A wearable device for use with a smart phone or tablet includes a measurement device having a light source with a plurality of light emitting diodes (LEDs) for measuring physiological parameters and configured to generate an optical beam with wavelengths including a near-infrared wavelength between 700 and 2500 nanometers. The measurement device includes lenses configured to deliver the optical beam to a sample of skin or tissue, which reflects the optical beam to a receiver located a first distance from one of the LEDs and a different distance from another of the LEDs, and is also configured to generate an output signal representing a non-invasive measurement on blood contained within the sample. The wearable device is configured to communicate with the smart phone or tablet, which receives, processes, stores and displays the output signal with the processed output signal configured to be transmitted over a wireless transmission link.