Intraoperative monitoring of cardiovascular autonomic control responsiveness

DSP hardware. Several algorithmic and programming optimizations were applied so that the algorithm runs in real time with a sampling rate of at least 12 kHz. Results: The algorithm achieved a 99.3% accuracy rate when evaluated using data (20 data sets) from the MIT-BIH Arrhythmia Database. Total beats, missed beats, false beats, correct beats, total errors, percent errors were 45 331, 195, 142, 45 136, 337, and 0.74, respectively. For the cardiac-gating applications, latency from the peak of the QRS complex to the trigger signal was 7 milliseconds. Sampling at 12 kHz, with a high-performance 16-bit DAC, resulted in a jitter of 193 microseconds. Conclusions: Radiofrequency pulses during MRI make it difficult to discern ECG signals from background static magnetic field and radiofrequency gradients. This technique of mathematical transformation may be useful in the improvement methods of real-time QRS detection and sampling during MRI.