How to stop/do something if analog value has not changed in a certain amount of time

Projects Programming
10 

void setup()
{
  Serial.begin(115200);
}

void loop()
{
  static int previousValue = analogRead(7);  //compiled for a Nano
  static int currentValue = previousValue;
  int deadband = 10;
  previousValue = currentValue;
  currentValue = analogRead(7);
  Serial.print(previousValue);
  Serial.print("\t");
  Serial.println(currentValue);
  if (abs(previousValue - currentValue) > deadband) //detect a change
  {
    Serial.print("value has changed by at least ");
    Serial.println(deadband);
  }
  else
  {
    Serial.println("no significant change");
  }
  previousValue = currentValue;
  delay(1000);
}