Tube Voltage Switching Waveform for CT Spectral Separation

The patent implements periodic switching between high energy kV and low energy kV modes, creating a pulsed action pattern. The tube voltage alternates between high and low states in periodic cycles, allowing the system to achieve spectral energy separation through multiple alternating measurements rather than continuous high voltage exposure. This periodic switching enables the use of high mV only during brief intervals when needed for energy separation, rather than maintaining continuously high dose levels.

The patent dynamically changes the tube voltage parameter (kV) between two distinct states: high energy kV and low energy kV. By switching between these different voltage parameters, the system achieves spectral energy separation capability without requiring continuous exposure at the highest voltage level. The parameter changes allow optimization of both image quality and dose reduction by selecting appropriate voltage levels for different measurement phases.

The patent applies preliminary action by pre-charging the output capacitance of the high voltage generator to the high energy kV level before the switching period begins. This preliminary charging ensures that when the switching to low energy kV is needed, the capacitance is already prepared and can discharge quickly, achieving fast transition without requiring excessive mV during the actual transition moment. The preparatory charging action eliminates the need for high mV discharge currents during operation.

The patent converts the potentially harmful effect of output capacitance (which normally causes slow kV fall time and requires high mV to discharge) into a beneficial element. By utilizing the capacitance discharge characteristic in a controlled periodic manner and pre-charging it appropriately, the system achieves fast transition times without requiring high mV during the actual switching, thereby converting the capacitance from a liability into an asset for achieving rapid kV transitions.