title: Evaluation of a Unique Defibrillation Unit with Dual-Vector Biphasic Waveform Capabilities: Towards a Miniaturized Defibrillator.
abstract: BACKGROUND
  Automated external defibrillators can provide life-saving therapies to treat ventricular fibrillation. We developed a prototype unit that can deliver a unique shock waveform produced by four independent capacitors that is delivered through two shock vectors, with the rationale of providing more robust shock pathways during emergent defibrillation. We describe the initial testing and feasibility of this unique defibrillation unit, features of which may enable downsizing of current defibrillator devices.
  
  
  METHODS
  We tested our defibrillation unit in four large animal models (two canine and two swine) under general anesthesia. Experimental defibrillation thresholds (DFT) were obtained by delivery of a unique waveform shock pulse via a dual-vector pathway with four defibrillation pads (placed across the chest). DFTs were measured and compared with those of a commercially available biphasic defibrillator (Zoll M series, Zoll Medical, Chelmsford, MA, USA) tested in two different vectors. Shocks were delivered after 10 seconds of stable ventricular fibrillation and the output characteristics and shock outcome recorded. Each defibrillation series used a step-down to failure protocol to define the defibrillation threshold.
  
  
  RESULTS
  A total of 96 shocks were delivered during ventricular fibrillation in four large animals. In comparison to the Zoll M series, which delivered a single-vector, biphasic shock, the energy required for successful defibrillation using the unique dual-vector biphasic waveform did not differ significantly (P = 0.65).
  
  
  CONCLUSIONS
  Our early findings support the feasibility of a unique external defibrillation unit using a dual-vector biphasic waveform approach. This warrants further study to leverage this unique concept and work toward a miniaturized, portable shock delivery system.
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Hideo
authors.initials: H
authors.lastname: Okamura
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Christopher V
authors.initials: CV
authors.lastname: Desimone
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Ammar M
authors.initials: AM
authors.lastname: Killu
authors.affiliation: Mayo Clinic Ventures, Mayo Clinic, Rochester, Minnesota.
authors.forename: Emily J
authors.initials: EJ
authors.lastname: Gilles
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Jason
authors.initials: J
authors.lastname: Tri
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Roshini
authors.initials: R
authors.lastname: Asirvatham
authors.affiliation: Mayo Clinic Ventures, Mayo Clinic, Rochester, Minnesota.
authors.forename: Dejae J
authors.initials: DJ
authors.lastname: Ladewig
authors.affiliation: Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Scott H
authors.initials: SH
authors.lastname: Suddendorf
authors.affiliation: Division of Cardiovascular Surgery, Mayo Clinic, Rochester, Minnesota.
authors.forename: Joanne M
authors.initials: JM
authors.lastname: Powers
authors.affiliation: Division of Biomedical Statistics and Informatics, Mayo Clinic, Rochester, Minnesota.
authors.forename: Christina M
authors.initials: CM
authors.lastname: Wood-Wentz
authors.affiliation: Employees and equity owners in CardioThrive, Walnut Creek, California.
authors.forename: Peter D
authors.initials: PD
authors.lastname: Gray
authors.affiliation: Employees and equity owners in CardioThrive, Walnut Creek, California.
authors.forename: Douglas M
authors.initials: DM
authors.lastname: Raymond
authors.affiliation: Employees and equity owners in CardioThrive, Walnut Creek, California.
authors.forename: Shelley J
authors.initials: SJ
authors.lastname: Savage
authors.affiliation: Employees and equity owners in CardioThrive, Walnut Creek, California.
authors.forename: Walter T
authors.initials: WT
authors.lastname: Savage
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Bruce
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Samuel J
authors.initials: SJ
authors.lastname: Asirvatham
authors.affiliation: Division of Cardiovascular Diseases, Mayo Clinic, Rochester, Minnesota.
authors.forename: Paul A
authors.initials: PA
authors.lastname: Friedman
mesh_terms: D000818:Animals; D047548:Defibrillators; D004285:Dogs; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D006801:Humans; D008904:Miniaturization; D010865:Pilot Projects; D013552:Swine; D013673:Technology Assessment, Biomedical; D013813:Therapy, Computer-Assisted / Q000295:instrumentation* / Q000379:methods; D016896:Treatment Outcome; D014693:Ventricular Fibrillation / Q000517:prevention & control*
keywords: defibrillator; dual-vector biphasic shock waveform; miniaturized