A method of adjusting a skin penetrating depth of a lancet structure of a portable handheld medical diagnostic device is provided. The method includes providing an elongated lancet structure having a skin piercing end and a blood transport portion adjacent the skin piercing end. The skin piercing end when displaced makes an incision at the skin site to produce an amount of bodily fluid from the skin site and in which the blood transport portion transports the amount of bodily fluid away from the skin site for use by the measurement system in making the physiological measurement. An adjustable linkage is adjusted that is connected to a drive member such that movement of the adjustable linkage moves the drive member toward and away from the lancet port to adjust a skin penetrating depth of the lancet structure.
