knockoutのview model変数へのアクセス

View Model定義
var appViewModel = function() {
    var self = this;
    self.cards = ko.observableArray([]);
    self.editMode =  ko.observable(false);
    self.selectedItems =  ko.observable(0);
};

Binding
window.vm = new appViewModel();
ko.applyBindings(vm,document.getElementById("#mycardpage"));

アクセス
window.vm.cards([]);