According to a recent paper published in the journal Nature · Electronics, engineers from the Massachusetts Institute of Technology and the California Institute of Technology showed a swallowable sensor, which can monitor its position when passing through the digestive tract, thus helping doctors diagnose gastrointestinal motility disorders more easily, such as constipation, gastroesophageal reflux and gastroparesis. Compared with the current endoscopy and other methods, the new equipment is less invasive, and patients can use it directly at home. The idea of the researchers is to develop a swallowable capsule that can send signals to reveal its position in the gastrointestinal tract, so that doctors can determine which part of the intestine causes the gastrointestinal peristalsis to slow down. Researchers have developed a "mini" magnetic sensor. Its working principle is to detect the magnetic field generated by the electromagnetic coil located outside the human body. The intensity of the magnetic field changes with the distance from the coil, so the position of the sensor can be calculated according to the measurement of the magnetic field by the sensor. In order to accurately locate the position of the device in the body, the system also includes a second sensor, which is left outside the body as a reference point. This sensor can be attached to the skin. By comparing its position with the position of the first sensor in the body, researchers can accurately calculate the position of the swallowing sensor in the gastrointestinal tract. The swallowable sensor also includes a wireless transmitter that can send the magnetic field measurement results to a nearby computer or smartphone. The current version of the system measures at any time when it receives the wireless trigger signal from the smart phone, but it can also be programmed to measure at a specific time interval. Researchers said that the system supports the localization of multiple devices without affecting the accuracy. In addition, it has a wide range of detection. The current version of the sensor can detect the magnetic field generated by the electromagnetic coil with a distance of 60 cm or less. (Xinhua News Agency)