| 摘要 |
The present invention measures cardiac power and power increase under stress, thus calculating contractile reserve (CR), the difference between cardiac peak power and cardiac power at rest by connecting a person to an electrocardiograph and determining the pressure-volume loop (PVL) of a patient's heart. While deflating an inflated cuff on the person's arm at a controlled rate, a series of data points from peak systolic to diastolic pressure is obtained, each point consisting of cuff pressure at penetration coupled with the time of its occurrence after the corresponding ORS complex; a curve-fitting procedure is applied to turn said data points into a pressure curve resembling the ascending limb of the aortic pressure wave. The end systolic pressure (ESP) is calculated using the expression ESP = DP + 2/3 (PSP - DP), where DP = diastolic pressure and PSP = peak systolic pressure. The volume at point ESP is calculated by integrating said flow curve throughout the ejection phase of the patient's heart.
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