A novel retractable laparoscopic device for mapping gastrointestinal slow wave propagation patterns
- 336 Downloads
Gastric slow waves regulate peristalsis, and gastric dysrhythmias have been implicated in functional motility disorders. To accurately define slow wave patterns, it is currently necessary to collect high-resolution serosal recordings during open surgery. We therefore developed a novel gastric slow wave mapping device for use during laparoscopic procedures.
The device consists of a retractable catheter constructed of a flexible nitinol core coated with Pebax. Once deployed through a 5-mm laparoscopic port, the spiral head is revealed with 32 electrodes at 5 mm intervals. Recordings were validated against a reference electrode array in pigs and tested in a human patient.
Recordings from the device and a reference array in pigs were identical in frequency (2.6 cycles per minute; p = 0.91), and activation patterns and velocities were consistent (8.9 ± 0.2 vs 8.7 ± 0.1 mm s−1; p = 0.2). Device and reference amplitudes were comparable (1.3 ± 0.1 vs 1.4 ± 0.1 mV; p = 0.4), though the device signal-to-noise ratio was higher (17.5 ± 0.6 vs 12.8 ± 0.6 dB; P < 0.0001). In the human patient, corpus slow waves were recorded and mapped (frequency 2.7 ± 0.03 cycles per minute, amplitude 0.8 ± 0.4 mV, velocity 2.3 ± 0.9 mm s−1).
In conclusion, the novel laparoscopic device achieves high-quality serosal slow wave recordings. It can be used for laparoscopic diagnostic studies to document slow wave patterns in patients with gastric motility disorders.
KeywordsGastric electrical activity Gastric dysrhythmia High-resolution mapping Nitinol
The authors gratefully acknowledge the assistance of Tim Angeli, Ryash Vather, Linley Nisbet, Grant Beban and the surgical staff at Auckland City Hospital with data collection.
This work was supported in part by grants from the International Foundation for Functional Gastrointestinal Disorders (IFFGD), Maurice and Phyllis Paykel Trust (MPPT), Health Research Council of New Zealand, NIH (R01 DK64775), and Medical Technologies Centre of Research Excellence (MedTech CoRE), New Zealand. RB was supported by a Commonwealth Scholarship, PD by the Marsden Fund and LC by a Fraunhofer-Bessel Research Award from the Alexander von Humboldt Foundation and the Fraunhofer IPA.
Compliance with ethical standards
Niranchan Paskaranandavadivel, Peng Du, Gregory O’Grady and Leo K. Cheng hold intellectual property and/or patent applications in the field of mapping gastrointestinal electrophysiology. Rachel Berry, Mark L. Trew and John A. Windsor report no conflict of interest or financial ties to disclose.
Ethical approval for pig experiments was obtained from the University of Auckland Animal Ethics Committee. Human studies were approved by the Northern Y Health and Disability Ethics Committee. The patient provided informed consent prior to participating.
- 9.O’Grady G, Angeli TR, Du P, Lahr C, Lammers WJEP, Windsor JA, Abell TL, Farrugia G, Pullan AJ, Cheng LK (2012) Abnormal initiation and conduction of slow-wave activity in gastroparesis, defined by high-resolution electrical mapping. Gastroenterol 143(589–598):e583Google Scholar
- 12.Cheng LK, Du P, O’Grady G (2013) Mapping and modeling gastrointestinal bioelectricity: from engineering bench to bedside. Physiology (Bethesda) 28:310–317Google Scholar
- 13.Du P, O’Grady G, Egbuji JU, Lammers WJ, Budgett D, Nielsen P, Windsor JA, Pullan AJ, Cheng LK (2009) High-resolution mapping of in vivo gastrointestinal slow wave activity using flexible printed circuit board electrodes: methodology and validation. Ann Biomed Eng 37:839–846CrossRefPubMedPubMedCentralGoogle Scholar
- 18.Feldman LA, Hui H (1997) Compatibility of medical devices and materials with low-temperature H2O2 gas plasma. Med Device Diagn Ind 19:63–77Google Scholar
- 21.Arkema Group Pebax® by Arkema. ArkemaGoogle Scholar
- 27.O’Grady G, Paskaranandavadivel N, Angeli TR, Du P, Windsor JA, Cheng LK, Pullan AJ (2011) A comparison of gold versus silver electrode contacts for high-resolution gastric electrical mapping using flexible printed circuit board arrays. Physiol Meas 32:N13–N22CrossRefPubMedPubMedCentralGoogle Scholar
- 28.Yassi R, O’Grady G, Paskaranandavadivel N, Du P, Angeli T, Pullan A, Cheng L, Erickson J (2012) The gastrointestinal electrical mapping suite (GEMS): software for analyzing and visualizing high-resolution (multi-electrode) recordings in spatiotemporal detail. BMC Gastroenterol 12:60CrossRefPubMedPubMedCentralGoogle Scholar
- 31.Erickson J, O’Grady G, Du P, Egbuji J, Pullan A, Cheng L (2011) Automated cycle partitioning and visualization of high-resolution activation time maps of gastric slow wave recordings: the Region Growing Using Polynomial Surface-estimate stabilization (REGROUPS) Algorithm. Ann Biomed Eng 39:469–483CrossRefPubMedGoogle Scholar
- 32.Weeks M (2010) Digital signal processing using matlab and wavelets, 2nd edn. Jones and Bartlett Publishers, LondonGoogle Scholar
- 33.Paskaranandavadivel N, Cheng L, Du P, O’Grady G, Pullan A (2011) Improved signal processing techniques for the analysis of high resolution serosal slow wave activity in the stomach. In: Conference of IEEE Eng Med Biol Soc:1737–1740Google Scholar
- 36.Du P, Wenlian Q, O’Grady G, Egbuji JU, Lammers W, Cheng LK, Pullan AJ (2009) Automated detection of gastric slow wave events and estimation of propagation velocity vector fields from serosal high-resolution mapping. In: Conference of IEEE Eng Med Biol Soc:2527–2530Google Scholar