Switched capacitor for elasticity mode imaging with ultrasound
The power supply in ultrasound imaging includes a switched capacitance. The capacitance is switched on to provide power during generation of pushing pulses for elasticity imaging and is switched off during other modes of imaging.
1. An ultrasound system for elasticity mode imaging with ultrasound, the ultrasound system comprising:
a power supply having an output;
a switch switchably connecting between the output and ground;
a capacitor in series with the switch, the capacitor and the switch forming a switchable path to the ground from a connection of the output of the power supply to a transmitter so that the switchable path operates on power provided as input to the transmitter, the switch and the capacitor not being in series with the transmitter and the power supply such that the switch does not switch the power supply from the transmitter, the capacitor arranged to provide additional power with the power supply to the transmitter for transmission when the switch is closed; and
an ultrasound scanner configured to perform the elasticity mode imaging using the transmitter.
2. The ultrasound system of claim 1 , wherein the switch comprises back-to-back N-channel MOSFETs.
3. The ultrasound system of claim 1 , wherein the switch comprises a back-to-back arrangement of a pair of transistors.
4. The ultrasound system of claim 1 , wherein the capacitor comprises one of a bank of capacitors connected in series with the switch.
5. The ultrasound system of claim 1 , wherein the power supply comprises a programmable power supply.
6. The ultrasound system of claim 1 , further comprising a controller configured to control the power supply and the switch to close the switch after the power supply causes a voltage across the capacitor.
7. The ultrasound system of claim 6 , wherein the controller is configured to transition the switch from open to closed only when a voltage across the switch is substantially zero.
8. The ultrasound system of claim 1 , further comprising a controller configured to maintain the switch open during B-mode imaging and to close the switch during elasticity mode imaging.
9. The ultrasound system of claim 8 , wherein the controller is configured to operate the switch differently in the elasticity mode imaging and the B-mode imaging, the controller configured to close the switch for at least part of the elasticity mode imaging and configured to open the switch for at least part of the B-mode imaging.
10. The ultrasound system of claim 8 , wherein the controller is configured to close the switch for pushing pulses for the elasticity mode imaging and to open the switch for the B-mode imaging.
11. The ultrasound system of claim 1 , further comprising a controller configured to limit a current of the power supply when the switch is closed based on heat generated by a low drop out regulator of the power supply.