Complex sentence: PROMIS was an interactive, touch screen system that allowed users to access a medical record within a largely body of medical knowledge; at its peak, the PROMIS system had over 60,000 frames of knowledge.
Split into simpler sentences: PROMIS was an interactive, touch screen system that allowed users to access a medical record within a large body of medical knowledge. At its peak, the PROMIS system had over 60,000 frames of knowledge.