Application of CT Slip Ring Technology

In order to improve the quality of CT images, pursuit of rapid continuous scanning. Slip ring transmission technology has been applied in CT scanning, generally referred to as CT slip ring.CT slip ring technology can be divided into high ressure slip ring and low pressure slip ring. The current CT machine has been developed to multi-row spiral scanning phase, slip ring technology must be used, Slip ring plays an important role in CT. Passing the scan control instructions and scanning the acquired data to provide power to the rotating part of the scanning operation, which can not be ignored for CT performance. The following analysis of high-pressure and low-pressure slip ring technology:

In the CT equipment using slip ring technology is to follow the electric power locomotive in the power line and contact arm, which use of high-quality materials made of power and data slip ring and X-ray tube, detection system combined to form a rotating parts, they are kept in relative position in rotation; The static part of the rack is in close with the high-quality brush and rotating power slip ring to achieve both inside and outside the two parts of the static and dynamic connection. In this way, you can not use cable connection. As the power slip ring by the outside will be hundreds of volts, DC power into the rack, low voltage, easy to achieve good insulation, safe and reliable, does not produce a large arc, the data transmission performance is also very stable and good. Thus solves the technical difficulties in the continuous unidirectional rapid scanning of CT devices. This technique deals with the feeding and signal transmission of the rotating parts and the stationary parts in the scanning frame,get rid of the winding restrictions of each cable, reduce the cable crimper, The whole system becomes compact, simple and lightweight. It eliminates the time spent in the previous scanning, acceleration, uniform, deceleration, braking and so on. Shorten the rotation period, increased number of scan layers per unit time. Because the low-pressure slip ring on the insulation material is not demanding, safe, stable and reliable, it is used by most CT manufacturers. The disadvantage of the low pressure slip ring is due to the fact that the high voltage generator is set on the rotating part and rotates with its X-ray tube, which increasing the weight and volume of the rotating part, making the scanning speed is relatively low.

High pressure slip ring, just as its name implies, the use of slip ring technology will high-voltage current feed into the machine frame for X ray tube has the X line called high-pressure slip ring. The advantage of high-pressure slip rings is that the high-voltage generator is external, on the one hand does not increase the weight of the rotating frame, also don’t have to worry about the temperature rise caused by the contact current, scanning faster; On the other hand, since the high voltage generator is not limited by the weight of the volume, the generator power can be made large, But because of the high pressure slip ring is easy to cause frame of the rotating parts and stationary parts and insulation between high voltage discharge and contact arm, brush more difficult, and high pressure arising from the noise and affect the data acquisition and transmission.

As the number of CT system probes increased, the speed of the rotation was increasing rapidly, and the amount of data collected over time was increasing, As a result, the industry has proposed the use of wireless capacitive coupling for data transmission, which is mainly applied in multi-row CT systems. The data transmission of the wireless capacitive coupling overcomes the effect of contact resistance and high voltage discharge on transmission signals, But wireless capacitively coupled electromagnetic field more vulnerable to external voltage, current and electromagnetic interference, so the accuracy of the high-speed data transmission and transmission rate is restricted and influence.