medical monitors sudden surge

The has been a sudden hit to trading volume on small company medical monitors since last friday when it had previously hit lows of around 2 cents. The company was floated 2 years ago and was previously known as defiance mining before the float. It floated at 20 c and has declined steadily ever since. It has been sitting around the 3 c mark for months and then declined to 2 cents a week ago before sudden trading movements has seen it reach 4.5 cents currently. No announcement has been made and usually there is little or no trade on this stock on a daily basis. Anyone know what is happening here?