Women who have difficulty getting pregnant frequently track their basal temperature — the lowest body temperature of the day — as an indication of when they are most fertile. (The lowest temp of the cycle is supposedly Go time.) One of the difficulties of getting an accurate reading is that your basal temperature is reached when you’re asleep.
YONO has started a Kickstarter campaign to sell an in-ear thermometer — about the size of a Motorola Hint Bluetooth headset — that you wear while you’re asleep. The device tracks your temperature all night and uploads the data in the morning for your review. The device sells for $150 outright, or for a four-month lease at $20/month. Delivery is set for December.
The trouble with YONO, aside from the general problems with crowdfunding, is that the science surrounding basal temperature is somewhat iffy. Medical research says that basal temperature alone is not a good predictor of fertility, and that inexpensive mercury thermometers are more accurate than digital thermometers.