Abstract: A device configured to determine a biological indicator level in tissue. The device includes at least one emitter configured to emit light, a detector configured to receive light and transmit data representative of the received light and a processor coupled to the at least one emitter and the detector. The device further includes a non-transitory storage medium coupled to the processor and configured to store instruction to cause the device to determine a level of a biological indicator.

Abstract: Optical-electronic device configured to generate a calibration factor for use in determining optical density. The device includes at least one emitter configured to emit light, a detector configured to receive light and transmit data representative of the received light and a processor coupled to the at least one emitter and the detector. The device further includes a non-transitory storage medium coupled to the processor and configured to store instruction to cause the device to perform the calibration method. Additionally, a calibration container includes a main body, upper lid, and a lower lid. The main body is configured to receive the device and an object having known optical properties.

Abstract: Apparatus for optical tissue detection and discrimination between a tissue of a user and non-tissue materials and method of optical tissue detection and discrimination between a tissue of a user and non-tissue materials are provided. The apparatus for optical tissue detection includes one or more of light sources. The apparatus can further include at least one photodetector. A processor can be operable to determine whether the detected light is from a tissue of a user.