IEEE Spectrum introduces how neural circuitry implanted in our brain can do life-saving work. Though the article doesn’t give out much info about the kind of neural circuity implanted, it does mention microprocessor and battery. So it looks like a really low power microprocessor running some kind of algorithm similar to neural net. The article suggests that learning takes place offline, but is silent on how the parameter update can be done or how easy/unintrusive it is.
Either way it shows another very compelling application for embedded systems capable of machine learning tasks.