Photocell Oscillometer for Measuring Systolic Pressure in Newborn

Abstract

The difficulty in hearing Korotkow sounds and in palpating the pulse in the newborn has led to the development of several alternative methods of determining systolic blood pressure. Woodbury¹and Haselhorst²have obtained intra-arterial pressures through the umbilical artery. The flush method^3,4depends on the flush of the blanched limb as the end-point and gives values a little lower than actual systolic blood pressure. A number of methods for determining systolic pressure employ oscillometers of various types to detect arterial pulsation. Ashworth et al.⁵used a second forearm cuff connected to xylol beads to indicate the onset of the pulse. Rice and Posener⁶use a second forearm cuff to transmit pulsation to a diaphragm which deflects a light beam which may be photographed. Schaffer⁷used impedance plethysmography to detect pulsation. Morse⁸has reported a method which uses a small, sensitive microphone imbedded in