In this study, an electronic insulin pen was designed for diabetic patients dependent on insulin use in order to prevent wrong timing and wrong dosage caused from old age, vision or mental illness. The insulin pen that can be used electronically for routine dose injections, and that is called as bilensulin, was designed to be able to used manually in the emergency. It is aimed that the patient can set the dose easily by using the fairly simple menu of the device. Additionally, the device was not designed as disposable, the device was designed as reusable by changing the insulin tube. Because the tube chamber was designed to be suitable for all types of insulin, it can be used by changing tube without using different pen. Dose accuracy was adjusted with low error by performing insulin dose measurements on a sensitive balance. Patent was attempted for the designed electronic insulin pen, and the studies on the device are continuing.