Abstract: The present invention provides a non-invasive apparatus for continuously measuring a plurality of physiological variables from a user's ear. The non-invasive apparatus includes a body, a temperature detector positioned on the body, a plastic housing encapsulating the body, a light emitting device for emitting a light beam to a tragus of the user's ear, and a light receiver for receiving the light beam penetrating through the tragus. The temperature detector can measure the user's body temperature from a tympanic membrane. The light emitting device incorporating the light receiver can measure the blood oxygen saturation of the user by detecting the energy loss of the light beam due to the penetration through the tragus. The plastic housing includes an awl-shaped portion capable of inserting into an auditory meatus of the user's ear and a protrusion capable of engaging with a triangular fossa of the user's ear.