A portable pulse measuring device having a lighting configuration having at least three elements selected from a light-emitting source for emitting radiant energy through a human body tissue and a light detector for detecting the intensity of said radiant energy after propagation through the human body tissue and for providing input signals representative of the propagation. The lighting configuration includes at least one light-emitting source and at least one light detector. A processor is provided for determining pulse rate in response to processing the input signals. The elements in the lighting configuration are arranged in the portable pulse measuring device in a configuration where the light-emitting sources in the lighting configuration are asymmetrically disposed in relation to the light detectors in the lighting configuration.