We use cookies to understand how you use our site and to improve your experience. This includes personalizing content and advertising. To learn more, click here. By continuing to use our site, you accept our use of cookies. Cookie Policy.

Features Partner Sites Information LinkXpress
Sign In
Advertise with Us
Ampronix,  Inc

Download Mobile App


ATTENTION: Due to the COVID-19 PANDEMIC, many events are being rescheduled for a later date, converted into virtual venues, or altogether cancelled. Please check with the event organizer or website prior to planning for any forthcoming event.
29 Aug 2020 - 02 Sep 2020
Virtual Venue

Magnetic Actuation Device Enhances Laparoscopic Surgery

By HospiMedica International staff writers
Posted on 15 Mar 2015
Print article
Image: An early prototype of the internal retractor unit (Photo courtesy of Vanderbilt University).
Image: An early prototype of the internal retractor unit (Photo courtesy of Vanderbilt University).
Two new studies describe a local magnetic actuation (LMA) approach using coaxial gears to ease tissue manipulation during minimally invasive surgery (MIS) procedures.

Researchers at Vanderbilt University (Nashville, TN, USA) developed An LMA actuation unit that consists of a pair of diametrically magnetized single-dipole cylindrical magnets, working as a gear system that crosses the abdominal wall. In principal, one unit is external, placed on a patient’s abdomen; the second is an internal unit small enough to fit through the access ports used in MIS. During operation, the internal unit is magnetically anchored to the inside of the abdominal wall, while the other unit provides the mechanical force that powers the device.

The magnet in the external unit is attached to the shaft of a powerful electric motor that causes it to spin. The magnet in the internal unit is also attached to a shaft, but one that drives a two-inch lever. When the electric motor on the external unit twirls its magnet, it generates a rotating magnetic field that forces the magnet on the shaft in the inner unit to spin at the same speed. When it spins in one direction, the lever opens up, and when it spins in the opposite direction, the lever closes.

To retract an organ, the surgeon inserts the internal unit with a laparoscopic grasper and inserts it through the port into the body. When the internal unit is close enough to the external unit, it snaps into position against the inner surface of the abdominal wall. The motor on the external unit is then engaged, lowering the lever. Using standard laparoscopic instruments, the surgeon attaches one end of a line to the tip of the lever and the other end to a clip or suction cup fastened to the organ that must be moved. The electric motor is run in reverse and the lever retracts, pulling the organ into the desired position.

The first LMA device the researchers built as proof of principle was used during liver resection in vivo on an anesthetized porcine model. The researchers found that when abdominal wall thickness is 2 cm, the retractor is able to lift more than ten times its own weight. The researchers concluded that LMA can enable the transfer of a larger amount of mechanical power than that possible by using motors on the laparoscopic instrument itself. The studies were published in the February 2015 issue of IEEE Transactions on Robotics and the March 2015 issue of ASME Journal of Medical Devices.

“This device demonstrates for the first time that controllable mechanical power can be transferred across the abdominal wall via an intelligent magnetic link to power a robotic instrument,” said lead author Assistant Professor of Mechanical Engineering Pietro Valdastri, MSc, PhD. “Besides the ability to deliver a lot of power, the magnetic actuation approach has some other important advantages; the internal units do not contain any expensive and delicate electronics, so they can be easily sterilized and, if manufactured in bulk, could be made inexpensively enough to be disposable.”

Related Links:

Vanderbilt University

Print article



view channel

Siemens to Acquire Varian Medical to Create Comprehensive Cancer Portfolio

Siemens Healthineers (Erlangen, Germany) has entered into an agreement to acquire Varian Medical Systems, Inc. (Palo Alto, CA, USA) that will lead to the creation of a global leader in healthcare with... Read more
Copyright © 2000-2020 Globetech Media. All rights reserved.