The document discusses three fields that are fertile for innovation in healthcare: 1) Philosophical/Paradigmatic Field, which involves principles like the constructionist principle and principles of anticipation; 2) Procedural/Technical Systems Field, which includes specialties like cardiology, oncology, and various surgical specialties; 3) Organizational/Social Systems Field, which involves principles of simultaneity, poetic principle, and positive principle. It also discusses tools an innovation accelerator can use like innovation jams, marketplace of ideas, and rapid prototyping to spur innovation in these fields.