Abstract:
A wearable device for measuring physiological parameters includes a light source having a plurality of semiconductor light emitting diodes (LEDs) each configured to generate an output optical beam, wherein at least a portion of the one or more optical beam wavelengths is a near-infrared wavelength. The light source is configured to increase signal-to-noise ratio by increasing light intensity for at least one of the LEDs and by increasing a pulse rate of at least one of the LEDs. A lens is configured to receive the output optical beam and to deliver a lens output beam to tissue. A detection system generates an output signal in response to the lens output beam reflected from the tissue, wherein the detection system is configured to be synchronized to the light source, and is located a different distance from a first one of the LEDs than a second one of the LEDs.
Abstract:
A measurement system includes a light source having semiconductor sources configured to generate an input optical beam, a multiplexer configured form an intermediate optical beam from the input optical beam, fibers including a fused silica fiber configured to receive the intermediate optical beam and to form an output optical beam. The output optical beam comprises wavelengths between 700 and 2500 nanometers with a bandwidth of at least 10 nanometers. A measurement apparatus is configured to deliver the output beam to a sample to generate a spectroscopy output beam. A receiver is configured to receive and process the spectroscopy output beam to generate an output signal, wherein the receiver processing includes chemometrics or multivariate analysis methods to permit identification of materials within the sample, the light source and the receiver are remote from the sample, and the sample includes plastics or food industry goods.
Abstract:
A wearable device for use with a smart phone or tablet includes LEDs for measuring physiological parameters by modulating the LEDs and generating a near-infrared multi-wavelength optical beam. At least one LED emits at a first wavelength having a first penetration depth and at least another LED emits at a second wavelength having a second penetration depth into tissue. The device includes lenses that deliver the optical beam to the tissue, which reflects the first and second wavelengths. A receiver is configured to capture light while the LEDs are off and while at least one of the LEDs is on and to difference corresponding signals to improve a signal-to-noise ratio of the optical beam reflected from the tissue. The signal-to-noise ratio is further increased by increasing light intensity of at least one of the LEDs. The device generates an output signal representing a non-invasive measurement on blood within the tissue.
Abstract:
A super continuum light source includes an input light source having semiconductor diodes generating an input beam having a wavelength shorter than 2.5 microns. Optical amplifiers receive the input beam and form an amplified optical beam having a spectral width. The optical amplifiers may include a cladding-pumped fiber amplifier doped with rare-earth materials. A nonlinear element may include mid-infrared fibers to receive the amplified optical beam and to broaden the spectral width of the received amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam, wherein the output beam is pulsed. At least a portion of the output beam is in a mid-infrared wavelength range between 2 microns and 5 microns and at least a portion of the one or more mid-infrared fibers comprises a ZBLAN fluoride fiber coupled to a chalcogenide fiber.
Abstract:
A white light spectroscopy system includes a super continuum light source having an input light source including semiconductor diodes to generate an input beam having a wavelength shorter than 2.5 microns. The light source includes a cladding-pumped fiber optical amplifier to receive the input beam, and a photonic crystal fiber to receive the amplified optical beam to broaden the spectral width to 100 nm or more forming an output beam in the visible wavelength range. The output beam is pulsed with a repetition rate of 1 Megahertz or higher. The system also includes a lens and/or mirror to receive the output beam, to send the output beam to a scanning stage, and to deliver the received output beam to a sample. A detection system includes dispersive optics and narrow band filters followed by one or more detectors to permit approximately simultaneous measurement of at least two wavelengths from the sample.
Abstract:
Non-invasive monitoring of blood constituents such as glucose, ketones, or hemoglobin A1c may be accomplished using near-infrared or short-wave infrared (SWIR) light sources through absorbance, diffuse reflection, or transmission spectroscopy. As an example, hydro-carbon related substances such as glucose or ketones have distinct spectral features in the SWIR between approximately 1500 and 2500 nm. An SWIR super-continuum laser based on laser diodes and fiber optics may be used as the light source for the non-invasive monitoring. Light may be transmitted or reflected through a tooth, since an intact tooth and its enamel and dentine may be nearly transparent in the SWIR. Blood constituents or analytes within the capillaries in the dental pulp may be detected. The non-invasive monitoring device may communicate with a device such as a smart phone or tablet, which may transmit a signal related to the measurement to the cloud with cloud-based value-added services.
Abstract:
A diagnostic system includes a semiconductor light emitter(s) configured to generate an input beam having a wavelength shorter than about 2.5 microns. An optical amplifier(s) configured to receive a portion of the input beam communicates an intermediate beam to an output end of the optical amplifier. An optical fiber(s) configured to receive a portion of the intermediate beam forms an output beam with an associated wavelength. A subsystem having lenses or mirrors receives a received portion of the output beam and delivers a delivered portion of the output beam to a sample. The delivered portion has a temporal duration greater than approximately 30 picoseconds and a repetition rate between continuous wave and Megahertz or higher. A time averaged intensity of the delivered portion is less than approximately 50 MW/cm2. A light detection system collects and analyzes a fraction of the delivered portion that reflects or transmits from the sample.
Abstract:
A system and method for using near-infrared or short-wave infrared (SWIR) sources such as lamps, thermal sources, LED's, laser diodes, super-luminescent laser diodes, and super-continuum light sources for early detection of dental caries measure transmission and/or reflectance. In the SWIR wavelength range, solid, intact teeth may have a low reflectance or high transmission with very few spectral features while a carious region exhibits more scattering, so the reflectance increases in amplitude. The spectral dependence of the transmitted or reflected light from the tooth may be used to detect and quantify the degree of caries. Instruments for applying SWIR light to one or more teeth may include a C-clamp design, a mouth guard design, or hand-held devices that may augment other dental tools. The measurement device may communicate with a smart phone or tablet, which may transmit a related signal to the cloud, where additional value-added services are performed.
Abstract:
A diagnostic system includes a semiconductor light emitter(s) configured to generate an input beam having a wavelength shorter than about 2.5 microns. An optical amplifier(s) configured to receive a portion of the input beam communicates an intermediate beam to an output end of the optical amplifier. An optical fiber(s) configured to receive a portion of the intermediate beam forms an output beam with an associated wavelength. A subsystem having lenses or mirrors receives a received portion of the output beam and delivers a delivered portion of the output beam to a sample. The delivered portion has a temporal duration greater than approximately 30 picoseconds and a repetition rate between continuous wave and Megahertz or higher. A time averaged intensity of the delivered portion is less than approximately 50 MW/cm2. A light detection system collects and analyzes a fraction of the delivered portion that reflects or transmits from the sample.
Abstract:
A remote sensing system comprises a time-of-flight sensor including an array of near-infrared laser diodes comprising Bragg reflectors and pulsed with durations approximately 0.5 to 2 nanoseconds whose light is directed to an object. The detection system comprises a photodiode array coupled to a processor, and the time-of-flight measurement is calculated from the temporal distribution of photons reflected from the object. The sensor is coupled to an optical system comprising an active illuminator with a plurality of light emitting diodes and a camera system configured to be synchronized to the illuminator. Furthermore, the sensor is coupled to a light sensing system comprising a multi-wavelength filter to separate incoming ambient light into a series of wavelength bands, and a detector array configured to capture some of the wavelength bands to generate a color output. The processor may be configured to control the active illuminator based on the received color output.