Ask HN: Can anyone in the medical device/software industry explain redundancies?

How can we be sure that our life support systems, surgery robots, interventional radiology equipment et al will not fail at critical moments? Have there been any recent cases of a technical failure that led to major complications? For example, if a heart-lung bypass machine failed during a heart surgery the patient would certainly expire. If anyone with experience in this field could give a brief rundown it would be appreciated.