Figure 4:

- A: Original records of 15 pulses of pulmonary pressure registered over 6.83 seconds. The first four pulsations (E) are amplified in Figure 4E.
- B: Contour module of these records.
- C: Three-dimensional contour image.
- D: Fourier spectrum of the original recordings.
- E: First four pulsations from Figure 4A, shown in an expanded time scale.
- F: Contour module of the 4 pressure pulsations shown in Figure 3E.