Improving the Performance of Phase-Change Perfluorocarbon Droplets for Medical Ultrasonography: Current Progress, Challenges, and Prospects
Figure 9
Signals produced by individual droplets vaporizing in the received transducer’s focus manifest as exponentially decaying sinusoids with very narrowband frequency content. Examples of (a) DFB droplet vaporization, (b) the associated frequency spectrum, and (c) and (d) OFP droplets oscillating at similar frequency produce larger amplitude oscillations even when exposed to significantly lower incident pressure as a result of greater droplet volatility. In all graphs, the blue trace shows the preceding pulse that did not produce a droplet vaporization event for the same sample and pulse pressure. Reproduced from [93] with permission from the Institute of Physics in Engineering and Medicine.
