Abstract: A method for determining blood glucose levels by measuring the glucose concentration in the ocular aqueous humor using optical refractometry by passing laser light the aqueous ocular humor, measuring the laser light's optical refractivity, and comparing the refractivity with known data, the comparison yielding the blood glucose level.

Abstract: Stimulated Raman spectroscopy is used to non-invasively measure the concentration of an Raman active molecule, preferably D-glucose in the ocular aqueous humor of living being. The apparatus and method make use of two monochromatic laser beams, a pump laser beam and a probe laser beam. The output power of the pump laser beam is amplitude modulated, combined with the probe laser beam and directed into the ocular aqueous humor. The introduction of the laser beams into the ocular aqueous humor induces scattered Raman radiation, which causes a portion of the energy at the pump frequency to shift over to the probe frequency. The pump and probe laser beams are then detected as they exit the ocular aqueous humor. The probe laser beam is filtered, converted into an electrical signal and amplified. It is then compared to the modulation signal to generate an electrical signal representative of the concentration of D-glucose in the ocular aqueous humor.

Abstract: The depth of water ahead of a vessel is detected by sonar means carried aboard a drone stationed by radio control ahead of the vessel. Detected depth information is transmitted from the drone to the vessel where it is displayed for use by the vessel pilot in navigating shallow waters.