Researchers have developed an ingestible capsule that can be controlled using Bluetooth wireless technology. The capsule — which can be customized to deliver drugs, sense environmental conditions, or both — can reside in the stomach for at least a month, transmitting information and responding to instructions from a user's smartphone.
The capsules, manufactured using 3D printing technology, could be deployed to deliver drugs to treat a variety of diseases, particularly in cases where drugs must be taken over a long period of time. They could also be used to communicate with other wearable and implantable medical devices that could pool information to be communicated to the patient's or doctor's smartphone.
This type of sensor could be used to diagnose early signs of disease and then respond with the appropriate medication; for example, it could be used to monitor people at high risk for infection such as patients who are receiving chemotherapy or immunosuppressive drugs. If infection is detected, the capsule could begin releasing antibiotics or the device could be designed to release antihistamines when it detects an allergic reaction.
Previously, the researchers designed a star-shaped capsule with six arms that fold up before being encased in a smooth capsule. After being swallowed, the capsule dissolves and the arms expand, allowing the device to lodge in the stomach. Similarly, the new device unfolds into a Y-shape after being swallowed. This enables the device to remain in the stomach for about a month before it breaks into smaller pieces and passes through the digestive tract.
One of these arms includes four small compartments that can be loaded with a variety of drugs. These drugs can be packaged within polymers that allow them to be released gradually over several days. The compartments could be opened remotely through wireless Bluetooth communication. The device can also carry sensors that monitor the gastric environment and relay information via a wireless signal. In previous work, the researchers designed sensors that can detect vital signs such as heart rate and breathing rate. The capsule could be used to monitor temperature and relay that information directly to a smartphone within arm's length.
To enable the manufacturing of all of these complex elements, the researchers 3D-printed the capsules, enabling incorporation of all components carried by the capsules, and building the capsule from alternating layers of stiff and flexible polymers, which helps it withstand stomach acid.
The current version of the device is powered by a small silver oxide battery; however, the battery could be replaced with alternative power sources such as an external antenna or stomach acid. Other types of sensors could be incorporated into the capsules.