| Frequency (f) | Carrier ultrasound frequency | 0.25 – 5 MHz |
| Intensity (Ispta) | Spatial-peak temporal-average intensity | 0.1 – 500 mW/cm² |
| Isppa | Spatial-peak pulse-average intensity | 1 – 100 W/cm² |
| Pressure amplitude (P) | Peak negative acoustic pressure | 0.01 – 1 MPa |
| Duty Cycle (DC) | Fraction of time ultrasound is ON (ton / T) | 0.1% – 100% |
| Pulse Repetition Frequency (PRF) | Rate of pulse envelope repetition | 10 – 3000 Hz |
| Pulse Duration (PD) | Duration of a single ON burst | 0.1 – 100 ms |
| Sonication Duration (SD) | Total duration of the stimulation train | 50 ms – 80 s |
| Burst Duration | Duration of a single ultrasonic burst within a pulse | 0.02 – 10 ms |
| Number of cycles per burst | Acoustic cycles within one burst | 5 – 10,000 |
| Mechanical Index (MI) | Cavitation risk proxy: P / √f | < 0.73 (FDA limit) |
| Thermal Index (TI) | Estimated tissue temperature rise proxy | < 1 (neuromodulation) |
| Center frequency | Primary resonant frequency of the transducer | 0.25 – 2.25 MHz (CNS) |