Apple Watch Digital Crown could eventually be replaced with optical sensors

In a new patent published by the US Patent & Trademark Office and noticed by Patently Apple, it appears Apple may have plans to eventually replace the Apple Watch Digital Crown with optical sensors for input.
Currently the Digital Crown allows users to make more precise adjustments than the smaller screen will allow as well as navigate Apple Watch without having to touch the screen. With the new technology, Apple states the following:
The user can provide motions and gestures near the input component that the input component can detect and interpret and user inputs to control an aspect of the watch. The motions and gestures provided by the user can be directly detected with optical systems of the input component, so that the number of moving parts are reduced and space within the watch is more efficiently utilized.
Starting with Apple Watch Series 4, the Digital Crown has also been the home to the ECG heart rate sensor. The patent explains that the new optical sensors will also be capable of measuring heart rate, blood oxygenation level, and more.