Thermal dose and acoustic dosimetry

The thermal side of acoustic safety and dose. The thermal index (TI) estimates the steady-state temperature rise a beam could cause (roughly, emitted acoustic power relative to that needed to raise tissue by one degree Celsius), while spatial-peak temporal-average intensity (ISPTA) captures time-averaged energy deposition; cumulative thermal effect is often summarised as an equivalent thermal dose (for example, cumulative equivalent minutes at 43 degrees Celsius).

For low-intensity neuromodulation and mote powering, the goal is to stay firmly sub-thermal so that any effect is non-thermal, whereas high-intensity focused ultrasound deliberately exploits heating for thermal ablation. Reporting the full acoustic dose — pressure, intensity, duty cycle, duration, and the resulting indices — is a basic requirement for reproducible and safe acoustic neurotechnology.