Abstract: A lancet assembly for pricking a person's skin for the purpose of causing a drop of blood to seep out, which can be collected and analyzed. The lance assembly comprises a housing and spring means carrying a lancet blade in the housing. The spring means has a non-linear characteristics, so that when the spring means is released from a compressed state a first spring constant is effective during an initial expansion of the spring means up to a predetermined limit of expansion, and a second spring constant smaller than the first spring constant is effective during a further expansion of the spring means beyond the predetermined limit of expansion.