A dedicated device for detection of vascular shunts can include a first chamber, a second chamber, and a third chamber. The first chamber can be configured to hold liquid, the second chamber to hold gas, and the third chamber can be in communication with the first and second chambers. The third chamber can include small-scale geometric features configured to produce gas bubbles as liquid from the first chamber and gas from the second chamber simultaneously flow into the third chamber. The device can also include a device opening in communication with the third chamber such that a mixture of liquid and gas bubbles can flow out of the device opening. The device can also include a plunger configured to force the liquid and the gas simultaneously from the first and second chambers, through the third chamber to mix with each other and produce bubbles, and further through the device opening.
