The device is designed so that it can monitor vital signs such as breathing and heart rate from inside the body and transmit data to an external device such as a laptop.

Scientists say the capsule has the potential to provide life-saving care to people at risk of opioid overdoses.

The team also hopes that the new device can help people with other health problems such as sleep disorders.

Lead author Professor Giovanni Traverso, a gastroenterologist, said: "The stomach generally offers some of the best signals, mainly because it is close to the heart and lungs, the ability to facilitate diagnosis and monitor many cases without having to go to the hospital can provide patients with easy access to healthcare and treatment support."

Capsule Test

• The researchers placed the device in the pigs' stomachs under anesthesia.
• The team gave a dose of fentanyl to the pigs causing them to stop breathing.
• The device measured respiratory rate and alerted the researchers when the animals stopped breathing.
• The team then tested the device on humans for the first time by giving the capsule to ten people with sleep apnea problems.
• The patients showed no adverse effects from swallowing the capsule, which went unnoticed through their digestive systems.
• Compared to external biomonitors, the capsule can monitor your heart rate with an accuracy of at least 96 percent.
• The experiment also showed that the device was safe, and that all participants secreted the device into their stool a few days after the experiment.