Magnetically controlled in the small bronchi

Thin and cleverly controlled: scientists have developed a probe system that can penetrate the tiny branches of the lung. The tentacle is only two millimeters wide and is automatically controlled externally by the magnetic forces that emanate from the robotic arms. The researchers say the system, which is now being further tested, could reach even deeper areas of the lungs than before for tissue sampling or treatment.

Endoscopes and catheters, probe systems introduced into the body from the outside have greatly expanded the possibilities of diagnosing and treating various diseases in recent decades. For the lungs, the current procedure is called bronchoscopy. A flexible, tubular instrument approximately 3.5 to 4 millimeters in diameter is inserted through the nose or mouth into the bronchus of the sedated patient. However, due to its size, the bronchoscope can only penetrate the upper levels of the bronchial tree. To go even deeper, a catheter or thin tube is inserted through the bronchoscope and eventually into the thinner tubes in the lungs.

Aim for smaller areas

These probes are only about two millimeters in diameter. However, with existing manual control techniques, they can only be conducted to a limited extent through the bronchial branched system, which means that some areas remain inaccessible. In addition, X-rays are often required during surgery, which can pose another technical challenge for healthcare professionals. It is therefore possible to optimize endoscopic and catheter technology. Scientists led by Pietro Valdastri from the University of Leeds are dedicated to this field of research. In particular, they are working to develop more manoeuvrable and more precisely controlled systems that require less effort.

This is how the concept of a catheter, which they call “magnetic tentacles”, was born. This structure consists of interconnected cylindrical segments, each with a diameter of two millimeters. The material is a soft elastomeric plastic, which, in addition to segmentation, provides the tentacles with great flexibility. In order to be able to remotely control its movements, magnetic particles are integrated into the material. Thus, the segments can be independently influenced by external magnetic fields. The result is a highly flexible structure that bends like a tentacle and is small enough not to snag on anatomical structures in the lungs, writes the University of Leeds.

Remote maneuverability

The tentacle is influenced by the magnetic fields that emanate from two robotic arms that move with precise motor control over the patient. They cause the catheter to change direction, allowing the probe to be maneuvered as it slowly moves to the suspect site in the lungs. However, this does not happen manually, but fully automatically: the path through the bronchial tree is planned based on the patient’s previous lung scans and then programmed into the robot system. “Thanks to our autonomous magnetic guidance system, the patient does not need to be x-rayed during the procedure,” says Valdastri.

So far, however, scientists have only provided a “proof of concept”: they have demonstrated the basic functionality of their concept through laboratory testing: they successfully guided the tentacle through a three-dimensional replica of a bronchial tree that has been modeled using anatomical data. Therefore, development work is still required before it can be used in clinical practice. For the next phase, the team now plans to test the system’s efficiency in navigating the lungs of a cadaver. The University of Leeds writes that with further trials, “magnetic tentacle” technology could begin to benefit patients for the first time in several years.

This could represent an important advance, Valdastri points out: “A magnetic catheter, which is only two millimeters wide and whose shape can be magnetically controlled to accommodate the anatomy of the bronchial tree, can reach most areas of the lungs and would be very important. a clinical tool for researching and treating possible lung cancer and other lung diseases, ‘concludes the researcher.

Source: University of Leeds

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