Concurrently, a revolution in sensors, batteries, and connectivity has led to a flood of “quantified self” devices such as Nike Fuel band, Jawbone’s UP, and the Basis Band. These wearable gadgets monitor an expansive array of biometrics, most of which can be used to hunt flow. And there are iPhone apps that do the same. We can now track cardiac coherence—when brain waves and heart waves synch up—which has been correlated with the state (but needs more research).
