Processing of arterial pressure waves with a digital computer

✍ Scribed by C.Frank Starmer; Philip A. McHale; Joseph C. Greenfield Jr.

• Publisher: Elsevier Science
• Year: 1973
• Tongue: English
• Weight: 478 KB
• Volume: 6
• Category: Article
• ISSN: 0010-4809
• DOI: 10.1016/0010-4809(73)90064-5

✦ Synopsis

A series of algorithms to identify the time of onset and end of ventricular ejection using a central aortic blood pressure and the electrocardiogram are presented. The reliability of these algorithms was evaluated by comparing the index points found by this method to those obtained by an algorithm which uses aortic blood flow. For the 659 cardiac cycles examined in four dogs with widely varying stroke volumes and arterial pressures, the mean difference between the two methods was both positive and negative with a maximum value of 9 f 1 msec (mean & SE). In addition, 153 cardiac cycles were manually identified and compared to the pressure-oriented algorithm identifications. The mean difference in this case was 1 & 1 msec for both the onset and end of ventricular ejection. An analog catheter simulation technique was used to define the minimum frequency response characteristics required of the blood pressure catheter system. A system with a damping factor of 0.4 and a natural resonant frequency of 11 Hz, which yielded a frequency response curve flat to 8 Hz and peaking at 10 Hz, was the minimum system consistent with reliable identification of the onset and end of ventricular ejection.