Interference of ups on high-end color Doppler ultrasound and its solution

The development of color Doppler ultrasound diagnostic equipment has entered the era of full digitization. At present, high-end ultrasound services all have computer digital platforms, built-in dual or multiple high-speed processors, digital imaging processing technology, network communication functions, and rich computer software packages for measurement, quantitative analysis and calculation, image analysis, image reconstruction, and post-processing. This type of high-end ultrasound equipment has higher requirements for the power quality of UPS uninterruptible power supply than before. Due to issues such as voltage surges, transients, overvoltage, undervoltage, and sudden power outages that may occur during peak electricity usage in the power grid, the software, calculation data, and image data of the computer system in color ultrasound may be damaged, and in severe cases, it may cause damage to certain computer hardware. Therefore, high-end ultrasound requires a power supply system with functions such as voltage stabilization, frequency stabilization, filtering, resistance to electromagnetic and radio frequency interference, and prevention of sudden voltage interruption. And Shenzhen Jingyuan Technology's UPS (Uninterruptible Power System) is precisely this suitable power supply system. In general, high-end ultrasound uses an online UPS uninterruptible power supply as the power supply. Shenzhen Jingyuan Technology's online UPS provides a stable sine wave power supply to the inverter output when there is mains power. When the mains power supply fails or is completely interrupted, the UPS's built-in or external battery pack continues to provide DC power to the inverter, ensuring that the inverter output of the UPS power supply is uninterrupted sine wave.

However, in the past two years, using UPS as the power supply for high-end color ultrasound has caused new problems. Taking the People's Hospital of Zhejiang Province as an example, the ultrasound department equipped a newly purchased high-end color ultrasound with a 6kVA online UPS uninterruptible power supply. As a result, serious radiation interference appeared on the two-dimensional echo image of the ultrasound, manifested as: the sector around 15 ° in the center of the phased array heart probe's fan-shaped echo area was filled with strong bright spot noise, High frequency intracavity and shallow probes have several wave shaped interferences composed of strong bright noise in the far field of the echo zone. These interferences seriously affect the diagnosis of ultrasound, especially cardiac ultrasound. Of course, the generation and strength of noise are related to the brand of UPS uninterruptible power supply and the brand of color Doppler ultrasound diagnostic equipment.

Shenzhen Jingyuan Technology Co., Ltd. has continuously practiced and found the following methods to reduce or completely eliminate the interference of UPS power supply on color ultrasound: (1) Good grounding and shielding. Install the ground wire according to the standard and connect it to the ground wire end of the UPS power supply and ultrasound. (2) Increase the distance. Due to the decrease in radiation interference with increasing distance, if conditions permit, the UPS power supply compartment can be placed or the distance between the UPS power supply and the ultrasound can be increased as much as possible. (3) Install a filter. Shenzhen Jingyuan Technology adds an AC filter to the output end of a regular high-frequency UPS uninterruptible power supply. We use a single-phase power filter produced by Beijing Zhongshi Electronics Co., Ltd., with a model of **********. It is worth noting that in the case of connecting a large capacity battery pack to the UPS, a DC power filter must also be installed at the output end of the battery pack or the battery inlet end of the UPS uninterruptible power supply host. The model we use is ***********. This is because the internal connections between each unit battery in the battery pack, as well as the connections from the battery pack to the UPS power supply host, should have a certain self inductance L and a very small resistance R in parallel when the UPS uninterruptible power supply inverter is working. Under the action of high-frequency pulsating current, it will excite high-frequency interference voltage, which will increase with the increase of the output load of the UPS uninterruptible power supply, and will also produce radiation interference. Therefore, if conditions permit, the length of the connection between the external battery pack and the UPS power host should also be shortened as much as possible and the cross-sectional area of the connection should be increased.