Various sensors and methods of assembling sensors are described. In some embodiments the sensor assembly includes a first end a body portion and a second end. The first end can include a neck portion and a connector portion and the second end can include a flap a first component a neck portion and a second component. A method is also described for sensor folding. The method can include using a circuit with an attached emitter and a detector that is separated by a portion of the circuit. The method can also include folding the portion of the circuit such that a first fold is created through the emitter and folding the portion of the circuit such that a second fold is created such that the first fold and second fold form an angle.
