| Popis: |
A preliminary study was performed to ensure reliable R-wave detection and fiducial mark location. A generalized phase-sampling model for spectral estimation was then used, based on an interest in beat-to-beat variations. Heart rate spectrum characteristics of 32 presumed-normal subjects and 44 records from the MIT-BIH electrocardiographic database (Massachusetts Institute of Technology, Cambridge, MA) were analyzed and three parameters were calculated: regression line slope, intercept, and cross correlation between the spectral data and the regression lines. Evaluation of these inverse power-law spectrum parameters provides a potential quantitative approach for characterizing erratic fluctuations of heart rate and is possibly used to distinguish between healthy and abnormal subjects. From the 44 recordings in the MIT-BIH database, a V-shaped curve was found in a plot of the regression line slope versus cross correlation. The results for both unmedicated and medicated patients with normal sinus rhythm cluster in the top left region of the graph. Also, 29 of the presumed-normal subjects cluster in the same region. Patients with premature ventricular contraction beats cluster in the top right region of the V-shaped curve. The rest of the recordings from the variety of arrhythmia cases in the database have low slopes and cross correlations, so they cluster near the apex of the V-shaped curve. Three volunteers who each had more than 32 atrial premature contraction and premature ventricular contraction beats also fall in this region of the graph. The results from 10 young volunteers from the United States and 15 volunteers from seven other countries cluster into different regions.(ABSTRACT TRUNCATED AT 250 WORDS) |
