Digital pulsed ultrasound transmitting device for fetal monitor

Abstract

The invention discloses a digital pulsed ultrasound transmitting device for a fetal monitor, relating to the field of medical equipment. The digital pulsed ultrasound transmitting device comprises an ultrasound probe and an ultrasound transmitting circuit which are connected with each other, wherein the ultrasound probe employs a plurality of wafers which integrates transmission and reception functions into a whole and has the transmitting frequency of 1.0 MHz, the wafers are arranged on the radiation surface of the probe uniformly. The digital pulsed ultrasound transmitting device has wide ultrasound transmission acoustic beams, and is hardly affected by fetal movement and uterine contraction during detection upon a fetal heart signal in a monitoring process, so that the monitoring result is more accurate and reliable; the transmitting circuit generates a transmission electric excitation square wave signal of 1.0 MHz by using a CPLD (Complex Programmable Logic Device) digital circuit, the transmission electric excitation square wave signal is coupled to the ultrasonic probe by a resonant amplification circuit so as to generate an ultrasonic wave of 1.0 MHz; and the digital pulsed ultrasound transmitting device is low in transmission frequency, less in attenuation in an ultrasound propagation process, strong in reflection echo, high in flexibility, low in noise, strong in anti-interference ability, and steady and reliable in performance.

Description

technical field [0001] The invention relates to the field of medical instruments, in particular to a digital pulsed ultrasonic emitting device for fetal monitors. Background technique [0002] At present, most fetal monitors use 2.0MHz~2.5MHz continuous ultrasonic Doppler method to pick up fetal heart signal. The ultrasonic probe structure is a chip in the middle, with a diameter of 2cm, which emits ultrasonic waves. The width of the emitted ultrasonic beam is 2~3cm. , This is also the capture range of the fetal heart rate. The surrounding 6 small chips receive ultrasonic waves, and the fetal heart rate signals picked up are processed and displayed or printed. The ultrasonic transmission frequency used by most monitors is between 2.0MHz and 2.5MHz, which is relatively high, because the attenuation of ultrasonic waves in the human body is proportional to the frequency of ultrasonic waves, so when ultrasonic waves with a certain intensity and higher frequency propagate, there ...

AI Technical Summary

Problems solved by technology

The ultrasonic transmission frequency used by most monitors is between 2.0MHz and 2.5MHz, which is relatively high, because the attenuation of ultrasonic waves in the human body is proportional to the frequency of ultrasonic waves, so when ultrasonic waves of a certain intensity and higher frequency propagate, there are the following Question: ①If the propagation distance is the same, the higher the frequency, the greater the attenuation, the weaker the reflected echo, the lower the sensitivity, and the less likely it is to detect the fetal heart signal; ②The higher the frequency, the greater the attenuation, and the effective transmission of ultrasonic waves the shorter the distance

[0005] 1) The sound beam of the ultrasonic probe is thin, the fetal heart rate capture range is narrow, and it is easily affected by fetal movement and uterine contraction, resulting in the loss or inaccurate measurement of fetal heart rate signals during fetal movement and uterine contraction

[0006] 2) The ultrasonic frequency of the transmitting circuit is high, the attenuation is large during the transmission process, the reflected echo is weak, and the sensitivity is low, which is not conducive to the monitoring of pregnant women with big bellies, fat pregnant women or pregnant women in the back of the pillow.

[0007] 3) The ultrasonic frequency of the transmitting circuit is easy to drift, the noise is large, and the anti-interference ability is poor

[0008] 4) The performance stability of the entire launch device is poor. Generally, after half a year of use, noise will appear, the sensitivity will decrease, and it is difficult to capture the fetal heart rate.

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