title: A novel retractable laparoscopic device for mapping gastrointestinal slow wave propagation patterns.
abstract: 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.
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Rachel
authors.initials: R
authors.lastname: Berry
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Niranchan
authors.initials: N
authors.lastname: Paskaranandavadivel
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Peng
authors.initials: P
authors.lastname: Du
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.
authors.forename: Mark L
authors.initials: ML
authors.lastname: Trew
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand.|Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: Gregory
authors.initials: G
authors.lastname: O'Grady
authors.affiliation: Department of Surgery, University of Auckland, Auckland, New Zealand.
authors.forename: John A
authors.initials: JA
authors.lastname: Windsor
authors.affiliation: Auckland Bioengineering Institute, University of Auckland, Private Bag 92019, Auckland, 1142, New Zealand. l.cheng@auckland.ac.nz.|Department of Surgery, Vanderbilt University, Nashville, TN, USA. l.cheng@auckland.ac.nz.
authors.forename: Leo K
authors.initials: LK
authors.lastname: Cheng
mesh_terms: D000818:Animals; D004566:Electrodes; D055724:Electrophysiological Phenomena; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D010535:Laparoscopy / Q000295:instrumentation*; D008297:Male; D008866:Microsurgery; D008875:Middle Aged; D012815:Signal Processing, Computer-Assisted; D059629:Signal-To-Noise Ratio; D013270:Stomach / Q000502:physiology*; D034421:Sus scrofa; D013552:Swine
keywords: Gastric dysrhythmia; Gastric electrical activity; High-resolution mapping; Nitinol