title: Design and testing of a percutaneously implantable fetal pacemaker.
abstract: We are developing a cardiac pacemaker with a small, cylindrical shape that permits percutaneous implantation into a fetus to treat complete heart block and consequent hydrops fetalis, which can otherwise be fatal. The device uses off-the-shelf components including a rechargeable lithium cell and a highly efficient relaxation oscillator encapsulated in epoxy and glass. A corkscrew electrode made from activated iridium can be screwed into the myocardium, followed by release of the pacemaker and a short, flexible lead entirely within the chest of the fetus to avoid dislodgement from fetal movement. Acute tests in adult rabbits demonstrated the range of electrical parameters required for successful pacing and the feasibility of successfully implanting the device percutaneously under ultrasonic imaging guidance. The lithium cell can be recharged inductively as needed, as indicated by a small decline in the pulsing rate.
authors.affiliation: Medical Device Development Facility, Department of Biomedical Engineering, Viterbi School of Engineering, University of Southern California, Denney Research Building, Rm. B11, 1042 Downey Way, Los Angeles, CA 90089-1112, USA. gloeb@usc.edu
authors.forename: Gerald E
authors.initials: GE
authors.lastname: Loeb
authors.forename: Li
authors.initials: L
authors.lastname: Zhou
authors.forename: Kaihui
authors.initials: K
authors.lastname: Zheng
authors.forename: Adriana
authors.initials: A
authors.lastname: Nicholson
authors.forename: Raymond A
authors.initials: RA
authors.lastname: Peck
authors.forename: Anjana
authors.initials: A
authors.lastname: Krishnan
authors.forename: Michael
authors.initials: M
authors.lastname: Silka
authors.forename: Jay
authors.initials: J
authors.lastname: Pruetz
authors.forename: Ramen
authors.initials: R
authors.lastname: Chmait
authors.forename: Yaniv
authors.initials: Y
authors.lastname: Bar-Cohen
mesh_terms: D000818:Animals; D002304:Cardiac Pacing, Artificial / Q000379:methods; D004567:Electrodes, Implanted; D004867:Equipment Design; D005333:Fetus; D006327:Heart Block / Q000628:therapy*; D015160:Hydrops Fetalis / Q000628:therapy*; D008422:Materials Testing; D010138:Pacemaker, Artificial; D011817:Rabbits