A comparison between ultralow-frequency ballistocardiograms and those secured by an improved high-frequency technique, with studies to explain remaining differences.

TLDR: The advance in ballistocardiographic instrumentation which has been so rapid and so encouraging in recent years has been due primarily to the use of certain physical principles, but on the assumption that well-known physical formulae could be properly applied to the vibration problems of the human body, a new viewpoint emerged.

About: This article is published in American Heart Journal.The article was published on 1962-07-01 and is currently open access. It has received 11 citations till now.

Figures

Table 1V. Average values and standard deviations for restoring jorce and damping as the 3 subjects were tightened on our HF table

Table V. Averages of the di’erences found between the four main systolic waves of ULF and HF ballistocardiograms in 30 healthy men and 20 healthy women

Fig. 2. Our ULF ballistocardiograph. A, The table. B, “Mine jacks,” columns of heavy pipe extending between floor and ceiling to support the frame from which the table is suspended. Only the base is shown in the figure. C, Support wires. D, Lateral support. F, Coils shown withdrawn from magnets E. G, Footboard.

Table VII. Comparison of the clinical interpretation given to HF and ULF records secured on the same persoq in 250 patients

Table III. Effect of tightening the subject on the HF table. The frequency and damping of movement between subject and table under various conditions

Fig. 19. Response of the ULF instruments to a triangular shaped internal acceleration of the center of gravity 2, (proportional to internal force) (boltom in B, D, F, and H). A, (kq5) The acceleration ib of the T’LF instrument for cases a and d of Fig. 18,A and B. D, (lop) The displacement xb of the HF instrument for the same cases. F, (top) The acceleration ?b of the ULF instrument for cases a and d of Fig. 18,D and E. H, (top) The displacement xb of the HF instrument for the same cases.

Frequently asked questions

Q1. What are the contributions in this paper?

With this experience before us the instrument used in this study was constructed by Mr. George Peirce. The authors expected that a study of the differences between the two force records would provide important information, because each instrument approached the problem from a different direction, and neither method seemed altogether free of error.