Making a difference.

Discusses the engineering developments in prosthetics and biomedical devices. Introduction of the SA node in pacemakers that generate electric impulse through the heart; Ability of artificial cochleas to replicate sound wave conversion using 300 transducers; Role of the dialysis machine as an external artificial kidney; Development of computer controlled replacement legs handling weight and energy return. INSETS: Organs--a potential growth area?;Customized designs.