To provide a medical device for setting further appropriate conditions for injecting medicinal solution to heavyweight and lightweight patients.

The medical device performs the following processes to determine injection conditions of contrast medium: determining a standard body weight of a patient; calculating a basic circulating blood volume (BV) of the patient using the patient's actual body weight as a parameter; calculating an ideal circulating blood volume (BV') of the patient using the patient's standard body weight as a parameter; calculating a ratio of the basic circulating blood volume (BV) to the ideal circulating blood volume (BV'); multiplying the standard body weight by the ratio to calculate a contrast basic body weight (CBW); and determining the injection conditions of the contrast medium based on the contrast basic body weight (CBW).