SAN FRANCISCO — When Omar Ishrak took over 18 months ago as CEO of Medtronic (Minneapolis), one of the largest med-tech companies in the world, he identified some major changes he wanted to make both in strategy and internal structure. During a wide-ranging interview with Medical Device Daily at the J.P. Morgan Healthcare Conference, Ishrak noted that much has been accomplished, but he stressed that the company still has more to do in order for it to be at the level that he has envisioned for Medtronic's future.