title: Creating a heart rate monitor
body: <p>I have been trying to create a heart rate monitor with chart.js, but I'm at odds as how to represent the graph.</p>
  
  <p>I want to build something along the lines of this demonstration:
  <a href="http://joakimkemeny.github.io/jke.d3.ecg/" rel="nofollow">link to demo.</a></p>
  
  <p>The charts in chart.js are made like this:</p>
  
  <pre><code>var data = {
      labels: ["Heart Rate Monitor"],
      datasets: [
          {
              label: "heart rate",
              data: [65, 59, 80, 81, 56, 55, 40]
          }
      ]
  };
  
  var myLineChart = new Chart(ctx).Line(data, {});
  </code></pre>
  
  <p>And we can update the data like this:</p>
  
  <pre><code>myLineChart.datasets[0].points[0].value = 50;
  </code></pre>
  
  <p>Which would set the first value in the array: 65, to 50. </p>
  
  <p>So I have made some attempts at creating an array with values that look like the demo, and move the first element to last, and every other element one down (-1) on the array and fill the chart with the values. This works, to a certain extent, but I am not able to change the speed of the values, which I need to do. </p>
  
  <p>Suggestions?</p>