how to describe the owner of something embedded inside them?

I have the following sentence in my story

Almost everyone has implanted under their skin a sensor that monitors their vitals and health in real-time and could alert the wearer of potentially hazardous health events. It can detect whether the wearer is unconscious and automatically call medical services.

I'm wondering if "wearer" is the appropriate word to describe the owner of the embedded sensor or if there is a better word since the sensor is technically inside them? I don't think "owner" describes it appropriately.

You can use

• "Subject" (as in "test subject" or "surveillance subject")
• "Host" (as in "host organism")