So you would like to come up with your own smart rings, headbands and patches? The SensWear Dev Kit has you covered. It is an open source wearable sensing kit with a flexible PCB main board that you can use for all kinds of wearables. It gives you access to raw sensor data and firmware to give you more control for your projects. This development kit has Python and TypeScript SDKs. It has a Zephyr-based firmware.
Since the core electronics are separated from the sensor modules and enclosure, you can use SensWear for custom wearable projects. According to the campaign page, a smart ring enclosure is included with every pack. There is a mobile app that shows device status and live sensor data. User-designed custom daughter boards are supported. This dev kit also has a curved 23 mAh battery.
