 The next year he collaborated with Alan Belgard, the chief electrical engineer and co-owner of the Electrodyne Company, to develop an efficient chest surface pacemaker to conform to Paul's needs.That collaboration became long-term as together they developed production model chest surface pacemakers, clinical alarmed heart rhythm monitors, chest surface defibrillators, cardiac monitor- automatic pacemakers, and long-term implantable self-contained pacemakers.Zoll's parents met in the US after emigrating from Eastern Europe.