Manual ultrasound power control for monitoring of the fetal heart rate in dependence upon the size of the patient

摘要

It is a continuous, not - invasive fetal heartbeats with the use of one or more firmly on the abdomen of the nut rendered ultrasonic transducer (24) is carried out. Each ultrasonic transducer (24) generates an ultrasound beam (26), which has a signal strength. The signal strength is determined by an excitation voltage, the to the ultrasonic transducer (24) is applied. An excitation voltage of an adjusting device (36) is connected between the excitation voltage generator (32) and the ultrasonic transducer (24) is arranged, in order to reduce the intensity of the ultrasonic beam can be selectively controlling. A user input device (44) enables an operator, the ultrasound signal strength to control the sensing range of the fetal heart frequency monitoring device (10) to vary.