Uncaught TypeError: this.sendNotification is not a function at OV.js:40

I think is thas something to do with where I place it because if I place it outside the interval function it does work. Maybe someone can point me in the right direction.

Module.register("OV",{
   // Default module config.
   defaults: {
   	text: "Openbaar Vervoer!lsdksdkk"
   },
   
   // Override dom generator.
   getDom: function() {
   	var wrapper = document.createElement("div");
   	
   	function updateOV() {
   	this.sendUpdate;
   	var xhttp = new XMLHttpRequest();
   	xhttp.onreadystatechange = function() {
   		if (this.readyState == 4 && this.status == 200) {
   		var string = "";
   		//console.log(this.responseText);
   		var data = JSON.parse(this.responseText);
   		//console.log(decodeURI(data.dest));
   		string += "<table>";
   		$.each(data, function( index, value ) {
   			string += "<tr>"
   			console.log(value );
   			string += "<td>" + value.service + "</td>";
   			string += "<td>" + decodeURI(value.dest) + "</td>";
   			string += "<td>" + value.time + "</td>";
   			string += "<td>" + value.state + "</td>";
   			string += "</tr>";
   		});
   		string += "</table>";
   		wrapper.innerHTML = string;
   		}
   	  };
   	  xhttp.open("GET", "http://192.168.1.167/esp/bustijden.php");
   	  xhttp.send();
   	}
   	
   	setInterval(function() {
   		updateOV();
   		this.sendNotification("SHOW_ALERT", {title: "OV", message: "Bustijden ge-update.", timer: "1000"});
   	}, 10000);
   	updateOV();
   	
   	return wrapper;
   },
   
   getScripts: function() {
   return [
   	'https://code.jquery.com/jquery-2.2.3.min.js',  // this file will be loaded from the jquery servers.
   ]
   },

});