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In situ and ex vivo evaluation of a wireless magnetoelastic biliary stent monitoring system

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Abstract

This paper presents the in situ and ex vivo evaluation of a system that wirelessly monitors the accumulation of intimal tissue and sludge in a biliary stent. The sensing element, located within the stent, is a magnetoelastic resonator that is queried by a wireless radio frequency signal. The in situ testing uses a commercially-available self-expanding biliary stent enhanced with a 1 mm × 25 mm magnetoelastic ribbon sensor (formed from Metglas™ 2605SA1). The stent has a conformal magnetic layer (consisting of strontium ferrite particles suspended in polydimethylsiloxane) that biases the sensor. The external interrogation module is able to acquire a signal from the sensor from a distance of at least 5 cm while the sensor is implanted in a porcine carcass and loaded with biological fluids. The ex vivo testing uses bile harvested from the porcine carcass. The response of a 1 mm × 25 mm magnetoelastic ribbon sensor is first calibrated with fluids of known density and viscosity, and the calibrated sensor is used to estimate that the viscosity of the harvested bile is 2.7–3.7 cP. The test results presented in this paper illustrate the fundamental usability of the system when the sensor is implanted, loaded by biological fluids, and interrogated in a surgical setup.

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Notes

  1. All surgical procedures in this experiment were performed by R. Kwon.

References

  • ASM Handbook, vol. 16, (ASM International, 1989)

  • A. Colas, J. Curtis, in Biomaterials Science: An Introduction to Materials in Medicine, ed. by B. Ratner, A. Hoffman, F. Schoen, J. Lemons, 2nd edn. (Elsevier Academic, London, 2004), p. 80

    Google Scholar 

  • C. Darvennes, S. Pardue, Boundary effect of a viscous fluid on a longitudinally vibrating bar: theory and application. J. Acoust. Soc. Am. 110(1), 216–224 (2001)

    Article  Google Scholar 

  • G. Donelli, E. Guaglianone, R. Di Rosa, F. Fiocca, A. Basoli, Plastic biliary stent occlusion: factors involved and possible preventive approaches. Clin. Med. Res. 5(1), 53–60 (2007)

    Article  Google Scholar 

  • G. Engdahl (ed.), Handbook of Giant Magnetostrictive Materials (Academic, London, 2000), pp. 1–19

    Google Scholar 

  • S. Green, Y.B. Gianchandani, Wireless magnetoelastic monitoring of biliary stents. J. Microelectromech. Syst. 18(1), 64–78 (2009)

    Article  Google Scholar 

  • S. Green, Y.B. Gianchandani, Tailored magnetoelastic sensor geometry for advanced functionality in wireless biliary stent monitoring systems. J. Micromech. Microeng. (2010), in review

  • D. Jungst, A. Niemeyer, I. Muller, B. Zundt, G. Meyer, M. Wilhelmi, R. del Pozo, Mucin and phospholipids determine the viscosity of gallbladder bile in patients with gallstones. World J. Gastroenterol. 7(2), 203–207 (2001)

    Google Scholar 

  • R. Kozarek, Metallic biliary stents for malignant obstructive jaundice: a review. World J. Gastroenterol. 6(5), 643–646 (2000)

    Google Scholar 

  • L. Lagorce, M. Allen, Magnetic and mechanical properties of micromachined strontium ferrite/polyimide composites. J. Microelectromech. Syst. 6(4), 307–312 (1997)

    Article  Google Scholar 

  • D. Nelson, Expandable metal stents: physical properties and tissue responses. Tech. Gastrointest. Endosc. 3(2), 70–74 (2001)

    Article  Google Scholar 

  • J. Sung, Bacterial biofilm and clogging of biliary stents. J. Ind. Microbiol. 15, 152–155 (1995)

    Article  Google Scholar 

Download references

Acknowledgements

Metglas Inc., Hoosier Magnetics, and Dow Corning provided samples for this project. This work was supported in part by a National Science Foundation (NSF) Graduate Research Fellowship to S. Green, the NSF ERC for Wireless Integrated Microsystems (WIMS), and the University of Michigan.

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Authors and Affiliations

  1. Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI, USA

    Scott Ryan Green & Yogesh B. Gianchandani

  2. Department of Internal Medicine - Gastroenterology, University of Michigan, Ann Arbor, MI, USA

    Richard S. Kwon & Grace H. Elta

  3. Department of Electrical Engineering and Computer Science, University of Michigan, Ann Arbor, MI, USA

    Yogesh B. Gianchandani

Authors
  1. Scott Ryan Green
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  2. Richard S. Kwon
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  3. Grace H. Elta
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  4. Yogesh B. Gianchandani
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Correspondence to Scott Ryan Green.

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Green, S.R., Kwon, R.S., Elta, G.H. et al. In situ and ex vivo evaluation of a wireless magnetoelastic biliary stent monitoring system. Biomed Microdevices 12, 477–484 (2010). https://doi.org/10.1007/s10544-010-9404-7

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  • DOI: https://doi.org/10.1007/s10544-010-9404-7

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