title: Batteryless implantable dual-sensor capsule for esophageal reflux monitoring.
abstract: BACKGROUND
  Chronic GERD affects approximately 15% of adults in the United States and is one of the most prevalent clinical conditions involving the GI tract. The commercial tools for monitoring GERD include multichannel intraluminal impedance (MII) probes and pH-sensing capsules. However, MII probes cause discomfort, which alters patients' regular activities, whereas the pH-sensing capsule lacks the ability to detect weak or nonacid episodes, misses reflux episodes with similar pH values, and has a limited sampling rate and battery life.
  
  
  OBJECTIVE
  To develop and test an implantable batteryless dual-sensor capsule that can be used to diagnose and monitor GERD.
  
  
  METHODS
  The implanted capsule is wirelessly powered by an external device. Simulated reflux episodes were created in 3 live porcine models. Impedance and pH data were continuously measured and recorded.
  
  
  METHODS
  The implant capsule was placed in the esophagus along with a commercial pH-sensing capsule for comparison.
  
  
  METHODS
  Precise impedance and pH readouts were obtained and compared with those from a commercial pH-sensing capsule.
  
  
  RESULTS
  The wireless energy supplied by the external unit was strong enough to power the implant. The pH sensor accurately measured pH levels and the impedance sensor precisely located the reflux episodes.
  
  
  CONCLUSIONS
  Simulated reflux events in a pig model.
  
  
  CONCLUSIONS
  Our wireless sensors are reliable in operation and provide accurate assessment of simulated reflux episodes. The entire device can potentially be used to diagnose and monitor GERD.
authors.affiliation: Electrical Engineering Department, The University of Texas at Arlington, Arlington, Texas, USA.
authors.forename: Hung
authors.initials: H
authors.lastname: Cao
authors.forename: Smitha
authors.initials: S
authors.lastname: Rao
authors.forename: Shou-jiang
authors.initials: SJ
authors.lastname: Tang
authors.forename: Harry F
authors.initials: HF
authors.lastname: Tibbals
authors.forename: Stuart
authors.initials: S
authors.lastname: Spechler
authors.forename: J-C
authors.initials: JC
authors.lastname: Chiao
mesh_terms: D000818:Animals; D004867:Equipment Design; D050782:Esophageal pH Monitoring / Q000295:instrumentation*; D005260:Female; D005764:Gastroesophageal Reflux / Q000175:diagnosis*; D020007:Implants, Experimental; D013552:Swine