AN INTERNAL WEARABLE FOR AUTOMATED FERTILITY PREDICTION

A wearable temperature sensor, worn internally, that can measure basal body temperature while the user is sleeping. The data can be used to accurately determine the fertile and infertile phases of a woman's menstrual cycle.

Internal Wearable Basal Body Temperature Sensor design idea

Why?

I am a programmer, I have been a Fertility Awareness Method (FAM) user and advocate for 15 years. I want to enable women to automate fetility predicion without expensive gadgets, synthetic hormones, and tedious calculations that are prone to errors. It is possible to automate fertility prediction in a safe, secure, and affordable way, and I believe in a future where automated fertility prediction is accessible for all women.

Why an internal sensor?

Here's the thing: A woman's internal body temperature (aka BBT) at rest changes over the course of her cycle. The best way to accurately measure this temperature is while sleeping, about one hour before waking up in the morning. The temperature shift is so subtle (0.6°F or 0.35°C) that it is critical to have a precise sensor that can track BBT at the optimal time of day. This is not trivial.
If ovulation has occurred, the BBT will generally shift at least 0.2 degrees Fahrenheit (.11 degrees Celsius) higher than the temperature of the previous 6 days' temperatures, and will be sustained at or above this higher temperature for three days or more.

Has this already been done?

Yes and no. TL;DR: There is not an existing internal wearable product that I am aware of except for one. There are many significant differences between the existing one and what I want to build. There is another one that is pre-launch. However, according to initial press reports about it, it is expensive and designed to be disposable. (Again, to target women trying to get pregnant who will use it for only a few months)
The products that do exist are: (my opinions are my own)
- CRITICALLY: Not a single existing product is willing to expose their fertility prediction algorithm. How can I be expected to trust that their algorithm serves my needs?
- All (except one) are external wearables. I am creating an interal wearable.
- Closed source
- Do not give API access
- Expensive
- Require monthly payment plans
- Are only targeted to women trying to become pregnant (what about the rest of us? What if I am waiting a year or so? What if I just want to monitor my fertility to better determine if I have PCOS? What if I don't want to conceive?)
- Who know's what they do with the data. Do they sell it?
- Terrible user experience
- Extremely cumbersome to use
- Flimsy, low quality design
- Confusing to use
- Unattractive
- Questionable materials and transmission devices
- Aren't licensed in all countries
- And more...