascular tissue on the Hct measurement, the tissue water fraction is determined before the occlusion cycle begins by measuring the diffuse transmittance or reflectance spectra of the tissue at selected wavelengths.

An optical waveguide comprises a core, an inner cladding laterally surrounding the core, and an outer cladding laterally surrounding the inner cladding, wherein the core, inner cladding, and outer cladding have a depressed well configuration. The waveguide operates in three or more wavelength bands, wherein a first wavelength band is centered at about 1300 nm, and wherein a second wavelength band is centered at about 1625 nm. The waveguide has bend losses that are less than or equal to 1.0 dB / turn when measured on a 5 mm radius bend at 1625 nm and bend losses that are less than or equal to 1.5 dB / turn when measured on a 5 mm radius bend at 1650 nm.

For detecting three-dimensional shapes of an elongated flexible body, a sensor cable to be placed in a passage or channel which is formed axially and coextensively within the elongated flexible body. The sensor cable has two pairs of fiber Bragg grating strands within a tubular carrier casing. A signal light beam containing Bragg wavelength bands is projected from a light source to input same to refractive index change portions in the fiber Bragg grating strands. Reflection diffraction light signals from the refractive index change portions are received by a signal processor to measure the degree of strain at each one of the respective refractive index change portions by comparing wavelengths of the reflection diffraction light signals with reference wavelength.

The present invention provides a low cost imaged-based system for detecting, measuring and / or counting labeled features of biological samples, particularly blood specimens. In one aspect, the invention includes a system for imaging multiple features of a specimen that includes one or more light sources capable of successively generating illumination beams each having a distinct wavelength band and a plurality of differentially excitable labels capable of labeling a specimen comprising multiple features, such that each different feature is labeled with a different differentially excitable label. System of the invention may further include a controller operationally associated with the one or more light sources for successively directing illumination beams onto the specimen so that each of the different differentially excitable labels is successively caused to emit an optical signal within the same wavelength band, an optical system capable of collecting such emitted optical signals and forming successive images corresponding to the labeled features of the specimen on a light-responsive surface to form successive sets of image data thereof, and a disposable cuvette for collection and optical analysis of non-red blood cells.