title: A novel laparoscopic device for measuring gastrointestinal slow-wave activity.
abstract: BACKGROUND
  A periodic electrical activity, termed "slow waves", coordinates gastrointestinal contractions. Slow-wave dysrhythmias are thought to contribute to dysmotility syndromes such as postoperative gastroparesis, but the clinical significance of these dysrhythmias remains poorly defined. Electrogastrography (EGG) has been unable to characterize dsyrhythmic activity reliably, and the most accurate method for evaluating slow waves is to record directly from the surface of the target organ. This study presents a novel laparoscopic device for recording serosal slow-wave activity, together with its validation.
  
  
  METHODS
  The novel device consists of a shaft (diameter, 4 mm; length, 300 mm) and a flexible connecting cable. It contains four individual electrodes and is fully shielded. Validation was performed by comparing slow-wave recordings from the laparoscopic device with those from a standard electrode platform in an open-abdomen porcine model. An intraoperative human trial of the device also was performed by recording activity from the gastric antrum of a patient undergoing a laparoscopic cholecystectomy.
  
  
  RESULTS
  Slow-wave amplitudes were similar between the laparoscopic device and the standard recording platform (mean 0.38 ± 0.03 mV vs range 0.36-0.38 ± 0.03 mV) (p = 0.94). The signal-to-noise ratio (SNR) also was similar between the two types of electrodes (13.7 dB vs 12.6 dB). High-quality antral slow-wave recordings were achieved in the intraoperative human trial (amplitude, 0.41 ± 0.04 mV; SNR, 12.6 dB), and an activation map was constructed showing normal aboral slow-wave propagation at a velocity of 6.3 ± 0.9 mm/s.
  
  
  CONCLUSIONS
  The novel laparoscopic device achieves high-quality serosal slow-wave recordings. It is easily deployable and atraumatic. It is anticipated that this device will aid in the clinical investigation of normal and dsyrhythmic slow-wave activity. In particular, it offers new potential for investigating the effect of surgical procedures on slow-wave activity.
authors.affiliation: Department of Surgery, The University of Auckland, Private Bag 92019, Auckland 1142, New Zealand. gog@ps.gen.nz
authors.forename: Gregory
authors.initials: G
authors.lastname: O'Grady
authors.forename: Peng
authors.initials: P
authors.lastname: Du
authors.forename: John U
authors.initials: JU
authors.lastname: Egbuji
authors.forename: Wim J E P
authors.initials: WJ
authors.lastname: Lammers
authors.forename: Athiq
authors.initials: A
authors.lastname: Wahab
authors.forename: Andrew J
authors.initials: AJ
authors.lastname: Pullan
authors.forename: Leo K
authors.initials: LK
authors.lastname: Cheng
authors.forename: John A
authors.initials: JA
authors.lastname: Windsor
mesh_terms: D000818:Animals; D017081:Cholecystectomy, Laparoscopic / Q000295:instrumentation; D041881:Cholecystitis, Acute / Q000601:surgery; D004566:Electrodes; D004867:Equipment Design; D005260:Female; D005769:Gastrointestinal Motility / Q000502:physiology*; D006801:Humans; D007430:Intraoperative Care / Q000295:instrumentation; D010535:Laparoscopy / Q000295:instrumentation*; D009130:Muscle, Smooth / Q000502:physiology; D011706:Pyloric Antrum / Q000502:physiology; D059629:Signal-To-Noise Ratio; D013270:Stomach / Q000502:physiology*; D034421:Sus scrofa; D055815:Young Adult