在MK600型超声诊断仪配备的两只7218B型双工扫描探头中,3MHz探头使用率远较5MHz探头高(约占全部使用的90％以上)。最近我院的3MHz探头在使用中,屏上图象突然消失,经检修,我们发现由于长期使用,这种机械式扫描探头内的一些部件如马达、光电池等都已老化,无法正常使用。由于这些配件在国内难以购到,待件备修会造成该探头长期搁置,大大降低了MK600超声仪的使用 In the MK600 ultrasonic diagnostic apparatus equipped with two 7218B duplex scan probe, 3MHz probe usage is much higher than the 5MHz probe (about all use of more than 90%). Recently in our hospital 3MHz probe in use, the image on the screen suddenly disappeared, after inspection, we found that due to long-term use, such mechanical scanning probe some of the components such as motors, photocell, etc. have been aging, can not be used normally. As these accessories are hard to come by in the country, spare parts maintenance will cause long-term shelving of the probe, greatly reducing the use of the MK600 system