Wearable Sensors Can Tell When You Are Getting Sick

Estimated reading time: 6 minutes

For Snyder, the Lyme diagnosis is just the tip of the iceberg — part of very early work to begin querying massive data sets of health information. The results of the current study raise the possibility of identifying inflammatory disease in individuals who may not even know they are getting sick. For example, in several participants, higher-than-normal readings for heart rate and skin temperature correlated with increased levels of C reactive protein in blood tests. C reactive protein is an immune system marker for inflammation and often indicative of infection, autoimmune diseases, developing cardiovascular disease or even cancer. Snyder’s own data revealed four separate bouts of illness and inflammation, including the Lyme disease infection and another that he was unaware of until he saw his sensor data and an increased level of C reactive protein.

The wearable devices could also help distinguish participants with insulin resistance, a precursor for Type 2 diabetes. Of 20 participants who received glucose tests, 12 were insulin- resistant. The team designed and tested an algorithm combining participants’ daily steps, daytime heart rate and the difference between daytime and nighttime heart rate. The algorithm was able to process the data from just these few simple measures to predict which individuals in the study were likely to be insulin-resistant.

The study also revealed that declines in blood-oxygen levels during airplane flights were correlated with fatigue. Fortunately, the study showed that people tend to adapt on long flights; oxygen levels in their blood go back up, and they generally feel less fatigued as the hours go by.

“The desaturation of oxygen in flight was not something I anticipated,” said Topol. “Whenever you walk up and down the aisle of a plane, everyone is sleeping, and I guess there may be another reason for that besides that they partied too hard the night before. That was really interesting, and I thought it was great that the authors did that.”

Topol noted that one of the biosensors used in the study doesn’t work very well and that another has been recalled. “A few are not going to hold up,” he said. “Either they are not going to be available or they are going to be proven to not be very accurate. But what is good about what the authors did here is that they weren’t just relying on one device. They did everything they could with the kind of sensors that are available today to get data that was meaningful.”

The future of wearable devices

During a visit to the doctor, patients normally have their blood pressure and body temperature measured, but such data is typically collected only every year or two and often ignored unless the results are outside of normal range for entire populations. But biomedical researchers envisage a future in which human health is monitored continuously.

“We have more sensors on our cars than we have on human beings,” said Snyder. In the future, he said, he expects the situation will be reversed and people will have more sensors than cars do. Already, consumers have purchased millions of wearable devices, including more than 50 million smart watches and 20 million other fitness monitors. Most monitors are used to track activity, but they could easily be adjusted to more directly track health measures, Snyder said.

We have more sensors on our cars than we have on human beings.

With a precision health approach, every person could know his or her normal baseline for dozens of measures. Automatic data analysis could spot patterns of outlier data points and flag the onset of ill health, providing an opportunity for intervention, prevention or cure.

Other Stanford-affiliated co-authors of the study are researcher Gao Zhou; postdoctoral scholars Wenyu Zhou, PhD, and Sophia Miryam Schüssler-Fiorenza Rose, MD, PhD; research dietician Dalia Perelman; undergraduate summer intern Ryan Runge; genetic counselor Shannon Rego; high school student Ria Sonecha; Somalee Datta, PhD, director of the Genetics Bioinformatics Service Center; and Tracey McLaughlin, MD, associate professor of medicine.

• < Previous Page