Pièces et principes de l'équipement de diagnostic médical à ultrasons
Le médical ultrasonic diagnostic instrument refers to the completion of the inspection function based on the characteristics of the ultrasonic wave. Ultrasound is a mechanical wave with a vibration frequency >20kHz, which exceeds the upper limit of human hearing. The frequency range of ultrasound is 2×10~2×10°Hz, while the frequency range of medical ultrasound is 200kHz~40MHz, and the frequency commonly used for ultrasound diagnosis is 1~10MHz. Due to the high frequency and short wavelength of ultrasonic waves, ultrasonic waves have characteristics such as orientation, refraction and reflection.
The medical ultrasonic diagnostic instrument mainly has two parts, namely the main unit of the equipment and the ultrasonic probe. The ultrasonic probe is a key component of ultrasonic imaging equipment, and its task is to convert electrical signals into ultrasonic signals or ultrasonic signals into electrical signals. The host part of the ultrasonic diagnostic instrument mainly processes and displays the signal received from the probe.
Principe de fonctionnement de medical ultrasonic diagnostic instrument
The oscillator is a synchronous trigger signal generator, which generates a synchronous trigger pulse to control the work of the system, which determines the repetition frequency of the transmitted pulse. The triggered transmitter generates high-voltage electrical pulses to excite the ultrasonic transducer to emit ultrasonic pulses to the detection target. The echo pulse signal formed by the target is converted into an electrical signal after being received by the transducer, and then enters the echo information processing system. The system consists of a radio frequency signal receiving amplifier, a detector and a video amplifier, etc., and is finally displayed by a monitor. Under the control of the synchronous pulse generated by the oscillator, the scanning generator outputs the scanning signal to the display, so that the display of the ultrasonic echogram is stable.
The host part of the medical ultrasonic diagnostic instrument
With the development of electronic technology, the internal circuit of the ultrasonic diagnostic instrument is gradually converted from the original analog circuit to a digital synthesis circuit, forming the current all-digital ultrasonic diagnostic instrument. The specific circuit modules are mainly the preamplifier circuit, A/D Conversion circuit, digital circuit and power supply part. The ultrasonic probe transmits the received signal to the preamplifier circuit for amplification, and then converts the analog signal into a digital signal through the A/D conversion circuit, and then undergoes synthesis processing of the digital circuit, and converts the processed image to DSC after digital scanning conversion. The video is shown on the display. The power supply part provides power for the above-mentioned parts.
Ultrasonic diagnostic instrument system maintenance
1. When performing maintenance or cleaning, put the system into STANDBY state, turn the power switch to OFF, and unplug the main switch. Note: Avoid using any strong solvents, such as thinner or benzene, so as not to damage the instrument casing.
(1) Regularly clean all exterior surfaces of the instrument with a milder detergent and a damp cloth.
(2) When cleaning the keyboard and display screen of the instrument, be careful not to let the liquid flow into the inside of the instrument, and warn not to scratch the display screen.
3. Air filtration
(1) The air filtration device of the system should be checked every week, at most 2 weeks, and cleaned if necessary.
(2) The filter device is located at the bottom of the front of the instrument or other parts. According to the air filtration condition, choose a vacuum cleaner or soapy water to clean the filter plate.
(3) Turn off the power switch when removing the filter device, and do not start the host system when the air filter plate is not installed.