Table 1.
Focused Ultrasound Treatment Parameters.
| Power (Watts) | Peak Negative Pressure (MPa) | Duty Factor (%) | Intensity (W/cm2) |
|---|---|---|---|
| 1 | 2.11 | 50 | 97.8 |
| 3 | 3.05 | 50 | 204.3 |
| 5 | 3.75 | 50 | 308.9 |
| 5 | 3.75 | 100 | 617.2 |
| 7 | 4.34 | 50 | 413.7 |
| 9 | 4.81 | 50 | 508.2 |
Intensity calculated according to Wu and Nyborg37 with an attenuation coefficient (α) of 0.1 dB/cm, approximately that of soft tissue at 1 MHz, speed of sound (c) was 1584.5 m/s, approximately the speed of sound in soft tissue at 37 °C, density (ρ) approximated at 1070 kg/m3 for soft tissue, distance (x) was 0.3 cm, or half the focal length. Peak negative pressure values were obtained from the Philips’ TIPS software, based on initial calibration calculations. 99.9% duty factor is the greatest possible with the device and will be denoted as 100%. Bold indicates the treatment used in vivo.