Once you get older you are likely to be prescribed more and more pills and at the same time you are likely to lose memory, hence skipping your daily "dose".
This is where Proteus comes in. They have invented (back in 2012) a sensor that gets powered by stomach acid. Attached to a pill, it is tiny, less than a mm square and one third of a mm thick, it has two metallic strips, one made of copper and one made of magnesium, that when bathed by the hydrochloric acid produced by your stomach generates electrical power (like a battery). This power is used to transmit a radio signal that is intercepted by a patch stuck on the skin by the navel. In turns the patch communicates with your smartphone to signal that the pill has been swallowed.
Different pills generate different radio signals so that the patch (the smartphone) can keep track of what and when you have been swallowing.
The sensor will be rapidly consumed by the acid and it will dissolve.
Clearly a nice way to monitor the effective use of a prescription. And as everything this also has a flip side. As pointed out in an article in The Verge, now that the Proteus sensors start to get used the privacy aspect comes to the fore.
Do we really want to be monitored in something as personal as getting pills? Personally I would say yes, but I can appreciated that someone else may not want to be "forced" to take a pill. And yet, if this monitoring is shared with your insurance company, they may actually impose the monitoring as a condition to pay for the cure, you lose quite a bit of privacy. I can also understand that an insurance company footing your health care bill may consider to be in its right to make sure that you get the prescribed medicine...
It is a thorny issue. And it is yet another case where the Digital Society meddles with our personal life.