摘要:
An active remote sensing system is provided with an array of laser diodes that generate light directed to an object having one or more optical wavelengths that include at least one near-infrared wavelength between 700 nanometers and 2500 nanometers. One of the laser diodes pulses with pulse duration of approximately 0.5 to 2 nanoseconds at repetition rate between one kilohertz and about 100 megahertz. A beam splitter receives the laser light, separates the light into a plurality of spatially separated lights and directs the lights to the object. A detection system includes a photodiode array synchronized to the array of laser diodes and performs a time-of-flight measurement by measuring a temporal distribution of photons received from the object. The time-of-flight measurement is combined with images from a camera system, and the remote sensing system is configured to be coupled to a wearable device, a smart phone or a tablet.
摘要:
An active remote sensing system is provided with an array of laser diodes that generate light directed to an object having one or more optical wavelengths that include at least one near-infrared wavelength between 600 nanometers and 1000 nanometers. One of the laser diodes pulses at a modulation frequency between 10 Megahertz and 1 Gigahertz and has a phase associated with the modulation frequency. A detection system includes a photo-detector, a lens, a spectral filter at an input to the photo-detector, and a processor that processes digitized signals received from the photo-detector to generate an output signal. The detection system uses a lock-in technique that synchronizes pulsing the one laser diode. The active remote sensing system is configured to be mounted on a vehicle or an airborne platform to provide distance information based on a time-of-flight measurement.
摘要:
A diagnostic system is provided with a plurality of semiconductor light emitters, each configured to generate an optical beam, and a beam combiner to generate a multiplexed optical beam. An optical fiber or waveguide communicates at least a portion of the multiplexed optical beam to form an output beam, wherein the output beam is pulsed. A filter, coupled to at least one of a lens and a mirror to receive at least a portion of the output beam, forms an output light. A beam splitter splits the light into a sample arm and a reference arm and directs at least a portion of the sample arm light to a sample. A detection system is configured to receive from the sample at least a portion of reflected sample light, to generate a sample detector output, and to use a lock-in technique with the pulsed output beam.
摘要:
A spectroscopy system includes a light source having an input light source, including semiconductor diodes generating an input beam with a wavelength shorter than 2.5 microns. Cladding-pumped fiber amplifiers receive the input beam and form an amplified optical beam having a spectral width. A nonlinear element broadens the spectral width of the amplified optical beam to 100 nm or more through a nonlinear effect forming an output beam that is pulsed. A filter is coupled to at least one of a lens and a mirror that receives the output beam and delivers the filtered output beam to a sample. A detection system includes detectors configured to receive the output beam reflected or transmitted from the sample. The detection system is configured to use a lock-in technique with the pulsed output beam and the spectroscopy system is adapted to detect chemicals in the sample.
摘要:
A system and method for selectively processing target tissue material in a patient include a laser subsystem for generating an output laser beam and a catheter assembly including an optical fiber for guiding the output laser beam. The beam has a predetermined selected wavelength between 900 nm and 2600 nm. The catheter assembly is sized to extend through an opening in a first part of the patient to a tissue material processing site within the patient. A beam delivery and focusing subsystem includes a focal distance, which may be adjustable, that positions the beam into at least one focused spot on the target tissue material disposed within a second part of the patient for a duration sufficient to allow laser energy to be absorbed by the target tissue material and converted to heat to produce a desired physical change in the target tissue material without causing undesirable changes to adjacent non-target material.
摘要:
A wearable device includes a measurement device adapted to be placed on a wrist or ear having a light source with LEDs to measure physiological parameters. The measurement device generates an optical beam having a near infrared wavelength between 700-2500 nanometers by modulating the LEDs, and lenses to deliver the beam to tissue, which reflects the beam to a receiver having spectral filters in front of spatially separated detectors coupled to analog to digital converters that generate at least two receiver outputs. Signal-to-noise ratio of the beam reflected from the tissue is improved by comparing the receiver outputs, and by increasing light intensity from the LEDs. The receiver is synchronized to the modulation of the LEDs and uses a lock-in technique that detects the modulation frequency. The measurement device generates an output signal representing a non-invasive measurement on blood within the tissue.
摘要:
A wearable device includes a measurement device having light emitting diodes (LEDs) measuring a physiological parameter. The measurement device modulates the LEDs to generate an optical beam having a near-infrared wavelength between 700-2500 nanometers. Lenses receive and deliver the optical beam to tissue, which reflects the optical beam to a receiver having spatially separated detectors coupled to analog-to-digital converters configured to generate receiver outputs. The receiver captures light while the LEDs are off, and reflected light from the tissue while the LEDs are on, to generate first and second signals, respectively. Signal-to-noise ratio is improved by differencing the first and second signals and by differencing the receiver outputs. The measurement device further improves signal-to-noise ratio of the reflected optical beam by increasing light intensity of the LEDs relative to an initial light intensity. The measurement device generates an output signal representing a non-invasive measurement on blood contained within the tissue.
摘要:
A measurement apparatus includes sensors adapted to be coupled to tissue containing blood and configured to generate signals associated with physiological parameters. The device is configured to communicate with a software application through a base device. The software application is configured to operate on a control system. The control system is capable of receiving physiological parameter signals. The control system includes a touch-screen, a proximity sensor, circuitry for obtaining movement information from a positioning sensor, a mechanical system having actuators, and a wireless transmitter to transmit data to a host. The software application is operable to generate the physiological information based on the signals from the sensors. The control system is further configured to receive voice input signals and manually entered input signals. The host is configured to generate status information from the data and includes a memory storage device and a communication device.
摘要:
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.
摘要:
A system and method for using near-infrared or short-wave infrared (SWIR) light sources between approximately 1.4-1.8 microns, 2-2.5 microns, 1.4-2.4 microns, 1-1.8 microns for active remote sensing or hyper-spectral imaging for detection of natural gas leaks or exploration sense the presence of hydro-carbon gases such as methane and ethane. Most hydro-carbons (gases, liquids and solids) exhibit spectral features in the SWIR, which may also coincide with atmospheric transmission windows (e.g., approximately 1.4-1.8 microns or 2-2.5 microns). Active remote sensing or hyper-spectral imaging systems may include a fiber-based super-continuum laser and a detection system and may reside on an aircraft, vehicle, handheld, or stationary platform. Super-continuum sources may emit light in the near-infrared or SWIR. An imaging spectrometer or a gas-filter correlation radiometer may be used to identify substances or materials such as oil spills, geology and mineralogy, vegetation, greenhouse gases, construction materials, plastics, explosives, fertilizers, paints, or drugs.