| 摘要 |
An alarm actuating circuit associated with an automatic blood pressure recorder is triggered when a patient's systolic or diastolic pressure does not fall within a prescribed range. The recorder is associated with a pneumatic regulator including a constant-volume reference chamber and associated pressure-sensitive inflation and deflation valves to effect a precise linear depressurization of an inflatable cuff which has been applied to the patient and pressurized to a value higher than the patient's systolic pressure. Pulses obtained from an ultrasonic or other suitable detector sensitive to movements of the patient's arterial wall in synchronism with the blood flow surges as the cuff is depressurized below the patient's systolic pressure are integrated and then translated into variable-duration marking impulses. Such impulses are successively applied to the actuating input of a pen or other marker associated with an X-Y recording chart, the pen being linearly scanned along one chart axis at the constant depressurization rate of the cuff. During such scan, the pen records, on the chart, a linear pattern of marks each of which has a length corresponding to the duration of the marking impulse then applied to its actuating input.
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