The present invention is made to provide a safe and efficient blood glucose measuring device capable of collectively performing blood glucose measurement process and collectively performing insulin administration process on many patients, while ruling out the risk of misidentification and misprescription among the patients. The detection beam profile overlaps the illumination beam profile in a detection region in which a section of a surface profile of the flat products is illuminated, the section being at least partially delimited by the illumination beam profile. The portable computing device can include at least a single piece housing with a cavity having a substantially flat bottom wall. Disclosed herein are preferred sites for adding cysteine residues or introducing cysteine substitutions into the proteins, and the proteins and protein derivatives produced thereby.