title: An implantable wireless biosensor for the immediate detection of upper GI bleeding: a new fluorescein-based tool for diagnosis and surveillance (with video).
abstract: BACKGROUND
  Early recurrent hemorrhage after endoscopic intervention for acute upper GI bleeding (UGIB) can approach 20% and leads to increased morbidity and mortality. Little has changed over the past several decades regarding immediate posthemorrhage surveillance, and there has likewise been no significant improvement in outcomes.
  
  
  OBJECTIVE
  To develop and test an endoscopically implantable wireless biosensor for real-time detection of fluorescein-labeled blood in ex vivo and in vivo porcine models of UGIB.
  
  
  METHODS
  Animal laboratory.
  
  
  METHODS
  Benchtop and acute animal studies.
  
  
  METHODS
  Five pigs.
  
  
  METHODS
  UGIB models were surgically created in living pigs. Biosensors were endoscopically deployed in the stomach using standard endoscopic clips. The ability to detect acute UGIB and estimated blood loss leading to biosensor activation were recorded. Feasibility of wireless data transmission out of the body to an external computer and cell phone was assessed.
  
  
  METHODS
  Technical feasibility and immediate complications.
  
  
  RESULTS
  A porcine UGIB model was successfully created. Biosensors were able to detect all acute bleeding events and wirelessly transmit out of the body, and successfully sent an emergency text message to the intended cell phone in all cases. Average estimated blood loss leading to biosensor activation was 30 mL (10-75 mL).
  
  
  CONCLUSIONS
  Animal study; small numbers.
  
  
  CONCLUSIONS
  An endoscopically implantable wireless biosensor successfully detected acute hemorrhage in a porcine UGIB model and sent an emergency cell-phone alert in real time.
authors.affiliation: Brigham & Women's Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Marvin
authors.initials: M
authors.lastname: Ryou
authors.forename: Alex
authors.initials: A
authors.lastname: Nemiroski
authors.forename: Dan
authors.initials: D
authors.lastname: Azagury
authors.forename: Sohail N
authors.initials: SN
authors.lastname: Shaikh
authors.forename: Michele B
authors.initials: MB
authors.lastname: Ryan
authors.forename: Robert M
authors.initials: RM
authors.lastname: Westervelt
authors.forename: Christopher C
authors.initials: CC
authors.lastname: Thompson
mesh_terms: D000818:Animals; D015374:Biosensing Techniques; D040421:Cell Phone; D004195:Disease Models, Animal; D016099:Endoscopy, Gastrointestinal; D019793:Fluorescein; D005456:Fluorescent Dyes; D006471:Gastrointestinal Hemorrhage / Q000175:diagnosis* / Q000209:etiology; D019736:Prostheses and Implants; D012008:Recurrence; D013552:Swine; D060145:Text Messaging
chemical_list: D005456:Fluorescent Dyes; D019793:Fluorescein