By gathering continuous data about sleep, heart rate, and physical activity, biowearable devices can give individuals more control over their well-being. But they also create a detailed digital record of our daily lives—one that the federal government may soon be able to access readily.
Consider this scenario.
You’ve recently received a government-subsidized biowearable. Accordingly, the authorities now know when you’re sleeping, because the device reports your sleep cycle, location, and daily movements in real time to a cloud server accessible through a legal process. It knows when you’re home. It knows when you leave.
Those data are then obtained by an FBI field office (either through direct purchase or, if necessary, a legal process), because a federal prosecutor has decided that your criticism of immigration enforcement operations and your social media posts supporting Immigration and Customs Enforcement protesters constitute “incitement to violence” against federal agents. Under the Trump administration’s elastic (and legally dubious) domestic terrorism definitions and designations, that is enough to open a criminal investigation.
And because the government has known for weeks when you’re at home sleeping, it knows exactly when to break down your door.
That scenario may sound far-fetched, but it is getting closer to reality. In March, the Department of Health and Human Services (HHS) announced that the Advanced Research Projects Agency for Health (ARPA-H) would begin investing in new biowearable technologies through a program it called Delphi, after the ancient Greek sanctuary where the maxim “know thyself” was inscribed. It’s a fitting name for a program designed to help people understand their bodies, but it also raises an uncomfortable question: Who else might come to know them just as well?
The program aims to develop biosensors capable of continuously monitoring cytokines (cellular inflammation markers) and hormone levels, going substantially beyond what current wearables can detect. Funding will be determined on a competitive basis as private-sector stakeholders submit proposals; no specific appropriation has been announced.
It remains unclear why this taxpayer funding is necessary in a field that is already thriving. The global wearables market was valued at roughly $43 billion in 2024 and is projected to exceed $168 billion by 2030.
Devices worn on the wrist, finger, or skin can already monitor heart rates, blood oxygen levels, sleep patterns, physical activity, and—in the case of continuous glucose monitors—blood sugar levels in real time. Some smartwatches can even conduct electrocardiograms capable of detecting irregular heart rhythms, such as atrial fibrillation.
Until recently, people could access most of this information only during periodic visits to a clinic or hospital. Biowearables now enable people to monitor many of these signals continuously in everyday life.
Hellbound and Down 