Ballistocardiograms were recorded on 100 male subjects and on 25 female subjects. All of these two groups of subjects were normal healthy persons without any cardiovascular symptoms, and averaging 24 years old (ranging from 17 to 33 years) in male group, and 19 years old (ranging from 17 to 25 years) in female group.
Recording at three states were (1) in the resting state (at least 3 hours postabsorptive,30minutes after smoking, and 5 minutes after resting in recumbent), (2) after excercise (20times of leg flection as rapid as possible), (3) and during deep respiration.
Lead 1 of the electrocardiogram was taken simultaneously in all case, to record timing of the onset of the cardiac cycle. The time of occurrence of each HIJ and K peak were measured from the onset of the QRS wave of the electrocardiogram.
Ballistocardiograms were recorded by direct method with the lever system electromagnetic pick-up modified from the original Dock-Tauman type, and the single beam type electrocardiograph (electromagnetic oscillograph). Following results were obtained.
1. High normality was obtained in 125 resting ballistocardiograms of healthy persons, as classified by Brown's classification.
2. In normal ballistocardiogram, all recording could be identified with each systolic waves (HIJ and K), The J wave was the highest deflaction of systolic waves, and the magnitude of the H and K deflection were 50% of J deflection, and I deflection was 60% of the J deflection. In male group, generally, higher records could be obtained than female group in amplitude. The IJ deflection which is designated as the ventricular ejection curve averaged 20% higher in male than in female.
3. In after excercise recording, general form of Ballistocardiograms were grossly identical with that of resting in male group, whereas the K wave was slightly less than that of resting record, and H and L waves were increased in proportion to the IJ deflection.
4. The ratio of inspiratory IJ deflection to expiratory IJ deflection (respiratory ratio)has a mean value of 1.3 at normal resting respiration. The deeper respiration the greater the respiratory ratio, and respiratory ratio reached to 2 at the deepest respiration. The increase in respiratory ratio in deep respiration was caused principally by the increase in inspiratory IJ deflection. The expiratory IJ deflection at resting and deep respiration was relatively constant.
5. The real amplitude of body ballistic movement was calculated from the induced electromotive force of the pick-up used and time interval of each waves. In normal healthy adult, calculated amplitude of real ballistic body movement due to heart contraction at resting state averaged from 100 to 200 microns.
View full abstract