{"id":299,"date":"2013-04-17T14:44:02","date_gmt":"2013-04-17T21:44:02","guid":{"rendered":"http:\/\/www.stanford.edu\/group\/sailsbury_robotx\/cgi-bin\/salisbury_lab\/?page_id=299"},"modified":"2013-06-06T10:53:46","modified_gmt":"2013-06-06T17:53:46","slug":"force-control-of-a-permanent-magnet-for-minimally-invasive-procedures","status":"publish","type":"page","link":"https:\/\/sr.stanford.edu\/?page_id=299","title":{"rendered":"Force Control of a Permanent Magnet for Minimally-Invasive Procedures"},"content":{"rendered":"

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Project Description<\/h2>\n

Magnetic actuation can be used for minimally\u00a0invasive control of medical devices such as robotic catheters.\u00a0However, current systems that use large permanent magnets\u00a0are limited in their ability to modulate the magnetic force. In\u00a0this project, we developed a proof-of-concept system for closed loop\u00a0force control of a permanent magnet using shielding\u00a0materials. Our system consists of a device that actuates pieces\u00a0of high-permeability metal (hymu-80) to redirect magnetic lines of flux.\u00a0This is used to regulate the attractive force exerted by a large\u00a0controlling magnet on a smaller moving magnet. We determined empirically and theoretically that a there is a linear relationship between the shielding gap distance and the force between the large and small magnets. Using our system, we were able to regulate a constant force on a small magnet whose distance from the larger magnet was varied in a triangular waveform. Without our system, the force would have varied strongly with the varying distance.<\/p>\n

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Related Publications<\/h2>\n

R. D. Brewer, K. E. Loewke, E. F. Duval, and J. K. Salisbury, \u201cForce Control of a Permanent Magnet for Minimally-Invasive Procedures.\u201d International Conference on Biomedical Robotics and Biomechatronics, 2008, pp. 580-586. (PDF)<\/a><\/p>\n

Project Staff<\/h2>\n