A method of driving a lancet structure in a portable handheld medical diagnostic device is provided. The method includes connecting a spring-driven motor to the lancet structure within a housing structure of the portable handheld medical diagnostic device. The spring-driven motor is wound to a cocked, triggerable configuration. The spring-driven motor is triggered such that, when triggered, the spring-driven motor (i) displaces a skin penetrating end of the lancet structure outwardly from the housing structure through a lancet port and (ii) retracts the skin penetrating end of the lancet structure back into the housing structure.
