Abstract: Techniques for detecting cannabinoid, opioid, and virus aerosols in an exhaled breath are provided. An example method of identifying a virus-containing aerosol in exhaled breath includes capturing a breath input in an aerosol filter cartridge, disposing the aerosol filter cartridge in an optical path in a spectroscopy system, detecting one or more infrared spectral features of the breath input with the spectroscopy system, and identifying the virus-containing aerosol based on the one or more infrared spectral features.

Abstract: A cerebral oximeter includes a first light source for emitting light in response to a first electrical signal, a second light source for emitting light in response to a second electrical signal, a first photodetector for detecting at least a portion of the light emitted from the first light source, and a second photodetector for detecting at least a portion of the light emitted from the second light source. The cerebral oximeter further includes a pseudonoise (PN) code modulator for modulating the first electrical signal and the second electrical signal using a spreading sequence to occupy an electrical bandwidth greater than necessary to send optical signal pulse amplitude information to a photodetector, and a time gate for filtering a first detection signal from the first photodetector and a second detection signal from the second photodetector based on a desired time-of-arrival.

Abstract: Techniques for detecting narcotics such as tetrahydrocannabinol (THC) or other aerosols such as cannabinoids, opioids, etc., in an exhaled breath using infrared spectroscopy are provided. An example of an apparatus for sensing THC according to the disclosure includes a tunable laser source, at least one photodetector, a sample cell disposed between the tunable laser source and the at least one photodetector, and at least one processor operably coupled to the tunable laser source and the at least one photodetector and configured to provide a control signal to the tunable laser source, determine a spectral absorption line or group of absorption lines associated with THC based on an intensity of infrared light detected by the at least one photodetector, and determine a THC concentration value based on the spectral absorption line intensity. A laser-based apparatus for sensing narcotics in exhaled breath may include a single, dual, or multi-optical frequency comb spectrometer.