Ultrasonic-wave fetal heart monitor and digital demodulation method for echo signal of ultrasonic wave fetal heart monitor

Abstract

The invention discloses an ultrasonic-wave fetal heart monitor and a digital demodulation method for an echo signal of the ultrasonic wave fetal heart monitor. The digital demodulation method includes the steps that A, a main control module outputs a control order to control a CPLD module to output a pulse excitation signal; B, the pulse excitation signal is amplified through a signal amplification module, and is processed through an impedance inverter circuit to be transmitted to an ultrasonic probe to be excited; an ultrasonic echo is received through the ultrasonic probe and converted into the echo signal; C, the echo signal is subjected to analog-digital conversion through an analog-digital conversion module to generate the digital echo signal, the digital echo signal is transmitted to the CPLD module to be subjected to digital demodulation to generate an I signal and a Q signal, and the I signal and the Q signal is fed back to the main control module; D, the main control module receives the I signal and the Q signal to output the control order again to the CPLD module, and transmits the I signal and the Q signal to a display screen to be displayed. A more-real I/Q signal envelope and a more-real frequency-shift signal envelope can be obtained, and the problem of the double heart rate is solved; tissue movement at the specific depth can be further monitored.

Description

technical field [0001] The invention relates to the technical field of ultrasonic fetal heart rate monitoring, in particular to an ultrasonic fetal heart rate monitor and a digital demodulation method for echo signals thereof. Background technique [0002] Ultrasonic fetal heart rate monitor is a monitoring instrument that uses ultrasound to detect fetal heartbeat. By using the instrument, the sound wave signal related to the fetal heartbeat frequency can be heard, and parameters such as the fetal heartbeat frequency can be learned by this. Ultrasonic fetal heart rate monitors currently on the market all use analog demodulation to extract fetal heart rate ultrasonic frequency shift information, that is, through an analog multiplier, the ultrasonic echo reflected by the fetal heart tissue is compared with the same ultrasonic base Multiply the sine wave signals with the same frequency and phase, and the same frequency, so as to obtain the frequency shift signal in the ultraso...

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Problems solved by technology

[0006] In view of the shortcomings of the above-mentioned prior art, the purpose of the present invention is to provide a digital demodulation method of an ultrasonic fe

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