Apple (AAPL) continues to delve into the medtech world. This week Chief Executive Officer Tim Cook was seen wearing a new device that monitors his blood sugar levels and tracks how those levels respond to things like diet and exercise.

First reported by CNBC, Cook has linked the device with his Apple Watch, which drives home the tech giant’s increased focus on diabetes treatment. In April, Apple further moved into diabetes management after reportedly hiring a group of biomedical engineers to develop sensors to monitor blood sugar levels. Apple has reportedly been moving into the direction of diabetes management for several years–with a particular focus on how a device could work in conjunction with the Apple Watch. In 2015, Cook said he didn’t want the Apple Watch itself to become a medical device because he did not want it to undergo the regulatory scrutiny by the U.S. Food and Drug Administration. However, Cook said he was interested in developing a medtech device that would work through the Apple Watch.

For the glucose monitor, Cook said the device has allowed him to "understand how his blood sugar responded to foods he was eating," CNBC said. Through that understanding, Cook was able to make modifications to keep his blood sugar levels constant.

The device is expected to be highly beneficial to diabetic patients who have to draw blood to measure their blood sugar.

"It's mentally anguishing to stick yourself many times a day to check your blood sugar," Cook said, according to CNBC . "There is lots of hope out there that if someone has constant knowledge of what they're eating, they can instantly know what causes the response... and that they can adjust well before they become diabetic."

The newly-tapped Apple team of biomedical engineers is based in Palo Alto. The world has been eagerly waiting to see what Apple (AAPL) comes up with in the world of wearable medtech. In 2016, the company posted listings for several new positions in its health technology division, including listings for biomedical engineers and a lab technician. Criteria for those positions called for candidates to have a good understanding of non-invasive sensors used to measure biological signals."

But, Apple is not the only tech-based company interested in developing wearable devices to benefit diabetics. Rival company Verily Life Sciences, Google (GOOG)’s life sciences division, has teamed up with Novartis (NVS) to develop a contact lens, the auto-focus lens, which measures the blood glucose levels of diabetics. Initially, the two companies expected the lens to enter clinical trials by the end of 2016, but they missed that window. The two companies said though that the project is continuing. One aspect of the lens would be an LED light system that would light up to warn the wearer when glucose levels were too high or low.

If these devices are eventually brought to market, there would be a huge number of potential customers. The U.S. Centers for Disease Control and Prevention estimates about 29 million Americans have diabetes, but about one-fourth of those do not yet know they have the condition. The number of suspected diabetics in the U.S. has risen from about 26 million in 2010, the CDC said. Not only that, but the CDC said about 86 million U.S. adults have prediabetes, where their blood sugar levels are higher than normal but not high enough to be classified as type 2 diabetes.