A Method to Realize Rate-adaptive Function in Pacemakers Based on Accelerometer Sensors

We have developed a method to realize rate-adaptive function in pacemakers, which can greatly improve patients´ exercise capacity. In our method, an accelerometer is employed to collect patients´ acceleration signals along moving direction, according to which efficient algorithms are applied afterwards for activity estimate. Further analysis indicates an approximate linear relationship between human metabolic level and normal sinus rate. Therefore, we imitate a similar relationship between activity estimate and target pacing rate in our algorithm. We also need a strategy of smooth transition instead of immediately changing the current pacing rate to the target pacing rate. Treadmill tests are applied to verify the performance of our rate-adaptive system. Compared with an Impulse pacemaker from Medtronic Inc., we find the pacing rate yielded by our system in great conformity with that yielded by the Impulse pacemaker, especially when testers experience moderate exercise. The results validate our proposed method for rate-adaptive function.