Magnetic mechanism for wireless capsule biopsy in the small bowel 

This work was part of my master thesis developed at the Biorobotics Institute of Sant’Anna School of Advanced studies, under the surpervision of Prof. Pietro Valdastri, Arianna Menciassi and dott. Massimiliano Simi.

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One of the main diagnostic limitations of current gastrointestinal (GI) capsule endoscopes is that they cannot get biopsies, thus requiring follow-up with flexible endoscopy whenever a suspicious lesion is identified. The ability of getting biopsies from a wireless capsule would save time and costs associated with the procedure, reducing at the same time invasiveness and discomfort for the patient.

The capsule contains a novel magneto mechanical elastic element that can be loaded remotely by varying the magnetic field surrounding it and that is able to store and release mechanical energy upon external triggering. The Magnetic Torsion Spring (MTS) is used as the core component of a self - contained miniature biopsy capsule ( 9 mm in diameter and 24 mm long) for random tissue sampling in the small bowel. Thanks to the MTS concept, the biopsy mechanism can be loaded wirelessly by a magnetic field applied from outside the body of the patient. At the same time, magnetic coupling guarantees stabilization against the small bowel tissue during sampling. Extreme miniaturization is possible with the proposed approach, since no electronics and no power supply is required onboard.

The capsule was also integrated with a magnetic hall-effect sensor and a wireless micro controller to explore the possibility of real-time feedback on the inner blade rotation.


References:

Simi, M., Gerboni, G., Menciassi, A., Valdastri, P. (2013). Magnetic torsion spring mechanism for a wireless biopsy capsule. Journal of Medical Devices, 7(4).

Simi M., Gerboni G., Menciassi A., Valdastri P. Magnetic Mechanism for Wireless Capsule Biopsy. ASME-DMD2012: Design of Medical Devices Conference. Minneapolis, MN, United States.

G. Gerboni,. M. Simi, P. Valdastri, A. Menciassi, “Magnetically Activated Biopsy Capsule”, IEEE International Conference on Biomedical Robotics and Biomechatronics (BioRob), Rome, Italy, June 24-27, 2012.