Most types of medical technology assessment are performed only after the technology has been developed. Consequently, they have only minor effects on changes in clinical practice. Our study introduces a new method of constructive medical technology assessment that can change the development and diffusion of a medical device to improve its later clinical effectiveness. The method, based on Saaty's Analytic Hierarchy Process, quantitatively supports discussions between various parties involved in technological development and diffusion. We applied this method in comparing a new blood pump with two competitors based on technical, medical and social requirements. These discussions changed the evaluators’ perspectives, reduced diasagreements, and ended in a reliable evaluation of the pump's performance. On the basis of these results, adaptations were derived which improved the design and diffusion of the blood pump. This application shows the adequate potential of our method to steer technological development and diffusion of artificial organs.