Apparatus (100) for detecting presence of a blood sample, the apparatus comprising a housing (107) having an aperture (105), the aperture configured to receive a body part of a user a camera (110) having a field of view that encompasses at least a portion of the aperture, the camera configured to capture images of the users body part and a processor (212) configured to control operation of the camera receive the captured images and determine whether a predetermined quantity of blood is present on the surface of the users body part, whereby the processor is configured to analyse the captured images to monitor a position of a lancet.
