2023 Author: Bryan Walter | [email protected]. Last modified: 2023-05-21 22:24
American engineers have created a self-propelled robot for endoscopy. It is fixed at the end of the cable, with electrical wires and tubes, but does not move by pushing the cable by the doctor, but independently - due to the tracked drives on the sides. The developers have successfully tested the device on both pig intestines and live pigs, and presented the results at the ICRA 2020 conference.
Colonoscopy is an effective way to diagnose many intestinal diseases, including the detection of malignant neoplasms in the early stages. Many doctors recommend that patients over 45-50 years old have a colonoscopy annually, but in fact, many do not comply with these instructions due to the nature of the procedure. During colonoscopy, the semi-rigid tube endoscope is mechanically pushed forward by the doctor behind the outside of the tube. In some cases, for example, with a sharp bend of the intestine, the end of the endoscope rests against the wall and you have to push it forward more and try to turn it in the right direction, which can cause painful sensations if the procedure is performed without anesthesia. Because of this, engineers are working on fully or partially autonomous endoscopes that can move independently and eliminate such cases.
Engineers from the University of Colorado at Boulder, led by Mark Rentschler, have created a self-propelled colonoscope, which, unlike analogs, integrates all the standard instruments a doctor needs to carry out procedures. In width, the size of the robot is three centimeters, and in thickness and length - 2, 3 and six centimeters, respectively. At the end there are instruments: a camera, two LEDs, channels for supplying water or air, as well as a port for additional equipment, including a biopsy forceps. On the other hand, the robot is connected to cables for energy and signals, as well as pipes for water and air.
On the sides of the robot, on its large edges, there are two caterpillar drive belts. They have small projections that provide adhesion to the surface of the mucous membranes. There are two such drives in the robot, each of which protrudes from two sides, so in total it has four spots of contact with the intestinal walls. Each track is driven by a separate motor at the base of the robot through a worm gear. In the current version, the robot is controlled by a doctor who can move it forward or backward, as well as turn it. In the future, developers will try to automate its movement.
The authors tested the colonoscope ex vitro and in vivo. In tests on live pigs, the developers successfully fed air to the intestines to increase pressure and water to rinse the surface of the camera lens, experienced LED-illuminated imaging, and took several mucosal samples with biopsy forceps. However, tests of the main function were unsuccessful: due to the small diameter of the sigmoid colon (half that of humans), the intestinal walls pressed too hard on the caterpillars. When tested on a separate pig intestine, the authors inflated it to the size of a human and after that the robot moved without problems at a speed of up to four centimeters per second.
There are other projects of self-propelled robotic colonoscopes with a different design. For example, in 2017, another group led by Mark Rentschler created a robot that moves forward through peristaltic movements - alternating contraction and expansion of certain parts. And Israeli engineers recently tested a robot in a pig intestine, which constantly bends in waves and thereby moves itself forward.