Your life or death scenario is an edge case with its own special complexities which should not be lumped in with discussions of the vastly voluntary choices we can make. Healthcare is heavily regulated as we all know. This raises the barrier to entry to new competitors, and leads to a less dynamic market where the status quo can last a long long time. So you end up with only 1 or a very small number of medical devices (with the associated software) for a given situation.

I would expect that the greater debate on privacy will, over time, hopefully lead to some changes in how we are able to control the data generated by our bodies. Until that happens, I’m going to take the thing that saves my wife’s life with the potential for some shadiness or simple distaste at what may happen to her data, or, I might look at it as her voluntary consent which was fully given with her and my knowledge well ahead of time — helps to save others lives, and some loss of control of that data is actually quite noble.

As you might guess, I started at the abstract, but ended up at the concrete, and my wife really does have such a device, similar to your example. And I also work in big data analytics industry, and get involved in these sorts of discussions pretty often.