The invention concerns a medical analyte testing system (10) and a method for its operation, the method comprising the steps of- providing a disposable test element (20) at an application site in a handheld meter (12),- applying body fluid from a user's body portion fluid on a reaction area of the test element (20),- detecting by means of a detection unit (22) of the meter (12) a series of measuring values from the reaction area of the test element (20) and determining the analyte concentration from the series of measuring values,- employing a proximity sensor (28) disposed within the meter (12) to sense the presence of the body portion (32) in a monitored space (36) in proximity to the reaction area of the test element (20), and- controlling the processing of the measuring values depending on an output signal of the proximity sensor (28).
