Endoscopy 2010; 42(6): 481-486
DOI: 10.1055/s-0029-1244170
Original article
 
© Georg Thieme Verlag KG Stuttgart · New York

A magnetic internal mechanism for precise orientation of the camera in wireless endoluminal applications

P.  Valdastri1 , C.  Quaglia1 , E.  Buselli1 , A.  Arezzo2 , N.  Di Lorenzo3 , M.  Morino2 , A.  Menciassi1 , P.  Dario1
  • 1Center for Research in Microengineering (CRIM Lab), Scuola Superiore Sant’Anna, Pontedera, Italy
  • 2Centre for Minimally Invasive Surgery, University of Torino, Italy
  • 3Department of Surgery, University of Tor Vergata, Rome, Italy
Further Information

Publication History

submitted 5 November 2009

accepted after revision 3 March 2010

Publication Date:
26 May 2010 (online)

Background and study aims: The use of magnetic fields to control operative devices has been recently described in endoluminal and transluminal surgical applications. The exponential decrease of magnetic field strength with distance has major implications for precision of the remote control. We aimed to assess the feasibility and functionality of a novel wireless miniaturized mechanism, based on magnetic forces, for precise orientation of the camera.

Materials and methods: A remotely controllable endoscopic capsule was developed as proof of concept. Two intracapsular moveable permanent magnets allow fine positioning, and an externally applied magnetic field permits gross movement and stabilization. Performance was assessed in ex vivo and in vivo bench tests, using porcine upper and lower gastrointestinal tracts.

Results: Fine control of capsule navigation and rotation was achieved in all tests with an external magnet held steadily about 15 cm from the capsule. The camera could be rotated in steps of 1.8°. This was confirmed by ex vivo tests; the mechanism could adjust the capsule view at 40 different locations in a gastrointestinal tract phantom model. Full 360° viewing was possible in the gastric cavity, while the maximal steering in the colon was 45° in total. In vivo, a similar performance was verified, where the mechanism was successfully operated every 5 cm for 40 cm in the colon, visually sweeping from side to side of the lumen; 360° views were obtained in the gastric fundus and body, while antrally the luminal walls prevented full rotation.

Conclusions: We report the feasibility and effectiveness of the combined use of external static magnetic fields and internal actuation to move small permanent intracapsular magnets to achieve wirelessly controllable and precise camera steering. The concept is applicable to capsule endoscopy as to other instrumentation for laparoscopic, endoluminal, or transluminal procedures.

References

P. ValdastriPhD 

CRIM Laboratory
Scuola Superiore Sant’Anna

viale R. Piaggio 34
56025 Pontedera
Italy

Fax: +39-0508-83497

Email: pietro@sssup.it

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